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Sample records for rapid antibiotic sensitivity

  1. Fluoromycobacteriophages for Rapid, Specific, and Sensitive Antibiotic Susceptibility Testing of Mycobacterium tuberculosis

    Science.gov (United States)

    Piuri, Mariana; Jacobs, William R.; Hatfull, Graham F.

    2009-01-01

    Rapid antibiotic susceptibility testing of Mycobacterium tuberculosis is of paramount importance as multiple- and extensively- drug resistant strains of M. tuberculosis emerge and spread. We describe here a virus-based assay in which fluoromycobacteriophages are used to deliver a GFP or ZsYellow fluorescent marker gene to M. tuberculosis, which can then be monitored by fluorescent detection approaches including fluorescent microscopy and flow cytometry. Pre-clinical evaluations show that addition of either Rifampicin or Streptomycin at the time of phage addition obliterates fluorescence in susceptible cells but not in isogenic resistant bacteria enabling drug sensitivity determination in less than 24 hours. Detection requires no substrate addition, fewer than 100 cells can be identified, and resistant bacteria can be detected within mixed populations. Fluorescence withstands fixation by paraformaldehyde providing enhanced biosafety for testing MDR-TB and XDR-TB infections. PMID:19300517

  2. HB&L System: rapid determination of antibiotic sensitivity of bacteria isolated from blood cultures.

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    Simone Barocci

    2010-03-01

    Full Text Available Introduction. Blood culture is an important method to detect microbial pathogens on blood, very useful for diagnosing bacterial infections. Unfortunately, classical diagnostic protocols cannot directly identify bacteria responsible for sepsis and accordingly their antimicrobial profiles. This problem causes a delay of almost two days in the availability of a specific antimicrobial profile. Objective. Among the main causes of death, sepsis have a relevant importance. For this reason it is important both to identify pathogens and to perform an antimicrobial susceptibility test in the shortest time as possible. For this purpose, the main aim of this study is the evaluation of the performances of an antimicrobial susceptibility determination directly performed on positive blood cultures. Materials and methods. This study has been performed on 70 positive blood cultures, during the period from January to July 2009. A number of 35 blood cultures were positive for Gram negative bacteria, and 35 were positive for Gram positive bacteria. From these positive blood cultures, after a short sample preparation, it has been possible to directly determine antimicrobial susceptibility profiles by using the HB&L (formerly URO-QUICK instrument. Results. The HB&L system results showed a very good correlation with both the classical disk diffusion method and VITEK 2 automatic system.The performances between the methods carried out in this study were equivalent. Conclusions. From data reported, thanks to the rapidity and simplicity of the method used, we can assert that the direct susceptibility test available with the HB&L system, is useful for a rapid and early choice of the antibiotic treatment.

  3. Rapid and sensitive determination of nine bisphenol analogues, three amphenicol antibiotics, and six phthalate metabolites in human urine samples using UHPLC-MS/MS.

    Science.gov (United States)

    Yao, Yuan; Shao, Yijun; Zhan, Ming; Zou, Xiaoli; Qu, Weidong; Zhou, Ying

    2018-06-01

    Bisphenol analogues, amphenicol antibiotics, and phthalate have widely aroused public concerns due to their adverse effects on human health. In this study, a rapid and sensitive method for determination of nine bisphenol analogues, three amphenicol antibiotics, and six phthalate metabolites in the urine based on ultra-high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry was developed and validated. The sample pretreatment condition on the base of mixed-mode anion-exchange (Oasis MAX) SPE was optimized to separate bisphenol analogues and amphenicol antibiotics from phthalate metabolites: the former were detected with a mobile phase of 0.1% ammonium water solution/methanol containing 0.1% ammonium water solution in negative mode, whereas the latter were determined with a mobile phase of 0.1% acetic acid solution/acetonitrile containing 0.1% acetic acid in negative mode. The limits of detection were less than 0.26 ng/mL for bisphenol analogues, 0.12 ng/mL for amphenicol antibiotics, and 0.14 ng/mL for phathalate metabolites. The recoveries of all target analytes in three fortification levels ranged from 72.02 to 117.64% with the relative standard deviations of no larger than 14.51%. The matrix effect was adjusted by isotopically labeled internal standards. This proposed method was successfully applied to analyze 40 actual urines and 13 out of 18 studied compounds were detected. Graphical abstract Simultaneous determination of nine bisphenol analogues, three amphenicol antibiotics, and six phthalate metabolites in human urine samples.

  4. Antibiotic Sensitivity of Micrococcus radiodurans

    Science.gov (United States)

    Hawiger, J.; Jeljaszewicz, J.

    1967-01-01

    A wild-type strain of Micrococcus radiodurans and its nonpigmented mutant W1 were tested for sensitivity to 10 antibiotics selected from the standpoint of their mechanism of action. Representatives of groups of antibiotics inhibiting deoxyribonucleic acid (DNA) synthesis, DNA-dependent ribonucleic acid synthesis, protein synthesis, and cell wall synthesis were selected. M. radiodurans and its mutant exhibited full susceptibility to all antibiotics tested (mitomycin C, actinomycin D, chloramphenicol, dihydrostreptomycin, erythromycin, neomycin, kanamycin, benzylpenicillin, bacitracin, and vancomycin), the degree of susceptibility being of the same order as that of a standard strain of Staphylococcus aureus 209 P, with the exception of dihydrostreptomycin. PMID:4166078

  5. Rapid and Sensitive Detection of Bacteria Response to Antibiotics Using Nanoporous Membrane and Graphene Quantum Dot (GQDs-Based Electrochemical Biosensors

    Directory of Open Access Journals (Sweden)

    Weiwei Ye

    2017-05-01

    Full Text Available The wide abuse of antibiotics has accelerated bacterial multiresistance, which means there is a need to develop tools for rapid detection and characterization of bacterial response to antibiotics in the management of infections. In the study, an electrochemical biosensor based on nanoporous alumina membrane and graphene quantum dots (GQDs was developed for bacterial response to antibiotics detection. Anti-Salmonella antibody was conjugated with amino-modified GQDs by glutaraldehyde and immobilized on silanized nanoporous alumina membranes for Salmonella bacteria capture. The impedance signals across nanoporous membranes could monitor the capture of bacteria on nanoporous membranes as well as bacterial response to antibiotics. This nanoporous membrane and GQD-based electrochemical biosensor achieved rapid detection of bacterial response to antibiotics within 30 min, and the detection limit could reach the pM level. It was capable of investigating the response of bacteria exposed to antibiotics much more rapidly and conveniently than traditional tools. The capability of studying the dynamic effects of antibiotics on bacteria has potential applications in the field of monitoring disease therapy, detecting comprehensive food safety hazards and even life in hostile environment.

  6. Loop-mediated isothermal amplification: Rapid and sensitive detection of the antibiotic resistance gene ISAba1-blaOXA-51-like in Acinetobacter baumannii.

    Science.gov (United States)

    Mu, Xiaoqin; Nakano, Ryuichi; Nakano, Akiyo; Ubagai, Tsuneyuki; Kikuchi-Ueda, Takane; Tansho-Nagakawa, Shigeru; Kikuchi, Hirotoshi; Kamoshida, Go; Endo, Shiro; Yano, Hisakazu; Ono, Yasuo

    2016-02-01

    Carbapenem-resistant Acinetobacter baumannii, which are mainly induced by the production of OXA-type β-lactamases, are among the leading causes of nosocomial infections worldwide. Among the β-lactamase genes, the presence of the OXA-51-like gene carrying the upstream insertion sequence, ISAba1, was found to be one of the most prevalent carbapenem resistance mechanisms utilized by these bacteria. Consequently, it is necessary to develop a rapid detection method for ISAba1-blaOXA-51-like sequence for the timely and appropriate antibiotic treatment of A. baumannii infection. In this study, a loop-mediated isothermal amplification (LAMP) assay was optimized for ISAba1-blaOXA-51-like detection. The LAMP primer set was designed to recognize distinct sequences in the ISAba1-blaOXA-51-like gene and could amplify the gene within 25 min at an isothermal temperature of 60°C. This LAMP assay was able to detect the ISAba1-blaOXA-51-like gene with high specificity; in addition, no cross-reactivity was observed for other types of β-lactamase producers (OXA-23-like, OXA-40-like, OXA-58-like, and IMP-1), as indicated by the absence of false positive or false negative results. The detection limit for this assay was found to be 10(0)CFU per tube which was 100-fold more sensitive than a polymerase chain reaction assay for ISAba1-blaOXA-51-like detection. Furthermore, the LAMP assay provided swift detection of the ISAba1-blaOXA-51-like gene, even directly from clinical specimens. In summary, we have described a new, rapid assay for the detection of the ISAba1-blaOXA-51-like gene from A. baumannii that could be useful in a clinical setting. This method might facilitate epidemiological studies and allow monitoring of the emergence of drug resistant strains. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Antibiotic Sensitivity Pattern of Microorganisms Isolated from ...

    African Journals Online (AJOL)

    Antibiotic sensitivity pattern of microorganisms isolated from smoked and frozen fishes sold in Benin and Warri metropolis were investigated. Adopting microbiological standard techniques, the results of the bacterial counts and fungal counts ranged from 5.4 x 106 (Ekpan market) to 25.1 x 106 (Ekpan market) and 1.1 x 105 ...

  8. Common Bacterial Pathogens and their Antibiotic Sensitivity

    African Journals Online (AJOL)

    these three drugs can be used in treating most from this study suggest that these three drugs can be used in treating most bacterial infections. This would be particularly useful in health set-ups where culturing and sensitivity testing is impossible, although the availability and cost effectiveness of these antibiotics is in ...

  9. Testing the sensitivity of Staphylococcus aureus antibiotics

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    Marioara Nicoleta FILIMON

    2009-11-01

    Full Text Available This study has in view to establish and test the sensitivity of Staphylococcus aureus antibiotics. There are different injuries caused by superficial skin infections: from simple pimples to infections that endanger our lives, like an abscess, furuncle septicemia, meningitis, toxic food, urinary tract infection at sexually active young women. Samples have been taken from 30 people with staphylococcus infections. They were nineteen women and eleven men, between the age of 2 and 79. During this study some antibiograms have been made, based on pharyngeal exudates, acne secretion and urine culture. It has been established that the most efficient recommended antibiotics are: oxacilin, erythromycin, rifampicin and ciprofloxacin. The penicillin turned out to be less efficient to remove and destroy the Staphylococcus aureus species.

  10. Reversing bacterial resistance to antibiotics by phage-mediated delivery of dominant sensitive genes.

    Science.gov (United States)

    Edgar, Rotem; Friedman, Nir; Molshanski-Mor, Shahar; Qimron, Udi

    2012-02-01

    Pathogen resistance to antibiotics is a rapidly growing problem, leading to an urgent need for novel antimicrobial agents. Unfortunately, development of new antibiotics faces numerous obstacles, and a method that resensitizes pathogens to approved antibiotics therefore holds key advantages. We present a proof of principle for a system that restores antibiotic efficiency by reversing pathogen resistance. This system uses temperate phages to introduce, by lysogenization, the genes rpsL and gyrA conferring sensitivity in a dominant fashion to two antibiotics, streptomycin and nalidixic acid, respectively. Unique selective pressure is generated to enrich for bacteria that harbor the phages carrying the sensitizing constructs. This selection pressure is based on a toxic compound, tellurite, and therefore does not forfeit any antibiotic for the sensitization procedure. We further demonstrate a possible way of reducing undesirable recombination events by synthesizing dominant sensitive genes with major barriers to homologous recombination. Such synthesis does not significantly reduce the gene's sensitization ability. Unlike conventional bacteriophage therapy, the system does not rely on the phage's ability to kill pathogens in the infected host, but instead, on its ability to deliver genetic constructs into the bacteria and thus render them sensitive to antibiotics prior to host infection. We believe that transfer of the sensitizing cassette by the constructed phage will significantly enrich for antibiotic-treatable pathogens on hospital surfaces. Broad usage of the proposed system, in contrast to antibiotics and phage therapy, will potentially change the nature of nosocomial infections toward being more susceptible to antibiotics rather than more resistant.

  11. Rapid optical determination of β-lactamase and antibiotic activity

    Science.gov (United States)

    2014-01-01

    Background The absence of rapid tests evaluating antibiotic susceptibility results in the empirical prescription of antibiotics. This can lead to treatment failures due to escalating antibiotic resistance, and also furthers the emergence of drug-resistant bacteria. This study reports a rapid optical method to detect β-lactamase and thereby assess activity of β-lactam antibiotics, which could provide an approach for targeted prescription of antibiotics. The methodology is centred on a fluorescence quenching based probe (β-LEAF – β-Lactamase Enzyme Activated Fluorophore) that mimics the structure of β-lactam antibiotics. Results The β-LEAF assay was performed for rapid determination of β-lactamase production and activity of β-lactam antibiotic (cefazolin) on a panel of Staphylococcus aureus ATCC strains and clinical isolates. Four of the clinical isolates were determined to be lactamase producers, with the capacity to inactivate cefazolin, out of the twenty-five isolates tested. These results were compared against gold standard methods, nitrocefin disk test for β-lactamase detection and disk diffusion for antibiotic susceptibility, showing results to be largely consistent. Furthermore, in the sub-set of β-lactamase producers, it was demonstrated and validated that multiple antibiotics (cefazolin, cefoxitin, cefepime) could be assessed simultaneously to predict the antibiotic that would be most active for a given bacterial isolate. Conclusions The study establishes the rapid β-LEAF assay for β-lactamase detection and prediction of antibiotic activity using S. aureus clinical isolates. Although the focus in the current study is β-lactamase-based resistance, the overall approach represents a broad diagnostic platform. In the long-term, these studies form the basis for the development of assays utilizing a broader variety of targets, pathogens and drugs. PMID:24708478

  12. Lab on a chip sensor for rapid detection and antibiotic resistance determination of Staphylococcus aureus.

    Science.gov (United States)

    Abeyrathne, Chathurika D; Huynh, Duc H; Mcintire, Thomas W; Nguyen, Thanh C; Nasr, Babak; Zantomio, Daniela; Chana, Gursharan; Abbott, Iain; Choong, Peter; Catton, Mike; Skafidas, Efstratios

    2016-03-21

    The Gram-positive bacterium, Staphylococcus aureus (S. aureus), is a major pathogen responsible for a variety of infectious diseases ranging from cellulitis to more serious conditions such as septic arthritis and septicaemia. Timely treatment with appropriate antibiotic therapy is essential to ensure clinical defervescence and to prevent further complications such as infective endocarditis or organ impairment due to septic shock. To date, initial antibiotic choice is empirical, using a "best guess" of likely organism and sensitivity- an approach adopted due to the lack of rapid identification methods for bacteria. Current culture based methods take up to 5 days to identify the causative bacterial pathogen and its antibiotic sensitivity. This paper provides proof of concept for a biosensor, based on interdigitated electrodes, to detect the presence of S. aureus and ascertain its sensitivity to flucloxacillin rapidly (within 2 hours) in a cost effective manner. The proposed method is label-free and uses non-faradic measurements. This is the first study to successfully employ interdigitated electrodes for the rapid detection of antibiotic resistance. The method described has important potential outcomes of faster definitive antibiotic treatment and more rapid clinical response to treatment.

  13. Rapid determination of antibiotic resistance in E. coli using dielectrophoresis

    International Nuclear Information System (INIS)

    Hoettges, Kai F; Dale, Jeremy W; Hughes, Michael P

    2007-01-01

    In recent years, infections due to antibiotic-resistant strains of bacteria such as methillicin-resistant Staphylococcus aureus and ciprofloxacin-resistant Escherichia coli are on the rise, and with them the demand for rapid antibiotic testing is also rising. Conventional tests, such as disc diffusion testing, require a primary sample to be tested in the presence of a number of antibiotics to verify which antibiotics suppress growth, which take approximately 24 h to complete and potentially place the patient at severe risk. In this paper we describe the use of dielectrophoresis as a rapid marker of cell death, by detecting changes in the electrophysiology of the cell caused by the administration of an antibiotic. In contrast to other markers, the electrophysiology of the cell changes rapidly during cell death allowing live cells to be distinguished from dead (or dying) cells without the need for culturing. Using polymyxin B as an example antibiotic, our studies indicate that significant changes in cell characteristics can be observed as soon as 1 h passes after isolating a culture from nutrient broth

  14. The Effect of Antioxidants on Antibiotic Sensitivity of Bacteria

    OpenAIRE

    Azade ATTAR; Akif İ. QURBANOV

    2007-01-01

    Objective: The effect of different concentrations of antioxidants (ascorbic acid, emoxipin, tocopherol acetate and ionol) on antibiotic sensitivity of bacteria was studied. Method: Bacteria belong to different respiration types: Pseudomonas aeruginosa as aerobe and Escherichia coli as facultative anaerobe were used. Antibiotic sensitivity of microorganisms was determined as minimum inhibitory concentration (MIC) by dilution test. Results: Different concentrations of antioxidants increased the...

  15. Antibiotics sensitivity profile of proteus species associated with ...

    African Journals Online (AJOL)

    Antibiotics sensitivity profile of proteus species associated with specific infections at University of Ilorin Teaching Hospital, Ilorin. ... Results of the antimicrobial sensitivity testing showed that Imipenem and Piperacillin antibiotics were the most effective against Proteus sppwith each having 100%, followed by Ceftazidime ...

  16. Antibiotic Sensitivity Patterns of Aerobic Bacterial Agents in Post ...

    African Journals Online (AJOL)

    Antibiotic Sensitivity Patterns of Aerobic Bacterial Agents in Post-Surgical ... those commonly used to treat orofacial infections were tested for sensitivity against the ... were the augmented Penicillins and newer generations Cephalosporins.

  17. Impact of Rapid Susceptibility Testing and Antibiotic Selection Strategy on the Emergence and Spread of Antibiotic Resistance in Gonorrhea.

    Science.gov (United States)

    Tuite, Ashleigh R; Gift, Thomas L; Chesson, Harrell W; Hsu, Katherine; Salomon, Joshua A; Grad, Yonatan H

    2017-11-27

    Increasing antibiotic resistance limits treatment options for gonorrhea. We examined the impact of a hypothetical point-of-care (POC) test reporting antibiotic susceptibility profiles on slowing resistance spread. A mathematical model describing gonorrhea transmission incorporated resistance emergence probabilities and fitness costs associated with resistance based on characteristics of ciprofloxacin (A), azithromycin (B), and ceftriaxone (C). We evaluated time to 1% and 5% prevalence of resistant strains among all isolates with the following: (1) empiric treatment (B and C), and treatment guided by POC tests determining susceptibility to (2) A only and (3) all 3 antibiotics. Continued empiric treatment without POC testing was projected to result in >5% of isolates being resistant to both B and C within 15 years. Use of either POC test in 10% of identified cases delayed this by 5 years. The 3 antibiotic POC test delayed the time to reach 1% prevalence of triply-resistant strains by 6 years, whereas the A-only test resulted in no delay. Results were less sensitive to assumptions about fitness costs and test characteristics with increasing test uptake. Rapid diagnostics reporting antibiotic susceptibility may extend the usefulness of existing antibiotics for gonorrhea treatment, but ongoing monitoring of resistance patterns will be critical. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

  18. Metabolic regulation of mycobacterial growth and antibiotic sensitivity.

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    Seung-Hun Baek

    2011-05-01

    Full Text Available Treatment of chronic bacterial infections, such as tuberculosis (TB, requires a remarkably long course of therapy, despite the availability of drugs that are rapidly bacteriocidal in vitro. This observation has long been attributed to the presence of bacterial populations in the host that are "drug-tolerant" because of their slow replication and low rate of metabolism. However, both the physiologic state of these hypothetical drug-tolerant populations and the bacterial pathways that regulate growth and metabolism in vivo remain obscure. Here we demonstrate that diverse growth-limiting stresses trigger a common signal transduction pathway in Mycobacterium tuberculosis that leads to the induction of triglyceride synthesis. This pathway plays a causal role in reducing growth and antibiotic efficacy by redirecting cellular carbon fluxes away from the tricarboxylic acid cycle. Mutants in which this metabolic switch is disrupted are unable to arrest their growth in response to stress and remain sensitive to antibiotics during infection. Thus, this regulatory pathway contributes to antibiotic tolerance in vivo, and its modulation may represent a novel strategy for accelerating TB treatment.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2014-08-11

    A colorimetric assay utilizing the formation of gold nanoparticles was developed to detect tetracycline antibiotics in fluidic samples. Tetracycline antibiotics showed the capability of directly reducing aurate salts into atomic gold which form gold nanoparticles spontaneously under proper conditions. The resulted gold nanoparticles showed characteristic plasmon absorbance at 526 nm, which can be visualized by naked eyes or with a spectrophotometer. UV-vis absorbance of the resulted gold nanoparticles is correlated directly with the concentrations of tetracycline antibiotics in the solution, allowing for quantitative colorimetric detection of tetracycline antibiotics. Reaction conditions, such as pH, temperature, reaction time, and ionic strength were optimized. Sensitivity of the colorimetric assay can be enhanced by the addition of gold nanoparticle seeds, a LOD as low as 20 ng mL(-1) can be achieved with the help of seed particles. The colorimetric assay showed minimum interference from ethanol, methanol, urea, glucose, and other antibiotics such as sulfonamides, amino glycosides etc. Validity of the method was also evaluated on urine samples spiked with tetracycline antibiotics. The method provides a broad spectrum detection method for rapid and sensitive detection of reductive substances such as tetracycline antibiotics in liquid and biological samples. Copyright © 2014 Elsevier B.V. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Li [Logistics School, Beijing Wuzi University, Beijing 101149 (China); Chen, Jing; Li, Na [Logistics School, Beijing Wuzi University, Beijing 101149 (China); He, Pingli [State Key Laboratory of Animal Nutrition, China Agricultural University, Beijing 100094 (China); Li, Zhen [State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193 (China)

    2014-08-11

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

  2. Gamma irradiation increase the sensitivity of Salmonella to antibiotics

    International Nuclear Information System (INIS)

    Ben Miloud, Najla; Barkallah, Insaf

    2008-01-01

    In order to study the effect of ionizing radiation on the resistance of Salmonella to antibiotics, four strains of Salmonella were isolated from foods, The different strains used in the present study are (S. Hadar isolate 287, S. Hadar isolate 63, S. Cerro isolate 291, S. Zanzibar isolate 1103), antibiogram analyses were made to test the in vitro-sensitivity of irradiated Salmonella isolates to different antibiotics.The analyse of Control and exposed antibiograms showed that gamma radiation have increased the sensitivity of Salmonella isolates to Cefalotin, Chloramphenicol, Nalidixic acid, Spiramycin and Gentamycin excepted S. Hadar isolate 287 that was resistant to Cefalotin and became sensitive after irradiation. Statistical analyses showed that the effect of different irradiation dose treatment on the antibiotic sensitivity is increasingly significant. The irradiation didn't induce modifications of the sensitivity to other antibiotics,probably because of their nature, of their penetration mode inside the cell or their action way

  3. Evaluation of multiplex polymerase chain reaction as an alternative to conventional antibiotic sensitivity test

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    K. Rathore

    2018-04-01

    Full Text Available Aim: This study was designed to evaluate the potential of the use of multiplex polymerase chain reaction (PCR as an alternative to conventional antibiotic sensitivity test. Materials and Methods: Isolates of Staphylococcus aureus (total = 36 from clinical cases presented to Teaching Veterinary Clinical Complex of College of Veterinary and Animal Sciences (CVAS, Navania, Udaipur, were characterized by morphological, cultural, and biochemical methods. Then, the isolates were further subjected to molecular characterization by PCR targeting S. aureus-specific sequence (107 bp. Phenotypic antibiotic sensitivity pattern was analyzed by Kirby Bauer disc diffusion method against 11 commonly used antibiotics in veterinary medicine in and around Udaipur region. The genotypic antibiotic sensitivity pattern was studied against methicillin, aminoglycosides, and tetracycline targeting the gene mecA, aacA-aphD, and tetK by multiplex PCR. Results: There was 100% correlation between the phenotype and genotype of aminoglycoside resistance, more than 90% correlation for methicillin resistance, and 58.3% in the case tetracycline resistance. Conclusion: As there is a good correlation between phenotype and genotype of antibiotic resistance, multiplex PCR can be used as an alternative to the conventional antibiotic susceptibility testing, as it can give a rapid and true prediction of antibiotic sensitivity pattern.

  4. Rapid antibiotic susceptibility testing in a microfluidic pH sensor.

    Science.gov (United States)

    Tang, Yanyan; Zhen, Li; Liu, Jingqing; Wu, Jianmin

    2013-03-05

    For appropriate selection of antibiotics in the treatment of pathogen infection, rapid antibiotic susceptibility testing (AST) is urgently needed in clinical practice. This study reports the utilization of a microfluidic pH sensor for monitoring bacterial growth rate in culture media spiked with different kinds of antibiotics. The microfluidic pH sensor was fabricated by integration of pH-sensitive chitosan hydrogel with poly(dimethylsiloxane) (PDMS) microfluidic channels. For facilitating the reflectometric interference spectroscopic measurements, the chitosan hydrogel was coated on an electrochemically etched porous silicon chip, which was used as the substrate of the microfluidic channel. Real-time observation of the pH change in the microchannel can be realized by Fourier transform reflectometric interference spectroscopy (FT-RIFS), in which the effective optical thickness (EOT) was selected as the optical signal for indicating the reversible swelling process of chitosan hydrogel stimulated by pH change. With this microfluidic pH sensor, we demonstrate that confinement of bacterial cells in a nanoliter size channel allows rapid accumulation of metabolic products and eliminates the need for long-time preincubation, thus reducing the whole detection time. On the basis of this technology, the whole bacterial growth curve can be obtained in less than 2 h, and consequently rapid AST can be realized. Compared with conventional methods, the AST data acquired from the bacterial growth curve can provide more detailed information for studying the antimicrobial behavior of antibiotics during different stages. Furthermore, the new technology also provides a convenient method for rapid minimal inhibition concentration (MIC) determination of individual antibiotics or the combinations of antibiotics against human pathogens that will find application in clinical and point-of-care medicine.

  5. Prophylaxis for infective endocarditis: antibiotic sensitivity of dental plaque.

    OpenAIRE

    MacFarlane, T W; McGowan, D A; Hunter, K; MacKenzie, D

    1983-01-01

    The antibiotic sensitivity pattern of bacteria isolated from bacteraemia after dental extraction was compared with that of bacteria isolated from dental plaque samples from the same patient. The results supported the current practice of using penicillin and erythromycin empirically for prophylaxis. The prediction of the most appropriate antibiotic for prophylaxis using dental plaque samples was most accurate when the minimum inhibitory concentration (MIC) of plaque isolates were used. It appe...

  6. Prognostic criteria of sensitivity to antibiotics of staphylococcus clinical strains

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    Gordiy Paliy

    2015-06-01

    Department of Microbiology, Virology and Immunology, Vinnytsya National Pirogov Memorial Medical University Ministry of Health of Ukraine   Abstract In the article, the new data of sensitivity to antibiotics in clinical strains of Staphylococci are presented. For the first time, analytic dependence of dynamic prognostic criteria of the change of sensitivity of S. aureus clinical strains, isolated from patients, was obtained by means of mathematical prediction. There were investigated prognosticated indexes of Staphylococcus strains’ sensitivity to beta-lactams (oxacillin, ceftriaxone, imipenem and meropenem, vancomycin and linezolid. The dynamic of sensitivity decreasing to oxacillin, ceftriaxone, carbapenems (imipenem, meropenem, vancomycin (92,5 % and high sensitivity to linezolid in clinical strains of S. aureus were found out. Key words: sensitivity, antibiotics, Staphylococcus, prognostic indexes.

  7. Sensitivity of some local isolates of Mycoplasma gallisepticum against antibiotics

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    Sutiastuti Wahyuwardani

    1998-03-01

    Full Text Available Sensitivity of five local isolates ofMycoplasma gallisepticum (MG strain and two standard MG isolates obtained from Australia were tested against antibiotics of oxytetracycline, doxycycline, erythromycin, bacitracin, vancomycin, methicillin and penicillin using antibiogram disc method. The result showed that one, 2 and 3 local MG isolates were resistent to doxycycline, erythromycin and oxytetracycline respectively . MG isolate of ADA7 from Australia was found to be resistent to all antibiotics tested. None ofthe local MG isolates were sensitive against bacitracin, vancomycin, methicillin and penicillin.

  8. Sensitivity of antibiotic resistant and antibiotic susceptible Escherichia coli, Enterococcus and Staphylococcus strains against ozone.

    Science.gov (United States)

    Heß, Stefanie; Gallert, Claudia

    2015-12-01

    Tolerance of antibiotic susceptible and antibiotic resistant Escherichia coli, Enterococcus and Staphylococcus strains from clinical and wastewater samples against ozone was tested to investigate if ozone, a strong oxidant applied for advanced wastewater treatment, will affect the release of antibiotic resistant bacteria into the aquatic environment. For this purpose, the resistance pattern against antibiotics of the mentioned isolates and their survival after exposure to 4 mg/L ozone was determined. Antibiotic resistance (AR) of the isolates was not correlating with higher tolerance against ozone. Except for ampicillin resistant E. coli strains, which showed a trend towards increased resistance, E. coli strains that were also resistant against cotrimoxazol, ciprofloxacin or a combination of the three antibiotics were similarly or less resistant against ozone than antibiotic sensitive strains. Pigment-producing Enterococcus casseliflavus and Staphylococcus aureus seemed to be more resistant against ozone than non-pigmented species of these genera. Furthermore, aggregation or biofilm formation apparently protected bacteria in subsurface layers from inactivation by ozone. The relatively large variance of tolerance against ozone may indicate that resistance to ozone inactivation most probably depends on several factors, where AR, if at all, does not play a major role.

  9. The Effect of Rapid Antigen Detection Test on Antibiotic Prescription Decision of Clinicians and Reducing Antibiotic Costs in Children with Acute Pharyngitis.

    Science.gov (United States)

    Kose, Engin; Sirin Kose, Seda; Akca, Deniz; Yildiz, Kerem; Elmas, Cengizhan; Baris, Mustafa; Anil, Murat

    2016-08-01

    We aimed to investigate the effect of rapid antigen detection test (RADT) in the diagnosis of streptococcal pharyngitis, its impact on antibiotic prescription decision of pediatricians and influence on reduction of antibiotic treatment costs in children with pharyngitis. The study group consisted of 223 patients who were diagnosed with pharyngitis by pediatricians. The sensitivity and specificity of RADT were 92.1% (95% Cl: 78.6-98.3%) and 97.3% (95% Cl: 93.8-99.1%), respectively. In the first assessment, before performing RADT, pediatricians decided to prescribe antibiotics for 178 (79.8%) patients with pharyngitis. After learning RADT results, pediatricians finally decided to prescribe antibiotics for 83 (37.2%) patients with pharyngitis, and antibiotic prescription decreased by 42.6%. Antibiotic costs in non-Group A streptococcus pharyngitis, Group A streptococcus pharyngitis and all subjects groups decreased by 80.8%, 48%, and 76.4%, respectively. Performing RADT in children with pharyngitis has an important impact on treatment decision of clinicians, reduction of unnecessary antibiotic prescriptions and antibiotic costs. © The Author [2016]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Targeted Treatment for Bacterial Infections: Prospects for Pathogen-Specific Antibiotics Coupled with Rapid Diagnostics

    OpenAIRE

    Maxson, Tucker; Mitchell, Douglas A.

    2015-01-01

    Antibiotics are a cornerstone of modern medicine and have significantly reduced the burden of infectious diseases. However, commonly used broad-spectrum antibiotics can cause major collateral damage to the human microbiome, causing complications ranging from antibiotic-associated colitis to the rapid spread of resistance. Employing narrower spectrum antibiotics targeting specific pathogens may alleviate this predicament as well as provide additional tools to expand an antibiotic repertoire th...

  11. Antibiotic sensitivity pattern of Staphylococcus aureus from clinical

    African Journals Online (AJOL)

    raoul

    2011-01-26

    Jan 26, 2011 ... Key words: Staphylococcus aureus, antibiotic sensitivity, Nigeria, Kano ... infection have an increased colonization risks [8]. ... confirmed Staphylococcus aureus isolates was prepared in peptone water to ... 5 g methicillin discs (oxoid, USA) were aseptically placed on the surface of the inoculated plates and ...

  12. Antibiotic Sensitivity Profile of Escherichia coli Isolated from Poultry ...

    African Journals Online (AJOL)

    A cross sectional study involving 300 cloaca swabs from apparently healthy birds from 8 small-medium scale poultry farms in Ibadan Oyo State was carried out. A total of 201 (67%) Escherichia coli isolates were recovered from the birds and they were subjected to in-vitro antibiotic sensitivity test by agar gel diffusion method.

  13. Antibiotic sensitivities of common bacterial pathogens in urinary tract ...

    African Journals Online (AJOL)

    Of the total isolates 71.5% were Gram negatives. Sensitivity tested against ten antibiotics showed that resistance was common, and the effectiveness of tetracycline, ampicillin, co-trimoxazole, chloramphenicol and penicillin was under 50.0%. The resistance rate was 71.5%, 62.2%, and 62.2%, 54.7% and 40.8%, respectively ...

  14. Bacterial Isolates andAntibiotic Sensitivity in Community Acquired ...

    African Journals Online (AJOL)

    Objective: The objective of the studywas to determine bacterial causes of community acquired pneumonia and their antibiotic sensitivity pattern amongst patients admitted intomedicalwards inAminu Kano Teaching Hospital, Kano, Nigeria Methods: The study incorporated patients aged fifteen years and above admitted into ...

  15. Sensitizing pathogens to antibiotics using the CRISPR-Cas system.

    Science.gov (United States)

    Goren, Moran; Yosef, Ido; Qimron, Udi

    2017-01-01

    The extensive use of antibiotics over the last century has resulted in a significant artificial selection pressure for antibiotic-resistant pathogens to evolve. Various strategies to fight these pathogens have been introduced including new antibiotics, naturally-derived enzymes/peptides that specifically target pathogens and bacteriophages that lyse these pathogens. A new tool has recently been introduced in the fight against drug-resistant pathogens-the prokaryotic defense mechanism-clustered regularly interspaced short palindromic repeats-CRISPR associated (CRISPR-Cas) system. The CRISPR-Cas system acts as a nuclease that can be guided to cleave any target DNA, allowing sophisticated, yet feasible, manipulations of pathogens. Here, we review pioneering studies that use the CRISPR-Cas system to specifically edit bacterial populations, eliminate their resistance genes and combine these two strategies in order to produce an artificial selection pressure for antibiotic-sensitive pathogens. We suggest that intelligent design of this system, along with efficient delivery tools into pathogens, may significantly reduce the threat of antibiotic-resistant pathogens. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. The Calgary Biofilm Device: New Technology for Rapid Determination of Antibiotic Susceptibilities of Bacterial Biofilms

    OpenAIRE

    Ceri, H.; Olson, M. E.; Stremick, C.; Read, R. R.; Morck, D.; Buret, A.

    1999-01-01

    Determination of the MIC, based on the activities of antibiotics against planktonic bacteria, is the standard assay for antibiotic susceptibility testing. Adherent bacterial populations (biofilms) present with an innate lack of antibiotic susceptibility not seen in the same bacteria grown as planktonic populations. The Calgary Biofilm Device (CBD) is described as a new technology for the rapid and reproducible assay of biofilm susceptibilities to antibiotics. The CBD produces 96 equivalent bi...

  17. Rapid antibiotic efficacy screening with aluminum oxide nanoporous membrane filter-chip and optical detection system.

    Science.gov (United States)

    Tsou, Pei-Hsiang; Sreenivasappa, Harini; Hong, Sungmin; Yasuike, Masayuki; Miyamoto, Hiroshi; Nakano, Keiyo; Misawa, Takeyuki; Kameoka, Jun

    2010-09-15

    We have developed a filter-chip and optical detection system for rapid antibiotic efficacy screening. The filter-chip consisted of a 1-mL reservoir and an anodic aluminum oxide (AAO) nanoporous membrane. Sample solution with liquid growth media, bacteria, and antibiotics was incubated in the reservoir for a specific period of time. The number of live bacteria on the surface of membrane was counted after the incubation with antibiotics and filtration. Using this biosensing system, we have demonstrated a 1-h antibiotic screening for patients' clinical samples, significantly faster than the conventional antibiotic susceptibility tests that typically take more than 24h. This rapid screening nature makes the filter-chip and detection system ideal for tailoring antibiotic treatment to individual patients by reducing the microbial antibiotic resistance, and improving the survival rate for patients suffering from postoperative infections. Published by Elsevier B.V.

  18. Temperate and lytic bacteriophages programmed to sensitize and kill antibiotic-resistant bacteria.

    Science.gov (United States)

    Yosef, Ido; Manor, Miriam; Kiro, Ruth; Qimron, Udi

    2015-06-09

    The increasing threat of pathogen resistance to antibiotics requires the development of novel antimicrobial strategies. Here we present a proof of concept for a genetic strategy that aims to sensitize bacteria to antibiotics and selectively kill antibiotic-resistant bacteria. We use temperate phages to deliver a functional clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated (Cas) system into the genome of antibiotic-resistant bacteria. The delivered CRISPR-Cas system destroys both antibiotic resistance-conferring plasmids and genetically modified lytic phages. This linkage between antibiotic sensitization and protection from lytic phages is a key feature of the strategy. It allows programming of lytic phages to kill only antibiotic-resistant bacteria while protecting antibiotic-sensitized bacteria. Phages designed according to this strategy may be used on hospital surfaces and hand sanitizers to facilitate replacement of antibiotic-resistant pathogens with sensitive ones.

  19. Factors influencing antibiotic prescribing habits and use of sensitivity testing amongst veterinarians in Europe.

    Science.gov (United States)

    De Briyne, N; Atkinson, J; Pokludová, L; Borriello, S P; Price, S

    2013-11-16

    The Heads of Medicines Agencies and the Federation of Veterinarians of Europe undertook a survey to gain a better insight into the decision-making process of veterinarians in Europe when deciding which antibiotics to prescribe. The survey was completed by 3004 practitioners from 25 European countries. Analysis was to the level of different types of practitioner (food producing (FP) animals, companion animals, equines) and country for Belgium, Czech Republic, France, Germany, Spain, Sweden and the UK. Responses indicate no single information source is universally considered critical, though training, published literature and experience were the most important. Factors recorded which most strongly influenced prescribing behaviour were sensitivity tests, own experience, the risk for antibiotic resistance developing and ease of administration. Most practitioners usually take into account responsible use warnings. Antibiotic sensitivity testing is usually performed where a treatment failure has occurred. Significant differences were observed in the frequency of sensitivity testing at the level of types of practitioners and country. The responses indicate a need to improve sensitivity tests and services, with the availability of rapid and cheaper testing being key factors.

  20. Global shortage of neonatal and paediatric antibiotic trials: rapid review.

    Science.gov (United States)

    Thompson, Georgina; Barker, Charlotte I; Folgori, Laura; Bielicki, Julia A; Bradley, John S; Lutsar, Irja; Sharland, Mike

    2017-10-13

    There have been few clinical trials (CTs) on antibiotics that inform neonatal and paediatric drug labelling. The rate of unlicensed and off-label prescribing in paediatrics remains high. It is unclear whether the current neonatal and paediatric antibiotic research pipeline is adequate to inform optimal drug dosing. Using the ClinicalTrials.gov registry, this review aims to establish the current global status of antibiotic CTs in children up to 18 years of age. Studies were identified using key word searches of the ClinicalTrials.gov registry and were manually filtered using prespecified inclusion/exclusion criteria. 76 registered open CTs of antibiotics in children were identified globally; 23 (30%) were recruiting newborns (only 8 (11%) included preterm neonates), 52 (68%) infants and toddlers, 58 (76%) children and 54 (71%) adolescents. The majority of registered trials were late phase (10 (15%) phase 3 and 23 (35%) phase 4/pharmacovigilance). Two-thirds were sponsored by non-profit organisations, compared with pharmaceutical companies (50 (66%) vs 26 (34%), respectively). A greater proportion of non-profit funded trials were efficacy-based strategic trials (n=34, 68%), in comparison with industry-led trials, which were most often focused on safety or pharmacokinetic data (n=17, 65%). Only 2 of the 37 antibiotics listed on the May 2016 Pew Charitable Trusts antibiotic development pipeline, currently being studied in adults, appear to be currently recruiting in open paediatric CTs. This review highlights that very few paediatric antibiotic CTs are being conducted globally, especially in neonates. There is a striking disparity noted between antibiotic drug development programmes in adults and children. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  1. MICROORGANISMS ANTIBIOTIC SENSITIVITY DETERMINATION IN URINARY TRACT INFECTIONS

    Directory of Open Access Journals (Sweden)

    Shapovalova O.V.

    2016-06-01

    Full Text Available Introduction. Nowadays Urinary tract infections (UTI are considered to be the most common bacterial infections. Escherichia coli is the most frequently uropathogen. Other microorganisms of the genera Enterococcus, Klebsiella, Enterobacter, Proteus, Morganella, Citrobacter, Serratia, Pseudomonas, Streptococcus, Staphylococcus, Candida are also isolated with variable frequency. In recent years there has been a decreasing tendency of the causative agents of UTI sensitivity to various antibiotics, which causes growth of an inefficiency treatment risk. In connection with the above the investigations were carried out with the purpose to identify the actual causative agents of bacteriuria and their sensitivity to antibiotics and antifungal drugs. Materials and methods. Bacteriological examination of urine was performed at 42 patients of SI "Sytenko Institute of Spine and Joint Pathology, AMS of Ukraine" clinic. The bacteriological method for determining the number of bacteria in the test material, cultural and bacterioscopic methods for identifying microorganisms and disk-diffusion method for sensitivity of microorganisms to antibiotics determining were used. The clinical material for the study was an average portion of the morning urine or urine collected by catheter. The biological material collection and bacteriological examination was carried by quantitative method, the isolated microorganisms identification and their sensitivity to antibiotics determining was performed by standard methods in accordance with current guidelines. We used the following antibiotics group to determine the microorganisms sensitivity: penicillin, cephalosporin, karbapenems, tetracyclines, aminoglycoside, fluoroquinolones, oxazolidinones, macrolides, lincosamides, glycopeptides, antifungal antibiotics. Results and discussion. During the biological material study 55 isolates of bacterial and fungal pathogens were obtained. The microorganisms’ concentration in urine was in

  2. New Technologies for Rapid Bacterial Identification and Antibiotic Resistance Profiling.

    Science.gov (United States)

    Kelley, Shana O

    2017-04-01

    Conventional approaches to bacterial identification and drug susceptibility testing typically rely on culture-based approaches that take 2 to 7 days to return results. The long turnaround times contribute to the spread of infectious disease, negative patient outcomes, and the misuse of antibiotics that can contribute to antibiotic resistance. To provide new solutions enabling faster bacterial analysis, a variety of approaches are under development that leverage single-cell analysis, microfluidic concentration and detection strategies, and ultrasensitive readout mechanisms. This review discusses recent advances in this area and the potential of new technologies to enable more effective management of infectious disease.

  3. Reversing Bacterial Resistance to Antibiotics by Phage-Mediated Delivery of Dominant Sensitive Genes

    OpenAIRE

    Edgar, Rotem; Friedman, Nir; Molshanski-Mor, Shahar; Qimron, Udi

    2012-01-01

    Pathogen resistance to antibiotics is a rapidly growing problem, leading to an urgent need for novel antimicrobial agents. Unfortunately, development of new antibiotics faces numerous obstacles, and a method that resensitizes pathogens to approved antibiotics therefore holds key advantages. We present a proof of principle for a system that restores antibiotic efficiency by reversing pathogen resistance. This system uses temperate phages to introduce, by lysogenization, the genes rpsL and gyrA...

  4. A radiotracer study of the sensitivity of bacteria to antibiotics

    International Nuclear Information System (INIS)

    Nagy, E.J.

    1975-01-01

    In the developed measuring apparatus the test bacterium E.coli was dissolved in 25 ml of the synthetic medium M9 (pH=7.0) and 2 μCi of D-glucose- 14 C (80 μg of glucose) was added to the solution. The test material was incubated at 37+-0.2 degC. In closed system the quantity of developing 14 CO 2 have been proportional to the multiplication rate of bacterium. The radioactive CO 2 have been absorbed in the box containing the liquid scintillation material. The absorption capacity of the toluene-base scintillation liquid was increased by adding diethanolamine (pH=10) and the multiplication was promoted by constant mixing. The sensitivity of the given bacterium to antibiotics like Penicillin G, Tetracyclin, Ampicillin, Polymycin B can be given in 60-120 min. (K.A.)

  5. Antibiotic sensitivity of Enterobacteriaceae at a tertiary care center in India

    Directory of Open Access Journals (Sweden)

    Summaiya Mulla

    2011-01-01

    Full Text Available Aims and Objectives: It has been observed that various microorganisms are acquiring resistance to most of the available potent antibiotics; hence, there is a need for every hospital to follow the use of antibiotics according to antibiotic sensitivity pattern in that particular hospital or geographical area. It has been reported that Enterobacteriaceae group of microorganisms are increasingly acquiring resistance to many antibiotics and this resistance varies geographically. As there is a short of recent data with respect to Indian hospital, this particular study was designed with the aim of establishing sensitivity pattern of Enterobacteriaceae group of microorganisms to various antibiotics. Materials and Methods: Data of antibiotic sensitivity from December 2010 to April 2011 of different Enterobacteriaceae was taken from the Department of Microbiology, Govt. Medical College, Surat. Sensitivity of different Enterobacteriaceae was shown as using descriptive statistics. Results: E. coli (55.6% and Klebsiella (31.2% were the most frequent bacteria isolated. Enterobacteriaceae were very less sensitive to amoxicillin + clavulanic acid (13.7%, chloramphenicol (7.6%, cefoperazone (14.4%, cefixime (15.7%, and cefuroxime (17.6. Sensitivity to aztreonam was 32.7%. Sensitivity to carbapenem group of drugs included in this study, i.e., meropenem was 69.8%. Highest sensitivity was shown for ceftazidime (74.1%. E. coli is more sensitive to meropenem as compared with Klebsiella. Conclusion: Sensitivity of Enterobacteriaceae group of microorganisms to known antibiotics is decreasing. Decreased sensitivity to carbapenem group of antibiotics is a matter of concern.

  6. Prevalent serogroups and antibiotic sensitivity of Neisseria gonorrhoeae

    Directory of Open Access Journals (Sweden)

    Aggarwal S

    1992-01-01

    Full Text Available One hundred and thirty two cases clinically labeled as acute gonorrhoea were investigated for gonococcal etiology. Smears were positive in 110 (83.3% cases and among these N. gonorrhoeae could be identified in 102 (77.3% cases by culture method. Strains were examined for serogrouping by monoclonal GC test which utilizes the principle of co-agglutination and detects the antigens of outer membrane protein. 96(94.1% strains belonged to serogroup W II/III, showing it to be the major serogroup circulating in the community. The strains were tested for sensitivity against 7 antibiotics. The largest proportion (30.4% of strains were resistant to penicillin (MIC>O. 125 IU/ml. Resistance to cotrimoxazole, erythromycin, cephalaxin and tetracycline was noted as 18.6, 17.6, 7.8 and 5.8 percent respectively. Strains showing resistance concurrently to two or more drugs were observed. All restrains were sensitive to gentamicin and norfloxacin. None of the strains was penicillinase producer.

  7. Isolation and antibiotic sensitivity of Aeromonas from children with diarrhea

    Directory of Open Access Journals (Sweden)

    Meiyanti Meiyanti

    2016-02-01

    Full Text Available Aeromonas species are gram-negative, motile, facultative anaerobic, rod shaped, oxidase positive bacteria of the recently assigned family Aeromonadaceae. The significance of Aeromonas species as causative agent of human diarrhoea has recently been established. The aim of the present study was to investigate the distribution, and antibiotic sensitivity of Aeromonas in nonhospitalized children with diarrhea.One hundred and seventeen rectal swabs from children with diarhhea were cultured for isolation of Aeromonas organisms as the etiological agents. In addition to Aeromonas, other enteric pathogens were also isolated. Overall, the isolates of enteric pathogens amounted to 36.8%, consisting of Salmonella, Shigella, Aeromonas, and Vibrio. Aeromonas was only found in 5.1% of cultures, with a ratio of A. caviae and A. hydrophila of 2:1, while Salmonella made up the majority of causative organisms with an isolation frequency of 18.8%, followed by Shigella with 11.1%. In this study no isolates of Vibrio cholerae O1 were found as etiological agents of diarrhea; however, V. cholerae non-O1 and V. parahaemolyticus were found in small numbers (<1%. All isolates of Aeromonas were resistant to ampicillin and tetracycline, but sensitive to ciprofloxacin and ceftriaxone, as were the other enteric pathogens. Although the frequency of isolation of these enteric pathogens was higher than for Vibrio spp., their role in infective diarrhea was less clearcut in comparison with Salmonella and Shigella.

  8. A SAFE PROTOCOL FOR RAPID DESENSITIZATION IN PATIENTS WITH CYSTIC FIBROSIS AND ANTIBIOTIC HYPERSENSITIVITY

    Science.gov (United States)

    Legere, Henry J.; Palis, Ross I.; Bouza, Tito Rodriguez; Uluer, Ahmet Z.; Castells, Mariana C.

    2009-01-01

    Background CF patients often demonstrate hypersensitivity to one or multiple antibiotics due to frequent and repeated exposures. Attempts at antibiotic desensitization in this population are historically complicated by higher reaction rates, failure to complete the procedure and consequent withholding of first-line therapy. This study evaluates the outcomes of a rapid desensitization protocol developed at our institution. Methods We retrospectively reviewed the medical records of 15 patients undergoing 52 rapid antibiotic desensitizations at Brigham and Women’s Hospital and Children’s Hospital Boston utilizing our protocol. Results Mean FEV1 % predicted was 44.1 (SD 16.5), with two patients at desensitized during bilateral lung transplantation. Adverse reactions during desensitization occurred in 13.4%, and most were mild. 100% of patients completed the protocol and ultimately tolerated subsequent full-strength antibiotic courses. Conclusions CF patients with antibiotic hypersensitivity can safely receive first-line antibiotics via our rapid desensitization protocol, including those with severe obstructive lung disease. PMID:19740711

  9. Antibiotics

    Science.gov (United States)

    Antibiotics are powerful medicines that fight bacterial infections. Used properly, antibiotics can save lives. They either kill bacteria or ... natural defenses can usually take it from there. Antibiotics do not fight infections caused by viruses, such ...

  10. Subclinical mastitis in sheep: Causes and their sensitivity to antibiotics

    Directory of Open Access Journals (Sweden)

    Vakanjac Slobodanka

    2010-01-01

    Full Text Available The California mastitis test (CMT was used to examine the milk of 6609 sheep, actually, from 13218 mammary complexes. A total of 986 milk samples were found to contain an increased number of somatic cells, and causes of mastitis were isolated from 910 (92.3% of these samples. The most frequently isolated microorganisms were: E. coli isolated from 189 (20.76% samples, Micrococcus sp from 186 (20.43% samples, Bacillus sp. from 177 (19.45%, Staphylococcus aureus from 172 (18.9% samples, and Proteus sp. from 121 (13.29% samples of sheep milk. Coagulase-negative staphylococci (CNS were isolated in a much smaller number, from 25 (2.74% samples, Streptococcus sp. was isolated from 19 (2.08% samples, Pseudomonas sp. from 14 (1.53% samples, haemolytic E. coli was isolated from only 6 (0.65% samples, and Streptococcus agalactiae from only one sample. Among the 25 isolates of coagulase-negative staphylococci, 16 (64% isolates were identified as Staphylococcus chromogenes, and 9 (36% isolates as Staphylococcus simulans. The sensitivity of the isolated causes of mastitis to antibiotics was examined using the disc diffusion method. .

  11. Rapid antibiotic susceptibility testing of Mycobacterium tuberculosis : Its utility in resource poor settings

    Directory of Open Access Journals (Sweden)

    Poojary A

    2006-01-01

    Full Text Available Purpose: To compare the rapid colorimetric nitrate reductase based antibiotic susceptibility (CONRAS test performed on Mycobacterium tuberculosis isolates with the conventional method i.e., the proportion method. Methods: One hundred clinical isolates of M. tuberculosis were tested for susceptibility to isoniazid (INH and rifampicin (RIF by the conventional proportion method and CONRAS in Middlebrook 7H9 liquid medium enriched with growth supplements (MB7H9S. Results: The performance of the CONRAS test was evaluated using proportion method as the gold standard. The sensitivity (ability to detect true drug resistance and specificity (ability to detect true drug susceptibility of the CONRAS test to INH was 93.75 and 98.52% and for RIF it was 96.10 and 100% respectively. The mean time for reporting was 6.3 days and the test showed excellent reproducibility. The kappa (k value for INH was 0.92 and for RIF was 0.99, indicating excellent agreement between the two methods. Conclusions: CONRAS test is a rapid and reliable method of drug susceptibility for M. tuberculosis.

  12. Locally prepared antibiotic sensitivity discs: a substitute for imported ...

    African Journals Online (AJOL)

    Zones of inhibition were compared with those obtained from commercial antibiotic discs. Results obtained showed that discs prepared locally from antibiotic tablets, performed comparably with commercially obtained discs. There was no significant statistical difference between the two tested discs. We therefore recommend ...

  13. Effect of antibiotic therapy on the sensitivity of indium-111-labeled leukocyte scans

    International Nuclear Information System (INIS)

    Datz, F.L.; Thorne, D.A.

    1986-01-01

    Although 111 In-labeled leukocytes have been shown to be a useful technique for detecting infection, it has been postulated that antibiotic therapy may reduce the sensitivity of the leukocyte scan. Many patients with suspected bacterial infections are placed on antibiotics before a definite site of infection has been identified. Three hundred twelve leukocyte scans on 271 patients were retrospectively reviewed and classified as positive or negative, and as to whether or not they were being treated with antibiotics at the time the leukocyte scan was performed. The overall sensitivity, considering all 312 studies, was 90%. One hundred sixty-nine patient studies were on patients receiving antibiotics; 143 studies were on patients not on antibiotics. The sensitivity of the leukocyte scan was 88.7% in patients on antibiotic therapy; it was 92.1% in those who were not receiving antibiotics. The differences in sensitivity between the two groups were not significantly different (p less than 0.05). We conclude that antibiotic therapy does not affect the sensitivity of the 111 In-labeled leukocyte scan

  14. Antibiotic Sensitivity in Pseudomonas aeruginosa of Diabetic Patient’s Foot Ulcer

    OpenAIRE

    Pratiwi Apridamayanti; Khairunnisa Azani Meilinasary; Rafika Sari

    2016-01-01

    Diabetes Mellitus (DM) patients are at risk to have the diabetic ulcer. The main reason for DM’s patient with ulcer complication to be treated and healed in hospital is bacterial infection. One of many bacteria that infects diabetic ulcer is Pseudomonas aeruginosa. This conditian can be treated by antibiotic. The using antibiotic is often inaccurate causing the microbe resistance. To choose the right antibiotic, it needs to test the antibiotic’s sensitivity towards Pseudomonas aeruginosa. The...

  15. Rapid bacterial antibiotic susceptibility test based on simple surface-enhanced Raman spectroscopic biomarkers

    Science.gov (United States)

    Liu, Chia-Ying; Han, Yin-Yi; Shih, Po-Han; Lian, Wei-Nan; Wang, Huai-Hsien; Lin, Chi-Hung; Hsueh, Po-Ren; Wang, Juen-Kai; Wang, Yuh-Lin

    2016-03-01

    Rapid bacterial antibiotic susceptibility test (AST) and minimum inhibitory concentration (MIC) measurement are important to help reduce the widespread misuse of antibiotics and alleviate the growing drug-resistance problem. We discovered that, when a susceptible strain of Staphylococcus aureus or Escherichia coli is exposed to an antibiotic, the intensity of specific biomarkers in its surface-enhanced Raman scattering (SERS) spectra drops evidently in two hours. The discovery has been exploited for rapid AST and MIC determination of methicillin-susceptible S. aureus and wild-type E. coli as well as clinical isolates. The results obtained by this SERS-AST method were consistent with that by the standard incubation-based method, indicating its high potential to supplement or replace existing time-consuming methods and help mitigate the challenge of drug resistance in clinical microbiology.

  16. Rapid, low-cost fluorescent assay of β-lactamase-derived antibiotic resistance and related antibiotic susceptibility

    Science.gov (United States)

    Erdem, S. Sibel; Khan, Shazia; Palanisami, Akilan; Hasan, Tayyaba

    2014-10-01

    Antibiotic resistance (AR) is increasingly prevalent in low and middle income countries (LMICs), but the extent of the problem is poorly understood. This lack of knowledge is a critical deficiency, leaving local health authorities essentially blind to AR outbreaks and crippling their ability to provide effective treatment guidelines. The crux of the problem is the lack of microbiology laboratory capacity available in LMICs. To address this unmet need, we demonstrate a rapid and simple test of β-lactamase resistance (the most common form of AR) that uses a modified β-lactam structure decorated with two fluorophores quenched due to their close proximity. When the β-lactam core is cleaved by β-lactamase, the fluorophores dequench, allowing assay speeds of 20 min to be obtained with a simple, streamlined protocol. Furthermore, by testing in competition with antibiotics, the β-lactamase-associated antibiotic susceptibility can also be extracted. This assay can be easily implemented into standard lab work flows to provide near real-time information of β-lactamase resistance, both for epidemiological purposes as well as individualized patient care.

  17. The Effect of Gamma Irradiation on Salmonella Chester and Its Sensitivity to Antibiotics

    International Nuclear Information System (INIS)

    Basry, T. Hasan

    2000-01-01

    The sensitivity changes of Salmonella chester (S. chester) to antibiotics as the results of gamma irradiation has not much been studied. To understand the sensitivity changes of S. chester to several antibiotics as the results of gamma irradiation with the doses of 1.0; 2.5; and 5.0 kGy, an investigation was carried out using re subculture method. The irradiation effects was evaluated by using Complete. Randomized Design with factorial pattern and the data processing by Analyses of Variance and Duincan test. It revealed that after irradiation with doses of 1.0; and 2.5 kGy, S. chester more sensitive to antibiotics Amphycillin, Tetracyclin and Chloramphenicol. It was also found that using different media culture during irradiation, the sensitivity of S. chester to antibiotics was also different

  18. Radioactivity measurements for determining bacterial increase and sensitivity to antibiotics. [/sup 14/C tracer

    Energy Technology Data Exchange (ETDEWEB)

    Jaszsagi-Nagy, E [Magyar Tudomanyos Akademia, Budapest; Lendvay, J [Orszagos Frederic Joliot-Curie Sugarbiologiai es Sugaregeszsegugyi Kutato Intezet, Budapest (Hungary)

    1976-01-01

    The authors elaborated a sensitive and objective measuring method for determining the bacteria increase in biological material and the sensitivity to antibiotics. When /sup 14/C glucose is added to the medium as the single source of sugar, the respiratory carbon dioxide formed by the bacteria reflects the rate of increase. The released /sup 14/C dioxide can be measured continuously without loss to the environment and the degree of bacterial infection and the antibiotic activity, respectively, can be determined.

  19. Bacteriological profile and antibiotic sensitivity pattern in patients with Urinary tract infection

    OpenAIRE

    N Subedi; S Pudasaini

    2017-01-01

    Background: Urinary tract infection is one of the common bacterial infections seeking treatment in clinical practice. A variety of organisms are associated with UTI and the most common organisms are Escherichia coli and other coliforms. Bacteriological investigations of UTI are not complete without antibiotic sensitivity test of the isolate. The aim of this study is to determine the bacteriological profile and antibiotic sensitivity patterns and their disease association.Materials and methods...

  20. Profile of antibiotic consumption, sensitivity and resistance in an urban area of Andhra Pradesh, India.

    Science.gov (United States)

    Peripi, Sunita Bhargavi; Thadepalli, Venu Gopala Rao; Khagga, Mukkanti; Tripuraribhatla, Prasanna Krishna; Bharadwaj, Dinesh Kumar

    2012-04-01

    Antibiotics are an important category of drugs in which indiscriminate use can affect the susceptibility patterns among infectious organisms, resulting in antibiotic resistance. Data on antibiotic usage and susceptibility patterns were collected from public and private health centres in Vijayawada, Andhra Pradesh, India, through the use of questionnaires. The data collected were then coded, tabulated, computed and evaluated using statistical analysis. The consumption profile of the different categories of drugs used in public and private hospitals was as follows: nutrition and metabolism products 19.0%; gastrointestinal disorder-related drugs 18.5%; antibiotics 16.8%; anti-pyretics and anti-analgesics 20.6%. These drugs were found to be in high demand. Among the antibiotics, aminoglycosides (amikacin), quinolones (ofloxacin, ciprofloxacin), tetracyclines (doxycycline), penicillin (ampicillin) and sulphonamides (co-trimoxazole) were the most commonly prescribed drugs for antibiotic therapy. 46% of the culture laboratory reports were positive with the following organism profile: Escherichia coli (36%), Klebsiella pneumoniae (16%), Staphylococcus aureus (29%), Enterococcus faecalis (9%) and Pseudomonas aeruginosa (10%). In terms of the sensitivity profile of antibacterials, amikacin (66.9%) was the only antibiotic showing sensitivity patterns, while the majority of antibiotics, such as cotrimoxazole, nalidixic acid, amoxicillin, gentamycin and norfloxacin, had acquired a resistance rate of 55.1%-80.6%. The results of this study suggest that indiscriminate prescription and consumption of new broad-spectrum antibiotics against sensitive organisms results in the development of antimicrobial resistance. Therefore, there is an urgent need to curb the excessive use of antibiotics in local hospitals in order to control the trend of increasing antimicrobial resistance to antibiotics.

  1. Profile of sensitivity and resistance to antibiotics of Staphylococcus ...

    African Journals Online (AJOL)

    Staphylococcus aureus is a bacterial specie that opposed more resistance again many antibiotics. This study aimed to determine the resistance profile of Staphylococcus aureus isolated from biological patient's liquids. A total of 303 samples including urine and vaginal pus samples from human were collected.

  2. Microbial profile, antibiotic sensitivity and heat resistance of bacterial ...

    African Journals Online (AJOL)

    Aim: This study was aimed at determining the prevalence, antibiotic resistance and heat resistance profile of bacterial isolates obtained from ready to eat roasted beef (suya) sold in Abuja, Nigeria. Methods and Results: Fifty samples of suya were purchased from different vendors within the Federal Capital Territory and ...

  3. Methicillin resistant S. aureus (MRSA) and their antibiotic sensitivity ...

    African Journals Online (AJOL)

    Method: One hundred and eighty five (185) S. aureus isolates from various clinical specimens obtained over a 12-month period in the Microbiology Department of Aminu Kano Teaching Hospital (AKTH) were subjected to methicillin susceptibility testing, while including susceptibility testing to other antibiotics by the disc ...

  4. A New Twist to the Kirby-Bauer Antibiotic Susceptibility Test Activity?Increasing Antibiotic Sensitivity of Pseudomonas fluorescens through Thermal Stress

    OpenAIRE

    Gerbig, Donald G.; Engohang-Ndong, Jean; Aubihl, Heather

    2013-01-01

    Antibiotic sensitivity and the effect of temperature on microbial growth are two standard laboratory activities found in most microbial laboratory manuals. We have found a novel way to combine the two activities to demonstrate how temperature can influence antibiotic sensitivity using a standard incubator in instructional laboratory settings. This activity reinforces the important concepts of microbial growth and temperature along with Kirby-Bauer antibiotic susceptibility testing. We found t...

  5. Selenium-mediated protection in reversing the sensitivity of bacterium to the bactericidal antibiotics.

    Science.gov (United States)

    Li, Zhonglei; Tan, Jun; Shao, Lei; Dong, Xiaojing; Ye, Richard D; Chen, Daijie

    2017-05-01

    Inducing production of damaging reactive oxygen species (ROS) is an important criterion to distinguish the bactericidal antibiotics from bacteriostatic antibiotics. Selenoenzymes were generally recognized to be a powerful antioxidant capable of scavenging free radicals, protecting the cells from the harmful effects of ROS. Therefore, the present study was carried out to investigate the selenium (Se)-mediated protection in reversing antibiotic sensitivity and the role of selenoenzymes in alleviating the negative effects of oxidative stress. The cellular antioxidant activity of Se-enriched bacteria was analyzed, as well as intracellular ROS production and elimination when Se-enriched bacteria in the presence of various antibiotics. Compared to complete inhibition of the parental strain by bactericidal antibiotics, it only exhibited slight and reversible inhibition of Se-enriched Escherichia coli ATCC25922 and Staphylococcus aureus ATCC25923 at the same conditions, which indicated that intracellular selenium provided substantial protection against antibiotics. ROS generation caused by bactericidal antibiotics was confirmed by fluorescence spectrophotometry using 2', 7'-dichloro- uorescein diacetate (DCFH-DA) as substrate. The time course experiments of pretreatment with selenium showed significant decrease of ROS level at 2h. In summary, the present study provides experimental evidence supporting selenoenzymes has good scavenging effect to ROS and can protect bacteria from oxidative stress injury induced by bactericidal antibiotics. Copyright © 2017 Elsevier GmbH. All rights reserved.

  6. Sensitivity of certain bacteria to antibiotics and irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Harsojo,; Andini, L S; Siagian, E G; Lina, M R; Zuleiha, S [National Atomic Energy Agency, Jakarta (Indonesia). Pasar Djumat Research Centre

    1981-07-01

    An experiment has been conducted to find vegetative forms of certain bacteria in Indonesia which are resistant to irradiation, the resistance of which will be compared to that of known radioresistant bacteria micrococcus radiodurans. To inactivate the vegetative forms of resistant bacteria to irradiation high doses are needed, while for storage purposes lower doses change the physical and chemical properties of the stored commodity are preferred. For this purpose the bacteria were irradiated in aerobic condition with gamma radiation doses of 0.1, 0.2 and 0.3 kGy, or treated with antibiotics e.g. tetracycline HCl or chloramphenicol with concentrations of 0.1, 0.2 and 0.3 ..mu..g/ml respectively. The results indicated that doses of 0.2 kGy and 0.1 ..mu..g/ml reduced the ability of the bacteria for multiplication.

  7. Multifaceted antibiotic treatment analysis of methicillin-sensitive Staphylococcus aureus bloodstream infections.

    Science.gov (United States)

    Weber, Zhanni; Ariano, Robert; Lagacé-Wiens, Philippe; Zelenitsky, Sheryl

    2016-12-01

    Given the overall prevalence and poor prognosis of Staphylococcus aureus bloodstream infections (BSIs), the study of treatment strategies to improve patient outcomes is important. The aim of this study was to conduct a multifaceted antibiotic treatment analysis of methicillin-sensitive S. aureus (MSSA) BSI and to characterise optimal early antibiotic therapy (within the first 7 days of drawing the index blood culture) for this serious infection. Antibiotic selection was categorised as optimal targeted (intravenous cloxacillin or cefazolin), optimal broad (piperacillin/tazobactam or meropenem), adequate (vancomycin) or inadequate (other antibiotics or oral therapy). A TSE (timing, selection, exposure) score was developed to comprehensively characterise early antibiotic therapy, where higher points corresponded to prompt initiation, optimal antibiotic selection and longer exposure (duration). Amongst 71 cases of complicated MSSA-BSI, end-of-treatment (EOT) response (i.e. clinical cure) was improved when at least adequate antibiotic therapy was initiated within 24 h [71.7% (33/46) vs. 48.0% (12/25); P = 0.047]. Clinical cure was also more likely when therapy included ≥4 days of optimal targeted antibiotics within the first 7 days [74.4% (29/39) vs. 50.0% (16/32); P = 0.03]. The TSE score was an informative index of early antibiotic therapy, with EOT cure documented in 72.0% (36/50) compared with 42.9% (9/21) of cases with scores above and below 15.2, respectively (P = 0.02). In multivariable analysis, lower Charlson comorbidity index, presence of BSI on admission, and optimising early antibiotic therapy, as described above, were associated with clinical cure in patients with MSSA-BSI. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  8. Endophthalmitis caused by Pantoea agglomerans: clinical features, antibiotic sensitivities, and outcomes

    Directory of Open Access Journals (Sweden)

    Venincasa VD

    2015-07-01

    Full Text Available Vincent D Venincasa, Ajay E Kuriyan, Harry W Flynn Jr, Jayanth Sridhar, Darlene Miller Department of Ophthalmology, Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, FL, USA Purpose: To report the clinical findings, antibiotic sensitivities, and visual outcomes associated with endophthalmitis caused by Pantoea agglomerans.Methods: A consecutive case series of patients with vitreous culture-positive endophthalmitis caused by P. agglomerans from January 1, 1990 to December 31, 2012 at a large university referral center. Findings from the current study were compared to prior published studies.Results: Of the three study patients that were identified, clinical settings included trauma (n=2 and post-cataract surgery (n=1. Presenting visual acuity was hand motion or worse in all three cases. All isolates were sensitive to ceftazidime, gentamicin, imipenem, and fluoroquinolones. All isolates were resistant to ampicillin. Initial treatment strategies were vitreous tap and intravitreal antibiotic injection (n=1 and pars plana vitrectomy with intravitreal antibiotic injection (n=2. At last follow-up, one patient had no light perception vision, while the other two had best-corrected visual acuity of 20/200 and 20/400.Conclusion: All Pantoea isolates were sensitive to ceftazidime, gentamicin, imipenem, and fluoroquinolones. All patients in the current study received at least one intravitreal antibiotic to which P. agglomerans was shown to be sensitive in vitro. In spite of this, the visual outcomes were generally poor.Keywords: ocular infection, trauma, antibiotic resistance

  9. A Survey on Antimicrobial Sensitivity Pattern of Different Antibiotics ...

    African Journals Online (AJOL)

    Michael Horsfall

    ABSTRACT: A study of antimicrobial sensitivity of Escherichia coli isolated from clinical sources of Medinova ... It also causes urinary tract infection and other .... Ceftriaxone- resistant Salmonella infection acquired by a child from cattle. N. Engl.

  10. Changes in antibiotic sensitivity and cell surface hydrophobicity in Escherichia coli injured by heating, freezing, drying or gamma radiation

    International Nuclear Information System (INIS)

    Mackey, B.M.

    1983-01-01

    Escherichia coli cells exposed to mild heating, freezing and thawing, drying or γ-radiation were sensitised to hydrophobic antibiotics and sodium deoxycholate but not to small hydrophilic antibiotics. These stress treatments also caused increases in cell surface hydrophobicity broadly reflecting the degree of sensitivity to hydrophobic antibiotics. (Auth.)

  11. The Adoption of a Standardized Antibiotic Sensitivity Test in the Philippines

    Directory of Open Access Journals (Sweden)

    Thelma Tupasi-Ramos

    1980-01-01

    Full Text Available With the development and the introduction of a great variety of antibiotic and chemotherapeutic agents, the outlook in the treatment of infections has improved significantly. Unfortunately, however, these agents are not necessarily innocuous to human tissues, so that their use in some instances is associated with some potential hazards including tissue toxicity, hypersensitivity reaction, emergence of bacterial antimicrobial resistance and the development of clinical superinfection. In view of these hazards, therefore, the administration of an antibiotic must be initiated only when there are definite objective evidences of an infection from clinical and laboratory parameters. Furthermore, the choice of antibiotic must be based on objective results of the antibiotic sensitivity test done on the isolated etiologic agent.

  12. Broad spectrum antibiotic enrofloxacin modulates contact sensitivity through gut microbiota in a murine model.

    Science.gov (United States)

    Strzępa, Anna; Majewska-Szczepanik, Monika; Lobo, Francis M; Wen, Li; Szczepanik, Marian

    2017-07-01

    Medical advances in the field of infection therapy have led to an increasing use of antibiotics, which, apart from eliminating pathogens, also partially eliminate naturally existing commensal bacteria. It has become increasingly clear that less exposure to microbiota early in life may contribute to the observed rise in "immune-mediated" diseases, including autoimmunity and allergy. We sought to test whether the change of gut microbiota with the broad spectrum antibiotic enrofloxacin will modulate contact sensitivity (CS) in mice. Natural gut microbiota were modified by oral treatment with enrofloxacin prior to sensitization with trinitrophenyl chloride followed by CS testing. Finally, adoptive cell transfers were performed to characterize the regulatory cells that are induced by microbiota modification. Oral treatment with enrofloxacin suppresses CS and production of anti-trinitrophenyl chloride IgG1 antibodies. Adoptive transfer experiments show that antibiotic administration favors induction of regulatory cells that suppress CS. Flow cytometry and adoptive transfer of purified cells show that antibiotic-induced suppression of CS is mediated by TCR αβ + CD4 + CD25 + FoxP3 + Treg, CD19 + B220 + CD5 + IL-10 + , IL-10 + Tr1, and IL-10 + TCR γδ + cells. Treatment with the antibiotic induces dysbiosis characterized by increased proportion of Clostridium coccoides (cluster XIVa), C coccoides-Eubacterium rectale (cluster XIVab), Bacteroidetes, and Bifidobacterium spp, but decreased segmented filamentous bacteria. Transfer of antibiotic-modified gut microbiota inhibits CS, but this response can be restored through oral transfer of control gut bacteria to antibiotic-treated animals. Oral treatment with a broad spectrum antibiotic modifies gut microbiota composition and promotes anti-inflammatory response, suggesting that manipulation of gut microbiota can be a powerful tool to modulate the course of CS. Copyright © 2017 American Academy of Allergy, Asthma & Immunology

  13. Biochemical characterization of systemic bacteria in bananas, sensitivity to antibiotics and plant phytotoxicity during shoot proliferation

    Directory of Open Access Journals (Sweden)

    Janiffe Peres de Oliveira

    2016-04-01

    Full Text Available The objective of this work was to characterize the biochemically systemic bacterial isolated from banana plants, to evaluate the bacterial sensitivity to antibiotics, and to determine the phytotoxicity of banana shoots during in vitro proliferation. Systemic bacteria belonging to the Klebsiella and Aeromonas genera were isolated from the “Maravilha” (FHIA 01 AAAB, “Preciosa” (PV 4285 AAAB and “Thap Maeo” (AAB varieties and were then characterized. Tests of shoot sensitivity to antibiotics were performed, and the minimum inhibitory concentration (MIC and phytotoxic effects of selected antibiotics to plants were determined. Among the 20 antibiotics evaluated, the strains showed sensitivity to cefaclor, cefalexin, cefalotin, nalidixic acid, chloramphenicol, and vancomycin. However, during MIC determination, the best results were obtained with cefaclor, vancomycin or nalidixic acid alone in concentrations ranging from 512 to 1,024 mg L-1. In culture medium, cefaclor at 1,024 mg L-1 was the only antibiotic to affect the multiplication and the shoot survival in culture.

  14. Antibiotic sensitivity pattern from pregnant women with urinary tract infection in Bangalore, India.

    Science.gov (United States)

    Sibi, G; Kumari, Pinki; Kabungulundabungi, Neema

    2014-09-01

    To determine the antibacterial profile of pregnant women with urinaty tract infections and analyze the antibiotic sensitivity pattern for the effective treatment. A total of 395 urine samples from pregnant women with different gestational age were processed for the isolation of uropathogens and tested against eight groups of antibiotics namely penicillins, cephalosporins, fluoroquinolones, aminoglycosides, macrolides, lincosamides, glycopeptides and sulfonamides. A positive culture percentage of 46.6% was obtained with the highest urinary tract infection in third trimester gestational age. Among the uropathogens isolated, 85.6% were Gram negative and 14.4% were Gram positive with Escherichia coli as the predominant bacteria (43.9%) followed by Klebsiella oxytoca (19.4%) and Klebsiella pneumoniae (13.3%). Antibiotic sensitivity assay revealed that amikacin had the highest overall sensitivity (n=136; 76.7%) and the subsequent highest sensitivity was observed with ciprofloxacin (n=132; 73.3%), clindamycin (n=124; 68.9%), cefotaxime (n=117; 65%) and nalidixic acid (n=115; 63.9%). The findings revealed that uropathogens were more resistant to penicillins, macrolides and glycopeptides which restrict their use in treating urinaty tract infections during pregnancy. In conclusion, common causative bacteria and their antibiotic sensitivity pattern are to be determined along with their safety to mother and fetus for the effective treatment of urinary tract infections during pregnancy. Copyright © 2014 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  15. Comparison of isolates and antibiotic sensitivity pattern in pediatric and adult cancer patients; is it different?

    Science.gov (United States)

    Prabhash, K; Bajpai, J; Gokarn, A; Arora, B; Kurkure, P A; Medhekar, A; Kelkar, R; Biswas, S; Gupta, S; Naronha, V; Shetty, N; Goyel, G; Banavali, S D

    2014-01-01

    Infection is a common cause of mortality and morbidity in cancer patients. Organisms are becoming resistant to antibiotics; age appears to be one of the factors responsible. We analyzed common organisms and their antibiotic sensitivity pattern in the correlation with age. This is a single institutional, retrospective analysis of all culture positive adult and pediatric cancer patients from January 2007 to December 2007. For statistical analysis, Chi-square test for trend was used and P values were obtained. Of 1251 isolates, 262 were from children 12 years of age). Gram-negative organisms were predominant (64.95) while Gram-positive constituted 35.09% of isolates. The most common source in all age groups was peripheral-blood, accounting to 47.8% of all samples. The most common organisms in adults were Pseudomonas aeruginosa (15.3%) while in children it was coagulase negative Staphylococcus aureus (19.8%). Antibiotic sensitivity was different in both groups. In pediatric group higher sensitivity was seen for Cefoparazone-sulbactum, Cefipime, Amikacin, and Tobramycin. No resistance was found for Linezolid. The isolates in both children and adults were predominantly Gram-negative though children had proportionately higher Gram-positive organisms. High-dose cytarabine use, cotrimoxazole prophylaxis, and frequent use of central lines in children especially in hematological malignancies could explain this observation. Children harbor less antibiotic resistance than adults; Uncontrolled, cumulative exposure to antibiotics in our community with increasing age, age-related immune factors and variable bacterial flora in different wards might explain the higher antibiotic resistance in adults. Thus age is an important factor to be considered while deciding empirical antibiotic therapy.

  16. Comparing the sensitivity of chlorophytes, cyanobacteria, and diatoms to major-use antibiotics.

    Science.gov (United States)

    Guo, Jiahua; Selby, Katherine; Boxall, Alistair B A

    2016-10-01

    The occurrence of antibiotic residues in the aquatic environment is an emerging concern. In contrast to daphnia and fish, algae are known to be particularly sensitive to antibiotic exposure. However, to date, a systematic evaluation of the sensitivity of different algal species to antibiotics has not been performed. The aim of the present study was therefore to explore the sensitivity of a battery of algal species toward antibiotic exposures. The present study investigated the growth inhibition effects of 3 major-use antibiotics, tylosin, lincomycin, and trimethoprim, on 7 algal species from the chlorophyte, cyanobacteria, and diatom groups. Based on median effective concentration (EC50) values, cyanobacteria (EC50 = 0.095-0.13 μmol/L) were found to be the most sensitive group to lincomycin followed by chlorophytes (EC50 = 7.36-225.73 μmol/L) and diatoms (EC50 > 225.73 μmol/L). Cyanobacteria were also the most sensitive group to tylosin (EC50 = 0.09-0.092 μmol/L), but, for this compound, diatoms (EC50 = 1.33-5.7 μmol/L) were more sensitive than chlorophytes (EC50 = 4.14-81.2 μmol/L). Diatoms were most sensitive to trimethoprim (EC50 = 7.36-74.61 μmol/L), followed by cyanobacteria (EC50 = 315.78-344.45 μmol/L), and chlorophytes (EC50 > 344.45 μmol/L) for trimethoprim. Although these results partly support the current approach to regulatory environmental risk assessment (whereby cyanobacterial species are recommended for use with antibiotic compounds), they indicate that for some antibiotics this group might not be the most appropriate test organism. It is therefore suggested that environmental risk assessments consider data on 3 algal groups (chlorophytes, cyanobacteria, and diatoms) and use test species from these groups, which are consistently found to be the most sensitive (Pseudokirchneriella subcapitata, Anabaena flos-aquae, and Navicula pelliculosa). Environ Toxicol Chem 2016;35:2587-2596. © 2016 SETAC.

  17. Phenotypic, Genotypic, and Antibiotic Sensitivity Patterns of Strains Isolated from the Cholera Epidemic in Zimbabwe

    NARCIS (Netherlands)

    Islam, Mohammad S.; Mahmud, Zahid H.; Ansaruzzaman, Mohammad; Faruque, Shah M.; Talukder, Kaisar A.; Qadri, Firdausi; Alam, Munirul; Islam, Shafiqul; Bardhan, Pradip K.; Mazumder, Ramendra N.; Khan, Azharul I.; Ahmed, Sirajuddin; Iqbal, Anwarul; Chitsatso, Owen; Mudzori, James; Patel, Sheetal; Midzi, Stanley M.; Charimari, Lincoln; Endtz, Hubert P.; Cravioto, Alejandro

    This paper details the phenotypic, genotypic, and antibiotic sensitivity patterns of 88 Vibrio cholerae strains from Zimbabwe. Of the 88 strains, 83 were classified as "altered El Tor" and 5 as "hybrid El Tor" strains. All of the strains were susceptible to tetracycline, doxycycline, ciprofloxacin,

  18. Differential antibiotic sensitivity determined by the large ribosomal subunit in thermophilic archaea.

    OpenAIRE

    Ruggero, D; Londei, P

    1996-01-01

    Hybrid ribosomes obtained by mixing the ribosomal subunits of the extremely thermophilic archaea Sulfolobus solfataricus and Desulfurococcus mobilis were tested for their sensitivity to selected antibiotics. It is shown that structural differences in the large ribosomal subunits determine qualitatively and quantitatively the patterns of response to alpha-sarcin and paromomycin in these species.

  19. Antibiotic sensitivity and resistance in Ornithobacterium rhinotracheale strains from Belgian broiler chickens.

    Science.gov (United States)

    Devriese, L A; De Herdt, P; Haesebrouck, F

    2001-06-01

    Establishing the antibiotic sensitivity of the avian respiratory pathogen Ornithobacterium rhinotracheale is difficult because of the organism's complex growth requirements and the unusually frequent occurrence of resistance. The minimal inhibitory concentrations of 10 antibiotics were determined for 45 strains of O. rhinotracheale from Belgian broiler chickens collected from 45 farms between 1995 and 1998. They were compared with the type strain, which was isolated from a turkey, and a strain isolated from a rook. All the broiler strains were resistant to lincomycin and to the beta-lactams ampicillin and ceftiofur. Less than 10% of the strains were sensitive to the macrolides tylosin and spiramycin, tilmicosin and flumequine. A few strains were sensitive to enrofloxacin and doxycycline. All strains were sensitive to tiamulin.

  20. ISOLATION AND ANTIBIOTIC SUSCEPTIBILITY TESTING OF RAPIDLY-GROWING MYCOBACTERIA FROM GRASSLAND SOILS

    Directory of Open Access Journals (Sweden)

    Martina Kyselková

    2013-08-01

    Full Text Available Rapidly growing mycobacteria (RGM are common soil saprophytes, but certain strains cause infections in human and animals. The infections due to RGM have been increasing in past decades and are often difficult to treat. The susceptibility to antibiotics is regularly evaluated in clinical isolates of RGM, but the data on soil RGM are missing. The objectives of this study was to isolate RGM from four grassland soils with different impact of manuring, and assess their resistance to antibiotics and the ability to grow at 37°C and 42°C. Since isolation of RGM from soil is a challenge, a conventional decontamination method (NaOH/malachite green/cycloheximide and a recent method based on olive oil/SDS demulsification were compared. The olive oil/SDS method was less efficient, mainly because of the emulsion instability and plate overgrowing with other bacteria. Altogether, 44 isolates were obtained and 23 representatives of different RGM genotypes were screened. The number of isolates per soil decreased with increasing soil pH, consistently with previous findings that mycobacteria were more abundant in low pH soils. Most of the isolates belonged to the Mycobacterium fortuitum group. The majority of isolates was resistant to 2-4 antibiotics. Multiresistant strains occurred also in a control soil that has a long history without the exposure to antibiotic-containing manure. Seven isolates grew at 37°C, including the species M. septicum and M. fortuitum known for infections in humans. This study shows that multiresistant RGM close to known human pathogens occur in grassland soils regardless the soil history of manuring.

  1. Effects of temperature, genetic variation and species competition on the sensitivity of algae populations to the antibiotic enrofloxacin

    NARCIS (Netherlands)

    Rico, Andreu; Zhao, Wenkai; Gillissen, Frits; Lürling, Miquel; Brink, van den Paul J.

    2018-01-01

    Primary producers are amongst the most sensitive organisms to antibiotic pollution in aquatic ecosystems. To date, there is little information on how different environmental conditions may affect their sensitivity to antibiotics. In this study we assessed how temperature, genetic variation and

  2. Trans-Cinnamaldehyde and Eugenol Increase Acinetobacter baumannii Sensitivity to Beta-Lactam Antibiotics

    Directory of Open Access Journals (Sweden)

    Deepti P. Karumathil

    2018-05-01

    Full Text Available Multi-drug resistant (MDR Acinetobacter baumannii is a major nosocomial pathogen causing a wide range of clinical conditions with significant mortality rates. A. baumannii strains are equipped with a multitude of antibiotic resistance mechanisms, rendering them resistant to most of the currently available antibiotics. Thus, there is a critical need to explore novel strategies for controlling antibiotic resistance in A. baumannii. This study investigated the efficacy of two food-grade, plant-derived antimicrobials (PDAs, namely trans-cinnamaldehyde (TC and eugenol (EG in decreasing A. baumannii’s resistance to seven β-lactam antibiotics, including ampicillin, methicillin, meropenem, penicillin, aztreonam, amoxicillin, and piperacillin. Two MDR A. baumannii isolates (ATCC 17978 and AB 251847 were separately cultured in tryptic soy broth (∼6 log CFU/ml containing the minimum inhibitory concentration (MIC of TC or EG with or without the MIC of each antibiotic at 37°C for 18 h. A. baumannii strains not exposed to the PDAs or antibiotics served as controls. Following incubation, A. baumannii counts were determined by broth dilution assay. In addition, the effect of PDAs on the permeability of outer membrane and efflux pumps in A. baumannii was measured. Further, the effect of TC and EG on the expression of A. baumannii genes encoding resistance to β-lactam antibiotics (blaP, efflux pumps (adeABC, and multi-drug resistant protein (mdrp was studied using real-time quantitative PCR (RT-qPCR. The experiment was replicated three times with duplicate samples of each treatment and control. The results from broth dilution assay indicated that both TC and EG in combination with antibiotics increased the sensitivity of A. baumannii to all the tested antibiotics (P < 0.05. The two PDAs inhibited the function of A. baumannii efflux pump, (AdeABC, but did not increase the permeability of its outer membrane. Moreover, RT-qPCR data revealed that TC and EG

  3. Trans-Cinnamaldehyde and Eugenol Increase Acinetobacter baumannii Sensitivity to Beta-Lactam Antibiotics.

    Science.gov (United States)

    Karumathil, Deepti P; Nair, Meera Surendran; Gaffney, James; Kollanoor-Johny, Anup; Venkitanarayanan, Kumar

    2018-01-01

    Multi-drug resistant (MDR) Acinetobacter baumannii is a major nosocomial pathogen causing a wide range of clinical conditions with significant mortality rates. A. baumannii strains are equipped with a multitude of antibiotic resistance mechanisms, rendering them resistant to most of the currently available antibiotics. Thus, there is a critical need to explore novel strategies for controlling antibiotic resistance in A. baumannii . This study investigated the efficacy of two food-grade, plant-derived antimicrobials (PDAs), namely trans -cinnamaldehyde (TC) and eugenol (EG) in decreasing A. baumannii 's resistance to seven β-lactam antibiotics, including ampicillin, methicillin, meropenem, penicillin, aztreonam, amoxicillin, and piperacillin. Two MDR A. baumannii isolates (ATCC 17978 and AB 251847) were separately cultured in tryptic soy broth (∼6 log CFU/ml) containing the minimum inhibitory concentration (MIC) of TC or EG with or without the MIC of each antibiotic at 37°C for 18 h. A. baumannii strains not exposed to the PDAs or antibiotics served as controls. Following incubation, A. baumannii counts were determined by broth dilution assay. In addition, the effect of PDAs on the permeability of outer membrane and efflux pumps in A. baumannii was measured. Further, the effect of TC and EG on the expression of A. baumannii genes encoding resistance to β-lactam antibiotics ( blaP ), efflux pumps ( adeABC ), and multi-drug resistant protein ( mdrp ) was studied using real-time quantitative PCR (RT-qPCR). The experiment was replicated three times with duplicate samples of each treatment and control. The results from broth dilution assay indicated that both TC and EG in combination with antibiotics increased the sensitivity of A. baumannii to all the tested antibiotics ( P increase the permeability of its outer membrane. Moreover, RT-qPCR data revealed that TC and EG down-regulated the expression of majority of the genes associated with β-lactam antibiotic

  4. Collateral sensitivity between aminoglycosides and beta-lactam antibiotics depends on active proton pumps.

    Science.gov (United States)

    Azimi, Leila; Rastegar Lari, Abdolaziz

    2017-11-01

    Selection inversion is the hypothesis for antibiotic resistant inhabitation in bacteria and collateral sensitivity is one of the proposed phenomena for achievement of this hypothesis. The presence of collateral sensitivity associated with the proton motivation pump between the aminoglycosides and beta-lactam group of antibiotics is one of the examples of collateral sensitivity in some studies. The aim of this study was to demonstrate that collateral sensitivity between aminoglycosides and beta-lactam antibiotics associated with proton motivation pump may not be true in all cases. In this study, 100 Pseudomonas aeruginosa were surveyed. Gentamicin and imipenem-resistant strains were confirmed by disc diffusion method and MIC. Active proton motivation pumps were screened by pumps inhibitor. Semi-quantitative Real-Time PCR assay was used to confirm gene overexpression. Seventy-six and 79 out of 100 strains were resistant to gentamicin and imipenem, respectively. Seventy-five strains were resistant to both gentamicin and imipenem. The results of proton pump inhibitor test showed the involvement of active proton motivation pump in 22 of 75 imipenem- and gentamicin-resistant strains. According to Real - Time PCR assay, mexX efflux gene was overexpressed in the majority of isolates tested. The collateral sensitivity effect cannot explain the involvement of active proton motivation pumps in both imipenem and gentamicin-resistant strains simultaneously. Active and/or inactive proton pump in gentamicin-sensitive and/or resistant strains cannot be a suitable example for explanation of collateral sensitivity between aminoglycosides and beta-lactam antibiotics. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. The sensitivity and the specifity of rapid antigen test in streptococcal upper respiratory tract infections.

    Science.gov (United States)

    Gurol, Yesim; Akan, Hulya; Izbirak, Guldal; Tekkanat, Zuhal Tazegun; Gunduz, Tehlile Silem; Hayran, Osman; Yilmaz, Gulden

    2010-06-01

    It is aimed to detect the sensitivity and specificity of rapid antigen detection of group A beta hemolytic streptococci from throat specimen compared with throat culture. The other goal of the study is to help in giving clinical decisions in upper respiratory tract infections according to the age group, by detection of sensitivity and positive predictive values of the rapid tests and throat cultures. Rapid antigen detection and throat culture results for group A beta hemolytic streptococci from outpatients attending to our university hospital between the first of November 2005 and 31st of December 2008 were evaluated retrospectively. Throat samples were obtained by swabs from the throat and transported in the Stuart medium and Quickvue Strep A [Quidel, San Diego, USA] cassette test was applied and for culture, specimen was inoculated on 5% blood sheep agar and identified according to bacitracin and trimethoprim-sulphametaxazole susceptibility from beta hemolytic colonies. During the dates between the first of November 2005 and 31st of December 2008, from 453 patients both rapid antigen detection and throat culture were evaluated. Rapid antigen detection sensitivity and specificity were found to be 64.6% and 96.79%, respectively. The positive predictive value was 80.95% whereas negative predictive value was 92.82%. Kappa index was 0.91. When the results were evaluated according to the age groups, the sensitivity and the positive predictive value of rapid antigen detection in children were 70%, 90.3% and in adults 59.4%, 70.4%. When bacterial infection is concerned to prevent unnecessary antibiotic use, rapid streptococcal antigen test (RSAT) is a reliable method to begin immediate treatment. To get the maximum sensitivity of RSAT, the specimen collection technique used and education of the health care workers is important. While giving clinical decision, it must be taken into consideration that the sensitivity and the positive predictive value of the RSAT is quite

  6. Antibiotic Resistant Bacterial Isolates from Captive Green Turtles and In Vitro Sensitivity to Bacteriophages

    Directory of Open Access Journals (Sweden)

    Alessandro Delli Paoli Carini

    2017-01-01

    Full Text Available This study aimed to test multidrug resistant isolates from hospitalised green turtles (Chelonia mydas and their environment in North Queensland, Australia, for in vitro susceptibility to bacteriophages. Seventy-one Gram-negative bacteria were isolated from green turtle eye swabs and water samples. Broth microdilution tests were used to determine antibiotic susceptibility. All isolates were resistant to at least two antibiotics, with 24% being resistant to seven of the eight antibiotics. Highest resistance rates were detected to enrofloxacin (77% and ampicillin (69.2%. More than 50% resistance was also found to amoxicillin/clavulanic acid (62.5%, ceftiofur (53.8%, and erythromycin (53.3%. All the enriched phage filtrate mixtures resulted in the lysis of one or more of the multidrug resistant bacteria, including Vibrio harveyi and V. parahaemolyticus. These results indicate that antibiotic resistance is common in Gram-negative bacteria isolated from hospitalised sea turtles and their marine environment in North Queensland, supporting global concern over the rapid evolution of multidrug resistant genes in the environment. Using virulent bacteriophages as antibiotic alternatives would not only be beneficial to turtle health but also prevent further addition of multidrug resistant genes to coastal waters.

  7. Rapid Assessment of Resistance to Antibiotic Inhibitors of Protein Synthesis in the Gram-Positive Pathogens, Enterococcus faecalis and Streptococcus pneumoniae, Based on Evaluation of the Lytic Response.

    Science.gov (United States)

    Otero, Fátima; Tamayo, María; Santiso, Rebeca; Gosálvez, Jaime; Bou, Germán; Fernández, José Luis

    2017-04-01

    A novel assay for rapid determination of resistance to antibiotic inhibitors of protein synthesis was developed for the gram-positive pathogens, Enterococcus faecalis and Streptococcus pneumoniae. To this purpose, a lytic response was obtained by a brief incubation with lysozyme or a mixture of lysozyme, Triton X-100, and EDTA for E. faecalis (n = 82) and S. pneumoniae (n = 51), respectively. Lysis was quantified by visualizing the released nucleoids. Antibiotic-susceptible bacteria treated with Clinical and Laboratory Standards Institute (CLSI) breakpoint doses of erythromycin, azithromycin, or doxycycline that inhibited protein synthesis demonstrated a large reduction of lysed cells with respect to the control, that is, without antibiotics. However, cell lysis prevention was much lower in nonsusceptible strains, with unsuccessful inhibition of protein synthesis. ROC analysis showed that a reduction value of ≥35.6% and ≥40.4% discriminates susceptible and nonsusceptible strains for erythromycin and for doxycycline, respectively, in E. faecalis, whereas ≥20.0% is adequate for both macrolides and doxycycline in S. pneumoniae. Resistant stains were identified in 90-120 min with sensitivity and specificity between 91.7% and 100%. This is a proof of concept that evaluation of the lytic response may be a rapid and efficient test for determination of resistance to antibiotic inhibitors of protein synthesis.

  8. In Vitro Sensitivity of Bacteria to Various Antibiotics, Obtained from Women Suffering From Cystits

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    Sena Erdogan Aydos

    2006-06-01

    Full Text Available % 25-30 of women between 20-40 ages have urinary tract infection. In our country every year 5 million cases of cystitis occur. Some investigators suggest that empiric treatment for a short duration without doing culture is useful, safe and cost effective by estimating the factors and antibiotic’s sensitivity in the beginning in women whom are diagnosed as acute uncomplicated cystitis. On the other hand, a problem due to treatments of urinary tract infection has begun because of resistance producing from widespread using antibiotics for inappropriate indications. Therefore, in order to define appropriate antibiotics in urinary tract infection periodic surveillance is needed for checking local resistance condition. In this study, we aim to assess a clinical approach for antibiotic selection in empiric treatment of cystitis without doing culture or in beginning of cystitis therapy while waiting for the culture’s results."

  9. Evaluation of a rapid antigen detection test in the diagnosis of streptococcal pharyngitis in children and its impact on antibiotic prescription.

    Science.gov (United States)

    Maltezou, Helen C; Tsagris, Vasilios; Antoniadou, Anastasia; Galani, Labrini; Douros, Constantinos; Katsarolis, Ioannis; Maragos, Antonios; Raftopoulos, Vasilios; Biskini, Panagiota; Kanellakopoulou, Kyriaki; Fretzayas, Andreas; Papadimitriou, Theodoros; Nicolaidou, Polyxeni; Giamarellou, Helen

    2008-12-01

    To study the performance of the Becton-Dickinson Link 2 Strep A Rapid Test, a rapid antigen detection test (RADT) for diagnosing streptococcal pharyngitis in children presenting to private offices and to the Pediatric Outpatient Clinic of a university hospital, in relation to clinical criteria (fever, tender anterior cervical lymph nodes, tonsillar exudate and absence of cough), and its impact on antibiotic prescription. Children were enrolled in Group A (enrolment by private-practice paediatricians; diagnosis by clinical picture only), Group B (enrolment by private-practice paediatricians; diagnosis by RADT and culture) or Group C (enrolment by hospital-affiliated paediatricians in the Pediatric Outpatient Clinic; diagnosis by RADT and culture). During a 2 year period, 820 children were enrolled [369 (45%) in Group A, 270 (33%) in Group B and 181 (22%) in Group C]. Streptococcal pharyngitis was diagnosed by RADT and culture in 146 (32.4%) of the 451 tested children. The sensitivity, specificity and positive and negative predictive values of the RADT were 83.1%, 93.3%, 82.4% and 93.6%, respectively. A stepwise increase in the sensitivity of the RADT was noted among children with one, two, three or four clinical criteria (60.9% to 95.8%). Paediatricians without access to laboratory tests were more likely to prescribe antibiotics compared with paediatricians with access to tests (72.2% versus 28.2%, P antibiotics more frequently compared with hospital-affiliated paediatricians (55.7% versus 19.9%, P antibiotic administration. Such a strategy has an important impact on limiting throat culture testing and is associated with reduced antibiotic prescription.

  10. Use of a radiorespirometric assay for testing the antibiotic sensitivity of catheter-associated bacteria

    International Nuclear Information System (INIS)

    Ladd, T.I.; Schmiel, D.; Nickel, J.C.; Costerton, J.W.

    1987-01-01

    A 14 C-radiorespirometric assay was used to show the sensitivity of fixed-film (sessile), catheter-associated and free-living (planktonic) cells of Pseudomonas aeruginosa to varying concentrations (100 micrograms/mL to 1000 micrograms/mL) tobramycin sulfate. This strain of P. aeruginosa has an MIC of 0.6 microgram/ml and an MBC of 50 micrograms/mL when tested by conventional methods. When 14 C-glutamic acid was used as a substrate in this radiorespirometric assay, it could be completed in less than one hour and planktonic samples showed a significant reduction in mineralization activity (evolution of 14 CO 2 ) within eight hours of the antibiotic challenge. These changes in respiratory activity appeared to be dose and time dependent. Within 18 hr. at 1000 micrograms/mL, there was no significant residual respiratory activity in planktonic samples. Some residual respiratory activity was detected, however, in samples exposed to 100 micrograms/mL for 36 hours. The mineralization activity of sessile catheter-associated bacteria was unaffected by four hr. and eight hr. exposures to 1000 micrograms/mL of the antibiotic. A significant reduction in respiratory activity was recorded in catheter samples exposed for 18 hr. or more at each concentration examined. Unlike the planktonic samples, however, the antibiotic challenge failed to eradicate the metabolic activity of the attached bacteria. Antibiotic stressed, catheter-associated bacteria transferred to a post-exposure enrichment broth showed a limited ability to re-establish respiratory activity. This apparent recovery was limited to antibiotic exposures less than 24 hr. and was not observed in planktonic samples. The radioisotopic assay is a non-culture method which can be used to assess the antibiotic sensitivity of both planktonic bacteria and in situ biofilm populations

  11. Antibiotic sensitivity pattern of uropathogens from pregnant women with urinary tract infection in Abakaliki, Nigeria

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    Onoh RC

    2013-12-01

    Full Text Available RC Onoh,1 OUJ Umeora,1 VE Egwuatu,2 PO Ezeonu,1 TJP Onoh31Department of Obstetrics and Gynecology, Federal Teaching Hospital Abakaliki, Ebonyi State, Nigeria; 2Department of Obstetrics and Gynecology, Enugu State University Teaching Hospital, Enugu State, Nigeria; 3Department of Pathology, Federal Teaching Hospital Abakaliki, Ebonyi State, NigeriaBackground: Urinary tract infection (UTI is a common bacterial infection during pregnancy and a significant cause of perinatal and maternal morbidity and mortality. The causative bacteria have remained virtually the same although with variations in individual prevalence. There has been an increasing resistance by these bacteria to the commonly available antibiotics.Objectives: To determine the prevalence of UTI, the common causative bacteria, and their antibiotic sensitivity pattern among pregnant women with UTI.Methodology: This is a descriptive study that was carried out at the Obstetrics Department of two tertiary institutions in Abakaliki, Ebonyi State, Nigeria (Federal Medical Center and Ebonyi State University Teaching Hospital over a period of 12 months. Midstream urine specimens from selected pregnant women with clinical features of UTI were collected for microscopy, culture, and sensitivity. The results were analyzed with the 2008 Epi Info™ software.Results: A total of 542 pregnant women presented with symptoms of UTI and were recruited for the study over the study period. Of the 542 pregnant women, 252 (46.5% had significant bacteriuria with positive urine culture and varying antibiotic sensitivity pattern. The prevalence of symptomatic UTI was 3%. Escherichia coli was the most common bacteria isolated with a percentage of 50.8%. Other isolated micro organisms included Stapylococcus aereus (52 cultures, 20.6%, Proteus mirabilis (24 cultures, 9.5%, S. saprophyticus (18 cultures, 7.1%, Streptococcus spp. (14 cultures, 5.6%, Citrobacter spp. (5 cultures, 2.0%, Klebsiella spp. (4 cultures, 1

  12. Frequency of common bacteria and their antibiotic sensitivity pattern in diabetics presenting with foot ulcer

    International Nuclear Information System (INIS)

    Rahim, F.; Ishfaq, M.; Rahman, S.U.; Afridi, A.K.

    2016-01-01

    Foot ulcers are one of the most important complications of diabetes mellitus and often lead to lower limb amputation. Diabetic foot ulcers are susceptible to infection. The objective of this study was to determine the frequency of common bacteria infecting these ulcers and their antibiotic sensitivity pattern. Methods: This descriptive cross-sectional study was performed in the Departments of Medicine and Surgery, Khyber Teaching Hospital, Peshawar from April, 2011 to February, 2012. Specimens collected from ulcers of 131 patients were inoculated on Blood Agar and MacConkey Agar, and antibiotic sensitivity was tested using standard disc diffusion method. Results: Out of 131, specimens from 120 patients yielded 176 bacteria. Sixty-six patients had monomicrobial infection while polymicrobial growth was obtained in 54 patients. Overall, Staphylococcus aureus (38.6%) was the most common isolate followed by Pseudomonas aeruginosa (27.3%). Staphylococcus aureus was most often sensitive to Moxifloxacin, Imipenem/Meropenem, Vancomycin and Linezolid while it showed varying sensitivity to Penicillins and Cephalosporins. 47.1% isolates of Staphylococcus aureus were resistant to Methicillin. Most of the gram negative rods were sensitive to Imipenem/Meropenem, Piperacillin-Tazobactam and Ticarcillin-Clavulanate. Majority of gram negative bacteria were found resistant to Cephalosporins and Moxifloxacin except Pseudomonas which showed variable sensitivity to Ceftriaxone, Ceftazidime and Moxifloxacin. Conclusions: Majority of isolates were found resistant to the commonly used antibiotics. Most commonly isolated bacterium, Staphylococcus aureus was most often sensitive to Moxifloxacin, Imipenem/Meropenem, Vancomycin and Linezolid, while majority isolated gram negative rods were sensitive to Imipenem/Meropenem, Piperacillin-Tazobactam and Ticarcillin-Clavulanate. (author)

  13. Bacterial agents and antibiotic sensitivity in children with urinary infection in two hospitals of Popayan, Colombia

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    Carolina Álvarez-Czeczotta

    2012-06-01

    Full Text Available Introduction: Urinary Tract Infection (UTI is a common condition in children. Isolation of bacteria and early management is a priority in order to contribute to the reduction of morbidity and avoid bacterial resistance. Objectives: To identify bacterial etiologic agents and antibiotic sensitivity in children (1 month to 5 years of age with UTI in two hospitals of Popayán, Colombia. Materials and methods: We conducted a cross-sectional study in children aged 1 month to 5 years of age who consulted the emergency services of two hospitals with clinical suspicion of UTI. The sample was 123 children. Using an instrument collected demographic variables, signs and symptoms, results of urinalysis, urine culture, sensitivity testing, treatment, and UTI classification. We determined the frequency and proportions of sociodemographic and clinical variables, bacterial agents and antibiotic resistance. Data was analyzed using SPSS 11.5 program. Results: We included 129 children diagnosed with UTI with positive urine culture, bladder catheter taken with 97.7% of cases. 74.8% of patients were female. Escherichia coli was the seed that was isolated more frequently (95.4%, then Sp Proteus (2.4%, and Klebsiella pneumoniae (1.6%. The antibiotics to which the bacteria showed adequate sensitivity were: ceftriaxone, amikacin, gentamicin, ciprofloxacin, nitrofurantoin, cefuroxime and cephalexin. Showed low sensitivity: ampicillin and trimethoprim sulfa. Conclusions: Escherichia coli was the bacteria that cause of UTI in our study population. For initial empiric treatment of hospitalized patients would recommend parenteral drug third generation cephalosporins (ceftriaxone and aminoglycosides (amikacin, gentamicin. For outpatient management, oral antibiotics showed greater sensitivity were nalidixic acid, cefuroxime and cephalexin.

  14. Survival of Antibiotic Resistant and Antibiotic Sensitive Strains of E. coli O157 and E. coli O26 in Food Matrices.

    OpenAIRE

    Walsh, Ciara; Duffy, Geraldine; Blair, I. S.; McDowell, D. A.

    2006-01-01

    Escherichia coli O157:H7 or E. coli O26, which were AS (antibiotic sensitive), AR (laboratory created antibiotic resistant mutants), or naturally MAR (multi-antibiotic resistant), were inoculated into laboratory media, yoghurt or orange juice and their growth/survival monitored during enrichment at 37 °C or storage at 4 °C. The strains were also inoculated into minced beef and their thermal inactivation (D-values) examined at 55 °C, with and without a prior heat shock at 48 °C. The growth kin...

  15. In vitro activity of XF-73, a novel antibacterial agent, against antibiotic-sensitive and -resistant Gram-positive and Gram-negative bacterial species.

    Science.gov (United States)

    Farrell, David J; Robbins, Marion; Rhys-Williams, William; Love, William G

    2010-06-01

    The antibacterial activity of XF-73, a dicationic porphyrin drug, was investigated against a range of Gram-positive and Gram-negative bacteria with known antibiotic resistance profiles, including resistance to cell wall synthesis, protein synthesis, and DNA and RNA synthesis inhibitors as well as cell membrane-active antibiotics. Antibiotic-sensitive strains for each of the bacterial species tested were also included for comparison purposes. XF-73 was active [minimum inhibitory concentration (MIC) 0.25-4 mg/L] against all of the Gram-positive bacteria tested, irrespective of the antibiotic resistance profile of the isolates, suggesting that the mechanism of action of XF-73 is unique compared with the major antibiotic classes. Gram-negative activity was lower (MIC 1 mg/L to > 64 mg/L). Minimum bactericidal concentration data confirmed that the activity of XF-73 was bactericidal. Time-kill kinetics against healthcare-associated and community-associated meticillin-resistant Staphylococcus aureus isolates demonstrated that XF-73 was rapidly bactericidal, with > 5 log(10) kill obtained after 15 min at 2 x MIC, the earliest time point sampled. The post-antibiotic effect (PAE) for XF-73 under conditions where the PAE for vancomycin was 5.4 h. XF-73 represents a novel broad-spectrum Gram-positive antibacterial drug with potentially beneficial characteristics for the treatment and prevention of Gram-positive bacterial infections. 2010. Published by Elsevier B.V.

  16. Rapid and Sensitive Detection of BLAD in Cattle Population

    Directory of Open Access Journals (Sweden)

    Daniela Elena Ilie

    2014-05-01

    Full Text Available Bovine leukocyte adhesion deficiency (BLAD is an autosomal recessive disorder with negative impact on dairy cattle breeding. The molecular basis of BLAD is a single point mutation (A→G, resulting in a single amino acid substitution (aspartic acid → glycine at amino acid 128 in the adhesion molecule CD18. The object of this study was to establish a fast and sensitive molecular genotyping assay to detect BLAD carriers using high-resolution melting (HRM curve analysis. We tested animals with known genotypes for BLAD that were previously confirmed by PCR-RFLP method, and then examined the sensitivity of mutation detection using PCR followed by HRM curve analysis. BLAD carriers were readily detectable using HRM assay. Thus, the PCR-HRM genotyping method is a rapid, easily interpretable, reliable and cost-effective assay for BLAD mutant allele detection. This assay can be useful in cattle genotyping and genetic selection.

  17. Investigation of colistin sensitivity via three different methods in Acinetobacter baumannii isolates with multiple antibiotic resistance.

    Science.gov (United States)

    Sinirtaş, Melda; Akalin, Halis; Gedikoğlu, Suna

    2009-09-01

    In recent years there has been an increase in life-threatening infections caused by Acinetobacter baumannii with multiple antibiotic resistance, which has lead to the use of polymyxins, especially colistin, being reconsidered. The aim of this study was to investigate the colistin sensitivity of A. baumannii isolates with multiple antibiotic resistance via different methods, and to evaluate the disk diffusion method for colistin against multi-resistant Acinetobacter isolates, in comparison to the E-test and Phoenix system. The study was carried out on 100 strains of A. baumannii (colonization or infection) isolated from the microbiological samples of different patients followed in the clinics and intensive care units of Uludağ University Medical School between the years 2004 and 2005. Strains were identified and characterized for their antibiotic sensitivity by Phoenix system (Becton Dickinson, Sparks, MD, USA). In all studied A. baumannii strains, susceptibility to colistin was determined to be 100% with the disk diffusion, E-test, and broth microdilution methods. Results of the E-test and broth microdilution method, which are accepted as reference methods, were found to be 100% consistent with the results of the disk diffusion tests; no very major or major error was identified upon comparison of the tests. The sensitivity and the positive predictive value of the disk diffusion method were found to be 100%. Colistin resistance in A. baumannii was not detected in our region, and disk diffusion method results are in accordance with those of E-test and broth microdilution methods.

  18. Re-sensitizing drug-resistant bacteria to antibiotics by designing Antisense Therapeutics

    Science.gov (United States)

    Courtney, Colleen; Chatterjee, Anushree

    2014-03-01

    ``Super-bugs'' or ``multi-drug resistant organisms'' are a serious international health problem, with devastating consequences to patient health care. The Center for Disease Control has identified antibiotic resistance as one of the world's most pressing public health problems as a significant fraction of bacterial infections contracted are drug resistant. Typically, antibiotic resistance is encoded by ``resistance-genes'' which express proteins that carryout the resistance causing functions inside the bacterium. We present a RNA based therapeutic strategy for designing antimicrobials capable of re-sensitizing resistant bacteria to antibiotics by targeting labile regions of messenger RNAs encoding for resistance-causing proteins. We perform in silico RNA secondary structure modeling to identify labile target regions in an mRNA of interest. A synthetic biology approach is then used to administer antisense nucleic acids to our model system of ampicillin resistant Escherichia coli. Our results show a prolonged lag phase and decrease in viability of drug-resistant E. colitreated with antisense molecules. The antisense strategy can be applied to alter expression of other genes in antibiotic resistance pathways or other pathways of interest.

  19. Antibiotic sensitivity pattern of uropathogens from pregnant women with urinary tract infection in Abakaliki, Nigeria.

    Science.gov (United States)

    Onoh, Rc; Umeora, Ouj; Egwuatu, Ve; Ezeonu, Po; Onoh, Tjp

    2013-01-01

    Urinary tract infection (UTI) is a common bacterial infection during pregnancy and a significant cause of perinatal and maternal morbidity and mortality. The causative bacteria have remained virtually the same although with variations in individual prevalence. There has been an increasing resistance by these bacteria to the commonly available antibiotics. To determine the prevalence of UTI, the common causative bacteria, and their antibiotic sensitivity pattern among pregnant women with UTI. This is a descriptive study that was carried out at the Obstetrics Department of two tertiary institutions in Abakaliki, Ebonyi State, Nigeria (Federal Medical Center and Ebonyi State University Teaching Hospital) over a period of 12 months. Midstream urine specimens from selected pregnant women with clinical features of UTI were collected for microscopy, culture, and sensitivity. The results were analyzed with the 2008 Epi Info™ software. A total of 542 pregnant women presented with symptoms of UTI and were recruited for the study over the study period. Of the 542 pregnant women, 252 (46.5%) had significant bacteriuria with positive urine culture and varying antibiotic sensitivity pattern. The prevalence of symptomatic UTI was 3%. Escherichia coli was the most common bacteria isolated with a percentage of 50.8%. Other isolated micro organisms included Stapylococcus aereus (52 cultures, 20.6%), Proteus mirabilis (24 cultures, 9.5%), S. saprophyticus (18 cultures, 7.1%), Streptococcus spp. (14 cultures, 5.6%), Citrobacter spp. (5 cultures, 2.0%), Klebsiella spp. (4 cultures, 1.6%), Enterobacter spp. (4 cultures, 1.6%), and Pseudomonas spp. (3 cultures, 1.2%). Levofloxacin had the highest overall antibiotic sensitivity of 92.5%. Others with overall antibiotic sensitivity pattern greater than 50% included cefpodoxime (87.3%), ofloxacin (77.4%), ciprofloxacin (66.7%), ceftriaxone (66.7%), and gentamicin (50.8%). E. coli was the most common etiological agent of UTI in pregnancy

  20. A rapid two-step algorithm detects and identifies clinical macrolide and beta-lactam antibiotic resistance in clinical bacterial isolates.

    Science.gov (United States)

    Lu, Xuedong; Nie, Shuping; Xia, Chengjing; Huang, Lie; He, Ying; Wu, Runxiang; Zhang, Li

    2014-07-01

    Aiming to identify macrolide and beta-lactam resistance in clinical bacterial isolates rapidly and accurately, a two-step algorithm was developed based on detection of eight antibiotic resistance genes. Targeting at genes linked to bacterial macrolide (msrA, ermA, ermB, and ermC) and beta-lactam (blaTEM, blaSHV, blaCTX-M-1, blaCTX-M-9) antibiotic resistances, this method includes a multiplex real-time PCR, a melting temperature profile analysis as well as a liquid bead microarray assay. Liquid bead microarray assay is applied only when indistinguishable Tm profile is observed. The clinical validity of this method was assessed on clinical bacterial isolates. Among the total 580 isolates that were determined by our diagnostic method, 75% of them were identified by the multiplex real-time PCR with melting temperature analysis alone, while the remaining 25% required both multiplex real-time PCR with melting temperature analysis and liquid bead microarray assay for identification. Compared with the traditional phenotypic antibiotic susceptibility test, an overall agreement of 81.2% (kappa=0.614, 95% CI=0.550-0.679) was observed, with a sensitivity and specificity of 87.7% and 73% respectively. Besides, the average test turnaround time is 3.9h, which is much shorter in comparison with more than 24h for the traditional phenotypic tests. Having the advantages of the shorter operating time and comparable high sensitivity and specificity with the traditional phenotypic test, our two-step algorithm provides an efficient tool for rapid determination of macrolide and beta-lactam antibiotic resistances in clinical bacterial isolates. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Real-Time Digital Bright Field Technology for Rapid Antibiotic Susceptibility Testing.

    Science.gov (United States)

    Canali, Chiara; Spillum, Erik; Valvik, Martin; Agersnap, Niels; Olesen, Tom

    2018-01-01

    Optical scanning through bacterial samples and image-based analysis may provide a robust method for bacterial identification, fast estimation of growth rates and their modulation due to the presence of antimicrobial agents. Here, we describe an automated digital, time-lapse, bright field imaging system (oCelloScope, BioSense Solutions ApS, Farum, Denmark) for rapid and higher throughput antibiotic susceptibility testing (AST) of up to 96 bacteria-antibiotic combinations at a time. The imaging system consists of a digital camera, an illumination unit and a lens where the optical axis is tilted 6.25° relative to the horizontal plane of the stage. Such tilting grants more freedom of operation at both high and low concentrations of microorganisms. When considering a bacterial suspension in a microwell, the oCelloScope acquires a sequence of 6.25°-tilted images to form an image Z-stack. The stack contains the best-focus image, as well as the adjacent out-of-focus images (which contain progressively more out-of-focus bacteria, the further the distance from the best-focus position). The acquisition process is repeated over time, so that the time-lapse sequence of best-focus images is used to generate a video. The setting of the experiment, image analysis and generation of time-lapse videos can be performed through a dedicated software (UniExplorer, BioSense Solutions ApS). The acquired images can be processed for online and offline quantification of several morphological parameters, microbial growth, and inhibition over time.

  2. A locked nucleic acid (LNA-based real-time PCR assay for the rapid detection of multiple bacterial antibiotic resistance genes directly from positive blood culture.

    Directory of Open Access Journals (Sweden)

    Lingxiang Zhu

    Full Text Available Bacterial strains resistant to various antibiotic drugs are frequently encountered in clinical infections, and the rapid identification of drug-resistant strains is highly essential for clinical treatment. We developed a locked nucleic acid (LNA-based quantitative real-time PCR (LNA-qPCR method for the rapid detection of 13 antibiotic resistance genes and successfully used it to distinguish drug-resistant bacterial strains from positive blood culture samples. A sequence-specific primer-probe set was designed, and the specificity of the assays was assessed using 27 ATCC bacterial strains and 77 negative blood culture samples. No cross-reaction was identified among bacterial strains and in negative samples, indicating 100% specificity. The sensitivity of the assays was determined by spiking each bacterial strain into negative blood samples, and the detection limit was 1-10 colony forming units (CFU per reaction. The LNA-qPCR assays were first applied to 72 clinical bacterial isolates for the identification of known drug resistance genes, and the results were verified by the direct sequencing of PCR products. Finally, the LNA-qPCR assays were used for the detection in 47 positive blood culture samples, 19 of which (40.4% were positive for antibiotic resistance genes, showing 91.5% consistency with phenotypic susceptibility results. In conclusion, LNA-qPCR is a reliable method for the rapid detection of bacterial antibiotic resistance genes and can be used as a supplement to phenotypic susceptibility testing for the early detection of antimicrobial resistance to allow the selection of appropriate antimicrobial treatment and to prevent the spread of resistant isolates.

  3. Epidemiology and antibiotic sensitivity of Staphylococcus aureus nasal carriage in children in Hungary.

    Science.gov (United States)

    Laub, Krisztina; Tóthpál, Adrienn; Kardos, Szilvia; Dobay, Orsolya

    2017-03-01

    The aim of this study was to assess the Staphylococcus aureus nasal carriage rate in healthy children all over Hungary and to specify some risk factors, the antibiotic resistance patterns of the bacteria, and their genetic relatedness. In total, 878 children (aged 3-6 years) were screened at 21 day-care centers in 16 different cities in Hungary, between February 2009 and December 2011. Samples taken from both nostrils were cultured on blood agar, and suspected S. aureus isolates were identified by β-hemolysis, catalase positivity, clump test, and nucA PCR. Methicillin-resistant strains were screened by mecA and mecC PCR. Antibiotic susceptibility was determined by agar dilution or gradient test strips. Pulsed-field gel electrophoresis was used for genotyping. S. aureus carriage rate was found to be 21.3%, which correlates well with international data. We found no statistically significant correlation between the gender or the sibling status and S. aureus carriage. All isolates were sensitive to oxacillin, trimethoprim-sulfamethoxazole, and mupirocin. The resistance rates for erythromycin, ciprofloxacin, clindamycin, gentamicin, and tetracycline were 7.5%, 0.5%, 1.1%, 3.7%, and 4.3%, respectively. The isolates showed very high genetic diversity. In summary, carried S. aureus isolates are more sensitive to antibiotics compared with clinical isolates in Hungary, and methicillin-resistant S. aureus carriage rate is very low yet.

  4. Antibiotic sensitivity pattern of bacteria from diabetic foot infections Haji Adam Malik central general hospital

    Science.gov (United States)

    Bulolo, B. A.; Pase, M. A.; Ginting, F.

    2018-03-01

    Increasing rate of Diabetic Foot Infections (DFIs) caused by multi-drug-resistance pathogens plays a huge role in the duration of hospitalization, morbidity, and mortality of diabetic patients. The aim of the study is to assess the antibiotic sensitivity pattern of bacteria in DFIs and causative microorganisms. Using cross-sectional retrospective study, data were collected from medical records of DFIs patients previously hospitalized atHaji Adam Malik Hospital, Medan from January to July 2017. 33 patients met the criteria and got enrolled in the study. The classification of DFIs was evaluated according to Wagner’s Classification. Evaluation of antibiotic sensitivity and identification of causative microorganisms were performed in standard microbiologic methods. The most common grade of DFIs was Grade-4 (48.5%), followed by Grade-3 (39.4%) and Grade-5 (9.1%). A total of 12 pathogens were identified. The most common infecting microorganism isolated on pus cultures was Klebsiella pneumonia (33.3%), followed by Escherichia coli (24.2%), Acinetobacter baumanni (12.1%), and Staphylococcus aureus (9.1%). Frequent susceptible antibiotics were Amikacin (88.8%), Imipenem (87%), Meropenem (84.6%), Erythromycin (75%), and Cefoperazone/Sulbactam (68.9%). DFIs are polymicrobial infections in this study K. pneumonia was the most common cause microorganism.

  5. SENSITIVITY TO ANTIBIOTICS, ANTISEPTICAL NOSOCOMIAL PSEUDOMONAS AERUGINOSA, ISOLATED IN UROLOGICAL PATIENTS

    Directory of Open Access Journals (Sweden)

    Rymsha E.V.

    2015-05-01

    Full Text Available Introduction. Given the active introduction into clinical practice of new groups of antibiotics and antiseptics, the problem of treatment of purulent-inflammatory complications after prostatectomy and today is relevant. Of particular concern belated cases of diagnosis and treatment of postoperative complications in urological practice patients receiving antibiotic therapy The use of traditional antibiotics is not prevents the development of infection, because the problem of resistance of microorganisms to antibiotics and antiseptics remains relevant. The solution to the problem of development of infectious complications and prevent the formation of resistant clinical strains largely depends on the isolated pathogen, susceptibility to antimicrobial agents based on its bioavailability , ability to spread and penetrate into cells and tissues, selection of dose, interval, and route of administration to maintain minimum bactericidal concentration Material and methods. The study involved 145 patients who were treated in the urology Department of the Vinnytsia regional clinical hospital named of M. I. Pirogov. Patients underwent the surgical treatment of benign hypertrophic prostate. Material for bacteriological studies of purulent-inflammatory diseases were urine, pieces of the prostate, remote operationally, urinary catheters, through which conducted irrigation of the bladder. Specimen collection, transportation was carried out in accordance with modern requirements. Identification was done by morphological, cultural and biochemical properties. The definition of antibiotic resistance were performed according to "guidelines for the definition of sensitivity of microorganisms to antibiotics by the method of diffusion in agar using discs" (No. 2675-83, Kiev, 2007 12 .]. Evaluation of the results of determining the sensitivity of microorganisms to antibiotics was carried out on the basis of the determination of the zone of growth (mm of the studied

  6. Antibiotic sensitivity and resistance in children with urinary tract infection in Sanliurfa.

    Science.gov (United States)

    Abuhandan, Mahmut; Güzel, Bülent; Oymak, Yeşim; Çiftçi, Halil

    2013-06-01

    This study aimed to evaluate antibiotic resistance in the province of Şanliurfa and to observe any difference between antibiotic resistance rates. The study comprised 107 children who presented at the pediatric polyclinic with complaints of urinary tract infection with the diagnosis of urinary tract infection and whose urine cultures exhibited bacterial growth. The patients were analyzed with respect to the frequency of proliferating pathogens, sensitivity to the antibiotics used and the rates of developed resistance to the antibiotics. A total of 107 patients aged between 1 year and 15 years were included in the study, encompassing 14 (13.1%) males and 93 (86.9%) females. According to the urine culture results, proliferation of Escherichia coli (E. coli) was observed in 69 (64.5%), Klebsiella spp. in 13 (12.1%), Proteus mirabilis in 9 (8.4%), Staphylococcus aureus in 5 (4.7%), Pseudomonas aeruginosa in 5 (4.7%), Acinetobacter spp. in 3 (2.8%) and Enterococcus spp. in 3 (2.8%) patients. For proliferating E. coli, high resistance rates to ceftriaxone (39.5%), nitrofurantoin (19.7%), ampicillin-sulbactam (64.1%), co-trimoxazole (41.5%), amoxicillinclavulanate (51.7%) and cefuroxime (38.1%) were observed. All of isolated microorganisms were resistant to ampicillin-sulbactam, amoxicillin-clavulanate, co-trimoxazole, ceftriaxone, cefuroxime and cefoxitin in decreasing frequencies. The most effective antimicrobial agents were determined to be imipenem, sulpera-zone, quinolone and aminoglycosides. In our region, parenteral antibiotics that should be selected for the empirical treatment of UTIs in all age groups are the aminoglycosides and 3(rd) generation cephalosporines. In contrast to other studies, these results suggest that co-trimoxazole should be used for children aged 0-1, and 2(nd) generation cephalosporins should be used for the oral treatment of children aged 1-5 due to the low rate of resistance to nitrofurantoin in patients aged over 5 years.

  7. Prevalence of enteropathogens and their antibiotic sensitivity pattern in puppies with hemorrhagic gastroenteritis

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    A. Kokila Priya

    2017-08-01

    Full Text Available Aim: Hemorrhagic gastroenteritis (HGE ranging from mild to severe forms is commonly encountered in puppies. The aim of the study was to identify the prevalence of common enteropathogens and the antibiotic sensitivity pattern in puppies reported with HGE. Materials and Methods: The canine HGE activity index, with little modification, was adopted to identify Grade III/ severely affected puppies below 6 months of age. Fecal polymerase chain reaction (PCR assay was employed to screen and compare the enteropathogens in puppies with hemorrhagic diarrhea and healthy control. Results: Canine parvovirus 2b was identified in 90.3% of the diarrheic and 10% of the non-diarrheic healthy puppies. Clostridium difficile was identified in all the diarrheic puppies and in 80% of the healthy puppies. Among the diarrheic puppies, 17.7% were positive for Clostridium perfringens enterotoxin, 9.7% were positive for C. perfringens alpha toxin, 6.4% were positive for Escherichia coli shiga toxin, 6.4% were positive for E. coli enterotoxin (LT, and 3.2% were positive for canine distemper virus. Whereas, none of the healthy puppies were positive for these bacteria and toxins. Fecal antibiotic sensitivity test pattern revealed gentamicin to be sensitive in 95% of the cases, azithromycin in 50%, enrofloxacin in 25%, cefotaxime in 20%, and tetracycline in 5% of the cases. Conclusion: Parvoviral enteritis is predominant among puppies. Yet, bacteria and their toxins also play an important role in HGE. Gentamicin has higher sensitivity against the enteropathogens associated with the condition.

  8. Bacterial pattern and antibiotic sensitivity in children and adolescents with infected atopic dermatitis

    Science.gov (United States)

    Samosir, C. T.; Ruslie, R. H.; Rusli, R. E.

    2018-03-01

    Atopic dermatitis (AD) is a pruritic and chronic inflammatory skin disease which affected approximately 20% in children. Bacterial infection is common in AD patients and correlates directly with AD severity. A cross-sectional study was conducted to evaluate the prevalence of bacterial skin infection in AD patients and its relation with severity of AD and also to study bacteria in the infected AD and its antibiotic sensitivity. Samples were 86 children and adolescents with an AD in Helvetia Community Health Center Medan from March 2016 until February 2017. Index of SCORing Atopic Dermatitis (SCORAD) was used to evaluate the severity of AD. Lesion and nonlesional skinwere swabbed to take sterile cultures. All bacteria noted and tested for antibiotic sensitivity. Datawere by using Chi-Square and Mann Whitney test with 95% CI and p-value<0.05 was considered statistically significant. Fifty-six AD patients (65.1%) were bacterial infected. There was a significant relationship between severity of AD and bacterial infection (p = 0.006). Staphylococcus aureus was the leading bacteria from all degrees of AD severity. Isolated Staphylococcus aureuswas sensitive to amoxicillin-clavulanate (93.3%), clindamycin (90%), erythromycin (90%), and gentamicin (90%), while sensitivity to tetracycline was low (20%).

  9. BACTERIAL PROFILE, ANTIBIOTIC SENSITIVITY AND RESISTANCE OF LOWER RESPIRATORY TRACT INFECTIONS IN UPPER EGYPT

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    Gamal Agmy

    2013-09-01

    Full Text Available BACKGROUND: Lower respiratory tract infections (LRTI account for a considerable proportion of morbidity and antibiotic use. We aimed to identify the causative bacteria, antibiotic sensitivity and resistance of hospitalized adult patients due to LRTI in Upper Egypt. METHODS: A multicentre prospective study was performed at 3 University Hospitals for 3 years. Samples included sputum or bronchoalveolar lavage (BAL for staining and culture, and serum for serology. Samples were cultured on 3 bacteriological media (Nutrient, Chocolate ,MacConkey's agars.Colonies were identified via MicroScan WalkAway-96. Pneumoslide IgM kit was used for detection of atypical pathogens via indirect immunofluorescent assay. RESULTS: The predominant isolates in 360 patients with CAP were S.pneumoniae (36%, C. pneumoniae (18%, and M. pneumoniae (12%. A higher sensitivity was recorded for moxifloxacin, levofloxacin, macrolides, and cefepime. A higher of resistance was recorded for doxycycline, cephalosporins, and β-lactam-β-lactamase inhibitors. The predominant isolates in 318 patients with HAP were, methicillin-resistant Staphylococcus aureus; MRSA (23%, K. pneumoniae (14%, and polymicrobial in 12%. A higher sensitivity was recorded for vancomycin, ciprofloxacin, and moxifloxacin. Very high resistance was recorded for β-lactam-β-lactamase inhibitors and cephalosporins. The predominant organisms in 376 patients with acute exacerbation of chronic obstructive pulmonary diseases (AECOPD were H. influnzae (30%, S. pneumoniae (25%, and M. catarrhalis(18%. A higher sensitivity was recorded for moxifloxacin, macrolides and cefepime. A higher rate of resistance was recorded for aminoglycosides and cephalosporins CONCLUSIONS: The most predominant bacteria for CAP in Upper Egypt are S. pneumoniae and atypical organisms, while that for HAP are MRSA and Gram negative bacteria. For acute exacerbation of COPD,H.influnzae was the commonest organism. Respiratory quinolones

  10. RESEARCH IN SENSITIVITY TO ANTIBIOTICS, ANTISEPTICS IN PSEUDOMONAS AERUGINOSA STRAINS ISOLATED FROM PATIENTS WITH INFECTIOUS COMPLICATIONS

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    O. A. Nazarchuk

    2017-07-01

    Full Text Available Background. Infections caused by Pseudomonas are one of the topical issues of medicine. Objective. The aim of the research was to study sensityvity to antibiotics, antiseptics of P. aeruginosa clinical strains that cause infectious complications in patients with burns. Methods. Microbiological study of biological material, received from 435 patients with burns of the 3rd-4th stages (2011-2015 years. In early terms of burn disease 127 clinical strains of P. aeruginosa were isolated from patients. Standard methods were used to identify clinical isolates of P. aeruginosa by their morphological, tinctirial, culture and biochemical properties. The research of antimicrobial action of antiseptics, antibiotics against Pseudomonas were carried out by means of standard methods according to the Directive of the Ministry of Health of Ukraine (No. 167 from 05.04.2007 р. and guidelines of National Committee of Clinical and Laboratory Study (NCCLS, 2002. Results. It was established that P. aeruginosa caused infectious complications in 23.9% of patients among other pathogens. Clinical isolates of P. aeruginosa were found to be low sensitive to amoxicillin/clavulanate (30.76%, ceftazidime (25.92%, cefoperazonum/sulbactam (46.15%, aztreonam (51.85%, tobramycin (38.46%, amicacin (70.34%, doxiciclini (26.92%, fluoroquinolones (59.26%. The analitical progistic criteria of decrease of sensitivity to ceftazidime, cefepim, meropenem and gatifloxacin were found in P. aeruginosa. This pathogen was determined to be sensitive to decasan ®, antimicrobial composition of decamethoxine ®, iodine pvidone. Conclusions. Clinical strains of Pseudomonas aeruginosa, being highly resistant to antibiotics, are also very sensitive to antiseptics decasan ®, antimicrobial of decamethoxine®, povidone iodine.

  11. Integrating rapid diagnostics and antimicrobial stewardship improves outcomes in patients with antibiotic-resistant Gram-negative bacteremia.

    Science.gov (United States)

    Perez, Katherine K; Olsen, Randall J; Musick, William L; Cernoch, Patricia L; Davis, James R; Peterson, Leif E; Musser, James M

    2014-09-01

    An intervention for Gram-negative bloodstream infections that integrated mass spectrometry technology for rapid diagnosis with antimicrobial stewardship oversight significantly improved patient outcomes and reduced hospital costs. As antibiotic resistance rates continue to grow at an alarming speed, the current study was undertaken to assess the impact of this intervention in a challenging patient population with bloodstream infections caused by antibiotic-resistant Gram-negative bacteria. A total of 153 patients with antibiotic-resistant Gram-negative bacteremia hospitalized prior to the study intervention were compared to 112 patients treated post-implementation. Outcomes assessed included time to optimal antibiotic therapy, time to active treatment when inactive, hospital and intensive care unit length of stay, all-cause 30-day mortality, and total hospital expenditures. Integrating rapid diagnostics with antimicrobial stewardship improved time to optimal antibiotic therapy (80.9 h in the pre-intervention period versus 23.2 h in the intervention period, P Gram-negatives. The intervention decreased hospital and intensive care unit length of stay, total hospital costs, and reduced all-cause 30-day mortality. Copyright © 2014. Published by Elsevier Ltd.

  12. Rapid and sensitive determination of deuterium concentration by gas chromatography

    International Nuclear Information System (INIS)

    Takahashi, Tomiki; Ohokoshi, Sumio; Shinriki, Nariko; Sato, Toshio

    1984-01-01

    Gas chromatographic determination of hydrogen isotopes D 2 and HD has hitherto been carried out with a molecular sieve column kept at -195 0 C under the H 2 carrier gas. However, the amount of D 2 in hydrogen gas containing low HD concentration of less than 5 % can be practically neglected judging from the equilibrium constant of H 2 -D 2 exchange reaction. Therefore, there is no need to separate HD from D 2 . As an improvement, in this paper, the gas chromatographic determination of HD in low concentration ( 2 as a carrier gas enabled us to enhance the cell current of TCD drastically, hence gave rise to high sensitivity of HD detection. The limit of determination of the concentration of HD was 0.01%. In the case of the higher concentration (>5%) of HD in hydrogen gas, D 2 and HD have been separated and determined by the method described above, but this method takes more than ten minutes. Therefore, we designed a new gas chromatographic analysis of the HD-D 2 mixture with an activated alumina column at -195 0 C under the H 2 carrier gas (330 ml/min). The advantages of this method are in (1) rapid analysis (in 1 min), (2) no need of the rigid activation temperature ((110--250) 0 C), (3) no change of the relative molar sensitivity of HD to D 2 at the various flow rates of H 2 carrier gas ((100--300)ml/min). (author)

  13. Rapid Estimation of Gustatory Sensitivity Thresholds with SIAM and QUEST

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    Richard Höchenberger

    2017-06-01

    Full Text Available Adaptive methods provide quick and reliable estimates of sensory sensitivity. Yet, these procedures are typically developed for and applied to the non-chemical senses only, i.e., to vision, audition, and somatosensation. The relatively long inter-stimulus-intervals in gustatory studies, which are required to minimize adaptation and habituation, call for time-efficient threshold estimations. We therefore tested the suitability of two adaptive yes-no methods based on SIAM and QUEST for rapid estimation of taste sensitivity by comparing test-retest reliability for sucrose, citric acid, sodium chloride, and quinine hydrochloride thresholds. We show that taste thresholds can be obtained in a time efficient manner with both methods (within only 6.5 min on average using QUEST and ~9.5 min using SIAM. QUEST yielded higher test-retest correlations than SIAM in three of the four tastants. Either method allows for taste threshold estimation with low strain on participants, rendering them particularly advantageous for use in subjects with limited attentional or mnemonic capacities, and for time-constrained applications during cohort studies or in the testing of patients and children.

  14. Bacterial Species and Antibiotic Sensitivity in Korean Patients Diagnosed with Acute Otitis Media and Otitis Media with Effusion.

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    Kim, Sang Hoon; Jeon, Eun Ju; Hong, Seok Min; Bae, Chang Hoon; Lee, Ho Yun; Park, Moo Kyun; Byun, Jae Yong; Kim, Myung Gu; Yeo, Seung Geun

    2017-04-01

    Changes over time in pathogens and their antibiotic sensitivity resulting from the recent overuse and misuse of antibiotics in otitis media (OM) have complicated treatment. This study evaluated changes over 5 years in principal pathogens and their antibiotic sensitivity in patients in Korea diagnosed with acute OM (AOM) and OM with effusion (OME). The study population consisted of 683 patients who visited the outpatient department of otorhinolaryngology in 7 tertiary hospitals in Korea between January 2010 and May 2015 and were diagnosed with acute AOM or OME. Aural discharge or middle ear fluid were collected from patients in the operating room or outpatient department and subjected to tests of bacterial identification and antibiotic sensitivity. The overall bacteria detection rate of AOM was 62.3% and OME was 40.9%. The most frequently isolated Gram-positive bacterial species was coagulase negative Staphylococcus aureus (CNS) followed by methicillin-susceptible S. aureus (MSSA), methicillin-resistant S. aureus (MRSA), and Streptococcus pneumonia (SP), whereas the most frequently isolated Gram-negative bacterium was Pseudomonas aeruginosa (PA). Regardless of OM subtype, ≥ 80% of CNS and MRSA strains were resistant to penicillin (PC) and tetracycline (TC); isolated MRSA strains showed low sensitivity to other antibiotics, with 100% resistant to PC, TC, cefoxitin (CFT), and erythromycin (EM); and isolated PA showed low sensitivity to quinolone antibiotics, including ciprofloxacin (CIP) and levofloxacin (LFX), and to aminoglycosides. Bacterial species and antibiotic sensitivity did not change significantly over 5 years. The rate of detection of MRSA was higher in OME than in previous studies. As bacterial predominance and antibiotic sensitivity could change over time, continuous and periodic surveillance is necessary in guiding appropriate antibacterial therapy. © 2017 The Korean Academy of Medical Sciences.

  15. Mannitol enhances antibiotic sensitivity of persister bacteria in Pseudomonas aeruginosa biofilms.

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    Nicolas Barraud

    Full Text Available The failure of antibiotic therapies to clear Pseudomonas aeruginosa lung infection, the key mortality factor for cystic fibrosis (CF patients, is partly attributed to the high tolerance of P. aeruginosa biofilms. Mannitol has previously been found to restore aminoglycoside sensitivity in Escherichia coli by generating a proton-motive force (PMF, suggesting a potential new strategy to improve antibiotic therapy and reduce disease progression in CF. Here, we used the commonly prescribed aminoglycoside tobramycin to select for P. aeruginosa persister cells during biofilm growth. Incubation with mannitol (10-40 mM increased tobramycin sensitivity of persister cells up to 1,000-fold. Addition of mannitol to pre-grown biofilms was able to revert the persister phenotype and improve the efficacy of tobramycin. This effect was blocked by the addition of a PMF inhibitor or in a P. aeruginosa mutant strain unable to metabolise mannitol. Addition of glucose and NaCl at high osmolarity also improved the efficacy of tobramycin although to a lesser extent compared to mannitol. Therefore, the primary effect of mannitol in reverting biofilm associated persister cells appears to be an active, physiological response, associated with a minor contribution of osmotic stress. Mannitol was tested against clinically relevant strains, showing that biofilms containing a subpopulation of persister cells are better killed in the presence of mannitol, but a clinical strain with a high resistance to tobramycin was not affected by mannitol. Overall, these results suggest that in addition to improvements in lung function by facilitating mucus clearance in CF, mannitol also affects antibiotic sensitivity in biofilms and does so through an active, physiological response.

  16. Evaluation of effect of high frequency electromagnetic field on growth and antibiotic sensitivity of bacteria.

    Science.gov (United States)

    Salmen, Saleh H; Alharbi, Sulaiman A; Faden, Asmaa A; Wainwright, M

    2018-01-01

    This study was aimed to evaluate the impact of high frequency electromagnetic fields (HF-EMF at 900 and 1800 MHz) on DNA, growth rate and antibiotic susceptibility of S. aureus , S. epidermidis , and P. aeruginosa . In this study, bacteria were exposed to 900 and 1800 MHz for 2 h and then inoculated to new medium when their growth rate and antibiotic susceptibility were evaluated. Results for the study of bacterial DNA unsuccessful to appearance any difference exposed and non-exposed S. aureus and S. epidermidis . Exposure of S. epidermidis and S. aureus to electromagnetic fields mostly produced no statistically significant decrease in bacterial growth, except for S. aureus when exposure to 900 MHz at 12 h. Exposure of P. aeruginosa to electromagnetic fields at 900 MHz however, lead to a significant reduction in growth rate, while 1800 MHz had insignificant effect. With the exception of S. aureus , treated with amoxicillin (30 µg) and exposed to electromagnetic fields, radiation treatment had no significant effect on bacterial sensitivity to antibiotics.

  17. Celecoxib sensitizes Staphylococcus aureus to antibiotics in macrophages by modulating SIRT1.

    Science.gov (United States)

    Annamanedi, Madhavi; Kalle, Arunasree M

    2014-01-01

    We have previously shown that celecoxib in combination with an antibiotic, increase the bacterial sensitivity to antibiotics. However, the underlying molecular mechanism remained elusive. Efficacy of the combinatorial treatment of celecoxib and ampicillin in vitro was evaluated on macrophage-phagocytosed S. aureus. To elucidate the mechanism, signaling pathway of infection and inflammation involving TLR2, JNK, SIRT1 and NF-κB was studied by FACS, Western blot, ELISA and activity assays. Combinatorial treatment of ampicillin and celecoxib reduced the bacterial load in the macrophages. Further studies clearly suggested the activation of the master regulator of oxidative stress and inflammation SIRT1, by celecoxib when used alone and/or in combination with ampicillin. Also, the results indicated that celecoxib inhibited JNK phosphorylation thereby stabilizing and activating SIRT1 protein that inhibited the COX-2 gene transcription with a significant decrease in the levels of protein inflammatory cytokines like IL-6, MIP-1α and IL-1β via inhibition of NF-κB. SIRT1 activation by celecoxib also resulted in increase of catalase and peroxidase activity with a decrease in Nitric oxide levels. In conclusion, we demonstrate a novel role of celecoxib in controlling inflammation as an enhancer of antibiotic activity against bacteria by modulating SIRT1.

  18. Can a simple urinalysis predict the causative agent and the antibiotic sensitivities?

    Science.gov (United States)

    Waseem, Muhammad; Chen, Justin; Paudel, Govinda; Sharma, Nirdesh; Castillo, Manuel; Ain, Yumna; Leber, Mark

    2014-04-01

    The objective of this study was (1) to determine the reliability of urinalysis (UA) for predicting urinary tract infection (UTI) in febrile children, (2) to determine whether UA findings can predict Escherichia coli versus non-E. coli urinary tract infection, and (3) to determine if empiric antibiotics should be selected based on E. coli versus non-E. coli infection predictions. This was a retrospective chart review of children from 2 months to 2 years of age who presented to the emergency department with fever (rectal temperature >100.4°F) and had a positive urine culture. This study was conducted between January 2004 and December 2007. Negative UA was defined as urine white blood cell count less than 5 per high-power field, negative leukocyte esterase, and negative nitrites. Urine cultures were classified into E. coli and non-E. coli groups. These groups were compared for sex, race, and UA findings. Multivariate forward logistic regression, using the Wald test, was performed to calculate the likelihood ratio (LR) of each variable (eg, sex, race, UA parameters) in predicting UTI. In addition, antibiotic sensitivities between both groups were compared. Of 749 medical records reviewed, 608 were included; negative UA(-) was present in 183 cases, and positive UA(+) was observed in 425 cases. Furthermore, 424 cases were caused by E. coli, and 184 were due to non-E. coli organisms. Among 425 UA(+) cases, E. coli was identified in 349 (82.1%), whereas non-E. coli organisms were present in 76 (17.9%); in contrast, in 183 UA(-) cases, 108 (59%) were due to non-E. coli organisms versus 75 (41%), which were caused by E. coli. Urinalysis results were shown to be associated with organism group (P Antibiotic sensitivity compared between UA groups demonstrated equivalent superiority of cefazolin (94.7% sensitive in UA(+) vs 84.0% in UA(-) group; P sensitivity to trimethoprim-sulfamethoxazole (82.2% vs 71.3% in UA(+); P = 0.008). Urinalysis is not an accurate predictor of UTI. A

  19. Beta-Lactam Antibiotic Sensitization and Its Relationship to Allergic Diseases in Tertiary Hospital Nurses

    Science.gov (United States)

    Han, Eui-Ryoung; Lim, Seong-Wook; Lim, Seong-Ryoon; Kim, Ji-Na; Park, Sin-Young; Chae, Su-Kyoung; Lim, Hye-Hyeun; Seol, Young-Ae; Bae, You-In; Won, Young-Ho

    2010-01-01

    Purpose Skin allergies through type 1 and 4 hypersensitivity reactions are the most frequent manifestations of drug allergies. We had previously experienced a case of a nurse with cefotiam-induced contact urticaria syndrome. To aid in preventing the progression of drug-induced allergic disease in nurses, we conducted a survey of tertiary hospital nurses who were likely to have been exposed professionally to antibiotics. Methods All 539 staff nurses at a tertiary hospital were asked to respond to a questionnaire regarding antibiotic exposure. Of the 457 nurses (84.8%) who responded, 427 (79.2%) received a physical examination of the hands and 318 (59.0%) received skin prick tests with the β-lactam antibiotics cefotiam, cefoperazone, ceftizoxime, flomoxef, piperacillin and penicillin G. Results A positive response to at least one of the antibiotics occurred in 8 (2.6%) of the 311 subjects included in the analysis and stages 1 and 2 contact urticaria syndrome were observed in 38 (8.9%) and 3 (0.7%) of 427 nurses, respectively. The frequencies of a positive antibiotic skin test (6.9 versus 1.3%, χ2=7.15, P=0.018), stage 1 contact urticaria syndrome (14.4 versus 7.4%, χ2=4.33, P=0.038) and drug allergy (15.3 versus 3.6%, χ2=18.28, P=0.000) were higher in subjects with a positive skin allergy history than in those without. Allergic rhinitis (P=0.02, OR=3.86, CI=1.23-12.06), night cough (P=0.04, OR=3.12, CI=1.03-9.41) and food allergy (P=0.00, OR=9.90, CI=3.38-29.98) were significant risk factors for drug allergy. Conclusions Antibiotic sensitization and drug allergy occurred more frequently in nurses with a positive skin allergy history. Atopy may be an important risk factor for drug allergy. PMID:20358025

  20. Persistence of antibiotic-resistant and -sensitive Proteus mirabilis strains in the digestive tract of the housefly (Musca domestica) and green bottle flies (Calliphoridae).

    Science.gov (United States)

    Wei, Ting; Miyanaga, Kazuhiko; Tanji, Yasunori

    2014-10-01

    Synanthropic flies have been implicated in the rapid dissemination of antibiotic-resistant bacteria and resistance determinants in the biosphere. These flies stably harbor a considerable number of bacteria that exhibit resistance to various antibiotics, but the mechanisms underlying this phenomenon remain unclear. In this study, we investigated the persistence of antibiotic-resistant bacteria in the digestive tract of houseflies and green bottle flies, using Proteus mirabilis as a model microorganism. One resistant strain carried the blaTEM and aphA1 genes, and another carried a plasmid containing qnrD gene. Quantitative PCR and 454 pyrosequencing were used to monitor the relative abundance of the Proteus strains, as well as potential changes in the overall structure of the whole bacterial community incurred by the artificial induction of Proteus cultures. Both antibiotic-resistant and -sensitive P. mirabilis strains persisted in the fly digestive tract for at least 3 days, and there was no significant difference in the relative abundance of resistant and sensitive strains despite the lower growth rate of resistant strains when cultured in vitro. Therefore, conditions in the fly digestive tract may allow resistant strains to survive the competition with sensitive strains in the absence of antibiotic selective pressure. The composition of the fly-associated bacterial community changed over time, but the contribution of the artificially introduced P. mirabilis strains to these changes was not clear. In order to explain these changes, it will be necessary to obtain more information about bacterial interspecies antagonism in the fly digestive tract.

  1. Investigations of sensitivity to antibiotics of salmonella strain species originating from poultry from different epizootiological areas

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    Stošić Zorica

    2006-01-01

    Full Text Available A total of 1666 samples were examined, of which 512 samples of parenchymatous organs of dead or deliberately sacrtificed animals, 60 samples of non-hatched fertilized eggs, 202 samples of feces, 652 samples of cloacal smears, 221 samples of smears from walls of maintenance objects, incubator stations, and transport vehicles, 19 samples of beddings and shavings. The samples originated from poultry farms and which were taken to a laboratory immediately on sampling and sown the same day. A total of 104 strains of Salmonella were isolated: 94 strains from samples of parenchymatous organs of dead chicks, 1 strain from non-hatched eggs, 3 strains from feces samples, 1 strain from samples of cloacal smears, 4 strains from samples of surface smears of maintenance objects and transport vehicles, and 1 strain from samples of beddings and shavings. Serological typization established the presence of the following serovarieties: Salmonella Enteritidis 79 strains, Salmonella Hartford 17 strains, Salmonella Typohimurium 5 strains, Salmonella Mbandaka 2 strains, and Salmonella Glostrup 1 strain. We examined the sensitivity of Salmonella strains to ampicillin, amoxicillin, gentamycin, streptomycin, neomycin, enrofloxacine, norfloxacine, flumequin, erythromycin, lincospectin, colistin, fluorphenicol, and a combination of sulphamethoxasole and trimethoprim. In S. Enteritidis strains, no resistence was established to colistin, fluorphenicol and sulphamethoxasole+trimethoprim, in fact, the sensitivity to these antibiotics and chemotherapeutics was 100%. Prevalence resitence of 0.96%, in only one strain, was established for enrofloxacine. A high prevalence resistence of 33.6% was established for neomycin, while prevalence resistence of 3.86% was established for the related aminoglycozide antibiotic gentamycin. The highest prevalence resistance in S.Hartford strains was established for erythromycin, 15.38%, and streptomycin, 7.6%. Resistence of S. Tyohimurium was

  2. The clinical spectrum and antibiotic sensitivity patterns of staphylococcal pyodermas in the community and hospital

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    Shireen Furtado

    2014-01-01

    Full Text Available Context: The uncontrolled use of antibiotics has resulted in a relentless spread of multiresistant strains of Staphylococcus aureus. There are studies conducted in medical colleges in Chandigarh, Chennai, Mumbai and Vellore comparing pyodermas in the community and hospital setting based on clinical and bacteriological parameters. Aims: This study, conducted over 1½ years from March 2009 to August 2010, aimed at analyzing the clinical spectrum and antibiotic sensitivity pattern of community and hospital-associated (HA staphylococcal pyoderma. It also assessed the prevalence of methicillin-resistant S. aureus (MRSA in the community and hospital cohort settings. Subjects and Methods: The study comprised of 200 cases of staphylococcal pyodermas, derived from the community (150 cases and hospital (50 cases. Patients were evaluated based on their clinical presentation; antibiotic susceptibility was tested using the Kirby-Bauer disk diffusion method. Statistical Analysis Used: Statistical significance between individual attributes between the community and HA staphylococcal pyoderma groups was analyzed using Chi-square test and mean differences using student′s t-test. Results: Factors associated with community-associated (CA pyodermas were young age (P = 0.0021, primary pyodermas, and involvement of extremities, while those with HA pyodermas were middle age, secondary pyodermas, and significantly increased body surface involvement (P = 0.041. Incidence of CA-MRSA was 11.3%, while that of HA-MRSA was 18%. Conclusions: A high level of resistance to first-line drugs such as penicillin, ciprofloxacin and cotrimoxazole was observed, more so in the hospital strain than in the community strain. S. aureus demonstrated good susceptibility to cephalosporins. Though the two strains of MRSA differed clinically, they showed 100% sensitivity to vancomycin and linezolid.

  3. Successful recovery of infective endocarditis-induced rapidly progressive glomerulonephritis by steroid therapy combined with antibiotics: a case report

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    Kikkawa Ryuichi

    2004-12-01

    Full Text Available Abstract Background The mortality rate among patients with infective endocarditis, especially associated with the presence of complications or coexisting conditions such as renal failure and the use of combined medical and surgical therapy remains still high. Prolonged parenteral administration of a bactericidal antimicrobial agent or combination of agents is usually recommended, however, the optimal therapy for infective endocarditis associated with renal injury is not adequately defined. Case presentation Patient was a 24-years old man who presented to our hospital with fever, fatigue, and rapidly progressive glomerulonephritis. He had a history of ventricular septum defect (VSD. A renal biopsy specimen revealed crescentic glomerulonephritis and echocardiogram revealed VSD with vegetation on the tricuspid valve. Specimens of blood demonstrated Propionibacterium Acnes. The intensive antibiotic therapy with penicillin G was started without clinical improvement of renal function or resolution of fever over the next 7 days. After the short-term treatment of low dose of corticosteroid combined with continuous antibiotics, high fever and renal insufficiency were dramatically improved. Conclusion Although renal function in our case worsened despite therapy with antibiotics, a short-term and low dose of corticosteroid therapy with antibiotics was able to recover renal function and the patient finally underwent tricuspid valve-plasty and VSD closure. We suggest that the patients with rapidly progressive glomerulonephritis associated with infective endocarditis might be treated with a short-term and low dose of corticosteroid successfully.

  4. Centrifuge: rapid and sensitive classification of metagenomic sequences.

    Science.gov (United States)

    Kim, Daehwan; Song, Li; Breitwieser, Florian P; Salzberg, Steven L

    2016-12-01

    Centrifuge is a novel microbial classification engine that enables rapid, accurate, and sensitive labeling of reads and quantification of species on desktop computers. The system uses an indexing scheme based on the Burrows-Wheeler transform (BWT) and the Ferragina-Manzini (FM) index, optimized specifically for the metagenomic classification problem. Centrifuge requires a relatively small index (4.2 GB for 4078 bacterial and 200 archaeal genomes) and classifies sequences at very high speed, allowing it to process the millions of reads from a typical high-throughput DNA sequencing run within a few minutes. Together, these advances enable timely and accurate analysis of large metagenomics data sets on conventional desktop computers. Because of its space-optimized indexing schemes, Centrifuge also makes it possible to index the entire NCBI nonredundant nucleotide sequence database (a total of 109 billion bases) with an index size of 69 GB, in contrast to k-mer-based indexing schemes, which require far more extensive space. © 2016 Kim et al.; Published by Cold Spring Harbor Laboratory Press.

  5. Rapid and sensitive measure of gluconeogenesis in isolated bovine hepatocytes

    International Nuclear Information System (INIS)

    Azain, M.J.; Kasser, T.R.; Atwell, C.A.; Baile, C.A.

    1986-01-01

    Available methods for determining glucose synthesis from radiolabelled precursors using ion exchange column chromatography limit the number of samples that can be processed. To facilitate this process, a rapid method for determining glucose synthesis from 3-carbon precursors was developed using suspensions of anion and cation exchange resins. Hepatocytes were prepared from calf liver by collagenase perfusion of the caudate lobe. Isolated cells were incubated with 14 C-labelled lactate or propionate in the presence or absence of glucagen and/or palmitate. Glucose synthesis was determined by vortexing an aliquot of cell suspension with a 50% slurry of anion exchange resin (acetate form), followed by cation exchange resin. After centrifugation 14 C-glucose was recovered in the supernatant and measured by scintillation counting. Using this method, more than 95% of unused labelled precursor was bound to the ion exchange resin and essentially 100% of 14 C-glucose tracer was recovered in the supernatant. In hepatocyte suspensions, radioactivity recovered in the supernatants was confirmed to be glucose by pre-incubating aliquots of media with glucose oxidase prior to addition of ion exchange resins. The present system allows determination of hepatic gluconeogenesis, is sensitive to substrate and hormonal manipulations and has the capacity for processing several hundred samples per day

  6. Isolation and Antibiotic Sensitivity of Bacillus thuringinesis Strain From Dump Soil

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    Sarker, D.

    2010-01-01

    Full Text Available Bacillus thuringiensis (or Bt is a commonly used as a pesticide. B. thuringiensis is a naturally-occurring soil bacterium, also occurs naturally in the gut of caterpillars of various types of moths and butterflies, as well as on the dark surface of plants. The xylanase producing bacterial strains were isolated from dump soil. The strains were isolated on xylan agar media and screening was carried out by xylanolysis method. To test the sensitivity of the isolates, ten different antibiotics were used. The strains were tested for resistance to doxycyclin, erythromycin, chloramphenical, cephallaxin, kanamycin, ampicillin, steptomycin, vancomycin, amoxycillin and neomycin. The strains showed sensitive to doxycyclin, erythromycin, chloramphenical, cephallaxin, kanamycin, ampicillin, steptomycin and vancomycin and also showed resistance to amoxycillin and neomycin, when tested by disc diffusion method on nutrient agar plate confirmed by antibiotic spread plate method. The inhibitory effect of B. thuringiensis strains against the test bacteria Bacillus subtilis, Sarcina lutca, Shigella dysenteriae, Shigella sonnei and Pseudomonus aeruginosa examined. It was found that, B. thuringiensis S1, B. thuringiensis S2 and B. thuringiensis S3 strains showed an inhibitory effect on all of the test bacteria.

  7. Rapid disc diffusion antibiotic susceptibility testing for Pseudomonas aeruginosa, Acinetobacter baumannii and Enterococcus spp.

    Science.gov (United States)

    Hombach, Michael; Jetter, Marion; Blöchliger, Nicolas; Kolesnik-Goldmann, Natalia; Keller, Peter M; Böttger, Erik C

    2018-01-01

    Abstract Background We investigated the feasibility of rapid disc diffusion antibiotic susceptibility testing (rAST) with reading of inhibition zones after 6 and/or 8 h of incubation for Enterococcus faecalis, Enterococcus faecium, Pseudomonas aeruginosa and Acinetobacter baumannii. In addition, we evaluated discrimination of resistant populations from the WT populations at early timepoints and the requirement for clinical breakpoint adaptations for proper interpretation of rAST data. Methods In total, 815 clinical strains [E. faecalis (n = 135), E. faecium (n = 227), P. aeruginosa (n = 295) and A. baumannii (n = 158)] were included in this study. Disc diffusion plates were streaked, incubated and imaged using the WASPLabTM automation system. WT populations and non-WT populations were defined using epidemiological cut-offs. Results and conclusions rAST at 6 and 8 h was possible for A. baumannii and enterococci with readability of inhibition zones >90%. Overall categorical agreement of rAST at 6 h with AST at 18 h was 97.2%, 97.4% and 95.3% for E. faecalis, E. faecium and A. baumannii, respectively. With few exceptions, major categorization error rates were <1% for A. baumannii, and vancomycin-resistant E. faecium were clearly separated from the WT at 6 h. For P. aeruginosa the average readability of inhibition zones was 68.9% at 8 h and we found an overall categorical agreement of 94.8%. Adaptations of clinical breakpoints and/or introduction of technical buffer zones, preferably based on aggregated population data from various epidemiological settings, are required for proper interpretation of rAST. PMID:29186434

  8. Rapid determination of resistance to antibiotics in surgical clinical practice based on the measurement of radioactive carbon dioxide

    International Nuclear Information System (INIS)

    Alant, O.; Jaszsagi-Nagy, E.; Lendvay, J.; Schmidt, M.

    1978-01-01

    For the objective choice of an antibiotic a method is needed which is capable of giving informations with an essentially shorter time delay than that of the conventional bacteriological tests i.e. practically in a few hours concerning the sensitivity to the tested antibiotic of the pathogen germ cultured from the sample withdrawn from the patient under surgical treatment. The new measurement method is based on the incubation of the test material in an adequate medium containing glucose labelled with C-14 as only sugar source. The amount of the formed 14 CO 2 is proportional to the multiplication rate of the bacterium. Experience observed with 312 surgical patients indicated that the sensitivity to an antibiotic agent can be determined in 4-6 hours from the septic intergrowth or from the discharge obtained during the surgical action and in the case of chronical diseases the successfulness of the treatment with the antibiotic can be established precisely. The equipment needed for the tests is simple and the measurements can be carried out readily in hospital laboratories. (P.J.)

  9. Gas Plasma Pre-treatment Increases Antibiotic Sensitivity and Persister Eradication in Methicillin-Resistant Staphylococcus aureus

    Science.gov (United States)

    Guo, Li; Xu, Ruobing; Zhao, Yiming; Liu, Dingxin; Liu, Zhijie; Wang, Xiaohua; Chen, Hailan; Kong, Michael G.

    2018-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of serious nosocomial infections, and recurrent MRSA infections primarily result from the survival of persister cells after antibiotic treatment. Gas plasma, a novel source of ROS (reactive oxygen species) and RNS (reactive nitrogen species) generation, not only inactivates pathogenic microbes but also restore the sensitivity of MRSA to antibiotics. This study further found that sublethal treatment of MRSA with both plasma and plasma-activated saline increased the antibiotic sensitivity and promoted the eradication of persister cells by tetracycline, gentamycin, clindamycin, chloramphenicol, ciprofloxacin, rifampicin, and vancomycin. The short-lived ROS and RNS generated by plasma played a primary role in the process and induced the increase of many species of ROS and RNS in MRSA cells. Thus, our data indicated that the plasma treatment could promote the effects of many different classes of antibiotics and act as an antibiotic sensitizer for the treatment of antibiotic-resistant bacteria involved in infectious diseases. PMID:29628915

  10. Neural mechanisms of rapid sensitivity to syntactic anomaly

    Directory of Open Access Journals (Sweden)

    Albert E. Kim

    2013-03-01

    Full Text Available Recent psycholinguistic models hypothesize that anticipatory processing can speed the response to linguistic input during language comprehension by pre-activating representations necessary for word recognition. We investigated the neurocognitive mechanisms of anticipatory processing by recording event-related brain responses (ERPs to syntactically anomalous (The thief was caught by for police and well-formed (e.g., The thief was caught by the police sentences. One group of participants saw anomalies elicited by the same word in every instance (e.g., for; low-variability stimuli, providing high affordances for predictions about the word-form appearing in the critical position. A second group saw anomalies elicited by seven different prepositions (at, of, on, for, from, over, with; high-variability stimuli across the study, creating a more difficult prediction task. Syntactic category anomalies enhanced the occipital-temporal N170 component of the ERP, indicating rapid sensitivity—within 200 ms of word onset—to syntactic anomaly. For low-variability but not the high-variability stimuli, syntactic anomaly also enhanced the earlier occipital-temporal P1 component, around 130 ms after word-onset, indicating that affordances for prediction engendered earlier sensitivity to syntactic anomaly. Independent components analysis revealed three sources within the ERP signal whose functional dynamics were consistent with predictive processing and early responses to syntactic anomaly. Distributed neural source modeling (sLORETA of these early-active sources produced a candidate network for early responses to words during reading in the right posterior-occipital, left occipital-temporal, and medial parietal cortex.

  11. Evaluation of the Specificity and Sensitivity of a Potential Rapid Influenza Screening System

    Science.gov (United States)

    2013-01-01

    misuse of antibiotic therapy for treatment of influenza infections. Rapid identification of influenza infections would further reduce transmission of...amplification tests in combination with Type I BESt™ Cassette have been developed and used to rapidly detect other pathogenic microorgan- isms including herpes ... simplex virus types 1 and 2 (Kim et al., 2011), Mycobacterium tuberculosis (Motre et al., 2011), human immunode- ficiency virus (Tang et al., 2010), and

  12. Intraspecies comparative genomics of three strains of Orientia tsutsugamushi with different antibiotic sensitivity.

    Science.gov (United States)

    Liao, Hsiao-Mei; Chao, Chien-Chung; Lei, Haiyan; Li, Bingjie; Tsai, Shien; Hung, Guo-Chiuan; Ching, Wei-Mei; Lo, Shyh-Ching

    2017-06-01

    We recently reported the genome of Orientia tsutsugamushi (OT) strain Karp (GenBank Accession #: NZ_LYMA00000000.2, https://www.ncbi.nlm.nih.gov/nuccore/NZ_LYMA00000000.2) with > 2 Mb in size through clone-based sequencing and high throughput genomic shotgun sequencing (HTS). The genomes of OT strains AFSC4 and AFSC7 were similarly sequenced by HTS Since strains AFSC4 (GenBank Accession #: NZ_LYMT00000000.1, https://www.ncbi.nlm.nih.gov/nuccore/1035784408) and AFSC7 (GenBank Accession #: NZ_LYMB00000000.1, https://www.ncbi.nlm.nih.gov/nuccore/1035854767) were more resistant to antibiotics than strain Karp, we conducted comparative analysis of the three draft genomes annotated by RAST server aimed to identify possible genetic bases of difference in microbial antibiotic sensitivity. Intraspecies comparative genomics analysis of the three OT strains revealed that two ORFs encoding hypothetical proteins in both strains AFSC4 and AFSC7 are absent in strain Karp.

  13. Epidemiology of urinary tract infections and antibiotics sensitivity among pregnant women at Khartoum North Hospital

    Directory of Open Access Journals (Sweden)

    Ali Salah K

    2011-01-01

    Full Text Available Abstract Background Urinary tract infections (UTI can lead to poor maternal and perinatal outcomes. Investigating epidemiology of UTI and antibiotics sensitivity among pregnant women is fundamental for care-givers and health planners. Methods A cross sectional study has been conducted at Khartoum north teaching hospital Antenatal Care Clinic between February-June 2010, to investigate epidemiology of UTI and antibiotics resistance among pregnant women. Structured questionnaires were used to gather data from pregnant women. UTI was diagnosed using mid stream urine culture on standard culture media Results Out of 235 pregnant women included, 66 (28.0% were symptomatic and 169 (71.9% asymptomatic. the prevalence of bacteriuria among symptomatic and asymptomatic pregnant women were (12.1%, and (14.7% respectively, with no significant difference between the two groups (P = 0.596, and the overall prevalence of UTI was (14.0%. In multivariate analyses, age, gestational age, parity, and history of UTI in index pregnancy were not associated with bacteriuria. Escherichia coli (42.4% and S. aureus (39.3% were the commonest isolated bacteria. Four, 2, 2, 3, 4, 2 and 0 out of 14 E. coli isolates, showed resistance to amoxicillin, naladixic acid, nitrofurantoin, ciprofloxacin, co-trimoxazole, amoxicillin/clavulanate and norfloxacin, respectively Conclusion Escherichia coli were the most prevalent causative organisms and showing multi drug resistance pattern, asymptomatic bacteriuria is more prevalent than symptomatic among pregnant women. Urine culture for screening and diagnosis purpose for all pregnant is recommended.

  14. Epidemiology of urinary tract infections and antibiotics sensitivity among pregnant women at Khartoum North Hospital.

    Science.gov (United States)

    Hamdan, Hamdan Z; Ziad, Abdel Haliem M; Ali, Salah K; Adam, Ishag

    2011-01-18

    Urinary tract infections (UTI) can lead to poor maternal and perinatal outcomes. Investigating epidemiology of UTI and antibiotics sensitivity among pregnant women is fundamental for care-givers and health planners. A cross sectional study has been conducted at Khartoum north teaching hospital Antenatal Care Clinic between February-June 2010, to investigate epidemiology of UTI and antibiotics resistance among pregnant women. Structured questionnaires were used to gather data from pregnant women. UTI was diagnosed using mid stream urine culture on standard culture media Out of 235 pregnant women included, 66 (28.0%) were symptomatic and 169 (71.9%) asymptomatic. the prevalence of bacteriuria among symptomatic and asymptomatic pregnant women were (12.1%), and (14.7%) respectively, with no significant difference between the two groups (P = 0.596), and the overall prevalence of UTI was (14.0%). In multivariate analyses, age, gestational age, parity, and history of UTI in index pregnancy were not associated with bacteriuria. Escherichia coli (42.4%) and S. aureus (39.3%) were the commonest isolated bacteria. Four, 2, 2, 3, 4, 2 and 0 out of 14 E. coli isolates, showed resistance to amoxicillin, naladixic acid, nitrofurantoin, ciprofloxacin, co-trimoxazole, amoxicillin/clavulanate and norfloxacin, respectively. Escherichia coli were the most prevalent causative organisms and showing multi drug resistance pattern, asymptomatic bacteriuria is more prevalent than symptomatic among pregnant women. Urine culture for screening and diagnosis purpose for all pregnant is recommended.

  15. DEFINITION OF ETIOLOGICAL ANTIBIOTIC SENSITIVITY FACTORS IN PURULENT-INFLAMMATORY PROCESSES.

    Science.gov (United States)

    Dubovyk, O; Mishyna, М; Malanchuk, S; Kuzmenko, A; Kozlov, O

    2017-10-01

    The purpose of the study - assessment of purulent-inflammatory processes etiologic factors and determination of microbial agents' in forms of plankton and biofilms sensitivity to antibiotics. Clinical microbial strains isolated from patients with purulent-inflammatory processes were the subject of the study. The study material comprised of wound tissue, pus, bandage and suture, catheters and drainage devices. Sensitivity of isolates to antimicrobial preparations with various mechanism of activity on the microbial cells was studied with the help of micro-test system. Formation of biofilms was studied with the help of definition of bacteria strains ability to adhesion to the surface of polystyrene flatbeds. It was revealed that one of the leading factors of purulent-inflammatory process development is S.aureus, which disseminated in 36,5% of cases; E.coli disseminated in 17,3% of cases. Among the agents of purulent-inflammatory processes the specific gravity attributed to: Proteus spp. - 14,6%, S.рyogenes - 12,8%, P.aeruginosa - 6,9%, K.pneumoniae - 6,7%. It was revealed that all isolates formed dense biofilms. It was demonstrated that most isolates in plankton form were sensitive to Novapime, Cefepime, Gatifloxacin, Imipenem; sensitive strains were registered in a smaller quantity to Gentamicin, Clindamycin and Doxycycline. In terms of sensitivity of isolates in the form of biofilm to antibacterial preparations it was revealed that most isolates were polyresistant to them. Thus, the study of the sensitivity of allotted microbial strains to antimicrobial preparations demonstrated, that there were strains among cultures with multiple resistances which was the consequence of a wide and not always effective use of antimicrobial preparations.

  16. Antibiotic sensitivity of escherichia coli isolated from urinary tract infection referred to Kermanshah central laboratory

    Directory of Open Access Journals (Sweden)

    Parviz Mohajeri

    2011-03-01

    Full Text Available Background: Escherichia coli (Ecoli has been considered as the most common agent of urinary tract infection in all regions. Recently, increased drug resistance has been lead to some problems in treatment related diseases. So, evaluation of resistance patterns of bacteria in each region could be a valuable guide for empirical treatment.Methods: All referred urine sample to Kermanshah Central Laboratory during 1998 that was reported positive to Ecoli were assessed. Susceptibility pattern to 19 antimicrobial agents was evaluated using Kirby Bauer method according to CLSI standards.Results: A total of 834 Ecoli isolated from 19,208 positive urine cultures. 84% of subjects were females and 16% males. Sensitivity rate for nitrofurantoin (84%, ceftizoxime (72%, norfloxacin (70%, cefotaxime (69%, Amikacin (66%, ciprofloxacin (65%, ceftriaxone (64%, ceftazidim (55% was higher than 50%. Sensitivity to nalidixic acid, cefexime, gentamicin, co-trimoxazole, ticarcillin, caphalexin, cephalotin, tetracycline, amoxicillin, amoxicillin clavulanate and ampicillin were determined less than 50%.Conclusion: Nitrofurantoin and ceftizoxime are currently effective against Ecoli, although an indiscriminate use of antibiotics should be avoided because of drug resistance probable. It seems that ampicillin could be excluded from routine sensitivity testing.

  17. Occurrence of Clostridium perfringens contamination in poultry feed ingredients: Isolation, identification and its antibiotic sensitivity pattern

    Directory of Open Access Journals (Sweden)

    Shanmugasundaram Udhayavel

    2017-09-01

    Full Text Available This work has been undertaken to study the occurrence of Clostridium perfringens contamination in the poultry feed ingredients and find out its in-vitro antibiotic sensitivity pattern to various antimicrobial drugs. Two hundred and ninety-eight poultry feed ingredient samples received at Poultry Disease Diagnosis and Surveillance Laboratory, Namakkal, Tamil Nadu in South India were screened for the presence of C. perfringens. The organisms were isolated in Perfringens agar under anaerobic condition and subjected to standard biochemical tests for confirmation. In vitro antibiogram assay has been carried out to determine the sensitivity pattern of the isolates to various antimicrobial drugs. One hundred and one isolates of C. perfringens were obtained from a total of 298 poultry feed ingredient samples. Overall positivity of 33.89% could be made from the poultry feed ingredients. Highest level of C. perfringens contamination was detected in fish meal followed by bone meal, meat and bone meal and dry fish. Antibiogram assay indicated that the organisms are highly sensitive to gentamicin (100%, chlortetracycline (96.67%, gatifloxacin (93.33%, ciprofloxacin (86.67%, ofloxacin (86.67% and lincomycin (86.67%. All the isolates were resistant to penicillin-G. Feed ingredients rich in animal proteins are the major source of C. perfringens contamination.

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

    Science.gov (United States)

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

    2016-05-01

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

  19. Antibacterial effect of mango (Mangifera indica Linn.) leaf extract against antibiotic sensitive and multi-drug resistant Salmonella typhi.

    Science.gov (United States)

    Hannan, Abdul; Asghar, Samra; Naeem, Tahir; Ikram Ullah, Muhammad; Ahmed, Ijaz; Aneela, Syeda; Hussain, Shabbir

    2013-07-01

    Alternative herbal medicine has been used to treat various infections from centuries. Natural plants contain phytoconstituents having similar chemical properties as of synthetic antibiotics. Typhoid fever is a serious infection and failure of its treatment emerged multi-drug resistant (MDR) bugs of Salmonella typhi. Due to multiple and repeated issues with antibiotics efficacy, it became essential to evaluate biological properties of plants from different geographical origins. Mango leaves have been Reported for various medicinal effects like antioxidant, antimicrobial, antihelminthic, antidiabetic and antiallergic etc. Objective of present study was to investigate anti-typhoid properties of acetone mango leaf extract (AMLE) against antibiotic sensitive and MDR S. typhi isolates. A total of 50 isolates of S. typhi including MDR (n=30) and antibiotic sensitive (n=20) were investigated. Staphylococcus aureus (ATCC 25923) and Salmonella typhimurium (ATCC14028) were used as quality control strains. AMLE was prepared and its antibacterial activity was evaluated by agar well diffusion screening method and minimum inhibitory concentration (MIC), by agar dilution technique. Zone of inhibition (mm) of AMLE against MDR and antibiotic sensitive isolates was 18±1.5mm (Mean±S.D). Zone of S. aureus (ATCC 25923) and S. typhimurium (ATCC14028) was 20±1.5mm (Mean±S.D). MIC of AMLE was Reported in range from 10-50 mg/ml. The present study described the inhibitory effects of mango leaves against S. typhi.

  20. A Signal-On Fluorosensor Based on Quench-Release Principle for Sensitive Detection of Antibiotic Rapamycin

    Directory of Open Access Journals (Sweden)

    Hee-Jin Jeong

    2015-03-01

    Full Text Available An antibiotic rapamycin is one of the most commonly used immunosuppressive drugs, and also implicated for its anti-cancer activity. Hence, the determination of its blood level after organ transplantation or tumor treatment is of great concern in medicine. Although there are several rapamycin detection methods, many of them have limited sensitivity, and/or need complicated procedures and long assay time. As a novel fluorescent biosensor for rapamycin, here we propose “Q’-body”, which works on the fluorescence quench-release principle inspired by the antibody-based quenchbody (Q-body technology. We constructed rapamycin Q’-bodies by linking the two interacting domains FKBP12 and FRB, whose association is triggered by rapamycin. The fusion proteins were each incorporated position-specifically with one of fluorescence dyes ATTO520, tetramethylrhodamine, or ATTO590 using a cell-free translation system. As a result, rapid rapamycin dose-dependent fluorescence increase derived of Q’-bodies was observed, especially for those with ATTO520 with a lowest detection limit of 0.65 nM, which indicates its utility as a novel fluorescent biosensor for rapamycin.

  1. A signal-on fluorosensor based on quench-release principle for sensitive detection of antibiotic rapamycin.

    Science.gov (United States)

    Jeong, Hee-Jin; Itayama, Shuya; Ueda, Hiroshi

    2015-03-26

    An antibiotic rapamycin is one of the most commonly used immunosuppressive drugs, and also implicated for its anti-cancer activity. Hence, the determination of its blood level after organ transplantation or tumor treatment is of great concern in medicine. Although there are several rapamycin detection methods, many of them have limited sensitivity, and/or need complicated procedures and long assay time. As a novel fluorescent biosensor for rapamycin, here we propose "Q'-body", which works on the fluorescence quench-release principle inspired by the antibody-based quenchbody (Q-body) technology. We constructed rapamycin Q'-bodies by linking the two interacting domains FKBP12 and FRB, whose association is triggered by rapamycin. The fusion proteins were each incorporated position-specifically with one of fluorescence dyes ATTO520, tetramethylrhodamine, or ATTO590 using a cell-free translation system. As a result, rapid rapamycin dose-dependent fluorescence increase derived of Q'-bodies was observed, especially for those with ATTO520 with a lowest detection limit of 0.65 nM, which indicates its utility as a novel fluorescent biosensor for rapamycin.

  2. A multiple antibiotic and serum resistant oligotrophic strain, Klebsiella pneumoniae MB45 having novel dfrA30, is sensitive to ZnO QDs

    Directory of Open Access Journals (Sweden)

    Chakrabarti Pinak

    2011-05-01

    Full Text Available Abstract Background The aim of this study was to describe a novel trimethoprim resistance gene cassette, designated dfrA30, within a class 1 integron in a facultatively oligotrophic, multiple antibiotic and human serum resistant test strain, MB45, in a population of oligotrophic bacteria isolated from the river Mahananda; and to test the efficiency of surface bound acetate on zinc oxide quantum dots (ZnO QDs as bactericidal agent on MB45. Methods Diluted Luria broth/Agar (10-3 media was used to cultivate the oligotrophic bacteria from water sample. Multiple antibiotic resistant bacteria were selected by employing replica plate method. A rapid assay was performed to determine the sensitivity/resistance of the test strain to human serum. Variable region of class 1 integron was cloned, sequenced and the expression of gene coding for antibiotic resistance was done in Escherichia coli JM 109. Identity of culture was determined by biochemical phenotyping and 16S rRNA gene sequence analyses. A phylogenetic tree was constructed based on representative trimethoprim resistance-mediating DfrA proteins retrieved from GenBank. Growth kinetic studies for the strain MB45 were performed in presence of varied concentrations of ZnO QDs. Results and conclusions The facultatively oligotrophic strain, MB45, resistant to human serum and ten antibiotics trimethoprim, cotrimoxazole, ampicillin, gentamycin, netilmicin, tobramycin, chloramphenicol, cefotaxime, kanamycin and streptomycin, has been identified as a new strain of Klebsiella pneumoniae. A novel dfr gene, designated as dfrA30, found integrated in class 1 integron was responsible for resistance to trimethoprim in Klebsiella pneumoniae strain MB45. The growth of wild strain MB45 was 100% arrested at 500 mg/L concentration of ZnO QDs. To our knowledge this is the first report on application of ZnO quantum dots to kill multiple antibiotics and serum resistant K. pneumoniae strain.

  3. Dual Recognition Strategy for Specific and Sensitive Detection of Bacteria Using Aptamer-Coated Magnetic Beads and Antibiotic-Capped Gold Nanoclusters.

    Science.gov (United States)

    Cheng, Dan; Yu, Mengqun; Fu, Fei; Han, Weiye; Li, Gan; Xie, Jianping; Song, Yang; Swihart, Mark T; Song, Erqun

    2016-01-05

    Food poisoning and infectious diseases caused by pathogenic bacteria such as Staphylococcus aureus (SA) are serious public health concerns. A method of specific, sensitive, and rapid detection of such bacteria is essential and important. This study presents a strategy that combines aptamer and antibiotic-based dual recognition units with magnetic enrichment and fluorescent detection to achieve specific and sensitive quantification of SA in authentic specimens and in the presence of much higher concentrations of other bacteria. Aptamer-coated magnetic beads (Apt-MB) were employed for specific capture of SA. Vancomycin-stabilized fluorescent gold nanoclusters (AuNCs@Van) were prepared by a simple one-step process and used for sensitive quantification of SA in the range of 32-10(8) cfu/mL with the detection limit of 16 cfu/mL via a fluorescence intensity measurement. And using this strategy, about 70 cfu/mL of SA in complex samples (containing 3 × 10(8) cfu/mL of other different contaminated bacteria) could be successfully detected. In comparison to prior studies, the developed strategy here not only simplifies the preparation procedure of the fluorescent probes (AuNCs@Van) to a great extent but also could sensitively quantify SA in the presence of much higher concentrations of other bacteria directly with good accuracy. Moreover, the aptamer and antibiotic used in this strategy are much less expensive and widely available compared to common-used antibodies, making it cost-effective. This general aptamer- and antibiotic-based dual recognition strategy, combined with magnetic enrichment and fluorescent detection of trace bacteria, shows great potential application in monitoring bacterial food contamination and infectious diseases.

  4. Distinct fermentation and antibiotic sensitivity profiles exist in salmonellae of canine and human origin.

    Science.gov (United States)

    Wallis, Corrin V; Lowden, Preena; Marshall-Jones, Zoe V; Hilton, Anthony C

    2018-02-26

    Salmonella enterica is a recognised cause of diarrhoea in dogs and humans, yet the potential for transfer of salmonellosis between dogs and their owners is unclear, with reported evidence both for and against Salmonella as a zoonotic pathogen. A collection of 174 S. enterica isolates from clinical infections in humans and dogs were analysed for serotype distribution, carbon source utilisation, chemical and antimicrobial sensitivity profiles. The aim of the study was to understand the degree of conservation in phenotypic characteristics of isolates across host species. Serovar distribution across human and canine isolates demonstrated nine serovars common to both host species, 24 serovars present in only the canine collection and 39 solely represented within the human collection. Significant differences in carbon source utilisation profiles and ampicillin, amoxicillin and chloramphenicol sensitivity profiles were detected in isolates of human and canine origin. Differences between the human and canine Salmonella collections were suggestive of evolutionary separation, with canine isolates better able to utilise several simple sugars than their human counterparts. Generally higher minimum inhibitory concentrations of three broad-spectrum antimicrobials, commonly used in veterinary medicine, were also observed in canine S. enterica isolates. Differential carbon source utilisation and antimicrobial sensitivity profiles in pathogenic Salmonella isolated from humans and dogs are suggestive of distinct reservoirs of infection for these hosts. Although these findings do not preclude zoonotic or anthroponotic potential in salmonellae, the separation of carbon utilisation and antibiotic profiles with isolate source is indicative that infectious isolates are not part of a common reservoir shared frequently between these host species.

  5. Clinical profile and antibiotics sensitivity in childhood urinary tract infection at Dhulikhel Hospital.

    Science.gov (United States)

    Singh, S D; Madhup, S K

    2013-01-01

    Urinary Tract Infection implies presence of actively multiplying organisms in the urinary tract. Although it is infrequently associated with mortality, it is still a significant cause of morbidity. Early diagnosis is critical to preserve renal function of growing kidney. Our purpose was to determine the clinical, microbiologic profile and antibiotic sensitivity of such infections in pediatric Urinary Tract Infection (UTI) patients at Dhulikhel Hospital. A hospital based prospective descriptive study of 135 children from 2 months to 16 years, with clinical diagnosis of urinary tract infection who visited the pediatric department of Dhulikhel Hospital over the period of 15 months were enrolled in the study. All patients underwent routine urine analysis and culture. Children with recurrent UTI underwent micturating cystourethrogram (MCUG). Children with recurrent UTI of more than two years and with feature of pyelonephritis underwent USG abdomen as well. Complications and response of the treatment was observed in all cases of UTI. All data were entered in Epidata and data analysis was done using spss 16 version. Among 135 children, 32.5% were male and 67.4% were female. Fever was the most common presenting symptom in 74.80% of patients followed by dysuria in 54.1%. Among these children 95.6% had significant pyuria and 45% had culture positive infection. Children who showed positive for bacteriuria, Escherichia coli (78.7%) was the most common organism and are more than 80% sensitive to Amikacin, Gentamicin, Ceftriaxone, Ofloxacin, Nalidixic acid, Imipenem and Vancomycin. Co-trimoxazole was the most common drug used for treatment with a mean drug respond time of (mean+/-S.D) of 2.21+/-.78 days. 2+/-. Children who had recurrent UTI were more prone to develop culture positive UTI (p=0.0001). Urinary Tract Infection in female was almost twice more common than in male. Cotrimoxazole was the most common drug used for treatment, sensitivity of this drug was less than 50% for

  6. Isolation and antibiotic susceptibility testing of rapidly-growing mycobacteria from grassland soils

    Czech Academy of Sciences Publication Activity Database

    Kyselková, Martina; Chroňáková, Alica; Němec, Jan; Kotrbová, Lucie; Elhottová, Dana

    2013-01-01

    Roč. 3, č. 1 (2013), s. 76-80 ISSN 1338-5178 R&D Projects: GA ČR GAP504/10/2077; GA MŠk LC06066; GA MŠk(CZ) EE2.3.30.0032 Grant - others:GA JU(CZ) GAJU 04-142/2010/P Institutional support: RVO:60077344 Keywords : mycobakterium isolation and cultivation * grassland soil * antibiotic resistance Subject RIV: EE - Microbiology, Virology

  7. Rapid resolution of cellulitis in patients managed with combination antibiotic and anti-inflammatory therapy.

    Science.gov (United States)

    Dall, Lawrence; Peterson, Sandford; Simmons, Tom; Dall, Amy

    2005-03-01

    There is some evidence to suggest that host inflammatory response has some effect on the clinical manifestations of cellulitis. The objective of this pilot study was to investigate whether the addition of oral nonsteroidal anti-inflammatory (NSAI) therapy to antibiotic treatment hastens resolution of cellulitis-related inflammation. Patients presenting in the emergency department with signs and symptoms of class II cellulitis were assigned to receive treatment with either antibiotic therapy alone (intravenous, supplemented with oral cephalexin or an equivalent) for 10 days (n = 33) or antibiotic therapy for 10 days plus an oral anti-inflammatory (ibuprofen 400 mg every 6 hours) for 5 days (n = 31). Patients were discharged as soon as possible to complete their therapy on an outpatient basis. The addition of an oral anti-inflammatory agent significantly (P < .05) shortened the time to regression of inflammation and complete resolution of cellulitis. Twenty-four of 29 evaluable patients (82.8%) who received supplemental anti-inflammatory treatment showed regression of inflammation within 1 to 2 days compared with only 3 of 33 patients (9.1%) treated without an anti-inflammatory in the same time frame. All patients receiving adjunctive anti-inflammatory treatment experienced complete resolution of cellulitis in 4 to 5 days or less, while 24.2% (8/33) of patients treated with antibiotic alone required 6 to 7 days, and 6.1% (2/33) required 7 days or more (P < .05). This small preliminary study provides some promising data, suggesting that the supplemental use of anti-inflammatory therapy may hasten the time to regression of inflammation and complete resolution of cellulitis.

  8. Integrating human and environmental health in antibiotic risk assessment: A critical analysis of protection goals, species sensitivity and antimicrobial resistance.

    Science.gov (United States)

    Le Page, Gareth; Gunnarsson, Lina; Snape, Jason; Tyler, Charles R

    2017-12-01

    Antibiotics are vital in the treatment of bacterial infectious diseases but when released into the environment they may impact non-target organisms that perform vital ecosystem services and enhance antimicrobial resistance development with significant consequences for human health. We evaluate whether the current environmental risk assessment regulatory guidance is protective of antibiotic impacts on the environment, protective of antimicrobial resistance, and propose science-based protection goals for antibiotic manufacturing discharges. A review and meta-analysis was conducted of aquatic ecotoxicity data for antibiotics and for minimum selective concentration data derived from clinically relevant bacteria. Relative species sensitivity was investigated applying general linear models, and predicted no effect concentrations were generated for toxicity to aquatic organisms and compared with predicted no effect concentrations for resistance development. Prokaryotes were most sensitive to antibiotics but the range of sensitivities spanned up to several orders of magnitude. We show reliance on one species of (cyano)bacteria and the 'activated sludge respiration inhibition test' is not sufficient to set protection levels for the environment. Individually, neither traditional aquatic predicted no effect concentrations nor predicted no effect concentrations suggested to safeguard for antimicrobial resistance, protect against environmental or human health effects (via antimicrobial resistance development). Including data from clinically relevant bacteria and also more species of environmentally relevant bacteria in the regulatory framework would help in defining safe discharge concentrations for antibiotics for patient use and manufacturing that would protect environmental and human health. It would also support ending unnecessary testing on metazoan species. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Sensitive and rapid detection of Mycoplasma capricolum subsp ...

    African Journals Online (AJOL)

    Compared with a polymerase chain reaction (PCR) test that targets the H2 gene sequences of MCCP, the sensitivity of the loop-mediated isothermal amplification (LAMP) assay was higher (approximately 0.75 fg DNA per reaction). The LAMP products could be visualized by agar gel electrophoresis. There were no cross ...

  10. The Most Prevalnet Organism in Diabetic Foot Ulcers and Its Drug Sensitivity and Resistance to Different Standard Antibiotics

    International Nuclear Information System (INIS)

    Nageen, A.

    2016-01-01

    Objective: To find the most prevalent organism in diabetic foot ulcers and its drug sensitivity and resistance to different standard antibiotics. Study Design: Adescriptive and cross-sectional study. Place and Duration of Study: Ward 7, Jinnah Postgraduate Medical Center, Karachi, from December 2010 to December 2012. Methodology: Ninety-five diabetic patients with infected foot wounds of Wegener grade 2 - 5 who had not received any previous antibiotics were included in the study by consecutive sampling. Pus culture specimen from wounds was taken and the organism isolated was identified. Also the most sensitive group of antibiotics and the most resistant one to that organism was noted. Results: Staphylococcus aureus was the most prevalent organism constituting 23.16% (n=22) of the organisms isolated; Escherichia coli with 17.89% (n=17) and Klebsiella with 12.63% (n=12) followed. Males presented more with diabetic foot (n=52) out of 95 patients. The most common age group affected was 41 - 60 years (73 patients). The organisms were most sensitive to Meropenem, effective in 90 (95%) patients and most resistant to Cotrimoxazole (80, 84% patients). Out of the 95 patients, 39 (41%) patients were hypertensive, 30 (31.5%) were obese and 14 (15%) were smokers. Staphylococcus aureus was the most prevalent organism overall irrespective to gender, age groups and co-morbidity of the patients. Conclusion: Staphylococcus aureus was the most frequent organism in diabetic foot ulcers; the most effective antibiotic is Meropenem and least effective is Cotrimoxazole. (author)

  11. Evaluation of sensitivity of modified star protocol microbiological method for beta-lactame antibiotics detection in raw cow milk

    Directory of Open Access Journals (Sweden)

    Borović Branka

    2013-01-01

    Full Text Available Antibiotic residues when present in animal tissues, through food chain, can enter human body, causing allergic reactions or facilitating the development of resistant bacterial strains. In order to determine the presence of antibiotics in animal tissues, it is appropriate to use convenient, reliable and sensitive methods. Microbiological methods applied for the detection of antibiotic residues in primary products of animal origin are based on the sensitivity of specific bacterial strains to a particular group of antibiotics. Regulatives on the amount of pesticides, metals and metalloids and other toxic substances, chemotherapeutics, anabolics and other substances which can be found in food ("Off. Gazette", No. 5/92, 11/92 - corr. and 32/02, state that milk and milk products can be used in commercial purposes only if not contain antibiotics in quantities that can be detected by reference methods. The applied method is modified STAR (Screening test for detection of antibiotics protocol, regulated by the CRL (Community Reference Laboratory Fougeres, France, in which the initial validation of the method had been carried out. In accordance with the demands of Regulative Commission EC No657/2002, the sensitivity of modified STAR protocol for beta lactam antibiotics group was examined , that is, there was carried out a contracted validation of the method, which initial validation had been performed at CRL. In a couple of series of experiments, 20 blank samples of raw cow milk originating from animals not treated by antibiotics, had been examined. By the beginning of the experiment samples were stored in a freezer at -20ºC. Samples of raw cow milk enriched by working solutions of seven beta-lactam antibiotics, in order to obtain concentrations at the level of 0.5, 1 and 1.5 MRL (Maximmum Residue Limit for each given antibiotic (Commission Regulation EC No. 37/2010. For detection of beta-lactam antibiotics, there was used Kundrat agar test with

  12. Impact of introduction of rapid diagnostic tests for malaria on antibiotic prescribing: analysis of observational and randomised studies in public and private healthcare settings.

    Science.gov (United States)

    Hopkins, Heidi; Bruxvoort, Katia J; Cairns, Matthew E; Chandler, Clare I R; Leurent, Baptiste; Ansah, Evelyn K; Baiden, Frank; Baltzell, Kimberly A; Björkman, Anders; Burchett, Helen E D; Clarke, Siân E; DiLiberto, Deborah D; Elfving, Kristina; Goodman, Catherine; Hansen, Kristian S; Kachur, S Patrick; Lal, Sham; Lalloo, David G; Leslie, Toby; Magnussen, Pascal; Jefferies, Lindsay Mangham; Mårtensson, Andreas; Mayan, Ismail; Mbonye, Anthony K; Msellem, Mwinyi I; Onwujekwe, Obinna E; Owusu-Agyei, Seth; Reyburn, Hugh; Rowland, Mark W; Shakely, Delér; Vestergaard, Lasse S; Webster, Jayne; Wiseman, Virginia L; Yeung, Shunmay; Schellenberg, David; Staedke, Sarah G; Whitty, Christopher J M

    2017-03-29

    Objectives  To examine the impact of use of rapid diagnostic tests for malaria on prescribing of antimicrobials, specifically antibiotics, for acute febrile illness in Africa and Asia. Design  Analysisof nine preselected linked and codesigned observational and randomised studies (eight cluster or individually randomised trials and one observational study). Setting  Public and private healthcare settings, 2007-13, in Afghanistan, Cameroon, Ghana, Nigeria, Tanzania, and Uganda. Participants  522 480 children and adults with acute febrile illness. Interventions  Rapid diagnostic tests for malaria. Main outcome measures  Proportions of patients for whom an antibiotic was prescribed in trial groups who had undergone rapid diagnostic testing compared with controls and in patients with negative test results compared with patients with positive results. A secondary aim compared classes of antibiotics prescribed in different settings. Results  Antibiotics were prescribed to 127 052/238 797 (53%) patients in control groups and 167 714/283 683 (59%) patients in intervention groups. Antibiotics were prescribed to 40% (35 505/89 719) of patients with a positive test result for malaria and to 69% (39 400/57 080) of those with a negative result. All but one study showed a trend toward more antibiotic prescribing in groups who underwent rapid diagnostic tests. Random effects meta-analysis of the trials showed that the overall risk of antibiotic prescription was 21% higher (95% confidence interval 7% to 36%) in intervention settings. In most intervention settings, patients with negative test results received more antibiotic prescriptions than patients with positive results for all the most commonly used classes: penicillins, trimethoprim-sulfamethoxazole (one exception), tetracyclines, and metronidazole. Conclusions  Introduction of rapid diagnostic tests for malaria to reduce unnecessary use of antimalarials-a beneficial public health outcome-could drive

  13. The Sensitization of Legionella pneumophila to Some Antibiotics by Reserpine and Anti-Legionella Effects of Different Benzofuranone Derivatives

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    Mohsen Khaleghi

    2015-10-01

    Full Text Available Background: Legionella pneumophila is  a  dangerous pathogenic bacterium can cause serious infectious diseases especially in hospitalized immuno-compromised patients. This bacterium is shown to be resistant against different antibiotics. Resistance against a wide range of antibiotics is usually mediated by efflux pump in bacteria. Efflux pumps are proteinaceous transporters localized in the cytoplasmic membrane of all kinds of cells which excreted antibiotics outside the cells. However, synthesis of new anti-Legionella compounds or selection of resistant modulating agents are useful strategy to combat with L. pneumophilain the future.Methods: In this study the antibacterial activity of some benzofuranone derivatives have been investigated by disk diffusion method against L. pneumophila. Also the sensitivity of this test strain was evaluated against 19 antibiotics and the combination effect of reserpine at a sub-inhibitory concentration was further studied with these antibiotics using disk diffusion method with some modifications.Conclusion: Among the different synthetic compounds which were tested against L. pneumophila, the most antibacterial activity was observed for compounds 1j and 1m which contain hydroxyl and methoxy groups on the C-6 and C-7 positionsagainst L. pneumophila. To evaluate whether efflux pumps are active in L. pneumophila or not an efflux inhibitor (reserpine was tested in combination of different antibiotics against this test strain. Reserpine significantly enhanced the antibacterial activities of kanamycin, nitrofurantoin, co-trimoxazole, erythromycin, ofloxacillin, gentamycin, rifampin, ciprofloxacin, nalidixic acid, minocycline, tobramycin, and amikacin against L. pneumophila which shows the resistances to these antibiotics are mediated by efflux system in this bacterium.

  14. Antibiotic resistant pattern of methicillin resistant and sensitive Staphylococcus aureus isolated from patients durining 2009-2010, Ahvaz, Iran.

    Directory of Open Access Journals (Sweden)

    N Parhizgari

    2013-12-01

    Full Text Available Abstract Background & aim: Staphylococcus aureus is one of the most important nosocomial infecting agents resistant to commonly used antibiotics. Nowadays, methicillin-resistant S. aureus (MRSA is considered one of the main causes of nosocomial infections. The aim of this study was to identify the antibiotic resistance pattern of methicicllin- resistant and susceptible strains in Ahwaz, Iran. Methods: In the present cross - sectional study, a number of 255 clinically suspected cases of Staphylococcus aureus were collected during a 19 month period. The bacteria were investigated using standard biochemical tests such as catalase, mannitol fermentation, coagulase and Dnase. Sensitive strains were confirmed by disk diffusion method compared to commonly used antibiotics. The collected data were analyzed using descriptive statistical tests. Results: of 255 suspected cases, 180 were confirmed as S.aureus, a total of 59 strains of S. aureus (2/37 percent were resistant to methicillin. Resistance to S. aureus strains resistant to methicillin included: chloramphenicol (3.38%, rifampin (45.76%, norfloxacin (89.83%, gentamicin (89.83%, ciprofloxacin, (91.52%, azithromycin, (88.13%, cotrimoxazole (86.44% and all isolates strains were sensitive to vancomycin and nitrofurantoin. A total of 10 different patterns of antibiotic resistance in methicillin-resistant Staphylococcus aureus strains were identified. Conclusion: Expression of new resistance factor in nosocomial infection is one of the major challenges in treating these infections. This study showed a high prevalence of resistance against some class of antibiotics in MRSA isolated from Imam Khomeini and Golestan hospital of Ahwaz, Iran. Key words: Nosocomial infection, Methicillin Resistant Staphylococcus aureus (MRSA, Antibiotic Resistant Pattern

  15. Isolation, identification, characterization and antibiotic sensitivity profile of pathogenic Legionella pneumophila isolates from different water sources

    Directory of Open Access Journals (Sweden)

    Kannan Subbaram

    2017-05-01

    Conclusions: Serious and fatal L. pneumophila infections may be transmitted through water. Legionella can survive under various conditions in various water sources. L. pneumophila is the important pathogen causing human disease. Great challenge prevails to health care professionals because these Legionellae acquired antibiotic resistance to many routinely prescribed antibiotics.

  16. Comparing the sensitivity of algal, cyanobacterial and bacterial bioassays to different groups of antibiotics

    NARCIS (Netherlands)

    van der Grinten, E.; Pikkemaat, M.G.; van den Brandhof, E.J.; Stroomberg, G.J.; Kraak, M.H.S.

    2010-01-01

    Antibiotics may affect both primary producers and decomposers, potentially disrupting ecosystem processes. Hence, it is essential to assess the impact of antibiotics on aquatic ecosystems. The aim of the present study was therefore to evaluate the potential of a recently developed test for detecting

  17. Rapid Assessment of Contrast Sensitivity with Mobile Touch-screens

    Science.gov (United States)

    Mulligan, Jeffrey B.

    2013-01-01

    The availability of low-cost high-quality touch-screen displays in modern mobile devices has created opportunities for new approaches to routine visual measurements. Here we describe a novel method in which subjects use a finger swipe to indicate the transition from visible to invisible on a grating which is swept in both contrast and frequency. Because a single image can be swiped in about a second, it is practical to use a series of images to zoom in on particular ranges of contrast or frequency, both to increase the accuracy of the measurements and to obtain an estimate of the reliability of the subject. Sensitivities to chromatic and spatio-temporal modulations are easily measured using the same method. We will demonstrate a prototype for Apple Computer's iPad-iPod-iPhone family of devices, implemented using an open-source scripting environment known as QuIP (QUick Image Processing,

  18. Microbial Contaminants of Cord Blood Units Identified by 16S rRNA Sequencing and by API Test System, and Antibiotic Sensitivity Profiling.

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    Luís França

    Full Text Available Over a period of ten months a total of 5618 cord blood units (CBU were screened for microbial contamination under routine conditions. The antibiotic resistance profile for all isolates was also examined using ATB strips. The detection rate for culture positive units was 7.5%, corresponding to 422 samples.16S rRNA sequence analysis and identification with API test system were used to identify the culturable aerobic, microaerophilic and anaerobic bacteria from CBUs. From these samples we recovered 485 isolates (84 operational taxonomic units, OTUs assigned to the classes Bacteroidia, Actinobacteria, Clostridia, Bacilli, Betaproteobacteria and primarily to the Gammaproteobacteria. Sixty-nine OTUs, corresponding to 447 isolates, showed 16S rRNA sequence similarities above 99.0% with known cultured bacteria. However, 14 OTUs had 16S rRNA sequence similarities between 95 and 99% in support of genus level identification and one OTU with 16S rRNA sequence similarity of 90.3% supporting a family level identification only. The phenotypic identification formed 29 OTUs that could be identified to the species level and 9 OTUs that could be identified to the genus level by API test system. We failed to obtain identification for 14 OTUs, while 32 OTUs comprised organisms producing mixed identifications. Forty-two OTUs covered species not included in the API system databases. The API test system Rapid ID 32 Strep and Rapid ID 32 E showed the highest proportion of identifications to the species level, the lowest ratio of unidentified results and the highest agreement to the results of 16S rRNA assignments. Isolates affiliated to the Bacilli and Bacteroidia showed the highest antibiotic multi-resistance indices and microorganisms of the Clostridia displayed the most antibiotic sensitive phenotypes.

  19. Microbial Contaminants of Cord Blood Units Identified by 16S rRNA Sequencing and by API Test System, and Antibiotic Sensitivity Profiling.

    Science.gov (United States)

    França, Luís; Simões, Catarina; Taborda, Marco; Diogo, Catarina; da Costa, Milton S

    2015-01-01

    Over a period of ten months a total of 5618 cord blood units (CBU) were screened for microbial contamination under routine conditions. The antibiotic resistance profile for all isolates was also examined using ATB strips. The detection rate for culture positive units was 7.5%, corresponding to 422 samples.16S rRNA sequence analysis and identification with API test system were used to identify the culturable aerobic, microaerophilic and anaerobic bacteria from CBUs. From these samples we recovered 485 isolates (84 operational taxonomic units, OTUs) assigned to the classes Bacteroidia, Actinobacteria, Clostridia, Bacilli, Betaproteobacteria and primarily to the Gammaproteobacteria. Sixty-nine OTUs, corresponding to 447 isolates, showed 16S rRNA sequence similarities above 99.0% with known cultured bacteria. However, 14 OTUs had 16S rRNA sequence similarities between 95 and 99% in support of genus level identification and one OTU with 16S rRNA sequence similarity of 90.3% supporting a family level identification only. The phenotypic identification formed 29 OTUs that could be identified to the species level and 9 OTUs that could be identified to the genus level by API test system. We failed to obtain identification for 14 OTUs, while 32 OTUs comprised organisms producing mixed identifications. Forty-two OTUs covered species not included in the API system databases. The API test system Rapid ID 32 Strep and Rapid ID 32 E showed the highest proportion of identifications to the species level, the lowest ratio of unidentified results and the highest agreement to the results of 16S rRNA assignments. Isolates affiliated to the Bacilli and Bacteroidia showed the highest antibiotic multi-resistance indices and microorganisms of the Clostridia displayed the most antibiotic sensitive phenotypes.

  20. Development and Evaluation of a Rapid and Sensitive EBOV-RPA Test for Rapid Diagnosis of Ebola Virus Disease.

    Science.gov (United States)

    Yang, Mingjuan; Ke, Yuehua; Wang, Xuesong; Ren, Hang; Liu, Wei; Lu, Huijun; Zhang, Wenyi; Liu, Shiwei; Chang, Guohui; Tian, Shuguang; Wang, Lihua; Huang, Liuyu; Liu, Chao; Yang, Ruifu; Chen, Zeliang

    2016-06-01

    Confirming Ebola virus disease (EVD), a deadly infectious disease, requires real-time RT-PCR, which takes up to a few hours to yield results. Therefore, a rapid diagnostic assay is imperative for EVD diagnosis. A rapid nucleic acid test based on recombinase polymerase amplification (EBOV-RPA) was developed to specifically detect the 2014 outbreak strains. The EBOV-RPA assay was evaluated by testing samples from suspected EVD patients in parallel with RT-PCR. An EBOV-RPA, which could be completed in 20 min, was successfully developed. Of 271 patients who tested positive for Ebola virus by RT-PCR, 264 (sensitivity: 97%, 95% CI: 95.5-99.3%) were positive by EBOV-RPA; 101 of 104 patients (specificity: 97%, 95% CI: 93.9-100%) who tested negative by RT-PCR were also negative by EBOV-RPA. The sensitivity values for samples with a Ct value of RPA had significantly high Ct values. Results of external quality assessment samples with EBOV-RPA were 100%, consistent with those of RT-PCR. The EBOV-RPA assay showed 97% sensitivity and 97% specificity for all EVD samples tested, making it a rapid and sensitive test for EVD diagnosis.

  1. Antibiotic sensitivity pattern of Staphylococcus aureus from clinical isolates in a tertiary health institution in Kano, Northwestern Nigeria

    Directory of Open Access Journals (Sweden)

    Nwankwo Emmanuel Onwubiko

    2011-01-01

    Full Text Available BACKGROUND: The importance of Staphylococcus aureus as a persistent nosocomial and community acquired pathogen has become a global health concern. It has a remarkable capability of evolving different mechanisms of resistance to most antimicrobial agents. The aim of the present study is to establish the incidence of S. aureus in clinical specimens and its antibiotic sensitivity pattern to various antibiotics in this locality. METHODS: One hundred and fifty consecutive isolates of S. aureus obtained from various clinical specimens between January and December 2009 sent to the Medical Microbiology Laboratory Department of Aminu Kano Teaching Hospital (AKTH were confirmed by standard bacteriological procedures. Antibiotic sensitivity pattern was carried out by disc diffusion method. RESULTS: The age group with the highest number of isolates was (0-10yrs while wound infection had the highest frequency of S. aureus isolates (30.7% in the study. Males (62.0% were more infected than females (38.0%. The sensitivity pattern of S. aureus to the following antibiotics; Gentamicin, Amoxycillin/clavulanate, Streptomycin, Cloxacillin, Erythromycin, Chloramphenicol, Cotrimoxazole, Tetracycline, Penicillin, Ciprofloxacin, Ofloxacin, Levofloxacin, Ceftriaxone, Amoxycillin and vancomycin were 92.4%, 63.0%, 44.2%, 35.8%, 52.4%, 61.9%, 15.5%, 31.2%, 7.1%, 78.9%, 76.6%, 100%, 71.4%, 30.7% and 100% respectively. Methicillin resistant isolates were sensitive to Levofloxacin 93.7% and Ofloxacin 68.7%. CONCLUSION: The results of the present study show that the fluoroquinolones are effective in the management of Staphylococcus aureus infections including methicillin resistant strains in this environment.

  2. BACTERIOLOGICAL PROFILE AND ANTIBIOTIC SENSITIVITY PATTERN IN ACUTE EXACERBATION OF ADVANCED CASES OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD

    Directory of Open Access Journals (Sweden)

    Avik

    2016-01-01

    Full Text Available Acute exacerbations are significant and frequent events in the natural history of chronic obstructive pulmonary disease. Majority of these exacerbations are of infectious aetiology, bacteria being responsible for 30-50% of these cases. With not many studies of similar type being conducted in the Indian context, this study was undertaken with the purpose of determining the bacteriology of acute exacerbations of chronic obstructive pulmonary disease in hospitalized patients with advanced disease and their antibiotic susceptibility pattern to formulate a cost effective algorithm for antibiotic usage while at the same time reducing the chances of emergence of drug resistance. Sputum sample from a total of 338 patients were send for Gram’s stain and culture sensitivity testing using an array of the commonly used antibiotics. Pathogenic bacteria were isolated from 203 (60.1% samples. Gram negative bacteria were isolated from 79.8 percent (162/203 cases while the rest were Gram positive. Klebsiella species were the commonest (49.2%; 100/203 Gram negative isolates from the sputum samples. Among the gram negative organisms, Carbapenem had the highest sensitivity (90.2% followed by Amikacin, Ciprofloxacin and Piperacillin-Tazobactam. Linezolid was found to be 100 percent sensitive amongst the Gram positive organisms while both Amoxicillin Clavulanate and Azithromycin showed a rather low sensitivity profile overall. 5.0 percent of the Klebsiella infections were multi drug resistant. It was thereby concluded that either Amikacin, Ciprofloxacin or Piperacillin-Tazobactam for be considered for Gram negative organisms and Linezolid be considered for Gram positive organisms as first line antibiotics in empirical therapy while Carbapenems may be kept as reserve drugs should the first line drugs fail.

  3. Strain Dependent Genetic Networks for Antibiotic-Sensitivity in a Bacterial Pathogen with a Large Pan-Genome.

    Directory of Open Access Journals (Sweden)

    Tim van Opijnen

    2016-09-01

    Full Text Available The interaction between an antibiotic and bacterium is not merely restricted to the drug and its direct target, rather antibiotic induced stress seems to resonate through the bacterium, creating selective pressures that drive the emergence of adaptive mutations not only in the direct target, but in genes involved in many different fundamental processes as well. Surprisingly, it has been shown that adaptive mutations do not necessarily have the same effect in all species, indicating that the genetic background influences how phenotypes are manifested. However, to what extent the genetic background affects the manner in which a bacterium experiences antibiotic stress, and how this stress is processed is unclear. Here we employ the genome-wide tool Tn-Seq to construct daptomycin-sensitivity profiles for two strains of the bacterial pathogen Streptococcus pneumoniae. Remarkably, over half of the genes that are important for dealing with antibiotic-induced stress in one strain are dispensable in another. By confirming over 100 genotype-phenotype relationships, probing potassium-loss, employing genetic interaction mapping as well as temporal gene-expression experiments we reveal genome-wide conditionally important/essential genes, we discover roles for genes with unknown function, and uncover parts of the antibiotic's mode-of-action. Moreover, by mapping the underlying genomic network for two query genes we encounter little conservation in network connectivity between strains as well as profound differences in regulatory relationships. Our approach uniquely enables genome-wide fitness comparisons across strains, facilitating the discovery that antibiotic responses are complex events that can vary widely between strains, which suggests that in some cases the emergence of resistance could be strain specific and at least for species with a large pan-genome less predictable.

  4. Sensitive and Simplified Detection of Antibiotic Influence on the Dynamic and Versatile Changes of Fecal Short-Chain Fatty Acids.

    Science.gov (United States)

    Zhao, Xiaoya; Jiang, Zhenzuo; Yang, Fan; Wang, Yan; Gao, Xiumei; Wang, Yuefei; Chai, Xin; Pan, Guixiang; Zhu, Yan

    2016-01-01

    Short-chain fatty acids (SCFAs), produced by anaerobic fermentation of mainly indigestible dietary carbohydrates by gut microbiota, have a profound influence on intestinal function and host energy metabolism. Antibiotics may seriously disturb the balance of fecal SCFAs. To evaluate the impacts of antibiotics on fecal SCFAs produced by gut microbiota, a simple, reproducible and accurate gas chromatography (GC) method, which can simultaneously analyze seven SCFAs in fecal samples, was developed and validated. The ranges of detection and quantitation of the SCFAs reached 0.0868 ~ 0.393 and 0.261 ~ 1.18 μg·mL-1 respectively, in an optimized protocol for SCFAs extraction and analysis that used 10 mL 75% ethanol aqueous solution containing 1% HCl, without ultrasonication. The technique exhibited excellent intra-day (relative standard deviation (RSD) ≤ 2.54%) and inter-day (RSD ≤ 4.33%) precisions for all the SCFAs. Later, we administered broad-spectrum antibiotics, cefdinir or azithromycin to rats and analyzed the alterations in fecal SCFAs. The total amount, types and distribution of nearly all fecal SCFAs were significantly altered during the administration and even after withdrawal of the antibiotics in rats. The effects of cefdinir on the SCFAs were more pronounced than those of azithromycin. Our findings suggest SCFAs may serve as sensitive indicators to monitor the influences of antibiotics on SCFAs originated by intestinal bacteria. Our improved SCFAs analysis method is a potential platform for a standard clinical test of the effects of new antibiotics on SCFAs.

  5. Radiorespirometric testing of antibiotic sensitivity in urinary tract infections: concise communication

    International Nuclear Information System (INIS)

    Singh, K.T.; Ganatra, R.D.; Shah, D.H.; Shanta, M.; Nimbkar, Y.S.; Gaitonde, B.B.; Dudani, R.A.; Jadav, S.K.; Acharya, V.N.

    1980-01-01

    A radiometric method, based on inhibition of 14 CO 2 release from bacterial metabolism of C-14-labeled glucose, was applied to test the susceptibility of urinary organisms to antibiotics. The testing was also carried out by the routine disc diffusion method after isolation of the organisms. Results of susceptibility to antibiotics could be obtained within 2 to 4 hr by the radiometric technique, compared with the 48 hr required for the disc method

  6. Sensitization of Staphylococcus aureus to methicillin and other antibiotics in vitro and in vivo in the presence of HAMLET.

    Directory of Open Access Journals (Sweden)

    Laura R Marks

    Full Text Available HAMLET (human alpha-lactalbumin made lethal to tumor cells is a protein-lipid complex from human milk with both tumoricidal and bactericidal activities. HAMLET exerts a rather specific bactericidal activity against some respiratory pathogens, with highest activity against Streptococcus pneumoniae, but lacks activity against most other bacterial pathogens, including Staphylococci. Still, ion transport associated with death in S. pneumoniae is also detected to a lower degree in insensitive organisms. In this study we demonstrate that HAMLET acts as an antimicrobial adjuvant that can increase the activity of a broad spectrum of antibiotics (methicillin, vancomycin, gentamicin and erythromycin against multi-drug resistant Staphylococcus aureus, to a degree where they become sensitive to those same antibiotics, both in antimicrobial assays against planktonic and biofilm bacteria and in an in vivo model of nasopharyngeal colonization. We show that HAMLET exerts these effects specifically by dissipating the proton gradient and inducing a sodium-dependent calcium influx that partially depolarizes the plasma membrane, the same mechanism induced during pneumococcal death. These effects results in an increased cell associated binding and/or uptake of penicillin, gentamicin and vancomycin, especially in resistant stains. Finally, HAMLET inhibits the increased resistance of methicillin seen under antibiotic pressure and the bacteria do not become resistant to the adjuvant, which is a major advantageous feature of the molecule. These results highlight HAMLET as a novel antimicrobial adjuvant with the potential to increase the clinical usefulness of antibiotics against drug resistant strains of S. aureus.

  7. Sensitization of Staphylococcus aureus to methicillin and other antibiotics in vitro and in vivo in the presence of HAMLET.

    Science.gov (United States)

    Marks, Laura R; Clementi, Emily A; Hakansson, Anders P

    2013-01-01

    HAMLET (human alpha-lactalbumin made lethal to tumor cells) is a protein-lipid complex from human milk with both tumoricidal and bactericidal activities. HAMLET exerts a rather specific bactericidal activity against some respiratory pathogens, with highest activity against Streptococcus pneumoniae, but lacks activity against most other bacterial pathogens, including Staphylococci. Still, ion transport associated with death in S. pneumoniae is also detected to a lower degree in insensitive organisms. In this study we demonstrate that HAMLET acts as an antimicrobial adjuvant that can increase the activity of a broad spectrum of antibiotics (methicillin, vancomycin, gentamicin and erythromycin) against multi-drug resistant Staphylococcus aureus, to a degree where they become sensitive to those same antibiotics, both in antimicrobial assays against planktonic and biofilm bacteria and in an in vivo model of nasopharyngeal colonization. We show that HAMLET exerts these effects specifically by dissipating the proton gradient and inducing a sodium-dependent calcium influx that partially depolarizes the plasma membrane, the same mechanism induced during pneumococcal death. These effects results in an increased cell associated binding and/or uptake of penicillin, gentamicin and vancomycin, especially in resistant stains. Finally, HAMLET inhibits the increased resistance of methicillin seen under antibiotic pressure and the bacteria do not become resistant to the adjuvant, which is a major advantageous feature of the molecule. These results highlight HAMLET as a novel antimicrobial adjuvant with the potential to increase the clinical usefulness of antibiotics against drug resistant strains of S. aureus.

  8. Improved sensitivity of nucleic acid amplification for rapid diagnosis of tuberculous meningitis

    DEFF Research Database (Denmark)

    Johansen, Isik Somuncu; Lundgren, Bettina; Tabak, Fehmi

    2004-01-01

    was adjusted from the recommended value of 3,400 to 1,000, the sensitivity of the modified procedure increased to 84.7%, with unchanged specificity. Results were obtained in 3 to 4 h. The new pretreatment procedure with the ProbeTec assay described here provides a rapid, simple, and sensitive tool...

  9. Comparative assessment of antibiotic susceptibility of coagulase-negative staphylococci in biofilm versus planktonic culture as assessed by bacterial enumeration or rapid XTT colorimetry.

    Science.gov (United States)

    Cerca, Nuno; Martins, Silvia; Cerca, Filipe; Jefferson, Kimberly K; Pier, Gerald B; Oliveira, Rosário; Azeredo, Joana

    2005-08-01

    To quantitatively compare the antibiotic susceptibility of biofilms formed by the coagulase-negative staphylococci (CoNS) Staphylococcus epidermidis and Staphylococcus haemolyticus with the susceptibility of planktonic cultures. Several CoNS strains were grown planktonically or as biofilms to determine the effect of the mode of growth on the level of susceptibility to antibiotics with different mechanisms of action. The utility of a new, rapid colorimetric method that is based on the reduction of a tetrazolium salt (XTT) to measure cell viability was tested by comparison with standard bacterial enumeration techniques. A 6 h kinetic study was performed using dicloxacillin, cefazolin, vancomycin, tetracycline and rifampicin at the peak serum concentration of each antibiotic. In planktonic cells, inhibitors of cell wall synthesis were highly effective over a 3 h period. Biofilms were much less susceptible than planktonic cultures to all antibiotics tested, particularly inhibitors of cell wall synthesis. The susceptibility to inhibitors of protein and RNA synthesis was affected by the biofilm phenotype to a lesser degree. Standard bacterial enumeration techniques and the XTT method produced equivalent results both in biofilms and planktonic assays. This study provides a more accurate comparison between the antibiotic susceptibilities of planktonic versus biofilm populations, because the cell densities in the two populations were similar and because we measured the concentration required to inhibit bacterial metabolism rather than to eradicate the entire bacterial population. While the biofilm phenotype is highly resistant to antibiotics that target cell wall synthesis, it is fairly susceptible to antibiotics that target RNA and protein synthesis.

  10. Field evaluation of a rapid point-of-care assay for targeting antibiotic treatment for trachoma control: a comparative study.

    Science.gov (United States)

    Michel, Claude-Edouard C; Solomon, Anthony W; Magbanua, Jose P V; Massae, Patrick A; Huang, Ling; Mosha, Jonaice; West, Sheila K; Nadala, Elpidio C B; Bailey, Robin; Wisniewski, Craig; Mabey, David C W; Lee, Helen H

    2006-05-13

    Trachoma results from repeated episodes of conjunctival infection with Chlamydia trachomatis and is the leading infectious cause of blindness. To eliminate trachoma, control programmes use the SAFE strategy (Surgery, Antibiotics, Face cleanliness, and Environmental improvement). The A component is designed to treat C trachomatis infection, and is initiated on the basis of the prevalence of the clinical sign trachomatous inflammation-follicular (TF). Unfortunately, TF correlates poorly with C trachomatis infection. We sought to assess a newly developed point-of-care (POC) assay compared with presence of TF for guiding the use of antibiotics for trachoma control. We compared performance outcomes of the POC assay and presence of TF using commercial PCR as a comparator in 664 children aged 1-9 years in remote, trachoma-endemic villages in Tanzania. Signs of trachoma were graded according to the WHO simplified trachoma grading system. Of 664 participants, 128 (19%) were positive for ocular C trachomatis infection by PCR. Presence of TF had a sensitivity of 64.1% (95% CI 55.8-72.4), specificity of 80.2% (76.8-83.6), and positive predictive value of 43.6% (36.5-50.7). By contrast, the POC assay had a sensitivity of 83.6% (77.2-90.0), specificity of 99.4% (98.8-100.0), and positive predictive value of 97.3% (94.2-100.3). Interagreements and intra-agreements between four novice operators were 0.988 (0.973-1.000) and 0.950 (0.894-1.000), respectively. The POC assay is substantially more accurate than TF prevalence in identifying the presence or absence of infection. Additional studies should assess the use of the assay in the planning and monitoring of trachoma control activities.

  11. A Highly Sensitive Rapid Diagnostic Test for Chagas Disease That Utilizes a Recombinant Trypanosoma cruzi Antigen

    Science.gov (United States)

    Barfield, C. A.; Barney, R. S.; Crudder, C. H.; Wilmoth, J. L.; Stevens, D. S.; Mora-Garcia, S.; Yanovsky, M. J.; Weigl, B. H.; Yanovsky, J.

    2011-01-01

    Improved diagnostic tests for Chagas disease are urgently needed. A new lateral flow rapid test for Chagas disease is under development at PATH, in collaboration with Laboratorio Lemos of Argentina, which utilizes a recombinant antigen for detection of antibodies to Trypanosoma cruzi. To evaluate the performance of this test, 375 earlier characterized serum specimens from a region where Chagas is endemic were tested using a reference test (the Ortho T. cruzi ELISA, Johnson & Johnson), a commercially available rapid test (Chagas STAT-PAK, Chembio), and the PATH–Lemos rapid test. Compared to the composite reference tests, the PATH–Lemos rapid test demonstrated an optimal sensitivity of 99.5% and specificity of 96.8%, while the Chagas STAT-PAK demonstrated a sensitivity of 95.3% and specificity of 99.5%. These results indicate that the PATH–Lemos rapid test shows promise as an improved and reliable tool for screening and diagnosis of Chagas disease. PMID:21342808

  12. Polypyrrole solid phase microextraction: A new approach to rapid sample preparation for the monitoring of antibiotic drugs

    International Nuclear Information System (INIS)

    Szultka, Malgorzata; Kegler, Ricarda; Fuchs, Patricia; Olszowy, Pawel; Miekisch, Wolfram; Schubert, Jochen K.; Buszewski, Boguslaw; Mundkowski, Ralf G.

    2010-01-01

    Simple or even rapid bioanalytical methods are rare, since they generally involve complicated, time-consuming sample preparation from the biological matrices like LLE or SPE. SPME provides a promising approach to overcome these limitations. The full potential of this innovative technique for medical diagnostics, pharmacotherapy or biochemistry has not been tapped yet. In-house manufactured SPME probes with polypyrrole (PPy) coating were evaluated using three antibiotics of high clinical relevance - linezolid, daptomycin, and moxifloxacin - from PBS, plasma, and whole blood. The PPy coating was characterised by scanning electron microscopy. Influences of pH, inorganic salt, and blood anticoagulants were studied for optimum performance. Extraction yields were determined from stagnant media as well as re-circulating human blood using the heart-and-lung machine model system. The PPy-SPME fibres showed high extraction yields, particularly regarding linezolid. The reproducibility of the method was optimised to achieve RSDs of 9% or 17% and 7% for SPME from stagnant or re-circulating blood using fresh and re-used fibres, respectively. The PPy-SPME approach was demonstrated to meet the requirements of therapeutic monitoring of the drugs tested, even from re-circulating blood at physiological flow rates. SPME represents a rapid and simple dual-step procedure with potency to significantly reduce the effort and expenditure of complicated sample preparations in biomedical analysis.

  13. Polypyrrole solid phase microextraction: A new approach to rapid sample preparation for the monitoring of antibiotic drugs

    Energy Technology Data Exchange (ETDEWEB)

    Szultka, Malgorzata [Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus, Copernicus University, Gagarin 7, 87-100 Torun (Poland); Kegler, Ricarda [Institute of Clinical Pharmacology, University of Rostock, Schillingallee 70, D-18057 Rostock (Germany); Fuchs, Patricia [Department of Anaesthesia and Intensive Care, University of Rostock, Schillingallee 35, D-18057 Rostock (Germany); Olszowy, Pawel [Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus, Copernicus University, Gagarin 7, 87-100 Torun (Poland); Miekisch, Wolfram; Schubert, Jochen K. [Department of Anaesthesia and Intensive Care, University of Rostock, Schillingallee 35, D-18057 Rostock (Germany); Buszewski, Boguslaw [Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus, Copernicus University, Gagarin 7, 87-100 Torun (Poland); Mundkowski, Ralf G., E-mail: ralf.mundkowski@med.uni-rostock.de [Institute of Clinical Pharmacology, University of Rostock, Schillingallee 70, D-18057 Rostock (Germany)

    2010-05-14

    Simple or even rapid bioanalytical methods are rare, since they generally involve complicated, time-consuming sample preparation from the biological matrices like LLE or SPE. SPME provides a promising approach to overcome these limitations. The full potential of this innovative technique for medical diagnostics, pharmacotherapy or biochemistry has not been tapped yet. In-house manufactured SPME probes with polypyrrole (PPy) coating were evaluated using three antibiotics of high clinical relevance - linezolid, daptomycin, and moxifloxacin - from PBS, plasma, and whole blood. The PPy coating was characterised by scanning electron microscopy. Influences of pH, inorganic salt, and blood anticoagulants were studied for optimum performance. Extraction yields were determined from stagnant media as well as re-circulating human blood using the heart-and-lung machine model system. The PPy-SPME fibres showed high extraction yields, particularly regarding linezolid. The reproducibility of the method was optimised to achieve RSDs of 9% or 17% and 7% for SPME from stagnant or re-circulating blood using fresh and re-used fibres, respectively. The PPy-SPME approach was demonstrated to meet the requirements of therapeutic monitoring of the drugs tested, even from re-circulating blood at physiological flow rates. SPME represents a rapid and simple dual-step procedure with potency to significantly reduce the effort and expenditure of complicated sample preparations in biomedical analysis.

  14. Bacteriological Study of 100 Cases of Pyodermas with Special Reference to Staphylococci, Their Antibiotic Sensitivity and Phage Pattern

    Directory of Open Access Journals (Sweden)

    T V Ramani

    1980-01-01

    Full Text Available One hundred new cases of pyodenna attending King George Hospital, Vishakhapatnam were investigated bacteriologically with antibiotic sensitivity of all the strains isolated and phage typing of coagulm positive staphylocci. Among these 50 had impetigo and 15 each ahd furunculosis and fouiculitis. The remaining included various other clinical entities. Children under 10 years were observed to have high incidence of pyoderma. A total of 88 strains of staphylococci (77 coagulase positive and 11 coagulase negative strains 25 strains of beta haemolytic streptococci and 3 strains of Klebsiella were isolated. Staphylococci were found to be the commonest aetiological agents either single or in association with other organisms. Of the 76 strains of coagulase positive staphylococci 32 strains were not phage typable and among the 44 typable strains 17 (38% belonged to group III and 15 (36.5% to mixed group. Coagulase positive staphylococci showed high sensitivity to garamycin, kanamycin and erythromycin and high resistance to penicillin and streptomycin. Multiple drug resistance was also high among these strains. Coagulase negative staphylococci were found to be more sensitive with less incidence of multiple drug resistance. Most of multiple drug resistant strains belonged to group III phage types. Beta haemolytic streptococci were found to be highly sensitive to all the antibiotics tested.

  15. The sensitivities to first-line antibiotic therapy of the common urinary ...

    African Journals Online (AJOL)

    Background: Urinary tract infections (UTIs) are among the most common human infections. Many urinary tract bacteria are capable of expressing drug resistance. Resistant bacteria may be present from the commencement of the infection or may develop during treatment. This study focused on the problem of antibiotic ...

  16. Serine Protease Zymography: Low-Cost, Rapid, and Highly Sensitive RAMA Casein Zymography.

    Science.gov (United States)

    Yasumitsu, Hidetaro

    2017-01-01

    To detect serine protease activity by zymography, casein and CBB stain have been used as a substrate and a detection procedure, respectively. Casein zymography has been using substrate concentration at 1 mg/mL and employing conventional CBB stain. Although ordinary casein zymography provides reproducible results, it has several disadvantages including time-consuming and relative low sensitivity. Improved casein zymography, RAMA casein zymography, is rapid and highly sensitive. RAMA casein zymography completes the detection process within 1 h after incubation and increases the sensitivity at least by tenfold. In addition to serine protease, the method also detects metalloprotease 7 (MMP7, Matrilysin) with high sensitivity.

  17. Study of Pre-disposing Factors of Acute Exacerbation of Chronic Obstructive Pulmonary Disease and Antibiotic Prescribing Pattern with Reference to Antibiotic Sensitivity Test.

    Science.gov (United States)

    Shrestha, R; Shrestha, B; Shakya Shrestha, S; Pant, A; Prajapati, B; Karmacharya, B M

    2015-01-01

    Background Chronic Obstructive Pulmonary Disease (COPD) affects about 329 million people worldwide, which is nearly 5% of the entire global population. In the context of Nepal, COPD accounts for 43% of the non-communicable disease burden and 2.56% of hospitalizations. Various pre-disposing factors like bacterial, viral, fungal, smoking, occupational exposures and genetic factors have been proposed to precipitate COPD and its exacerbation though, the definitive pre-disposing factors and factors related to acute exacerbation have not been determined in the context of Nepal. Objective To find out the pre-disposing factors and the related causative agents for COPD. Method A cross sectional study was conducted in a tertiary care hospital. Patients of all age group who were diagnosed as COPD and admitted in the hospital were included in this study. Patients were interviewed using structured questionnaire. The sociodemographic data including personal and medical history were recorded from those participants. In addition, sputum from those patients was sent for culture to investigate the possible responsible pathogens as well as its antibiotic sensitivity pattern. Result A total of 150 patients having Acute Exacerbation of Chronic Obstructive Pulmonary Disease (AECOPD) who have admitted from either emergency or out-patient department of the hospital were included in this study. Among the total number of patients, more than half of them were female (n=82). In addition, analysis of occupations shows that most of them were either farmer (36.0%) or housewife (30.7%). In total studied patients (n=150), most of them were using traditional firewood (83%) for cooking purpose and majority of patients (91%) were smokers. Most of the sputum samples show growth of gram-positive cocci (26.7%) and gram negative bacilli (27.5%). Considering the overall sensitivity pattern, the higher sensitivity was recorded for Co-trimoxazole and Ciprofloxacin while higher rate of resistance was noted

  18. When rapid adaptation paradigm is not too rapid: Evidence of face-sensitive N170 adaptation effects.

    Science.gov (United States)

    Tian, Tengxiang; Feng, Xue; Feng, Chunliang; Gu, Ruolei; Luo, Yue-Jia

    2015-07-01

    Recent findings have demonstrated that N170 adaptation effects evoked by face adaptors are general to face and non-face tests, implicating adaptor-locked interferences in the rapid adaptation paradigm. Here we examined the extent to which adaptor-locked interferences confound N170 adaptation effects in different experimental parameters by manipulating the stimulus onset asynchrony (SOA) duration and jitter between adaptors and tests. In the short SOA, those interferences were well visible for the grand-average ERP waveforms evoked by tests, and they are likely to render rapid adaptation paradigm with short SOA unreliable. The adaptor-locked interferences were attenuated by appropriately increasing SOA duration, such that face-sensitive adaptation effects were evident in the long SOA for both baseline-to-peak and peak-to-peak N170 measurements. These findings suggest that the rapid adaptation paradigm may work with a relative long SOA. Our findings provide useful information for future studies regarding the choosing of appropriate experimental parameters and measurements for the rapid adaptation paradigm. In addition, future studies are needed to investigate how to objectively subtract the overlaps of adaptors from tests and to validate the N170 adaptation effect with appropriate behavioral performance. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Sensitive rapid analysis of iodine-labelled protein mixture on flat substrates with high spatial resolution

    International Nuclear Information System (INIS)

    Zanevskij, Yu.V.; Ivanov, A.B.; Movchan, S.A.; Peshekhonov, V.D.; Chan Dyk Tkhan'; Chernenko, S.P.; Kaminir, L.B.; Krejndlin, Eh.Ya.; Chernyj, A.A.

    1983-01-01

    Usability of rapid analysis by electrophoresis of the admixture of I 125 -labelled proteins on flat samples by means of URAN type installation developed using a multiwire proportional chamber is studied. The sensitivity of the method is better than 200 cpm/cm 2 and the spatial resolution is approximately 1 mm. The procedure of the rapid analysis is no longer than several tens of minutes

  20. Ammonia produced by bacterial colonies promotes growth of ampicillin-sensitive Serratia sp. by means of antibiotic inactivation.

    Science.gov (United States)

    Cepl, Jaroslav; Blahůšková, Anna; Cvrčková, Fatima; Markoš, Anton

    2014-05-01

    Volatiles produced by bacterial cultures are known to induce regulatory and metabolic alterations in nearby con-specific or heterospecific bacteria, resulting in phenotypic changes including acquisition of antibiotic resistance. We observed unhindered growth of ampicillin-sensitive Serratia rubidaea and S. marcescens on ampicillin-containing media, when exposed to volatiles produced by dense bacterial growth. However, this phenomenon appeared to result from pH increase in the medium caused by bacterial volatiles rather than alterations in the properties of the bacterial cultures, as alkalization of ampicillin-containing culture media to pH 8.5 by ammonia or Tris exhibited the same effects, while pretreatment of bacterial cultures under the same conditions prior to antibiotic exposure did not increase ampicillin resistance. Ampicillin was readily inactivated at pH 8.5, suggesting that observed bacterial growth results from metabolic alteration of the medium, rather than an active change in the target bacterial population (i.e. induction of resistance or tolerance). However, even such seemingly simple mechanism may provide a biologically meaningful basis for protection against antibiotics in microbial communities growing on semi-solid media. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  1. Clinical score and rapid antigen detection test to guide antibiotic use for sore throats: randomised controlled trial of PRISM (primary care streptococcal management).

    Science.gov (United States)

    Little, Paul; Hobbs, F D Richard; Moore, Michael; Mant, David; Williamson, Ian; McNulty, Cliodna; Cheng, Ying Edith; Leydon, Geraldine; McManus, Richard; Kelly, Joanne; Barnett, Jane; Glasziou, Paul; Mullee, Mark

    2013-10-10

    To determine the effect of clinical scores that predict streptococcal infection or rapid streptococcal antigen detection tests compared with delayed antibiotic prescribing. Open adaptive pragmatic parallel group randomised controlled trial. Primary care in United Kingdom. Patients aged ≥ 3 with acute sore throat. An internet programme randomised patients to targeted antibiotic use according to: delayed antibiotics (the comparator group for analyses), clinical score, or antigen test used according to clinical score. During the trial a preliminary streptococcal score (score 1, n=1129) was replaced by a more consistent score (score 2, n=631; features: fever during previous 24 hours; purulence; attends rapidly (within three days after onset of symptoms); inflamed tonsils; no cough/coryza (acronym FeverPAIN). Symptom severity reported by patients on a 7 point Likert scale (mean severity of sore throat/difficulty swallowing for days two to four after the consultation (primary outcome)), duration of symptoms, use of antibiotics. For score 1 there were no significant differences between groups. For score 2, symptom severity was documented in 80% (168/207 (81%) in delayed antibiotics group; 168/211 (80%) in clinical score group; 166/213 (78%) in antigen test group). Reported severity of symptoms was lower in the clinical score group (-0.33, 95% confidence interval -0.64 to -0.02; P=0.04), equivalent to one in three rating sore throat a slight versus moderate problem, with a similar reduction for the antigen test group (-0.30, -0.61 to -0.00; P=0.05). Symptoms rated moderately bad or worse resolved significantly faster in the clinical score group (hazard ratio 1.30, 95% confidence interval 1.03 to 1.63) but not the antigen test group (1.11, 0.88 to 1.40). In the delayed antibiotics group, 75/164 (46%) used antibiotics. Use of antibiotics in the clinical score group (60/161) was 29% lower (adjusted risk ratio 0.71, 95% confidence interval 0.50 to 0.95; P=0.02) and in the

  2. Differential sensitivity of pigmented and non-pigmented marine bacteria to metals and antibiotics

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, S.; Chandramohan, D.; LokaBharathi, P.A.

    . Appl. em'ir. Microbiol. 33, 975-976. Nelson J. D. Jr and Colwell R. R. (1975) The ecology of mercury resistant bacteria in Chesapeake bay. Microbioi. Ecol. 1, 191-218. Oison B. H. and Thornton I. (1982) The resistance patterns to metals... to metals em- ploying epifluorescent microscopy. J. microbiol. Met& 7, 143-155. Zemelman R., Silva J. and Herriques, M. (1980) Antibiotic resistant bacteria in seawater from Concepcion Bay. Archs Biol. Exp. 13, 121. ...

  3. Factors influencing antibiotic prescribing habits and use of sensitivity testing amongst veterinarians in Europe

    OpenAIRE

    De Briyne, N.; Atkinson, J.; Pokludov?, L.; Borriello, S. P.; Price, S.

    2013-01-01

    The Heads of Medicines Agencies and the Federation of Veterinarians of Europe undertook a survey to gain a better insight into the decision-making process of veterinarians in Europe when deciding which antibiotics to prescribe. The survey was completed by 3004 practitioners from 25 European countries. Analysis was to the level of different types of practitioner (food producing (FP) animals, companion animals, equines) and country for Belgium, Czech Republic, France, Germany, Spain, Sweden and...

  4. Repeat Rifaximin for Irritable Bowel Syndrome: No Clinically Significant Changes in Stool Microbial Antibiotic Sensitivity.

    Science.gov (United States)

    Pimentel, M; Cash, B D; Lembo, A; Wolf, R A; Israel, R J; Schoenfeld, P

    2017-09-01

    Rifaximin has demonstrated efficacy and safety for diarrhea-predominant irritable bowel syndrome (IBS-D). To determine the rifaximin repeat treatment effect on fecal bacterial antibiotic susceptibility. Patients with IBS in Trial 3 (TARGET 3) study who responded to open-label rifaximin 550 mg three times daily for 2 weeks, with symptom recurrence within 18 weeks, were randomized to double-blind treatment: two 2-week repeat courses of rifaximin or placebo, separated by 10 weeks. Prospective stool sample collection occurred before and after open-label rifaximin, before and after the first repeat course, and at the end of the study. Susceptibility testing was performed with 11 antibiotics, including rifaximin and rifampin, using broth microdilution or agar dilution methods. Of 103 patients receiving open-label rifaximin, 73 received double-blind rifaximin (n = 37) or placebo (n = 36). A total of 1429 bacterial and yeast isolates were identified, of which Bacteroidaceae (36.7%) and Enterobacteriaceae (33.9%) were the most common. In the double-blind phase, Clostridium difficile was highly susceptible to rifaximin [minimum inhibitory concentration (MIC) range 0.008-1 µg/mL] and rifampin (MIC range 0.004-0.25 µg/mL). Following double-blind rifaximin treatment, Staphylococcus isolates remained susceptible to rifaximin at all visits (MIC 50 range ≤0.06-32 µg/mL). Rifaximin exposure was not associated with long-term cross-resistance of Bacteroidaceae, Enterobacteriaceae, and Enterococcaceae to rifampin or nonrifamycin antibiotics tested. In this study, short-term repeat treatment with rifaximin has no apparent long-term effect on stool microbial susceptibility to rifaximin, rifampin, and nonrifamycin antibiotics. CLINICALTRIALS. NCT01543178.

  5. RESEARCH IN SENSITIVITY TO ANTIBIOTICS, ANTISEPTICS IN PSEUDOMONAS AERUGINOSA STRAINS ISOLATED FROM PATIENTS WITH INFECTIOUS COMPLICATIONS

    OpenAIRE

    O. A. Nazarchuk; D. V. Paliy; N. I. Osadchuk

    2017-01-01

    Background. Infections caused by Pseudomonas are one of the topical issues of medicine. Objective. The aim of the research was to study sensityvity to antibiotics, antiseptics of P. aeruginosa clinical strains that cause infectious complications in patients with burns. Methods. Microbiological study of biological material, received from 435 patients with burns of the 3rd-4th stages (2011-2015 years). In early terms of burn disease 127 clinical strains of P. aeruginosa were isolated fr...

  6. Effects of temperature, genetic variation and species competition on the sensitivity of algae populations to the antibiotic enrofloxacin.

    Science.gov (United States)

    Rico, Andreu; Zhao, Wenkai; Gillissen, Frits; Lürling, Miquel; Van den Brink, Paul J

    2018-02-01

    Primary producers are amongst the most sensitive organisms to antibiotic pollution in aquatic ecosystems. To date, there is little information on how different environmental conditions may affect their sensitivity to antibiotics. In this study we assessed how temperature, genetic variation and species competition may affect the sensitivity of the cyanobacterium Microcystis aeruginosa and the green-algae Scenedesmus obliquus to the antibiotic enrofloxacin. First, we performed single-species tests to assess the toxicity of enrofloxacin under different temperature conditions (20°C and 30°C) and to assess the sensitivity of different species strains using a standard temperature (20°C). Next, we investigated how enrofloxacin contamination may affect the competition between M. aeruginosa and S. obliquus. A competition experiment was performed following a full factorial design with different competition treatments, defined as density ratios (i.e. initial bio-volume of 25/75%, 10/90% and 1/99% of S. obliquus/M. aeruginosa, respectively), one 100% S. obliquus treatment and one 100% M. aeruginosa treatment, and four different enrofloxacin concentrations (i.e. control, 0.01, 0.05 and 0.10mg/L). Growth inhibition based on cell number, bio-volume, chlorophyll-a concentration as well as photosynthetic activity were used as evaluation endpoints in the single-species tests, while growth inhibition based on measured chlorophyll-a was primarily used in the competition experiment. M. aeruginosa photosynthetic activity was found to be the most sensitive endpoint to enrofloxacin (EC50-72h =0.02mg/L), followed by growth inhibition based on cell number. S. obliquus was found to be slightly more sensitive at 20°C than at 30°C (EC50-72h cell number growth inhibition of 38 and 41mg/L, respectively), whereas an opposite trend was observed for M. aeruginosa (0.047 and 0.037mg/L, respectively). Differences in EC50-72h values between algal strains of the same species were within a factor

  7. The sensitivity to antibiotics of strains of group B streptococcus isolates from pregnant women in Belgrade

    Directory of Open Access Journals (Sweden)

    Jovanović Luka

    2016-01-01

    Full Text Available Introduction: Group B streptococcus (GBS is a significant human pathogen. GBS colonizes the vagina and it is one of the most important causes of early neonatal sepsis and meningitis. In many countries, screening of pregnant women and intrapartal use of antibiotics are common practice. Macrolide and lincosamide resistant strains of GBS are a significant problem, because these antibiotics are the second line therapy in case of penicillin allergy. Aim: Our aim was to investigate the frequency of antibiotic resistant strains of GBS and to detect macrolide resistance phenotypes in GBS strains obtained from pregnant women in Belgrade. Material and Methods: 105 GBS isolates were obtained from vaginal swabs of pregnant women attending two Gynecology and Obstetrics Centers in Belgrade. The isolates were tested for antimicrobial susceptibility pattern and D test were performed on Mueller Hinton agar. Results: Macrolide and lincosamide resistance was found in 30.4 %, and 23.8 % of isolates, respectively. There was a high frequency of tetracycline resistant strains (88.6 %. Most frequent macrolide resistant phenotype was iMLSb (macrolide and inducibile lincosamide resistance (62.4%. Conclusion: The results of our study indicate that there is a high level of macrolide resistance among GBS isolates in Serbia and the active surveillance is needed.

  8. Species-specific sensitivity of coagulase-negative Staphylococci to single antibiotics and their combinations.

    Science.gov (United States)

    Szymańska, Grazyna; Szemraj, Magdalena; Szewczyk, Eligia M

    2011-01-01

    The activity of beta-lactam antibiotics (oxacillin, cloxacillin, cephalotin), vancomycin, gentamicin and rifampicin applied in vitro individually and in combination against 37 nosocomial methicillin-resistant strains of coagulase-negative staphylococci (CNS) was assessed to demonstrate the heterogeneity of this group of bacteria and estimate the chance of the efficacy of such therapy. The strains belonged to four species: Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus cohnii, Staphylococcus hominis. They originated from a hospital environment and from the skin of medical staff of the intensive care unit of a paediatric ward at a university hospital. All strains were methicillin-resistant, according to CLSI standards, but individual strains differed in MIC(ox) values. Susceptibility to other tested antibiotics was also characteristic for the species. The increased susceptibility to antibiotics in combinations, tested by calculating the fractional inhibitory concentration (FIC) index, concerned 26 out of 37 investigated strains and it was a feature of a particular species. Combinations of vancomycin and cephalotin against S. epidermidis and oxacillin with vancomycin were significant, as well as cephalotin and rifampicin in growth inhibition of multiresistant S. haemolyticus strains.

  9. Surgical site infection in orthopedic implants and its common bacteria with their sensitivities to antibiotics, in open reduction internal fixation

    International Nuclear Information System (INIS)

    Shah, M.Q.; Zardad, M.S.; Khan, A.; Ahmed, S.; Awan, A. S.; Mohammad, T.

    2017-01-01

    Surgical site infection in orthopaedic implants is a major problem, causing long hospital stay, cost to the patient and is a burden on health care facilities. It increases rate of non-union, osteomyelitis, implant failure, sepsis, multiorgan dysfunction and even death. Surgical site infection is defined as pain, erythema, swelling and discharge from wound site. Surgical site infection in orthopaedic implants is more challenging to the treating orthopaedic surgeon as the causative organism is protected by a biofilm over the implant's surface. Antibiotics cannot cross this film to reach the bacteria's, causing infection. Method: This descriptive case series study includes 132 patients of both genders with ages between 13 years to 60 years conducted at Orthopaedic Unit, Ayub Medical College, Abbottabad from 1st October 2015 to 31st March 2016. Patients with close fractures of long bones were included in the study to determine the frequency of surgical site infection in orthopaedic implants and the type of bacteria involved and their sensitivity to various antibiotics. All implants were of stainless steel. The implants used were Dynamic hip screws, Dynamic compression screws, plates, k-wires, Interlocking nails, SIGN nails, Austin Moore prosthesis and tension band wires. Pre-op and post-op antibiotics used were combination of Sulbactum and Cefoperazone which was given 1 hour before surgery and continued for 72 hours after surgery. Patients were followed up to 4 weeks. Pus was taken on culture stick, from those who developed infection. Results were entered in the pro forma. Results: A total of 132 patients of long bone fractures, who were treated with open reduction and internal fixation, were studied. Only 7 patients developed infection. Staphylococcus Aureus was isolated from all 7 patients. Staphylococcus aureus was sensitive to Linezolid, Fusidic Acid, and vancomycin. Cotrimoxazole, tetracycline, Gentamycin and Clindamycin were partially effective. Conclusion

  10. Association of Pattern of Bacteria Sensitivity During the Empirical Antibiotics Use to the Achievement of Clinical Outcome in Pediatric Patients with Pneumonia

    Directory of Open Access Journals (Sweden)

    Vesara A. Gatera

    2014-12-01

    Full Text Available Pneumonia is one of infectious diseases that require a comprehensive and effective effort in its treatment, including in the use of empirical antibiotics. The use of empirical antibiotics should be based on patterns of sensitivity toward bacteria. The aim of this study was to evaluate the use of antibiotics based on the sensitivity patterns by clinical outcomes as the goal of treatment. This study was conducted in Hasan Sadikin Hospital Bandung in October–December 2013 using a retrospective cross-sectional study design. Secondary data were obtained from medical records during January 2011–December 2012. This study consisted of 24 patients with positive culture test and received antibiotic prescription. The results showed the percentage of the use of cefotaxime-ampicillin (37.5%, cefotaxime (33.3%, ceftriaxone (20.8%, and Ampicillin (8.4%. The most influential antibiotics for achieving clinical outcome using 95% confidence level is combination of cefotaxime-ampiciline (P=0.044 with 77.7% sensitivity level. This study suggested that the pattern of antibiotic sensitivity affected the clinical outcomes of pediatric patients with pneumonia.

  11. Rapid and sensitive enzymatic-radiochemical assay for the determination of triglycerides

    International Nuclear Information System (INIS)

    Khoo, J.C.; Miller, E.; Goldberg, D.I.

    1987-01-01

    An enzymatic-radiochemical method suitable for the determination of triglyceride levels of cells in culture is described. The method is based on the enzymatic hydrolysis of triglycerides to free fatty acids which then complex with 63 Ni. The method is rapid, accurate, and inexpensive. The procedure extends the sensitivity of triglyceride measurement to as low as 0.25 nanomoles

  12. The ion-sensitive field effect transistor in rapid acid-base titrations

    NARCIS (Netherlands)

    Bos, M.; Bergveld, Piet; van Veen-Blaauw, A.M.W.

    1979-01-01

    Ion-sensitive field effect transistors (ISFETs) are used as the pH sensor in rapid acid—base titrations. Titration speeds at least five times greater than those with glass electrodes are possible for accuracies better than ±1%.

  13. Sensitive and rapid immunoassay for parathyroid hormone using magnetic particle labels and magnetic actuation

    NARCIS (Netherlands)

    Dittmer, W.U.; Kievit, de P.; Prins, M.W.J.; Vissers, J.L.M.; Mersch, M.E.C.; Martens, M.F.W.C.

    2008-01-01

    A rapid method for the sensitive detection of proteins using actuated magnetic particle labels, which are measured with a giant magneto-resistive (GMR) biosensor, is described. The technique involves a 1-step sandwich immunoassay with no fluid replacement steps. The various assay binding reactions

  14. In Vitro Sensitivity Test in Antibiotics from the Fermentation Process in a Sugar-Alcohol Plant in the State of Paraná, Brazil

    OpenAIRE

    Lopes, Murilo Brandão; Faculdade de Apucarana – FAP; Silva, Thaís Medeiros Boldrin; Faculdade Metropolitana de Maringá – UNIFAMMA

    2011-01-01

    Since the development of different types of microorganisms is common during the fermentation process in sugar-alcohol plants, due to the processing states of prime matter, microbiological control is mandatory. In vitro sensitivity test is highly important for the fermentation process at sugar-alcohol plants since the type of antibiotic with the best antibacterial activity is evaluated. The test classifies antibiotics through their effects, namely, efficient, less efficient, slightly efficient...

  15. Characterization of the rapid transcriptional response to long-term sensitization training in Aplysia californica.

    Science.gov (United States)

    Herdegen, Samantha; Holmes, Geraldine; Cyriac, Ashly; Calin-Jageman, Irina E; Calin-Jageman, Robert J

    2014-12-01

    We used a custom-designed microarray and quantitative PCR to characterize the rapid transcriptional response to long-term sensitization training in the marine mollusk Aplysia californica. Aplysia were exposed to repeated noxious shocks to one side of the body, a procedure known to induce a long-lasting, transcription-dependent increase in reflex responsiveness that is restricted to the side of training. One hour after training, pleural ganglia from the trained and untrained sides of the body were harvested; these ganglia contain the sensory nociceptors which help mediate the expression of long-term sensitization memory. Microarray analysis from 8 biological replicates suggests that long-term sensitization training rapidly regulates at least 81 transcripts. We used qPCR to test a subset of these transcripts and found that 83% were confirmed in the same samples, and 86% of these were again confirmed in an independent sample. Thus, our new microarray design shows strong convergent and predictive validity for analyzing the transcriptional correlates of memory in Aplysia. Fully validated transcripts include some previously identified as regulated in this paradigm (ApC/EBP and ApEgr) but also include novel findings. Specifically, we show that long-term sensitization training rapidly up-regulates the expression of transcripts which may encode Aplysia homologs of a C/EBPγ transcription factor, a glycine transporter (GlyT2), and a vacuolar-protein-sorting-associated protein (VPS36). Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Highly sensitive multianalyte immunochromatographic test strip for rapid chemiluminescent detection of ractopamine and salbutamol

    International Nuclear Information System (INIS)

    Gao, Hongfei; Han, Jing; Yang, Shijia; Wang, Zhenxing; Wang, Lin; Fu, Zhifeng

    2014-01-01

    Graphical abstract: A multianalyte immunochromatographic test strip was developed for the rapid detection of two β 2 -agonists. Due to the application of chemiluminescent detection, this quantitative method shows much higher sensitivity. - Highlights: • An immunochromatographic test strip was developed for detection of multiple β 2 -agonists. • The whole assay process can be completed within 20 min. • The proposed method shows much higher sensitivity due to the application of CL detection. • It is a portable analytical tool suitable for field analysis and rapid screening. - Abstract: A novel immunochromatographic assay (ICA) was proposed for rapid and multiple assay of β 2 -agonists, by utilizing ractopamine (RAC) and salbutamol (SAL) as the models. Owing to the introduction of chemiluminescent (CL) approach, the proposed protocol shows much higher sensitivity. In this work, the described ICA was based on a competitive format, and horseradish peroxidase-tagged antibodies were used as highly sensitive CL probes. Quantitative analysis of β 2 -agonists was achieved by recording the CL signals of the probes captured on the two test zones of the nitrocellulose membrane. Under the optimum conditions, RAC and SAL could be detected within the linear ranges of 0.50–40 and 0.10–50 ng mL −1 , with the detection limits of 0.20 and 0.040 ng mL −1 (S/N = 3), respectively. The whole process for multianalyte immunoassay of RAC and SAL can be completed within 20 min. Furthermore, the test strip was validated with spiked swine urine samples and the results showed that this method was reliable in measuring β 2 -agonists in swine urine. This CL-based multianalyte test strip shows a series of advantages such as high sensitivity, ideal selectivity, simple manipulation, high assay efficiency and low cost. Thus, it opens up new pathway for rapid screening and field analysis, and shows a promising prospect in food safety

  17. Febrile neutropenia in paediatric peripheral blood stem cell transplantation, in vitro sensitivity data and clinical response to empirical antibiotic therapy

    International Nuclear Information System (INIS)

    Ansari, S.H.; Nasim, S.; Ahmed, A.; Irfan, M.; Ishaque, A.; Farzana, T.; Panjwani, V.K.; Taj, M.; Shamsi, T.S.

    2006-01-01

    To find the in-vitro sensitivity data and clinical response in order to determine the changes required in empiric antibiotic therapy for management of febrile neutropenia in paediatric patients undergoing peripheral blood stem cell transplantation. All patients were treated according to institutional protocol for febrile neutropenia. Empirical antibiotics include Ceftriaxone and Amikacin. In non-responders, changes made included Imipenem and Amikacin, Piperacillin Tazobactum/Tiecoplanin or Vancomycin/Cloxacilin/Ceftazidime. In non-responders, amphotaracin was added until recovery. Out of 52 patients, 5 did not develop any fever; in the remaining 47 patients there were 57 episodes of febrile neutropenia. The mean days of febrile episodes were 4.71 (range 3-8). Fever of unknown origin (FUO) occurred in 31 (54.3%) episodes. Microbiologically documented infection (MDI) occurred in 17 (29.8%) episodes of fever. Clinically documented infection (CDI) occurred in 9 (15.7%) episodes. Gram-negative organisms were isolated in 10 while gram-positive organisms in 7. Klebseilla, S. aureus were the most common isolates. Empirical therapy was effective in 12 of the 33 (36%) episodes. Out of 28, 26 (92%) responded to Imipenem/Amikacin as second line therapy while those who received any other second line combination, only 11 out of 22 (50%) showed response. Systemic Amphotericin was used in 4 patients, 2 responded. Infection related mortality rate was 4%. (author)

  18. Rv2477c is an antibiotic-sensitive manganese-dependent ABC-F ATPase in Mycobacterium tuberculosis.

    Science.gov (United States)

    Daniel, Jaiyanth; Abraham, Liz; Martin, Amanda; Pablo, Xyryl; Reyes, Shelby

    2018-01-01

    The Rv2477c protein of Mycobacterium tuberculosis (Mtb) belongs to the ATP-binding cassette (ABC) subfamily F that contains proteins with tandem nucleotide-binding domains but lacking transmembrane domains. ABC-F subfamily proteins have been implicated in diverse cellular processes such as translation, antibiotic resistance, cell growth and nutrient sensing. In order to investigate the biochemical characteristics of Rv2477c, we expressed it in Escherichia coli, purified it and characterized its enzymatic functions. We show that Rv2477c displays strong ATPase activity (V max  = 45.5 nmol/mg/min; K m  = 90.5 μM) that is sensitive to orthovanadate. The ATPase activity was maximal in the presence of Mn 2+ at pH 5.2. The Rv2477c protein was also able to hydrolyze GTP, TTP and CTP but at lower rates. Glutamate to glutamine substitutions at amino acid residues 185 and 468 in the two Walker B motifs of Rv2477c severely inhibited its ATPase activity. The antibiotics tetracycline and erythromycin, which target protein translation, were able to inhibit the ATPase activity of Rv2477c. We postulate that Rv2477c could be involved in mycobacterial protein translation and in resistance to tetracyclines and macrolides. This is the first report of the biochemical characterization of an ABC-F subfamily protein in Mtb. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. COMMON ORGANISMS AND ANTIBIOTIC SENSITIVITY OF E COLI IN URINARY TRACT INFECTION, IN A TERTIARY CARE TEACHING HOSPITAL, NORTHERN KERALA

    Directory of Open Access Journals (Sweden)

    Shanavas

    2015-11-01

    Full Text Available Urinary tract infection (UTI includes a spectrum of Asymptomatic Bacteruria (ABU, Cystitis, Prostitis and Pyelonephritis. Except in ABU, UTI is represented by symptomatic disease that warrants antimicrobial therapy. 1 Many of the studies have shown increasing antibiotic resistance to these agents. This study consists of a retrospective observational study of culture and sensitivity of 150 urinary samples, collected from patients who presented with symptoms of UTI, in a tertiary care teaching hospital, Northern Kerala, irrespective of their age and sex for a period of six months from June 2015 to November 2015. These results are then analyzed to find common organisms causing UTI in different age groups in either sex and their respective antibiotic resistance are noted. Out of 150 urinary samples 69.34% were sterile, while 30.66% were culture positive. Among the culture positive patients sex distribution was almost equal, with a slight female predominance, having a contribution of 54.35% females and 45.65% males. The most common organism was found to be E.coli, which contributed more than 50 per cent of total culture positivity (54.35%. Others include Staphylococci, Klebsiella Pnuemoniae, Proteus species, Pseudomonas, Enterococci, Candida Albicans etc. Collateral damage is an ecological adverse effect that resist the use of a highly efficacious drug to be considered as first line agent. Our study shows that drugs causing minimal collateral damages like Nitrofurantoin and Fosfomycin can be used as first line agent for treatment of UTI.

  20. Screen-printed fluorescent sensors for rapid and sensitive anthrax biomarker detection

    International Nuclear Information System (INIS)

    Lee, Inkyu; Oh, Wan-Kyu; Jang, Jyongsik

    2013-01-01

    Highlights: •We fabricated flexible anthrax sensors with a simple screen-printing method. •The sensors selectively detected B. anthracis biomarker. •The sensors provide the visible alarm against anthrax attack. -- Abstract: Since the 2001 anthrax attacks, efforts have focused on the development of an anthrax detector with rapid response and high selectivity and sensitivity. Here, we demonstrate a fluorescence sensor for detecting anthrax biomarker with high sensitivity and selectivity using a screen-printing method. A lanthanide–ethylenediamine tetraacetic acid complex was printed on a flexible polyethersulfone film. Screen-printing deposition of fluorescent detecting moieties produced fluorescent patterns that acted as a visual alarm against anthrax

  1. Use of rapid-scan EPR to improve detection sensitivity for spin-trapped radicals.

    Science.gov (United States)

    Mitchell, Deborah G; Rosen, Gerald M; Tseitlin, Mark; Symmes, Breanna; Eaton, Sandra S; Eaton, Gareth R

    2013-07-16

    The short lifetime of superoxide and the low rates of formation expected in vivo make detection by standard continuous wave (CW) electron paramagnetic resonance (EPR) challenging. The new rapid-scan EPR method offers improved sensitivity for these types of samples. In rapid-scan EPR, the magnetic field is scanned through resonance in a time that is short relative to electron spin relaxation times, and data are processed to obtain the absorption spectrum. To validate the application of rapid-scan EPR to spin trapping, superoxide was generated by the reaction of xanthine oxidase and hypoxanthine with rates of 0.1-6.0 μM/min and trapped with 5-tert-butoxycarbonyl-5-methyl-1-pyrroline-N-oxide (BMPO). Spin trapping with BMPO to form the BMPO-OOH adduct converts the very short-lived superoxide radical into a more stable spin adduct. There is good agreement between the hyperfine splitting parameters obtained for BMPO-OOH by CW and rapid-scan EPR. For the same signal acquisition time, the signal/noise ratio is >40 times higher for rapid-scan than for CW EPR. Rapid-scan EPR can detect superoxide produced by Enterococcus faecalis at rates that are too low for detection by CW EPR. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  2. RAMBO-K: Rapid and Sensitive Removal of Background Sequences from Next Generation Sequencing Data.

    Directory of Open Access Journals (Sweden)

    Simon H Tausch

    Full Text Available The assembly of viral or endosymbiont genomes from Next Generation Sequencing (NGS data is often hampered by the predominant abundance of reads originating from the host organism. These reads increase the memory and CPU time usage of the assembler and can lead to misassemblies.We developed RAMBO-K (Read Assignment Method Based On K-mers, a tool which allows rapid and sensitive removal of unwanted host sequences from NGS datasets. Reaching a speed of 10 Megabases/s on 4 CPU cores and a standard hard drive, RAMBO-K is faster than any tool we tested, while showing a consistently high sensitivity and specificity across different datasets.RAMBO-K rapidly and reliably separates reads from different species without data preprocessing. It is suitable as a straightforward standard solution for workflows dealing with mixed datasets. Binaries and source code (java and python are available from http://sourceforge.net/projects/rambok/.

  3. A rapid method based on hot water extraction and liquid chromatography-tandem mass spectrometry for analyzing tetracycline antibiotic residues in cheese.

    Science.gov (United States)

    Bogialli, Sara; Coradazzi, Cristina; Di Corcia, Antonio; Lagana, Aldo; Sergi, Manuel

    2007-01-01

    A rapid, specific, and sensitive procedure for determining residues of 4 widely used tetracycline antibiotics and 3 of their 4-epimers in cheese is presented. The method is based on the matrix solid-phase dispersion (MSPD) technique followed by liquid chromatography/tandem mass spectrometry (LC/MS/MS). After dispersing samples of mozzarella, asiago, parmigiano, gruyere, emmenthal, and camembert on sand, target compounds were eluted from the MSPD column by passing through it 6 mL water heated at 70 degrees C. After acidification and filtration, 200 microL of the aqueous extract was directly injected into the LC column. For analyte identification and quantification, MS data acquisition was performed in the multireaction monitoring mode, selecting 2 precursor ion-to-product ion transitions for each target compound. Hot water appeared to be an efficient extractant, because absolute recoveries were no lower than 78%. Using demeclocycline as a surrogate analyte, recoveries of analyte added to the 6 types of cheeses at the 30 ng/g level were 96-117%, with relative standard deviation (RSD) not higher than 9%. Statistical analysis of the mean recovery data showed that the extraction efficiency was not dependent on the type of cheese analyzed. This result indicates that this method could be applied to other cheese types not considered here. At the lowest concentration considered, i.e., 10 ng/g, the accuracy of the method ranged between 90 and 107%, with RSDs not larger than 12%. Based on a signal-to-noise ratio of 10, limits of quantitation were estimated to be 1-2 ng/g.

  4. Fluorescent Metal-Organic Framework (MOF) as a Highly Sensitive and Quickly Responsive Chemical Sensor for the Detection of Antibiotics in Simulated Wastewater.

    Science.gov (United States)

    Zhu, Xian-Dong; Zhang, Kun; Wang, Yu; Long, Wei-Wei; Sa, Rong-Jian; Liu, Tian-Fu; Lü, Jian

    2018-02-05

    A Zn(II)-based fluorescent metal-organic framework (MOF) was synthesized and applied as a highly sensitive and quickly responsive chemical sensor for antibiotic detection in simulated wastewater. The fluorescent chemical sensor, denoted FCS-1, exhibited enhanced fluorescence derived from its highly ordered, 3D MOF structure as well as excellent water stability in the practical pH range of simulated antibiotic wastewater (pH = 3.0-9.0). Remarkably, FCS-1 was able to effectively detect a series of sulfonamide antibiotics via photoinduced electron transfer that caused detectable fluorescence quenching, with fairly low detection limits. Two influences impacting measurements related to wastewater treatment and water quality monitoring, the presence of heavy-metal ions and the pH of solutions, were studied in terms of fluorescence quenching, which was nearly unaffected in sulfonamide-antibiotic detection. Additionally, the effective detection of sulfonamide antibiotics was rationalized by the theoretical computation of the energy bands of sulfonamide antibiotics, which revealed a good match between the energy bands of FCS-1 and sulfonamide antibiotics, in connection with fluorescence quenching in this system.

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

    Directory of Open Access Journals (Sweden)

    Liasi, S. A.

    2009-01-01

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

  6. The IRIDICA BAC BSI Assay: Rapid, Sensitive and Culture-Independent Identification of Bacteria and Candida in Blood

    Science.gov (United States)

    Rothman, Richard E.; Peterson, Stephen; Carroll, Karen C.; Zhang, Sean X.; Avornu, Gideon D.; Rounds, Megan A.; Carolan, Heather E.; Toleno, Donna M.; Moore, David; Hall, Thomas A.; Massire, Christian; Richmond, Gregory S.; Gutierrez, Jose R.; Sampath, Rangarajan; Ecker, David J.; Blyn, Lawrence B.

    2016-01-01

    Bloodstream infection (BSI) and sepsis are rising in incidence throughout the developed world. The spread of multi-drug resistant organisms presents increasing challenges to treatment. Surviving BSI is dependent on rapid and accurate identification of causal organisms, and timely application of appropriate antibiotics. Current culture-based methods used to detect and identify agents of BSI are often too slow to impact early therapy and may fail to detect relevant organisms in many positive cases. Existing methods for direct molecular detection of microbial DNA in blood are limited in either sensitivity (likely the result of small sample volumes) or in breadth of coverage, often because the PCR primers and probes used target only a few specific pathogens. There is a clear unmet need for a sensitive molecular assay capable of identifying the diverse bacteria and yeast associated with BSI directly from uncultured whole blood samples. We have developed a method of extracting DNA from larger volumes of whole blood (5 ml per sample), amplifying multiple widely conserved bacterial and fungal genes using a mismatch- and background-tolerant PCR chemistry, and identifying hundreds of diverse organisms from the amplified fragments on the basis of species-specific genetic signatures using electrospray ionization mass spectrometry (PCR/ESI-MS). We describe the analytical characteristics of the IRIDICA BAC BSI Assay and compare its pre-clinical performance to current standard-of-care methods in a collection of prospectively collected blood specimens from patients with symptoms of sepsis. The assay generated matching results in 80% of culture-positive cases (86% when common contaminants were excluded from the analysis), and twice the total number of positive detections. The described method is capable of providing organism identifications directly from uncultured blood in less than 8 hours. Disclaimer: The IRIDICA BAC BSI Assay is not available in the United States. PMID:27384540

  7. Enhanced Sensitivity to Rapid Input Fluctuations by Nonlinear Threshold Dynamics in Neocortical Pyramidal Neurons.

    Science.gov (United States)

    Mensi, Skander; Hagens, Olivier; Gerstner, Wulfram; Pozzorini, Christian

    2016-02-01

    The way in which single neurons transform input into output spike trains has fundamental consequences for network coding. Theories and modeling studies based on standard Integrate-and-Fire models implicitly assume that, in response to increasingly strong inputs, neurons modify their coding strategy by progressively reducing their selective sensitivity to rapid input fluctuations. Combining mathematical modeling with in vitro experiments, we demonstrate that, in L5 pyramidal neurons, the firing threshold dynamics adaptively adjust the effective timescale of somatic integration in order to preserve sensitivity to rapid signals over a broad range of input statistics. For that, a new Generalized Integrate-and-Fire model featuring nonlinear firing threshold dynamics and conductance-based adaptation is introduced that outperforms state-of-the-art neuron models in predicting the spiking activity of neurons responding to a variety of in vivo-like fluctuating currents. Our model allows for efficient parameter extraction and can be analytically mapped to a Generalized Linear Model in which both the input filter--describing somatic integration--and the spike-history filter--accounting for spike-frequency adaptation--dynamically adapt to the input statistics, as experimentally observed. Overall, our results provide new insights on the computational role of different biophysical processes known to underlie adaptive coding in single neurons and support previous theoretical findings indicating that the nonlinear dynamics of the firing threshold due to Na+-channel inactivation regulate the sensitivity to rapid input fluctuations.

  8. Quantum Dot-Fullerene Based Molecular Beacon Nanosensors for Rapid, Highly Sensitive Nucleic Acid Detection.

    Science.gov (United States)

    Liu, Ye; Kannegulla, Akash; Wu, Bo; Cheng, Li-Jing

    2018-05-15

    Spherical fullerene (C 60 ) can quench the fluorescence of a quantum dot (QD) through energy transfer and charge transfer processes, with the quenching efficiency regulated by the number of proximate C 60 on each QD. With the quenching property and its small size compared with other nanoparticle-based quenchers, it is advantageous to group a QD reporter and multiple C 60 -labeled oligonucleotide probes to construct a molecular beacon (MB) probe for sensitive, robust nucleic acid detection. We demonstrated a rapid, high-sensitivity DNA detection method using the nanosensors composed of QD-C 60 based MBs carried by magnetic nanoparticles (MNPs). The assay was accelerated by first dispersing the nanosensors in analytes for highly efficient DNA capture resulting from short-distance 3-dimensional diffusion of targets to the sensor surface and then concentrating the nanosensors to a substrate by magnetic force to amplify the fluorescence signal for target quantification. The enhanced mass transport enabled a rapid detection (< 10 min) with a small sample volume (1-10 µl). The high signal-to-noise ratio produced by the QD-C 60 pairs and magnetic concentration yielded a detection limit of 100 fM (~106 target DNA copies for a 10 µl analyte). The rapid, sensitive, label-free detection method will benefit the applications in point-of-care molecular diagnostic technologies.

  9. Ablation of capsaicin sensitive afferent nerves impairs defence but not rapid repair of rat gastric mucosa.

    Science.gov (United States)

    Pabst, M A; Schöninkle, E; Holzer, P

    1993-07-01

    Capsaicin sensitive afferent neurones have previously been reported to play a part in gastric mucosal protection. The aim of this study was to investigate whether these nociceptive neurones strengthen mucosal defence against injury or promote rapid repair of the damaged mucosa, or both. This hypothesis was examined in anaesthetised rats whose stomachs were perfused with ethanol (25 or 50% in saline, wt/wt) for 30 minutes. The gastric mucosa was inspected 0 and 180 minutes after ethanol had been given at the macroscopic, light, and scanning electron microscopic level. Rapid repair of the ethanol injured gastric mucosa (reduction of deep injury, partial re-epithelialisation of the denuded surface) took place in rats anaesthetised with phenobarbital, but not in those anaesthetised with urethane. Afferent nerve ablation as a result of treating rats with a neurotoxic dose of capsaicin before the experiment significantly aggravated ethanol induced damage as shown by an increase in the area and depth of mucosal erosions. Rapid repair of the injured mucosa, however, as seen in rats anesthetised with phenobarbital 180 minutes after ethanol was given, was similar in capsaicin and vehicle pretreated animals. Ablation of capsaicin sensitive afferent neurones was verified by a depletion of calcitonin gene related peptide from the gastric corpus wall. These findings indicate that nociceptive neurones control mechanisms of defence against acute injury but are not required for rapid repair of injured mucosa.

  10. Bacteriological profile and antibiotic sensitivity pattern of neonatal septicaemia in a rural tertiary care hospital in North India

    Directory of Open Access Journals (Sweden)

    S Thakur

    2016-01-01

    Full Text Available Background: There is not much published literature on neonatal septicemia available for the Sub-Himalayan region of North India. Hence, we undertook this study to find out the bacteriological profile and antibiotic sensitivity pattern of neonatal septicemia in the neonatal Intensive Care Unit. Material and Methods: Blood cultures were performed for all clinically suspected neonatal septicemia cases for 1-year. Identification of all pathogenic isolates was followed by antibiotic sensitivity testing. Results: We did blood cultures for 450 neonates and 42% were culture positive. Early onset sepsis were 92 (49% and 96 (51% were late onset sepsis. Gram-positive isolates were 60% and 40% were Gram-negative. Staphylococcus aureus (40%, coagulase negative Staphylococcus species (16%, non-fermenter group of organisms (NFGOs (15%, and Klebsiella pneumoniae (10% were the main isolates. Nasal cannula 101 (54%, birth asphyxia 91 (48%, and prematurity 73 (38% were the prominent risk factors associated with septicemia. Gram-positive organisms were highly resistant to penicillin (87% whereas Gram-negative isolates showed high resistance to third generation cephalosporins (53–89% and aminoglycosides (50–67%. The S. aureus isolates were methicillin-resistant in 41% whereas extended spectrum beta lactamase production was seen in 48% Gram-negative isolates.Conclusion: Our study highlights the recent emergence of Gram-positive organisms as predominant cause of neonatal septicemia in this part of Sub-Himalayan region, along with the review of literature which shows similar results from North India and rest of the world too. Though Gram-negative bacteria still remain the main cause of mortality in neonatal septicemia, we want to dispel the common notion among practitioners that they are the predominant isolates in neonatal septicemia.

  11. Sensitivity and specificity of various beta-lactam antibiotics and phenotypical methods for detection of TEM, SHV and CTX-M extended-spectrum beta-lactamases.

    Science.gov (United States)

    Bedenic, B; Vranes, J; Mihaljevic, Lj; Tonkic, M; Sviben, M; Plecko, V; Kalenic, S

    2007-04-01

    The aim of this study was to compare the sensitivity and specificity of six different beta-lactam antibiotics using five phenotypical tests for detection of extended spectrum beta-lactamases (ESBLs) based on synergism of beta-lactam antibiotics and clavulanate. Experiments were performed on a set of 80 Klebsiella pneumoniae strains and 105 Escherichia coli strains with previously characterized ESBLs (SHV, TEM and CTX-M). ESBLs were detected by five different phenotypical methods: MIC (minimum inhibitory concentration) determination of beta-lactam antibiotics with and without clavulanate, double-disk synergy test (DDST), inhibitor-potentiated disk-diffusion test (IPDDT), CLSI-Clinical and Laboratory Standard Institution (former NCCLS) combined-disk-test, and modified MAST-disk-diffusion test (MAST-DD-test). Seven antibiotics were tested as indicators of ESBL production: ceftazidime, cefotaxime, ceftriaxone, aztreonam, ceftibuten, cefpodoxime and cefepime. Ceftazidime and aztreonam were the best indicators for SHV-5, SHV-12 and TEM beta-lactamases whereas cefotaxime and ceftriaxone were the most sensitive in detection of SHV-2 and CTX-M beta-lactamases in DDST, IPDDT and CLSI test. MIC determination of beta-lactam antibiotics with and without clavulanate was the most sensitive method. DDST was the least sensitive test. Double-disk synergy test, which is the most frequently used test for detection of ESBLs in routine laboratories, was the least sensitive independently of the indicator antibiotic. Since MIC determination is a very laborious and time consuming method, we would recommend the NCCLS combined disk test or IPDD test for detection of ESBLs in routine laboratories with 5 mm zone augmentation breakpoint.

  12. Normal flora of conjunctiva and lid margin, as well as its antibiotic sensitivity, in patients undergoing cataract surgery at Phramongkutklao Hospital.

    Science.gov (United States)

    Ratnumnoi, Ravee; Keorochana, Narumon; Sontisombat, Chavalit

    2017-01-01

    This study aimed to evaluate the normal flora of conjunctiva and lid margin, as well as its antibiotic sensitivity. This was a prospective cross-sectional study. A prospective study was conducted on 120 patients who underwent cataract surgery at the Phramongkutklao Hospital from September 2014 to October 2014. Conjunctival and lid margin swabs were obtained from patients before they underwent cataract surgery. These swabs were used to inoculate blood agar and chocolate agar plates for culturing. After growth of the normal flora, the antibiotic sensitivity method using tobramycin, moxifloxacin, levofloxacin, and cefazolin was applied. Normal flora of conjunctiva and lid margin, along with its antibiotic sensitivity, from patients who underwent cataract surgery was assessed. A total of 120 eyes were included in this study, and bacterial isolation rates were identified. Five bacteria from the lid margin were cultured, namely, coagulase-negative staphylococcus (58.33%), Streptococcus spp. (2.5%), Corynebacterium (1.67%), Micrococcus spp. (1.67%), and Staphylococcus aureus (0.83%). Two bacteria from the conjunctiva were cultured, namely, coagulase-negative staphylococcus (30%) and Streptococcus spp. (0.83%). Results of antibiotic sensitivity test showed that all isolated bacteria are sensitive to cefazolin 100%, tobramycin 98.67%, levofloxacin 100%, and moxifloxacin 100%. Coagulase-negative staphylococci are the most common bacteria isolated from conjunctiva and lid margin.

  13. Rapid identification and susceptibility testing of uropathogenic microbes via immunosorbent ATP-bioluminescence assay on a microfluidic simulator for antibiotic therapy.

    Science.gov (United States)

    Dong, Tao; Zhao, Xinyan

    2015-02-17

    The incorporation of pathogen identification with antimicrobial susceptibility testing (AST) was implemented on a concept microfluidic simulator, which is well suited for personalizing antibiotic treatment of urinary tract infections (UTIs). The microfluidic device employs a fiberglass membrane sandwiched between two polypropylene components, with capture antibodies immobilized on the membrane. The chambers in the microfluidic device share the same geometric distribution as the wells in a standard 384-well microplate, resulting in compatibility with common microplate readers. Thirteen types of common uropathogenic microbes were selected as the analytes in this study. The microbes can be specifically captured by various capture antibodies and then quantified via an ATP bioluminescence assay (ATP-BLA) either directly or after a variety of follow-up tests, including urine culture, antibiotic treatment, and personalized antibiotic therapy simulation. Owing to the design of the microfluidic device, as well as the antibody specificity and the ATP-BLA sensitivity, the simulator was proven to be able to identify UTI pathogen species in artificial urine samples within 20 min and to reliably and simultaneously verify the antiseptic effects of eight antibiotic drugs within 3-6 h. The measurement range of the device spreads from 1 × 10(3) to 1 × 10(5) cells/mL in urine samples. We envision that the medical simulator might be broadly employed in UTI treatment and could serve as a model for the diagnosis and treatment of other diseases.

  14. Highly sensitive multianalyte immunochromatographic test strip for rapid chemiluminescent detection of ractopamine and salbutamol

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Hongfei; Han, Jing; Yang, Shijia; Wang, Zhenxing; Wang, Lin; Fu, Zhifeng, E-mail: fuzf@swu.edu.cn

    2014-08-11

    Graphical abstract: A multianalyte immunochromatographic test strip was developed for the rapid detection of two β{sub 2}-agonists. Due to the application of chemiluminescent detection, this quantitative method shows much higher sensitivity. - Highlights: • An immunochromatographic test strip was developed for detection of multiple β{sub 2}-agonists. • The whole assay process can be completed within 20 min. • The proposed method shows much higher sensitivity due to the application of CL detection. • It is a portable analytical tool suitable for field analysis and rapid screening. - Abstract: A novel immunochromatographic assay (ICA) was proposed for rapid and multiple assay of β{sub 2}-agonists, by utilizing ractopamine (RAC) and salbutamol (SAL) as the models. Owing to the introduction of chemiluminescent (CL) approach, the proposed protocol shows much higher sensitivity. In this work, the described ICA was based on a competitive format, and horseradish peroxidase-tagged antibodies were used as highly sensitive CL probes. Quantitative analysis of β{sub 2}-agonists was achieved by recording the CL signals of the probes captured on the two test zones of the nitrocellulose membrane. Under the optimum conditions, RAC and SAL could be detected within the linear ranges of 0.50–40 and 0.10–50 ng mL{sup −1}, with the detection limits of 0.20 and 0.040 ng mL{sup −1} (S/N = 3), respectively. The whole process for multianalyte immunoassay of RAC and SAL can be completed within 20 min. Furthermore, the test strip was validated with spiked swine urine samples and the results showed that this method was reliable in measuring β{sub 2}-agonists in swine urine. This CL-based multianalyte test strip shows a series of advantages such as high sensitivity, ideal selectivity, simple manipulation, high assay efficiency and low cost. Thus, it opens up new pathway for rapid screening and field analysis, and shows a promising prospect in food safety.

  15. Phage type and sensitivity to antibiotics of Staphylococcus aureus film-forming strains isolated from airway mucosa

    Directory of Open Access Journals (Sweden)

    O. S. Voronkova

    2014-10-01

    Full Text Available Today film-forming strains of bacteria play very important role in clinical pathology. Staphylococci are ones of most dangerous of them. This bacteria can determine different pathological processes, for example, complication of airway mucosa. The ability to form a biofilm is one of the main properties of nosocomial strains. These strains should be monitored and their carriers are to be properly treated. To determine the origin of staphylococci strains we used bacteriophages from the International kit. The aim of research was to determine the phage type of staphylococci film-forming strains, that were isolated from naso-pharingial mucosa. Phage typing has been carried out for 16 film-forming strains of S. aureus. To solve this problem, we used the International phage kit by Fisher’s method. As a result, sensitivity to phages from the International kit showed 53.8% of studied strains of S. aureus. 64.3% of sensitivity strains were lysed by one of the phage, 21.4% – were by two of the phages, 14.3% – by three of the phages. Isolates were sensitive to phages: 81 – 42.9%, 75 – 35.7%, 28.6% were sensitive to phages 47 and 53. All cases of detection of sensitivity to phage 47 coincided with the ability to form biofilm. Among non-film-forming strains there was no sensitive strains for this phage. Film-forming strains resist to erythromycin (62.5%, ciprofloxacin (43.8%, gentamicin (56.3%, tetracycline (87.5%, amoxicillin (93.8%, and cefuroxime (37.5%. All cases of sensitivity to phage 47 coincided with resistance to erythromycin, amoxicillin and tetracycline. For two of these strains, we also defined resistance to gentamicin and for one of them – to ciprofloxacin. Results of research allowed to relate the bacterial cultures for determining the type. This may have implications for studying of film-forming ability, because surface structures of bacterial cell take place in this process. Belonging of an isolate to specific phage type may

  16. Sensitive and rapid immunoassay for parathyroid hormone using magnetic particle labels and magnetic actuation.

    Science.gov (United States)

    Dittmer, W U; de Kievit, P; Prins, M W J; Vissers, J L M; Mersch, M E C; Martens, M F W C

    2008-09-30

    A rapid method for the sensitive detection of proteins using actuated magnetic particle labels, which are measured with a giant magneto-resistive (GMR) biosensor, is described. The technique involves a 1-step sandwich immunoassay with no fluid replacement steps. The various assay binding reactions as well as the bound/free separation are entirely controlled by magnetic forces induced by electromagnets above and below the sensor chip. During the assay, particles conjugated with tracer antibodies are actuated through the sample for target capture, and rapidly brought to the sensor surface where they bind to immobilized capture antibodies. Weakly or unbound labels are removed with a magnetic force oriented away from the GMR sensor surface. For the measurement of parathyroid hormone (PTH), a detection limit in the 10 pM range is obtained with a total assay time of 15 min when 300 nm particles are used. The same sensitivity can be achieved in 5 min when 500 nm particles are used. If 500 nm particles are employed in a 15-minute assay, then 0.8 pM of PTH is detectable. The low sample volume, high analytical performance and high speed of the test coupled with the compact GMR biosensor make the system especially suitable for sensitive testing outside of laboratory environments.

  17. Characterization and antimicrobial susceptibility of one antibiotic-sensitive and one multidrug-resistant Corynebacterium kroppenstedtii strain isolated from patients with granulomatous mastitis

    Directory of Open Access Journals (Sweden)

    I. Fernández-Natal

    2016-11-01

    Full Text Available Human infections associated with Corynebacterium kroppenstedtii are rarely reported, and this organism is usually described as antibiotic sensitive. Almost all published cases of C. kroppenstedtii infections have been associated with breast pathology in women and have been described in New Zealand, France, Canada, India and Japan. Here we describe the microbiologic characteristics of two strains isolated from two women diagnosed of granulomatous mastitis in Spain. One C. kroppenstedtii isolate was antibiotic sensitive while the other was multidrug resistant. Biochemical identification was possible using a wide battery of methods including API Coryne V2.0, API Strep, API NH, API NE, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rRNA gene amplification and sequencing. Antimicrobial susceptibility to 28 antibiotics as determined by Etest showed one isolate being sensitive to benzylpenicillin, ciprofloxacin, moxifloxacin, gentamicin, vancomycin, clindamycin, tetracycline, linezolid and rifampin. The second isolate showed resistance to ciprofloxacin, moxifloxacin, clindamycin, tetracycline and rifampin. The multidrug-resistant isolate contained the erm(X, tet(W, cmx, aphA1-IAB, strAB and sul1 resistance genes known from the R plasmid pJA144188 of Corynebacterium resistens. These genes were absent in the genome of the antibiotic-sensitive isolate. This report confirms the tropism of this microorganism for women's breasts and presents the first description of a multidrug-resistant C. kroppenstedtii strain.

  18. A rapid enhancement of locomotor sensitization to amphetamine by estradiol in female rats.

    Science.gov (United States)

    Zovkic, Iva B; McCormick, Cheryl M

    2017-11-14

    not. The results suggest rapid effects of estradiol on amphetamine sensitization consistent with rapid effects of estradiol reported for other behaviours. Copyright © 2017. Published by Elsevier Inc.

  19. Novel quorum-quenching agents promote methicillin-resistant Staphylococcus aureus (MRSA) wound healing and sensitize MRSA to β-lactam antibiotics.

    Science.gov (United States)

    Kuo, David; Yu, Guanping; Hoch, Wyatt; Gabay, Dean; Long, Lisa; Ghannoum, Mahmoud; Nagy, Nancy; Harding, Clifford V; Viswanathan, Rajesh; Shoham, Menachem

    2015-03-01

    The dwindling repertoire of antibiotics to treat methicillin-resistant Staphylococcus aureus (MRSA) calls for novel treatment options. Quorum-quenching agents offer an alternative or an adjuvant to antibiotic therapy. Three biaryl hydroxyketone compounds discovered previously (F1, F12, and F19; G. Yu, D. Kuo, M. Shoham, and R. Viswanathan, ACS Comb Sci 16:85-91, 2014) were tested for efficacy in MRSA-infected animal models. Topical therapy of compounds F1 and F12 in a MRSA murine wound infection model promotes wound healing compared to the untreated control. Compounds F1, F12, and F19 afford significant survival benefits in a MRSA insect larva model. Combination therapy of these quorum-quenching agents with cephalothin or nafcillin, antibiotics to which MRSA is resistant in monotherapy, revealed additional survival benefits. The quorum-quenching agents sensitize MRSA to the antibiotic by a synergistic mode of action that also is observed in vitro. An adjuvant of 1 μg/ml F1, F12, or F19 reduces the MIC of nafcillin and cephalothin about 50-fold to values comparable to those for vancomycin, the antibiotic often prescribed for MRSA infections. These findings suggest that it is possible to resurrect obsolete antibiotic therapies in combination with these novel quorum-quenching agents. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  20. Rapid diagnosis of equine influenza by highly sensitive silver amplification immunochromatography system.

    Science.gov (United States)

    Yamanaka, Takashi; Nemoto, Manabu; Bannai, Hiroshi; Tsujimura, Koji; Kondo, Takashi; Matsumura, Tomio; Fu, Tao Qi Huang; Fernandez, Charlene Judith; Gildea, Sarah; Cullinane, Ann

    2017-06-16

    Equine influenza (EI) is a respiratory disease caused by equine influenza A virus (EIV, H3N8) infection. Rapid diagnosis is essential to limit the disease spread. We previously reported that some rapid antigen detection (RAD) tests are fit for diagnosing EI although their sensitivity is not optimal. Here, we evaluated the performance of the newly developed RAD test using silver amplification immunochromatography (Quick Chaser Auto Flu A, B: QCA) to diagnose EI. The detection limits of QCA for EIVs were five-fold lower than the conventional RAD tests. The duration of virus antigen detection in the infected horses was longer than the conventional RAD tests. We conclude that QCA could be a valuable diagnostic method for EI.

  1. A rapid and sensitive method for measuring N-acetylglucosaminidase activity in cultured cells.

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    Victor Mauri

    Full Text Available A rapid and sensitive method to quantitatively assess N-acetylglucosaminidase (NAG activity in cultured cells is highly desirable for both basic research and clinical studies. NAG activity is deficient in cells from patients with Mucopolysaccharidosis type IIIB (MPS IIIB due to mutations in NAGLU, the gene that encodes NAG. Currently available techniques for measuring NAG activity in patient-derived cell lines include chromogenic and fluorogenic assays and provide a biochemical method for the diagnosis of MPS IIIB. However, standard protocols require large amounts of cells, cell disruption by sonication or freeze-thawing, and normalization to the cellular protein content, resulting in an error-prone procedure that is material- and time-consuming and that produces highly variable results. Here we report a new procedure for measuring NAG activity in cultured cells. This procedure is based on the use of the fluorogenic NAG substrate, 4-Methylumbelliferyl-2-acetamido-2-deoxy-alpha-D-glucopyranoside (MUG, in a one-step cell assay that does not require cell disruption or post-assay normalization and that employs a low number of cells in 96-well plate format. We show that the NAG one-step cell assay greatly discriminates between wild-type and MPS IIIB patient-derived fibroblasts, thus providing a rapid method for the detection of deficiencies in NAG activity. We also show that the assay is sensitive to changes in NAG activity due to increases in NAGLU expression achieved by either overexpressing the transcription factor EB (TFEB, a master regulator of lysosomal function, or by inducing TFEB activation chemically. Because of its small format, rapidity, sensitivity and reproducibility, the NAG one-step cell assay is suitable for multiple procedures, including the high-throughput screening of chemical libraries to identify modulators of NAG expression, folding and activity, and the investigation of candidate molecules and constructs for applications in

  2. [Cefazolin efficacy and antibiotic sensitivity against pathogenic bacteria in pediatric with acute upper urinary tract infection].

    Science.gov (United States)

    Fuke, Toshiya; Abe, Yoshifusa; Hoshino, Akihiro; Oto, Hideyasu; Sakai, Naho; Murayama, Junichiro; Yoshida, Koichiro; Itabashi, Kazuo

    2010-05-01

    Acute upper urinary tract infection may cause sepsis, especially in neonates and infants, mandating the choice of appropriate, effective antibacterials minimizing increasing bacterial resistance. Frequently prescribing broad-spectrum cephalosporinin is one such example. Different antibacterial therapies are initiated clinically due to treatment protocol differences among institutions, disease severity, etc. We studied the efficacy of cefazolin (CEZ), a first-generation cephalosporin, as first-line parenteral treatment in acute upper urinary tract infection. We found that 88.9% of microbial infections have indications for CEZ. CEZ efficacy is 91.3%, and 97.2% of urine cultures show negative results. Escherichia coli sensitivity to antibacterial agents is 90.9% of the minimal inhibitory concentration (MIC) pediatric therapy in acute upper urinary tract infection.

  3. Highly sensitive and rapid bacteria detection using molecular beacon-Au nanoparticles hybrid nanoprobes.

    Science.gov (United States)

    Cao, Jing; Feng, Chao; Liu, Yan; Wang, Shouyu; Liu, Fei

    2014-07-15

    Since many diseases are caused by pathogenic bacterial infections, accurate and rapid detection of pathogenic bacteria is in urgent need to timely apply appropriate treatments and to reduce economic costs. To end this, we designed molecular beacon-Au nanoparticle hybrid nanoprobes to improve the bacterial detection efficiency and sensitivity. Here, we show that the designed molecular beacon modified Au nanoparticles could specifically recognize synthetic DNAs targets and can readily detect targets in clinical samples. Moreover, the hybrid nanoprobes can recognize Escherichia coli within an hour at a concentration of 10(2) cfu/ml, which is 1000-folds sensitive than using molecular beacon directly. Our results show that the molecular beacon-Au nanoparticle hybrid nanoprobes have great potential in medical and biological applications. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Rapid, quantitative and sensitive immunochromatographic assay based on stripping voltammetric detection of a metal ion label

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Fang; Wang, Kaihua; Lin, Yuehe

    2005-10-10

    A novel, sensitive immunochromatographic electrochemical biosensor (IEB) which combines an immunochromatographic strip technique with an electrochemical detection technique is demonstrated. The IEB takes advantages of the speed and low-cost of the conventional immunochromatographic test kits and high-sensitivity of stripping voltammetry. Bismuth ions (Bi3+) have been coupled with the antibody through the bifunctional chelating agent diethylenetriamine pentaacetic acid (DTPA). After immunoreactions, Bi3+ was released and quantified by anodic stripping voltammetry at a built-in single-use screen-printed electrode. As an example for the applications of such novel device, the detection of human chorionic gonadotronphin (HCG) in a specimen was performed. This biosensor provides a more user-friendly, rapid, clinically accurate, and less expensive immunoassay for such analysis in specimens than currently available test kits.

  5. Rapid and sensitive detection of Didymella bryoniae by visual loop-mediated isothermal amplification assay

    Directory of Open Access Journals (Sweden)

    Xiefeng Yao

    2016-08-01

    Full Text Available Didymella bryoniae is a pathogenic fungus that causes gummy stem blight (GSB in Cucurbitaceae crops (e.g. cantaloupe, muskmelon, cucumber, and watermelon. GSB produces lesions on the stems and leaves, and can also be spread by seeds. Here, we developed a rapid, visual, and sensitive loop-mediated amplification (LAMP assay for D. bryoniae detection based on sequence-characterized amplified regions (GenBank accession nos GQ872461 and GQ872462 common to the two random amplification of polymorphic DNA group genotypes (RGI and RGII of D. bryoniae; ideal conditions for detection were optimized for completion in 45 min at 63°C. The sensitivity and specificity of the LAMP assay were further analyzed in comparison with those of a conventional polymerase chain reaction (PCR. The sensitivity of the LAMP assay was 1000-fold higher than that of conventional PCR with a detection limit of 0.1 fg μL−1 of targeted DNA. The LAMP assay could be accomplished in about 45 min, with the results visible to the naked eye. The assay showed high specificity in discriminating all D. bryoniae isolates from seven other fungal pathogens that occur in Cucurbitaceae crops. The LAMP assay also detected D. bryoniae infection in young muskmelon leaves with suspected early symptoms of GSB disease. Hence, the technique has great potential for developing rapid and sensitive visual detection methods for the D. bryoniae pathogen in crops and seeds. This method has potential application in early prediction of disease and reducing the risk of epidemics.

  6. Fluorescent immunochromatography for rapid and sensitive typing of seasonal influenza viruses.

    Directory of Open Access Journals (Sweden)

    Akira Sakurai

    Full Text Available Lateral flow tests also known as Immunochromatography (IC is an antigen-detection method conducted on a nitrocellulose membrane that can be completed in less than 20 min. IC has been used as an important rapid test for clinical diagnosis and surveillance of influenza viruses, but the IC sensitivity is relatively low (approximately 60% and the limit of detection (LOD is as low as 10³ pfu per reaction. Recently, we reported an improved IC assay using antibodies conjugated with fluorescent beads (fluorescent immunochromatography; FLIC for subtyping H5 influenza viruses (FLIC-H5. Although the FLIC strip must be scanned using a fluorescent reader, the sensitivity (LOD is significantly improved over that of conventional IC methods. In addition, the antibodies which are specific against the subtypes of influenza viruses cannot be available for the detection of other subtypes when the major antigenicity will be changed. In this study, we established the use of FLIC to type seasonal influenza A and B viruses (FLIC-AB. This method has improved sensitivity to 100-fold higher than that of conventional IC methods when we used several strains of influenza viruses. In addition, FLIC-AB demonstrated the ability to detect influenza type A and influenza type B viruses from clinical samples with high sensitivity and specificity (Type A: sensitivity 98.7% (74/75, specificity 100% (54/54, Type B: sensitivity 100% (90/90, specificity 98.2% (54/55 in nasal swab samples in comparison to the results of qRT-PCR. And furthermore, FLIC-AB performs better in the detection of early stage infection (under 13 h than other conventional IC methods. Our results provide new strategies to prevent the early-stage transmission of influenza viruses in humans during both seasonal outbreaks and pandemics.

  7. Multi-colored immunochromatography using nanobeads for rapid and sensitive typing of seasonal influenza viruses.

    Science.gov (United States)

    Sakurai, Akira; Takayama, Katsuyoshi; Nomura, Namiko; Yamamoto, Naoki; Sakoda, Yoshihiro; Kobayashi, Yukuharu; Kida, Hiroshi; Shibasaki, Futoshi

    2014-12-01

    Immunochromatography (IC) is an antigen-detection assay that plays an important role in the rapid diagnosis of influenza viruses because of its rapid turnaround and ease of use. Despite the usefulness of IC, the limit of detection of common IC kits is as high as 10(3)-10(4) plaque forming units (pfu) per reaction, resulting in their limited sensitivities. Early diagnosis within 24h would provide more appropriate timing of treatment. In this study, a multi-colored NanoAct™ bead IC was established to detect seasonal influenza viruses. This method has approximately 10-fold higher sensitivity than that of colloidal gold or colored latex bead IC assays, and does not require specific instruments. More notably, NanoAct™ bead IC can distinguish influenza A and B viruses from clinical samples with a straightforward readout composed of colored lines. Our results will provide new strategies for the diagnosis, treatment, and a chance to survey of influenza viruses in developing countries and in the field research. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Antibacterial activity of exogenous glutathione and its synergism on antibiotics sensitize carbapenem-associated multidrug resistant clinical isolates of Acinetobacter baumannii.

    Science.gov (United States)

    Alharbe, Roaa; Almansour, Ayidh; Kwon, Dong H

    2017-10-01

    A major clinical impact of A. baumannii is hospital-acquired infections including ventilator-associated pneumonia. The treatment of this pathogen is often difficult due to its innate and acquired resistance to almost all commercially available antibiotics. Infections with carbapenem-associated multidrug resistant A. baumannii is the most problematic. Glutathione is a tripeptide thiol-antioxidant and antibacterial activity of exogenous glutathione was reported in some bacteria. However, clinical relevance and molecular details of the antibacterial activity of glutathione are currently unclear. Seventy clinical isolates of A. baumannii including 63 carbapenem-associated multidrug resistant isolates and a type strain A. baumannii ATCC 19606 were used to determine minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Fractional inhibitory concentration (FIC) and time-killing activity with meropenem and/or glutathione were also determined in the carbapenem-associated multidrug resistant isolates. In addition, the roles of exogenous glutathione in multidrug efflux pumps and β-lactamase production were examined. Levels of MIC and MBC were ranged from 10 to 15mM of exogenous glutathione. All tested carbapenem-associated multidrug resistant isolates were sensitized by all tested antibiotics in combination with subinhibitory concentrations of glutathione. FIC levels of glutathione with carbapenem (meropenem) were allcarbapenem-associated multidrug resistant isolates were killed by subinhibitory concentrations of both glutathione and meropenem at>2log10 within 12h, suggesting glutathione synergistically interacts with meropenem. The roles of multidrug efflux pumps and β-lactamase production were excluded for the glutathione-mediated antibiotic susceptibility. Overall results demonstrate that the antibacterial activity of glutathione is clinically relevant and its synergism on antibiotics sensitizes clinical isolates of A. baumannii regardless

  9. Aptamer-mediated colorimetric method for rapid and sensitive detection of chloramphenicol in food.

    Science.gov (United States)

    Yan, Chao; Zhang, Jing; Yao, Li; Xue, Feng; Lu, Jianfeng; Li, Baoguang; Chen, Wei

    2018-09-15

    We report an aptamer-mediated colorimetric method for sensitive detection of chloramphenicol (CAP). The aptamer of CAP is immobilized by the hybridization with pre-immobilized capture probe in the microtiter plate. The horseradish peroxidase (HRP) is covalently attached to the aptamer by the biotin-streptavidin system for signal production. CAP will preferably bind with aptamer due to the high binding affinity, which attributes to the release of aptamer and HRP and thus, affects the optical signal intensity. Quantitative determination of CAP is successfully achieved in the wide range from 0.001 to 1000 ng/mL with detection limit of 0.0031 ng/mL, which is more sensitive than traditional immunoassays. This method is further validated by measuring the recovery of CAP spiked in two different food matrices (honey and fish). The aptamer-mediated colorimetric method can be a useful protocol for rapid and sensitive screening of CAP, and may be used as an alternative means for traditional immunoassays. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Colorimetry and SERS dual-mode detection of telomerase activity: combining rapid screening with high sensitivity.

    Science.gov (United States)

    Zong, Shenfei; Wang, Zhuyuan; Chen, Hui; Hu, Guohua; Liu, Min; Chen, Peng; Cui, Yiping

    2014-01-01

    As an important biomarker and therapeutic target, telomerase has attracted considerable attention concerning its detection and monitoring. Here, we present a colorimetry and surface enhanced Raman scattering (SERS) dual-mode telomerase activity detection method, which has several distinctive advantages. First, colorimetric functionality allows rapid preliminary discrimination of telomerase activity by the naked eye. Second, the employment of SERS technique results in greatly improved detection sensitivity. Third, the combination of colorimetry and SERS into one detection system can ensure highly efficacious and sensitive screening of numerous samples. Besides, the avoidance of polymerase chain reaction (PCR) procedures further guarantees fine reliability and simplicity. Generally, the presented method is realized by an "elongate and capture" procedure. To be specific, gold nanoparticles modified with Raman molecules and telomeric repeat complementary oligonucleotide are employed as the colorimetric-SERS bifunctional reporting nanotag, while magnetic nanoparticles functionalized with telomerase substrate oligonucleotide are used as the capturing substrate. Telomerase can synthesize and elongate telomeric repeats onto the capturing substrate. The elongated telomeric repeats subsequently facilitate capturing of the reporting nanotag via hybridization between telomeric repeat and its complementary strand. The captured nanotags can cause a significant difference in the color and SERS intensity of the magnetically separated sediments. Thus both the color and SERS can be used as indicators of the telomerase activity. With fast screening ability and outstanding sensitivity, we anticipate that this method would greatly promote practical application of telomerase-based early-stage cancer diagnosis.

  11. Influence of regular reporting on local Pseudomonas aeruginosa and Acinetobacter spp. sensitivity to antibiotics on consumption of antibiotics and resistance patterns.

    Science.gov (United States)

    Djordjevic, Z M; Folic, M M; Jankovic, S M

    2017-10-01

    Regular surveillance of antimicrobial resistance is an important component of multifaceted interventions directed at the problem with resistance of bacteria causing healthcare-associated infections (HAIs) in intensive care units (ICUs). Our aim was to analyse antimicrobial consumption and resistance among isolates of Pseudomonas aeruginosa and Acinetobacter spp. causing HAIs, before and after the introduction of mandatory reporting of resistance patterns to prescribers. A retrospective observational study was conducted between January 2011 and December 2015, at an interdisciplinary ICU of the Clinical Centre Kragujevac, Serbia. The intervention consisted of continuous resistance monitoring of all bacterial isolates from ICU patients and biannual reporting of results per isolate to prescribers across the hospital. Both utilization of antibiotics and density of resistant isolates of P. aeruginosa and Acinetobacter spp. were followed within the ICU. Resistance densities of P. aeruginosa to all tested antimicrobials were lower in 2015, in comparison with 2011. Although isolates of Acinetobacter spp. had lower resistance density in 2015 than in 2011 to the majority of investigated antibiotics, a statistically significant decrease was noted only for piperacillin/tazobactam. Statistically significant decreasing trends of consumption were recorded for third-generation cephalosporins, aminoglycosides and fluoroquinolones, whereas for the piperacillin/tazobactam, ampicillin/sulbactam and carbapenems, utilization trends were decreasing, but without statistical significance. In the same period, increasing trends of consumption were observed for tigecycline and colistin. Regular monitoring of resistance of bacterial isolates in ICUs and reporting of summary results to prescribers may lead to a significant decrease in utilization of some antibiotics and slow restoration of P. aeruginosa and Acinetobacter spp. susceptibility. © 2017 John Wiley & Sons Ltd.

  12. Rapid, highly sensitive detection of Gram-negative bacteria with lipopolysaccharide based disposable aptasensor.

    Science.gov (United States)

    Zhang, Jian; Oueslati, Rania; Cheng, Cheng; Zhao, Ling; Chen, Jiangang; Almeida, Raul; Wu, Jayne

    2018-07-30

    Gram-negative bacteria are one of the most common microorganisms in the environment. Their differential detection and recognition from Gram-positive bacteria has been attracting much attention over the years. Using Escherichia coli (E. coli) as a model, we demonstrated on-site detection of Gram-negative bacteria by an AC electrokinetics-based capacitive sensing method using commercial microelectrodes functionalized with an aptamer specific to lipopolysaccharides. Dielectrophoresis effect was utilized to enrich viable bacteria to the microelectrodes rapidly, achieving a detection limit of 10 2 cells/mL within a 30 s' response time. The sensor showed a negligible response to Staphylococcus aureus (S. aureus), a Gram-positive species. The developed sensor showed significant advantages in sensitivity, selectivity, cost, operation simplicity, and response time. Therefore, this sensing method has shown great application potential for environmental monitoring, food safety, and real-time diagnosis. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Rapid recycling of Ca2+ between IP3-sensitive stores and lysosomes.

    Directory of Open Access Journals (Sweden)

    Cristina I López Sanjurjo

    Full Text Available Inositol 1,4,5-trisphosphate (IP3 evokes release of Ca2+ from the endoplasmic reticulum (ER, but the resulting Ca2+ signals are shaped by interactions with additional intracellular organelles. Bafilomycin A1, which prevents lysosomal Ca2+ uptake by inhibiting H+ pumping into lysosomes, increased the amplitude of the initial Ca2+ signals evoked by carbachol in human embryonic kidney (HEK cells. Carbachol alone and carbachol in combination with parathyroid hormone (PTH evoke Ca2+ release from distinct IP3-sensitive Ca2+ stores in HEK cells stably expressing human type 1 PTH receptors. Bafilomycin A1 similarly exaggerated the Ca2+ signals evoked by carbachol or carbachol with PTH, indicating that Ca2+ released from distinct IP3-sensitive Ca2+ stores is sequestered by lysosomes. The Ca2+ signals resulting from store-operated Ca2+ entry, whether evoked by thapsigargin or carbachol, were unaffected by bafilomycin A1. Using Gd3+ (1 mM to inhibit both Ca2+ entry and Ca2+ extrusion, HEK cells were repetitively stimulated with carbachol to assess the effectiveness of Ca2+ recycling to the ER after IP3-evoked Ca2+ release. Blocking lysosomal Ca2+ uptake with bafilomycin A1 increased the amplitude of each carbachol-evoked Ca2+ signal without affecting the rate of Ca2+ recycling to the ER. This suggests that Ca2+ accumulated by lysosomes is rapidly returned to the ER. We conclude that lysosomes rapidly, reversibly and selectively accumulate the Ca2+ released by IP3 receptors residing within distinct Ca2+ stores, but not the Ca2+ entering cells via receptor-regulated, store-operated Ca2+ entry pathways.

  14. Rapid recycling of Ca2+ between IP3-sensitive stores and lysosomes.

    Science.gov (United States)

    López Sanjurjo, Cristina I; Tovey, Stephen C; Taylor, Colin W

    2014-01-01

    Inositol 1,4,5-trisphosphate (IP3) evokes release of Ca2+ from the endoplasmic reticulum (ER), but the resulting Ca2+ signals are shaped by interactions with additional intracellular organelles. Bafilomycin A1, which prevents lysosomal Ca2+ uptake by inhibiting H+ pumping into lysosomes, increased the amplitude of the initial Ca2+ signals evoked by carbachol in human embryonic kidney (HEK) cells. Carbachol alone and carbachol in combination with parathyroid hormone (PTH) evoke Ca2+ release from distinct IP3-sensitive Ca2+ stores in HEK cells stably expressing human type 1 PTH receptors. Bafilomycin A1 similarly exaggerated the Ca2+ signals evoked by carbachol or carbachol with PTH, indicating that Ca2+ released from distinct IP3-sensitive Ca2+ stores is sequestered by lysosomes. The Ca2+ signals resulting from store-operated Ca2+ entry, whether evoked by thapsigargin or carbachol, were unaffected by bafilomycin A1. Using Gd3+ (1 mM) to inhibit both Ca2+ entry and Ca2+ extrusion, HEK cells were repetitively stimulated with carbachol to assess the effectiveness of Ca2+ recycling to the ER after IP3-evoked Ca2+ release. Blocking lysosomal Ca2+ uptake with bafilomycin A1 increased the amplitude of each carbachol-evoked Ca2+ signal without affecting the rate of Ca2+ recycling to the ER. This suggests that Ca2+ accumulated by lysosomes is rapidly returned to the ER. We conclude that lysosomes rapidly, reversibly and selectively accumulate the Ca2+ released by IP3 receptors residing within distinct Ca2+ stores, but not the Ca2+ entering cells via receptor-regulated, store-operated Ca2+ entry pathways.

  15. Facile and Sensitive Epifluorescent Silica Nanoparticles for the Rapid Screening of EHEC

    Directory of Open Access Journals (Sweden)

    Pravate Tuitemwong

    2013-01-01

    Full Text Available This study was to develop antibodies conjugated fluorescent dye-doped silica nanoparticles (FDS-NPs aiming to increase signals for the rapid detection of Escherichia coli O157:H7 with glass slide method. The FDS-NPs were produced with microemulsion/sol-gel techniques resulting in spherical in shape with 47 ± 6 nm in diameter. The particles showed high intensity and stable orange color Rubpy luminescent dye. The XRD spectrum showed a broad diffraction peak in the range of – (centered at indicating an amorphous structure. Surface modifications for bioconjugation with affinity chromatography purified (IgGs antibodies were successful. The properties were evident from FTIR spectra at 1631.7 . Results indicated that nanoparticles could attach onto cells of E. coli O157:H7 coated on a glass slide, and give distinctively bright color under epifluorescence microscope (400x. It was shown that FDS-NPs could detect a very low amount of cells of E. coli O157:H7 (16 CFU in 10 ml in 60 min. The phosphate buffered saline (PBS with ionic strength of 1.70 gave zeta potential of good particle dispersion (−40 mV. This work demonstrated that highly sensitive bioconjugated E. coli O157:H7 FDS-NPs were successfully developed with a potential to be used for the rapid detection of E. coli O157:H7 in foods.

  16. Rapid and Sensitive Lateral Flow Immunoassay Method for Procalcitonin (PCT Based on Time-Resolved Immunochromatography

    Directory of Open Access Journals (Sweden)

    Xiang-Yang Shao

    2017-02-01

    Full Text Available Procalcitonin (PCT is a current, frequently-used marker for severe bacterial infection. The aim of this study was to develop a cost-effective detection kit for rapid quantitative and on-site detection of PCT. To develop the new PCT quantitative detecting kit, a double-antibody sandwich immunofluorescent assay was employed based on time-resolved immunofluorescent assay (TRFIA combined with lateral flow immunoassay (LFIA. The performance of the new developed kit was evaluated in the aspects of linearity, precision, accuracy, and specificity. Two-hundred thirty-four serum samples were enrolled to carry out the comparison test. The new PCT quantitative detecting kit exhibited a higher sensitivity (0.08 ng/mL. The inter-assay coefficient of variation (CV and the intra-assay CV were 5.4%–7.7% and 5.7%–13.4%, respectively. The recovery rates ranged from 93% to 105%. Furthermore, a high correlation (n = 234, r = 0.977, p < 0.0001 and consistency (Kappa = 0.875 were obtained when compared with the PCT kit from Roche Elecsys BRAHMS. Thus, the new quantitative method for detecting PCT has been successfully established. The results indicated that the newly-developed system based on TRFIA combined with LFIA was suitable for rapid and on-site detection for PCT, which might be a useful platform for other biomarkers in point-of-care tests.

  17. The antibiotic resistome.

    Science.gov (United States)

    Wright, Gerard D

    2010-08-01

    Antibiotics are essential for the treatment of bacterial infections and are among our most important drugs. Resistance has emerged to all classes of antibiotics in clinical use. Antibiotic resistance has, proven inevitable and very often it emerges rapidly after the introduction of a drug into the clinic. There is, therefore, a great interest in understanding the origins, scope and evolution of antibiotic resistance. The review discusses the concept of the antibiotic resistome, which is the collection of all genes that directly or indirectly contribute to antibiotic resistance. The review seeks to assemble current knowledge of the resistome concept as a means of understanding the totality of resistance and not just resistance in pathogenic bacteria. The concept of the antibiotic resistome provides a framework for the study and understanding of how resistance emerges and evolves. Furthermore, the study of the resistome reveals strategies that can be applied in new antibiotic discoveries.

  18. Rapid and highly sensitive detection of Enterovirus 71 by using nanogold-enhanced electrochemical impedance spectroscopy

    International Nuclear Information System (INIS)

    Li, Hsing-Yuan; Tseng, Shing-Hua; Cheng, Tsai-Mu; Chu, Hsueh-Liang; Lu, Yu-Ning; Wang, Fang-Yu; Tu, Lung-Chen; Chang, Chia-Ching; Tsai, Li-Yun; Shieh, Juo-Yu; Yang, Jyh-Yuan; Juan, Chien-Chang

    2013-01-01

    Enterovirus 71 (EV71) infection is an emerging infectious disease causing neurological complications and/or death within two to three days after the development of fever and rash. A low viral titre in clinical specimens makes the detection of EV71 difficult. Conventional approaches for detecting EV71 are time consuming, poorly sensitive, or complicated, and cannot be used effectively for clinical diagnosis. Furthermore, EV71 and Coxsackie virus A16 (CA16) may cross react in conventional assays. Therefore, a rapid, highly sensitive, specific, and user-friendly test is needed. We developed an EV71-specific nanogold-modified working electrode for electrochemical impedance spectroscopy in the detection of EV71. Our results show that EV71 can be distinguished from CA16, Herpes simplex virus, and lysozyme, with the modified nanogold electrode being able to detect EV71 in concentrations as low as 1 copy number/50 μl reaction volume, and the duration between sample preparation and detection being 11 min. This detection platform may have the potential for use in point-of-care diagnostics. (paper)

  19. Rapid and highly sensitive detection of Enterovirus 71 by using nanogold-enhanced electrochemical impedance spectroscopy

    Science.gov (United States)

    Li, Hsing-Yuan; Tseng, Shing-Hua; Cheng, Tsai-Mu; Chu, Hsueh-Liang; Lu, Yu-Ning; Wang, Fang-Yu; Tsai, Li-Yun; Shieh, Juo-Yu; Yang, Jyh-Yuan; Juan, Chien-Chang; Tu, Lung-Chen; Chang, Chia-Ching

    2013-07-01

    Enterovirus 71 (EV71) infection is an emerging infectious disease causing neurological complications and/or death within two to three days after the development of fever and rash. A low viral titre in clinical specimens makes the detection of EV71 difficult. Conventional approaches for detecting EV71 are time consuming, poorly sensitive, or complicated, and cannot be used effectively for clinical diagnosis. Furthermore, EV71 and Coxsackie virus A16 (CA16) may cross react in conventional assays. Therefore, a rapid, highly sensitive, specific, and user-friendly test is needed. We developed an EV71-specific nanogold-modified working electrode for electrochemical impedance spectroscopy in the detection of EV71. Our results show that EV71 can be distinguished from CA16, Herpes simplex virus, and lysozyme, with the modified nanogold electrode being able to detect EV71 in concentrations as low as 1 copy number/50 μl reaction volume, and the duration between sample preparation and detection being 11 min. This detection platform may have the potential for use in point-of-care diagnostics.

  20. A Sensitive Assay for Rapid Detection and Quantification of Aphanomyces euteiches in Soil.

    Science.gov (United States)

    Gangneux, Christophe; Cannesan, Marc-Antoine; Bressan, Mélanie; Castel, Lisa; Moussart, Anne; Vicré-Gibouin, Maïté; Driouich, Azeddine; Trinsoutrot-Gattin, Isabelle; Laval, Karine

    2014-10-01

    Aphanomyces euteiches is a widespread oomycete pathogen causing root rot in a wide range of leguminous crops. Losses can reach up to 100% for pea culture and there is currently no registered pesticide for its control. Crop management remains the most efficient tool to control root rot, and avoidance of infested soil seems to be the optimal solution. A test was developed to identify fields suitable for pea crops, consisting of the determination of the inoculum potential of soil using baiting plants. A new rapid, specific, and sensitive molecular method is described allowing the quantification of less than 10 oospores per gram of soil. This challenge is achieved by a real-time polymerase chain reaction procedure targeting internal transcribed spacer 1 from the ribosomal DNA operons. A preliminary study based on typical soils from northwestern France demonstrated that the A. euteiches oospore density in soil is related to the inoculum potential. Furthermore, this method has proved sensitive enough to accurately study the influence of biotic factors that may govern the actual emergence of root rot.

  1. Normal flora of conjunctiva and lid margin, as well as its antibiotic sensitivity, in patients undergoing cataract surgery at Phramongkutklao Hospital

    OpenAIRE

    Ratnumnoi,Ravee; Keorochana,Narumon; Sonthisombat,Chavalit

    2017-01-01

    Ravee Ratnumnoi, Narumon Keorochana, Chavalit Sontisombat Department of Ophthalmology, Phramongkutklao Hospital, Bangkok, Thailand Objective: This study aimed to evaluate the normal flora of conjunctiva and lid margin, as well as its antibiotic sensitivity. Design: This was a prospective cross-sectional study. Patients and methods: A prospective study was conducted on 120 patients who underwent cataract surgery at the Phramongkutklao Hospital from September 2014 to October 2014. Conjunctiva...

  2. Development of a novel and automated fluorescent immunoassay for the analysis of beta-lactam antibiotics

    NARCIS (Netherlands)

    Benito-Pena, E.; Moreno-Bondi, M.C.; Orellana, G.; Maquieira, K.; Amerongen, van A.

    2005-01-01

    An automated immunosensor for the rapid and sensitive analysis of penicillin type -lactam antibiotics has been developed and optimized. An immunogen was prepared by coupling the common structure of the penicillanic -lactam antibiotics, i.e., 6-aminopenicillanic acid to keyhole limpet hemocyanin.

  3. Antibacterial activity of epigallocatechin-3-gallate (EGCG) and its synergism with β-lactam antibiotics sensitizing carbapenem-associated multidrug resistant clinical isolates of Acinetobacter baumannii.

    Science.gov (United States)

    Lee, Spencer; Razqan, Ghaida Saleh Al; Kwon, Dong H

    2017-01-15

    Infections caused by Acinetobacter baumannii were responsive to conventional antibiotic therapy. However, recently, carbapenem-associated multidrug resistant isolates have been reported worldwide and present a major therapeutic challenge. Epigallocatechin-3-Gallate (EGCG) extracted from green tea exhibits antibacterial activity. We evaluated the antibacterial activity of EGCG and possible synergism with antibiotics in carbapenem-associated multidrug resistant A. baumannii. A potential mechanism for synergism was also explored. Seventy clinical isolates of A. baumannii collected from geographically different areas were analyzed by minimal inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of EGCG. Checkerboard and time-killing assays were performed to exam the synergism between EGCG and antibiotics. The effects of EGCG on a multidrug efflux pump inhibitor (1-[1-naphthylmethyl] piperazine; NMP) and β-lactamase production were also examined in A. baumannii. Sixty-three of 70 clinical isolates of A. baumannii carried carbapenemase-encoding genes with carbapenem-associated multidrug resistance. Levels of MIC and MBC of EGCG ranged from 64 to 512µg/ml and from 128 to ≥1024µg/ml, respectively among the clinical isolates. MIC 90 and MBC 86 levels were 256µg/ml and 512µg/ml of EGCG, respectively. Subinhibitory concentration of EGCG in combination with all antibiotics tested, including carbapenem, sensitized (MICs fall≤1.0µg/ml) all carbapenem-associated multidrug resistant isolates. Checkerboard and time-killing assays showed synergism between EGCG and meropenem (or carbenicillin) counted as fractional inhibitory concentration of 2log10 within 12h, respectively. EGCG significantly increased the effect of NMP but was unrelated to β-lactamase production in A. baumannii, suggesting EGCG may be associated with inhibition of efflux pumps. Overall we suggest that EGCG-antibiotic combinations might provide an alternative approach to treat

  4. A rapid, sensitive and reliable diagnostic test for scrub typhus in China

    Directory of Open Access Journals (Sweden)

    Zhang Lijuan

    2011-01-01

    Full Text Available Purpose: To evaluate the performances for detection of IgM and IgG antibodies to Orientia. tsutsugamushi (Ot using a gold conjugate-based rapid diagnostic test (RDT. Materials and Methods: The RDT employing mixture recombinant 56-kDa proteins of O. tsutsugamushi and the mIFA assay was performed on 33 patients from Fujian and Yunnan province respectively and 94 positive sera (36 from Hainan province and 58 from Jiangsu province from convalescent stages of the patients with scrub typhus respectively and 82 negative sera from healthy farmers from Anhui province and Beijing City respectively in 2009. A comparison of the RDT and mIFA assay was performed by using the c2 test and the P level of ≤0.05 was considered to be significant. Results: Among these 94 positive sera from convalescent stages of the illness and 82 sera from control farmers, the specificity of RDT was 100% for both IgM and IgG tests. In 33 cases with scrub typhus, 5 cases were positively detected earlier by RDT than by mIFA for the IgM test, and 2 cases were positive for the IgG test. The sensitivities of RDT were 93.9% and 90.9% for IgM and IgG, respectively. Considering IgM and IgG together, the sensitivity was 100%. The geometric mean titre (GMT of IFA and the RDT assay in diluted sera from confirmed cases were 1:37 versus 1:113 respectively (P<0.001 for IgM test and 1:99 versus 1:279 respectively (P<0.016 for IgG. Conclusions: The RDT was more sensitive than the traditional IFA for the early diagnosis of scrub typhus and was particularly suitable for use in rural areas.

  5. Rapid and sensitive detection of ketamine in blood using novel fluorescence genosensor.

    Science.gov (United States)

    Ding, Yanjun; Li, Xingmei; Guo, Yadong; Yan, Jie; Ling, Jiang; Li, Weichen; Lan, Lingmei; Chang, Yunfeng; Cai, Jifeng; Zha, Lagabaiyla

    2017-12-01

    In recent years, drug abuse has been considered as a most challenging social problem that aroused public attention. Ketamine has increased in unregulated use as a 'recreational drug' in teenagers. However, there is no suitable and maneuverable detection method for ketamine in situ at the moment. Fluorescence sensor technique, with predominant recognition and simple operation, is a good potential application in drug detection. Here, we first reported a highly sensitive and selective fluorescence genosensor for rapid detection of ketamine based on DNA-templated silver nanoclusters (DNA-AgNCs) probes, in which the DNA sequence could specially recognize ketamine with high affinity. Parameters affecting detection efficiency were investigated and optimized. Under optimum conditions, the as-prepared genosensor can allow for the determination of ketamine in the concentration range of 0.0001-20 μg/mL with two linear equations: one is y = 2.84x-7.139 (R 2 = 0.987) for 0.0001-0.1 μg/mL, and the other is y = 1.87x-0.091 (R 2 = 0.962) for 0.1-20 μg/mL, and the estimated detection limit of ketamine is 0.06 ng/mL. Moreover, the feasibility of this proposed method was also demonstrated by analyzing forensic blood samples. Compared with official gas chromatography/mass spectrometry (GC/MS), this fluorescence genosensor is simple, rapid, and accurate for quantitative determination of ketamine in blood for pharmaceutical and forensic analysis. Overall, it is the first report on a fluorescence genosensor for detecting ketamine directly in blood. This research may provide a new insight for the analyst to band fluorescence genosensor technology together with drug monitoring in the battle against drug abuse and forensic examination. Graphical abstract High selectively detection of ketamine using a novel fluorescence genosensor based on DNA-AgNCs probe.

  6. Rapid and sensitive PCR-dipstick DNA chromatography for multiplex analysis of the oral microbiota.

    Science.gov (United States)

    Tian, Lingyang; Sato, Takuichi; Niwa, Kousuke; Kawase, Mitsuo; Tanner, Anne C R; Takahashi, Nobuhiro

    2014-01-01

    A complex of species has been associated with dental caries under the ecological hypothesis. This study aimed to develop a rapid, sensitive PCR-dipstick DNA chromatography assay that could be read by eye for multiplex and semiquantitative analysis of plaque bacteria. Parallel oligonucleotides were immobilized on a dipstick strip for multiplex analysis of target DNA sequences of the caries-associated bacteria, Streptococcus mutans, Streptococcus sobrinus, Scardovia wiggsiae, Actinomyces species, and Veillonella parvula. Streptavidin-coated blue-colored latex microspheres were to generate signal. Target DNA amplicons with an oligonucleotide-tagged terminus and a biotinylated terminus were coupled with latex beads through a streptavidin-biotin interaction and then hybridized with complementary oligonucleotides on the strip. The accumulation of captured latex beads on the test and control lines produced blue bands, enabling visual detection with the naked eye. The PCR-dipstick DNA chromatography detected quantities as low as 100 pg of DNA amplicons and demonstrated 10- to 1000-fold higher sensitivity than PCR-agarose gel electrophoresis, depending on the target bacterial species. Semiquantification of bacteria was performed by obtaining a series of chromatograms using serial 10-fold dilution of PCR-amplified DNA extracted from dental plaque samples. The assay time was less than 3 h. The semiquantification procedure revealed the relative amounts of each test species in dental plaque samples, indicating that this disposable device has great potential in analysis of microbial composition in the oral cavity and intestinal tract, as well as in point-of-care diagnosis of microbiota-associated diseases.

  7. Rapid and Sensitive PCR-Dipstick DNA Chromatography for Multiplex Analysis of the Oral Microbiota

    Directory of Open Access Journals (Sweden)

    Lingyang Tian

    2014-01-01

    Full Text Available A complex of species has been associated with dental caries under the ecological hypothesis. This study aimed to develop a rapid, sensitive PCR-dipstick DNA chromatography assay that could be read by eye for multiplex and semiquantitative analysis of plaque bacteria. Parallel oligonucleotides were immobilized on a dipstick strip for multiplex analysis of target DNA sequences of the caries-associated bacteria, Streptococcus mutans, Streptococcus sobrinus, Scardovia wiggsiae, Actinomyces species, and Veillonella parvula. Streptavidin-coated blue-colored latex microspheres were to generate signal. Target DNA amplicons with an oligonucleotide-tagged terminus and a biotinylated terminus were coupled with latex beads through a streptavidin-biotin interaction and then hybridized with complementary oligonucleotides on the strip. The accumulation of captured latex beads on the test and control lines produced blue bands, enabling visual detection with the naked eye. The PCR-dipstick DNA chromatography detected quantities as low as 100 pg of DNA amplicons and demonstrated 10- to 1000-fold higher sensitivity than PCR-agarose gel electrophoresis, depending on the target bacterial species. Semiquantification of bacteria was performed by obtaining a series of chromatograms using serial 10-fold dilution of PCR-amplified DNA extracted from dental plaque samples. The assay time was less than 3 h. The semiquantification procedure revealed the relative amounts of each test species in dental plaque samples, indicating that this disposable device has great potential in analysis of microbial composition in the oral cavity and intestinal tract, as well as in point-of-care diagnosis of microbiota-associated diseases.

  8. A Method for Rapid Measurement of Contrast Sensitivity on Mobile Touch-Screens

    Science.gov (United States)

    Mulligan, Jeffrey B.

    2016-01-01

    Touch-screen displays in cell phones and tablet computers are now pervasive, making them an attractive option for vision testing outside of the laboratory or clinic. Here we de- scribe a novel method in which subjects use a finger swipe to indicate the transition from visible to invisible on a grating which is swept in both contrast and frequency. Because a single image can be swiped in about a second, it is practical to use a series of images to zoom in on particular ranges of contrast or frequency, both to increase the accuracy of the measurements and to obtain an estimate of the reliability of the subject. Sensitivities to chromatic and spatio-temporal modulations are easily measured using the same method. A proto- type has been developed for Apple Computer's iPad/iPod/iPhone family of devices, implemented using an open-source scripting environment known as QuIP (QUick Image Processing, http://hsi.arc.nasa.gov/groups/scanpath/research.php). Preliminary data show good agreement with estimates obtained from traditional psychophysical methods as well as newer rapid estimation techniques. Issues relating to device calibration are also discussed.

  9. NBLAST: Rapid, Sensitive Comparison of Neuronal Structure and Construction of Neuron Family Databases.

    Science.gov (United States)

    Costa, Marta; Manton, James D; Ostrovsky, Aaron D; Prohaska, Steffen; Jefferis, Gregory S X E

    2016-07-20

    Neural circuit mapping is generating datasets of tens of thousands of labeled neurons. New computational tools are needed to search and organize these data. We present NBLAST, a sensitive and rapid algorithm, for measuring pairwise neuronal similarity. NBLAST considers both position and local geometry, decomposing neurons into short segments; matched segments are scored using a probabilistic scoring matrix defined by statistics of matches and non-matches. We validated NBLAST on a published dataset of 16,129 single Drosophila neurons. NBLAST can distinguish neuronal types down to the finest level (single identified neurons) without a priori information. Cluster analysis of extensively studied neuronal classes identified new types and unreported topographical features. Fully automated clustering organized the validation dataset into 1,052 clusters, many of which map onto previously described neuronal types. NBLAST supports additional query types, including searching neurons against transgene expression patterns. Finally, we show that NBLAST is effective with data from other invertebrates and zebrafish. VIDEO ABSTRACT. Copyright © 2016 MRC Laboratory of Molecular Biology. Published by Elsevier Inc. All rights reserved.

  10. Rapid, Simple, and Sensitive Spectrofluorimetric Method for the Estimation of Ganciclovir in Bulk and Pharmaceutical Formulations

    Directory of Open Access Journals (Sweden)

    Garima Balwani

    2013-01-01

    Full Text Available A new, simple, rapid, sensitive, accurate, and affordable spectrofluorimetric method was developed and validated for the estimation of ganciclovir in bulk as well as in marketed formulations. The method was based on measuring the native fluorescence of ganciclovir in 0.2 M hydrochloric acid buffer of pH 1.2 at 374 nm after excitation at 257 nm. The calibration graph was found to be rectilinear in the concentration range of 0.25–2.00 μg mL−1. The limit of quantification and limit of detection were found to be 0.029 μg mL−1 and 0.010 μg mL−1, respectively. The method was fully validated for various parameters according to ICH guidelines. The results demonstrated that the procedure is accurate, precise, and reproducible (relative standard deviation <2% and can be successfully applied for the determination of ganciclovir in its commercial capsules with average percentage recovery of 101.31 ± 0.90.

  11. Rapid and sensitive reporter gene assays for detection of antiandrogenic and estrogenic effects of environmental chemicals

    DEFF Research Database (Denmark)

    Vinggaard, Anne; Jørgensen, E.C.B.; Larsen, John Christian

    1999-01-01

    Reports on increasing incidences in developmental abnormalities of the human male reproductive tract and the recent identifications of environmental chemicals with antiandrogenic activity necessitate the screening of a larger number of compounds in order to get an overview of potential antiandrog......Reports on increasing incidences in developmental abnormalities of the human male reproductive tract and the recent identifications of environmental chemicals with antiandrogenic activity necessitate the screening of a larger number of compounds in order to get an overview of potential...... antiandrogenic chemicals present in our environment. Thus, there is a great need for an effective in vitro screening method for (anti)androgenic chemicals. We have developed a rapid, sensitive, and reproducible reporter gene assay for detection of antiandrogenic chemicals. Chinese Hamster Ovary cells were...... calcium phosphate transfection method, this method has the advantage of being more feasible, as the assay can be scaled down to the microtiter plate format. Furthermore, the transfection reagent is noncytotoxic, allowing its addition together with the test compounds thereby reducing the hands...

  12. A rapid and sensitive alcohol oxidase/catalase conductometric biosensor for alcohol determination.

    Science.gov (United States)

    Hnaien, M; Lagarde, F; Jaffrezic-Renault, N

    2010-04-15

    A new conductometric biosensor has been developed for the determination of short chain primary aliphatic alcohols. The biosensor assembly was prepared through immobilization of alcohol oxidase from Hansenula sp. and bovine liver catalase in a photoreticulated poly(vinyl alcohol) membrane at the surface of interdigitated microelectrodes. The local conductivity increased rapidly after alcohol addition, reaching steady-state within 10 min. The sensitivity was maximal for methanol (0.394+/-0.004 microS microM(-1), n=5) and decreased by increasing the alcohol chain length. The response was linear up to 75 microM for methanol, 70 microM for ethanol and 65 microM for 1-propanol and limits of detection were 0.5 microM, 1 microM and 3 microM, respectively (S/N=3). No significant loss of the enzyme activities was observed after 3 months of storage at 4 degrees C in a 20mM phosphate buffer solution pH 7.2 (two or three measurements per week). After 4 months, 95% of the initial signal still remained. The biosensor response to ethanol was not significantly affected by acetic, lactic, ascorbic, malic, oxalic, citric, tartaric acids or glucose. The bi-enzymatic sensor was successfully applied to the determination of ethanol in different alcoholic beverages. (c) 2009 Elsevier B.V. All rights reserved.

  13. Identification of Mycobacterial Genes Involved in Antibiotic Sensitivity: Implications for the Treatment of Tuberculosis with β-Lactam-Containing Regimens

    Science.gov (United States)

    Viswanathan, Gopinath; Yadav, Sangya

    2017-01-01

    ABSTRACT In a Mycobacterium smegmatis mutant library screen, transposon mutants with insertions in fhaA, dprE2, rpsT, and parA displayed hypersusceptibility to antibiotics, including the β-lactams meropenem, ampicillin, amoxicillin, and cefotaxime. Sub-MIC levels of octoclothepin, a psychotic drug inhibiting ParA, phenocopied the parA insertion and enhanced the bactericidal activity of meropenem against Mycobacterium tuberculosis in combination with clavulanate. Our study identifies novel factors associated with antibiotic resistance, with implications in repurposing β-lactams for tuberculosis treatment. PMID:28438925

  14. Incremental cost of nosocomial bacteremia according to the focus of infection and antibiotic sensitivity of the causative microorganism in a university hospital.

    Science.gov (United States)

    Riu, Marta; Chiarello, Pietro; Terradas, Roser; Sala, Maria; Garcia-Alzorriz, Enric; Castells, Xavier; Grau, Santiago; Cots, Francesc

    2017-04-01

    To estimate the incremental cost of nosocomial bacteremia according to the causative focus and classified by the antibiotic sensitivity of the microorganism.Patients admitted to Hospital del Mar in Barcelona from 2005 to 2012 were included. We analyzed the total hospital costs of patients with nosocomial bacteremia caused by microorganisms with a high prevalence and, often, with multidrug-resistance. A control group was defined by selecting patients without bacteremia in the same diagnosis-related group.Our hospital has a cost accounting system (full-costing) that uses activity-based criteria to estimate per-patient costs. A logistic regression was fitted to estimate the probability of developing bacteremia (propensity score) and was used for propensity-score matching adjustment. This propensity score was included in an econometric model to adjust the incremental cost of patients with bacteremia with differentiation of the causative focus and antibiotic sensitivity.The mean incremental cost was estimated at &OV0556;15,526. The lowest incremental cost corresponded to bacteremia caused by multidrug-sensitive urinary infection (&OV0556;6786) and the highest to primary or unknown sources of bacteremia caused by multidrug-resistant microorganisms (&OV0556;29,186).This is one of the first analyses to include all episodes of bacteremia produced during hospital stays in a single study. The study included accurate information about the focus and antibiotic sensitivity of the causative organism and actual hospital costs. It provides information that could be useful to improve, establish, and prioritize prevention strategies for nosocomial infections.

  15. An International Model for Antibiotics Regulation.

    Science.gov (United States)

    Aguirre, Emilie

    We face a global antibiotics resistance crisis. Antibiotic drugs are rapidly losing their effectiveness, potentially propelling us toward a post-antibiotic world. The largest use of antibiotics in the world is in food-producing animals. Food producers administer these drugs in routine, low doses—the types of doses that are incidentally the most conducive to breeding antibiotic resistance. In general, individual countries have been too slow to act in regulating misuse and overuse of antibiotics in foodproducing animals. This problem will only worsen with the significant projected growth in meat consumption and production expected in emerging economies in the near future. Although individual countries regulating antibiotics can have important effects, one country alone cannot insulate itself entirely from the effects of antibiotic resistance, nor can one country solve the crisis for itself or for the world. The global nature of the food system and the urgency of the problem require immediate global solutions. Adapting a democratic experimentalist approach at the international level can help achieve this goal. Using an international democratic experimentalist framework in conjunction with the World Organization for Animal Health (OIE) would provide for increased systematized data collection and lead to heightened, scientifically informed OIE standards, enforceable by the World Trade Organization (WTO), which could have a significant impact on the reduction of subtherapeutic use of antibiotics internationally. International democratic experimentalism addresses the global intricacy, time sensitivity, context- and culture-specificity, and knowledgeintensiveness of this problem. By encouraging more countries to experiment to solve this problem, the democratic experimentalist model would help develop a larger database of solutions to enable more meaningful cross-country comparisons across a wider range of contexts. This approach maintains democratic governance and

  16. Rapid and Sensitive Quantification of Isotopic Mixtures Using a Rapidly-Swept External Cavity Quantum Cascade Laser

    Directory of Open Access Journals (Sweden)

    Brian E. Brumfield

    2016-05-01

    Full Text Available A rapidly-swept external-cavity quantum cascade laser with an open-path Herriott cell is used to quantify gas-phase chemical mixtures of D2O and HDO at a rate of 40 Hz (25-ms measurement time. The chemical mixtures were generated by evaporating D2O liquid near the open-path Herriott cell, allowing the H/D exchange reaction with ambient H2O to produce HDO. Fluctuations in the ratio of D2O and HDO on timescales of <1 s due to the combined effects of plume transport and the H/D exchange chemical reaction are observed. Noise-equivalent concentrations (1σ (NEC of 147.0 ppbv and 151.6 ppbv in a 25-ms measurement time are determined for D2O and HDO, respectively, with a 127-m optical path. These NECs are improved to 23.0 and 24.0 ppbv with a 1-s averaging time for D2O and HDO, respectively. NECs <200 ppbv are also estimated for N2O, 1,1,1,2–tetrafluoroethane (F134A, CH4, acetone and SO2 for a 25-ms measurement time. The isotopic precision for measurement of the [D2O]/[HDO] concentration ratio of 33‰ and 5‰ is calculated for the current experimental conditions for measurement times of 25 ms and 1 s, respectively.

  17. The prevalence and antibiotic sensitivity of oral Viridans streptococci in healthy children and children with disabilities in Kuwait.

    Science.gov (United States)

    Salako, Nathanael O; Rotimi, Vincent; Philip, Leeba; Haidar, Hussien A; Hamdan, Hussien M

    2007-01-01

    The purpose of this study was to compare the antibiotic susceptibility profiles of Viridans streptococci (VS) isolated from the oral cavity of healthy children and children with disabilities in Kuwait. Plaque samples were collected from the tooth and tongue surfaces of 102 healthy children and 102 children who were intellectually disabled and institutionalized. The resistance to seven antibiotics (amoxicillin, cephalothin, clindamycin, erythromycin, penicillin G, tetracycline, and vancomycin) was tested. A total of 330 (44.5%) VS were isolated from the children who were healthy and 411 (55.5%) from children with disabilities. The most common isolates were S. salivarius (27.3%) in healthy children; S. sanguis (22.6%) was predominant among children who were disabled. S. mutans was found in 12.1% of the healthy children and in 16.5% of the children who were disabled. The combined percentage of resistant strains (healthy and disabled) was found to be highest with amoxicillin (43%) and lowest with vancomycin (12%). S. sanguis, S. mitis and S. oralis were more resistant in healthy children (45%, 56%, and 55% respectively) than in children with disabilities (40%, 47% and 47% respectively). S. mutans was the least resistant species to all antibiotics in both groups of children. About 56% of all streptococci isolated from both groups were resistant to at least one of the antibiotics tested. The data showed that there was a difference in the level of resistance of oral VS isolated from healthy children and children with disabilities to some antibiotics commonly used in dentistry.

  18. Combination of methylated-DNA precipitation and methylation-sensitive restriction enzymes (COMPARE-MS) for the rapid, sensitive and quantitative detection of DNA methylation.

    Science.gov (United States)

    Yegnasubramanian, Srinivasan; Lin, Xiaohui; Haffner, Michael C; DeMarzo, Angelo M; Nelson, William G

    2006-02-09

    Hypermethylation of CpG island (CGI) sequences is a nearly universal somatic genome alteration in cancer. Rapid and sensitive detection of DNA hypermethylation would aid in cancer diagnosis and risk stratification. We present a novel technique, called COMPARE-MS, that can rapidly and quantitatively detect CGI hypermethylation with high sensitivity and specificity in hundreds of samples simultaneously. To quantitate CGI hypermethylation, COMPARE-MS uses real-time PCR of DNA that was first digested by methylation-sensitive restriction enzymes and then precipitated by methyl-binding domain polypeptides immobilized on a magnetic solid matrix. We show that COMPARE-MS could detect five genome equivalents of methylated CGIs in a 1000- to 10,000-fold excess of unmethylated DNA. COMPARE-MS was used to rapidly quantitate hypermethylation at multiple CGIs in >155 prostate tissues, including benign and malignant prostate specimens, and prostate cell lines. This analysis showed that GSTP1, MDR1 and PTGS2 CGI hypermethylation as determined by COMPARE-MS could differentiate between malignant and benign prostate with sensitivities >95% and specificities approaching 100%. This novel technology could significantly improve our ability to detect CGI hypermethylation.

  19. Development of field-applicable tests for rapid and sensitive detection of Candidatus Phytoplasma oryzae.

    Science.gov (United States)

    Wambua, Lillian; Schneider, Bernd; Okwaro, Allan; Wanga, Joseph Odhiambo; Imali, Olive; Wambua, Peninah Nduku; Agutu, Lavender; Olds, Cassandra; Jones, Chris Stephen; Masiga, Daniel; Midega, Charles; Khan, Zeyaur; Jores, Joerg; Fischer, Anne

    2017-10-01

    Napier grass Stunt Disease (NSD) is a severe disease of Napier grass (Pennisetum purpureum) in Eastern Africa, caused by the leafhopper-transmitted bacterium Candidatus Phytoplasma oryzae. The pathogen severely impairs the growth of Napier grass, the major fodder for dairy cattle in Eastern Africa. NSD is associated with biomass losses of up to 70% of infected plants. Diagnosis of NSD is done by nested PCR targeting the phytoplasma DNA, which is difficult to perform in developing countries with little infrastructure. We report the development of an easy to use, rapid, sensitive and specific molecular assay for field diagnosis of NSD. The procedure is based on recombinase polymerase amplification and targets the imp gene encoding a pathogen-specific immunodominant membrane protein. Therefore we followed a two-step process. First we developed an isothermal DNA amplification method for real time fluorescence application and then transferred this assay to a lateral flow format. The limit of detection for both procedures was estimated to be 10 organisms. We simplified the template preparation procedure by using freshly squeezed phloem sap from Napier grass. Additionally, we developed a laboratory serological assay with the potential to be converted to a lateral flow assay. Two murine monoclonal antibodies with high affinity and specificity to the immunodominant membrane protein IMP of Candidatus Phytoplasma oryzae were generated. Both antibodies specifically reacted with the denatured or native 17 kDa IMP protein. In dot blot experiments of extracts from infected plant, phytoplasmas were detected in as little as 12,5 μg of fresh plant material. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. Rapid identification of bacterial resistance to Ciprofloxacin using surface-enhanced Raman spectroscopy

    Science.gov (United States)

    Kastanos, Evdokia; Hadjigeorgiou, Katerina; Pitris, Costas

    2014-02-01

    Due to its effectiveness and broad coverage, Ciprofloxacin is the fifth most prescribed antibiotic in the US. As current methods of infection diagnosis and antibiotic sensitivity testing (i.e. an antibiogram) are very time consuming, physicians prescribe ciprofloxacin before obtaining antibiogram results. In order to avoid increasing resistance to the antibiotic, a method was developed to provide both a rapid diagnosis and the sensitivity to the antibiotic. Using Surface Enhanced Raman Spectroscopy, an antibiogram was obtained after exposing the bacteria to Ciprofloxacin for just two hours. Spectral analysis revealed clear separation between sensitive and resistant bacteria and could also offer some inside into the mechanisms of resistance.

  1. Prevalence of bacterial agents isolated from clinical cases of bovine mastitis in the dry period and the determination of their antibiotic sensitivity in Tabriz, Iran

    Directory of Open Access Journals (Sweden)

    Samad Mosaferi

    2015-09-01

    Full Text Available Objective: To determine the prevalence of mastitis-causing bacteria in the dry period and its antibiotic sensitivity. Methods: In this study, 852 dry cows were examined. A total of 30 cows with clinical mastitis symptoms were detected and their milk samples were collected. In order to purify the bacteria, brain heart infusion and blood agar media were applied and single colonies were used for Gram staining, oxidase and catalase testing, cultivating in O-F medium to determine the genus and species of bacteria. Then, antimicrobial susceptibility was tested by the agar disk diffusion method. Results: The prevalence of isolated bacteria was 2.46%, in which coagulase positive Staphylococcus, coagulase negative Staphylococcus, Streptococcus dysgalactiae, Streptococcus faecalis, Escherichia coli, Pseudomonas, Bacillus and yeast were (9/99%, (6/66%, (13/32%, (3/33%, (6/66%, (13/32%, (9/99% and (6/66%, respectively. After tests of antibiotic susceptibility, the most and the least sensitivity were reported to enrofloxacin and ampicillin respectively. Conclusions: This study indicated that Streptococcus dysgalactiae is the most commonly isolated bacteria with the greatest sensitivity to enrofloxacin and tetracycline which can be used to treat mastitis in the dry period in Tabriz.

  2. Rapid induction of dopamine sensitization in the nucleus accumbens shell induced by a single injection of cocaine.

    Science.gov (United States)

    Singer, Bryan F; Bryan, Myranda A; Popov, Pavlo; Robinson, Terry E; Aragona, Brandon J

    2017-05-01

    Repeated intermittent exposure to cocaine results in the neurochemical sensitization of dopamine (DA) transmission within the nucleus accumbens (NAc). Indeed, the excitability of DA neurons in the ventral tegmental area (VTA) is enhanced within hours of initial psychostimulant exposure. However, it is not known if this is accompanied by a comparably rapid change in the ability of cocaine to increase extracellular DA concentrations in the ventral striatum. To address this question we used fast-scan cyclic voltammetry (FSCV) in awake-behaving rats to measure DA responses in the NAc shell following an initial intravenous cocaine injection, and then again 2-h later. Both injections quickly elevated DA levels in the NAc shell, but the second cocaine infusion produced a greater effect than the first, indicating sensitization. This suggests that a single injection of cocaine induces sensitization-related plasticity very rapidly within the mesolimbic DA system. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Dielectrophoretic assay of bacterial resistance to antibiotics

    International Nuclear Information System (INIS)

    Johari, Juliana; Huebner, Yvonne; Hull, Judith C; Dale, Jeremy W; Hughes, Michael P

    2003-01-01

    The dielectrophoretic collection spectra of antibiotic-sensitive and antibiotic-resistant strains of Staphylococcus epidermidis have been determined. These indicate that in the absence of antibiotic treatment there is a strong similarity between the dielectric properties of sensitive and resistant strains, and that there is a significant difference between the sensitive strains before and after treatment with the antibiotic streptomycin after 24 h exposure. This method offers possibilities for the assessment of bacterial resistance to antibiotics. (note)

  4. The diagnostic sensitivity of dengue rapid test assays is significantly enhanced by using a combined antigen and antibody testing approach.

    Directory of Open Access Journals (Sweden)

    Scott R Fry

    2011-06-01

    Full Text Available BACKGROUND: Serological tests for IgM and IgG are routinely used in clinical laboratories for the rapid diagnosis of dengue and can differentiate between primary and secondary infections. Dengue virus non-structural protein 1 (NS1 has been identified as an early marker for acute dengue, and is typically present between days 1-9 post-onset of illness but following seroconversion it can be difficult to detect in serum. AIMS: To evaluate the performance of a newly developed Panbio® Dengue Early Rapid test for NS1 and determine if it can improve diagnostic sensitivity when used in combination with a commercial IgM/IgG rapid test. METHODOLOGY: The clinical performance of the Dengue Early Rapid was evaluated in a retrospective study in Vietnam with 198 acute laboratory-confirmed positive and 100 negative samples. The performance of the Dengue Early Rapid in combination with the IgM/IgG Rapid test was also evaluated in Malaysia with 263 laboratory-confirmed positive and 30 negative samples. KEY RESULTS: In Vietnam the sensitivity and specificity of the test was 69.2% (95% CI: 62.8% to 75.6% and 96% (95% CI: 92.2% to 99.8 respectively. In Malaysia the performance was similar with 68.9% sensitivity (95% CI: 61.8% to 76.1% and 96.7% specificity (95% CI: 82.8% to 99.9% compared to RT-PCR. Importantly, when the Dengue Early Rapid test was used in combination with the IgM/IgG test the sensitivity increased to 93.0%. When the two tests were compared at each day post-onset of illness there was clear differentiation between the antigen and antibody markers. CONCLUSIONS: This study highlights that using dengue NS1 antigen detection in combination with anti-glycoprotein E IgM and IgG serology can significantly increase the sensitivity of acute dengue diagnosis and extends the possible window of detection to include very early acute samples and enhances the clinical utility of rapid immunochromatographic testing for dengue.

  5. Antibiotics and Antibiotic Resistance

    Science.gov (United States)

    ... all that ails you. Antibiotics, also known as antimicrobial drugs, are drugs that fight infections caused by bacteria. ... Information for Consumers and Health Professionals Information by drug class Antimicrobial Resistance Animal and Veterinary Related Resources Further information ...

  6. Rapid and Highly Sensitive Non-Competitive Immunoassay for Specific Detection of Nodularin

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    Sultana Akter

    2017-09-01

    Full Text Available Nodularin (NOD is a cyclic penta-peptide hepatotoxin mainly produced by Nodularia spumigena, reported from the brackish water bodies of various parts of the world. It can accumulate in the food chain and, for safety reasons, levels of NOD not only in water bodies but also in food matrices are of interest. Here, we report on a non-competitive immunoassay for the specific detection of NOD. A phage display technique was utilized to interrogate a synthetic antibody phage library for binders recognizing NOD bound to an anti-ADDA (3-Amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4(E,6(E-dienoic acid monoclonal antibody (Mab. One of the obtained immunocomplex binders, designated SA32C11, showed very high specificity towards nodularin-R (NOD-R over to the tested 10 different microcystins (microcystin-LR, -dmLR, -RR, -dmRR, -YR, -LY, -LF, -LW, -LA, -WR. It was expressed in Escherichia coli as a single chain antibody fragment (scFv fusion protein and used to establish a time-resolved fluorometry-based assay in combination with the anti-ADDA Mab. The detection limit (blank + 3SD of the immunoassay, with a total assay time of 1 h 10 min, is 0.03 µg/L of NOD-R. This represents the most sensitive immunoassay method for the specific detection of NOD reported so far. The assay was tested for its performance to detect NOD using spiked (0.1 to 3 µg/L of NOD-R water samples including brackish sea and coastal water and the recovery ranged from 79 to 127%. Furthermore, a panel of environmental samples, including water from different sources, fish and other marine tissue specimens, were analyzed for NOD using the assay. The assay has potential as a rapid screening tool for the analysis of a large number of water samples for the presence of NOD. It can also find applications in the analysis of the bioaccumulation of NOD in marine organisms and in the food chain.

  7. Rapid differentiation of methicillin-resistant and methicillin-susceptible Staphylococcus aureus by flow cytometry after brief antibiotic exposure.

    Science.gov (United States)

    Shrestha, Nabin K; Scalera, Nikole M; Wilson, Deborah A; Procop, Gary W

    2011-06-01

    We noticed that methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) isolates yielded side-scatter (SSC) and fluorescence intensity (FI) differences on flow cytometry (FCM) following incubation in oxacillin broth. The purpose of this study was to determine whether MRSA and MSSA could be reliably differentiated by FCM. S. aureus isolates were incubated in oxacillin-containing Mueller-Hinton broth, stained using the FASTEST total viable organisms kit, and analyzed by FCM in the MicroPRO instrument. SSC versus FI were examined, and gates 1 and 2 were defined to encompass the majority of MSSA and MRSA signal events, respectively. A count ratio (CR) was defined as the ratio of counts in gate 2 to those in gate 1. Initially, 33 isolates were tested after 4 h of incubation for proof-of-concept. Twenty others were then tested after incubation intervals ranging from 30 min to 4 h to determine the earliest possible time for differentiation. Next, 100 separate isolates were tested to determine the best CR cutoff value. Finally, the CR was validated by using an independent cohort of 121 isolates. We noted that MRSA isolates had higher SSC and FI readings than did MSSA isolates after 2 h of incubation. The receiver-operator characteristics curve showed that a CR cutoff of 0.0445 reliably differentiated MRSA from MSSA. In the validation cohort, this cutoff had a sensitivity of 100% and a specificity of 98.7% for identifying MRSA from among S. aureus isolates, following 2 h of incubation. This study demonstrates that MRSA and MSSA can be accurately differentiated by FCM after 2 h of incubation in an oxacillin-containing liquid culture medium.

  8. Rapid Differentiation of Methicillin-Resistant and Methicillin-Susceptible Staphylococcus aureus by Flow Cytometry after Brief Antibiotic Exposure▿

    Science.gov (United States)

    Shrestha, Nabin K.; Scalera, Nikole M.; Wilson, Deborah A.; Procop, Gary W.

    2011-01-01

    We noticed that methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) isolates yielded side-scatter (SSC) and fluorescence intensity (FI) differences on flow cytometry (FCM) following incubation in oxacillin broth. The purpose of this study was to determine whether MRSA and MSSA could be reliably differentiated by FCM. S. aureus isolates were incubated in oxacillin-containing Mueller-Hinton broth, stained using the FASTEST total viable organisms kit, and analyzed by FCM in the MicroPRO instrument. SSC versus FI were examined, and gates 1 and 2 were defined to encompass the majority of MSSA and MRSA signal events, respectively. A count ratio (CR) was defined as the ratio of counts in gate 2 to those in gate 1. Initially, 33 isolates were tested after 4 h of incubation for proof-of-concept. Twenty others were then tested after incubation intervals ranging from 30 min to 4 h to determine the earliest possible time for differentiation. Next, 100 separate isolates were tested to determine the best CR cutoff value. Finally, the CR was validated by using an independent cohort of 121 isolates. We noted that MRSA isolates had higher SSC and FI readings than did MSSA isolates after 2 h of incubation. The receiver-operator characteristics curve showed that a CR cutoff of 0.0445 reliably differentiated MRSA from MSSA. In the validation cohort, this cutoff had a sensitivity of 100% and a specificity of 98.7% for identifying MRSA from among S. aureus isolates, following 2 h of incubation. This study demonstrates that MRSA and MSSA can be accurately differentiated by FCM after 2 h of incubation in an oxacillin-containing liquid culture medium. PMID:21471343

  9. Ribosomal Antibiotics: Contemporary Challenges

    Directory of Open Access Journals (Sweden)

    Tamar Auerbach-Nevo

    2016-06-01

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

  10. Rapid Rule-Out of Acute Myocardial Injury Using a Single High-Sensitivity Cardiac Troponin I Measurement.

    Science.gov (United States)

    Sandoval, Yader; Smith, Stephen W; Shah, Anoop S V; Anand, Atul; Chapman, Andrew R; Love, Sara A; Schulz, Karen; Cao, Jing; Mills, Nicholas L; Apple, Fred S

    2017-01-01

    Rapid rule-out strategies using high-sensitivity cardiac troponin assays are largely supported by studies performed outside the US in selected cohorts of patients with chest pain that are atypical of US practice, and focused exclusively on ruling out acute myocardial infarction (AMI), rather than acute myocardial injury, which is more common and associated with a poor prognosis. Prospective, observational study of consecutive patients presenting to emergency departments [derivation (n = 1647) and validation (n = 2198) cohorts], where high-sensitivity cardiac troponin I (hs-cTnI) was measured on clinical indication. The negative predictive value (NPV) and diagnostic sensitivity of an hs-cTnI concentration rules out acute myocardial injury, regardless of etiology, with an excellent NPV and diagnostic sensitivity, and identifies patients at minimal risk of AMI or cardiac death at 30 days. ClinicalTrials.gov Identifier: NCT02060760. © 2016 American Association for Clinical Chemistry.

  11. Recent advances in biochemical and molecular diagnostics for the rapid detection of antibiotic-resistant Enterobacteriaceae: a focus on ß-lactam resistance.

    Science.gov (United States)

    Decousser, Jean-Winoc; Poirel, Laurent; Nordmann, Patrice

    2017-04-01

    The rapid detection of resistance is a challenge for clinical microbiologists who wish to prevent deleterious individual and collective consequences such as (i) delaying efficient antibiotic therapy, which worsens the survival rate of the most severely ill patients, or (ii) delaying the isolation of the carriers of multidrug-resistant bacteria and promoting outbreaks; this last consequence is of special concern, and there are an increasing number of approaches and market-based solutions in response. Areas covered: From simple, cheap biochemical tests to whole-genome sequencing, clinical microbiologists must select the most adequate phenotypic and genotypic tools to promptly detect and confirm β-lactam resistance from cultivated bacteria or from clinical specimens. Here, the authors review the published literature from the last 5 years about the primary technical approaches and commercial laboratory reagents for these purposes, including molecular, biochemical and immune assays. Furthermore, the authors discuss their intrinsic and relative performance, and we challenge their putative clinical impact. Expert commentary: Until the availability of fully automated wet and dry whole genome sequencing solutions, microbiologists should focus on inexpensive biochemical tests for cultured isolates or monomicrobial clinical specimen and on using the expensive molecular PCR-based strategies for the targeted screening of complex biological environments.

  12. An intervention with access to C-reactive protein rapid test reduces antibiotic overprescribing in acute exacerbations of chronic bronchitis and COPD

    DEFF Research Database (Denmark)

    F. Strykowski, David; Nielsen, Anni Brit Sternhagen; Llor, Carles

    2015-01-01

    Background. In acute exacerbation of chronic obstructive pulmonary disease (AECOPD) antibiotic overprescribing leads to antimicrobial resistance and underprescribing may cause poor patient outcomes. Objective. This study aimed to evaluate changes in over- and underprescribing of antibiotics after...... = 0.075). No statistically significant changes were found in the PIG. Conclusion. Antibiotic overprescribing was only reduced when CRP test was available. Simultaneously, underprescribing was not significantly increased, but this could be due to sample size limitations....

  13. Development of a loop-mediated Isothermal amplification assay for sensitive and rapid detection of Vibrio parahaemolyticus

    Directory of Open Access Journals (Sweden)

    Kawahara Ryuji

    2008-09-01

    Full Text Available Abstract Background Vibrio parahaemolyticus is a marine seafood-borne pathogen causing gastrointestinal disorders in humans. Thermostable direct hemolysin (TDH and TDH-related hemolysin (TRH are known as major virulence determinants of V. parahaemolyticus. Most V. parahaemolyticus isolates from the environment do not produce TDH or TRH. Total V. parahaemolyticus has been used as an indicator for control of seafood contamination toward prevention of infection. Detection of total V. parahaemolyticus using conventional culture- and biochemical-based assays is time-consuming and laborious, requiring more than three days. Thus, we developed a novel and highly specific loop-mediated isothermal amplification (LAMP assay for the sensitive and rapid detection of Vibrio parahaemolyticus. Results The assay provided markedly more sensitive and rapid detection of V. parahaemolyticus strains than conventional biochemical and PCR assays. The assay correctly identified 143 V. parahaemolyticus strains, but did not detect 33 non-parahaemolyticus Vibrio and 56 non-Vibrio strains. Sensitivity of the LAMP assay for direct detection of V. parahaemolyticus in pure cultures and in spiked shrimp samples was 5.3 × 102 CFU per ml/g (2.0 CFU per reaction. The sensitivity of the LAMP assay was 10-fold more sensitive than that of the conventional PCR assay. The LAMP assay was markedly faster, requiring for amplification 13–22 min in a single colony on TCBS agar from each of 143 V. parahaemolyticus strains and less than 35 min in spiked shrimp samples. The LAMP assay for detection of V. parahaemolyticus required less than 40 min in a single colony on thiosulfate citrate bile salt sucrose (TCBS agar and 60 min in spiked shrimp samples from the beginning of DNA extraction to final determination. Conclusion The LAMP assay is a sensitive, rapid and simple tool for the detection of V. parahaemolyticus and will facilitate the surveillance for control of contamination of V

  14. Rapid and Persistent Suppression of Feeding Behavior Induced by Sensitization Training in "Aplysia"

    Science.gov (United States)

    Acheampong, Ama; Kelly, Kathleen; Shields-Johnson, Maria; Hajovsky, Julie; Wainwright, Marcy; Mozzachiodi, Riccardo

    2012-01-01

    In "Aplysia," noxious stimuli induce sensitization of defensive responses. However, it remains largely unknown whether such stimuli also alter nondefensive behaviors. In this study, we examined the effects of noxious stimuli on feeding. Strong electric shocks, capable of inducing sensitization, also led to the suppression of feeding. The use of…

  15. Rapid and sensitive detection of malachite green in aquaculture water by electrochemical preconcentration and surface-enhanced Raman scattering.

    Science.gov (United States)

    Xu, Kai-Xuan; Guo, Mei-Hong; Huang, Yu-Ping; Li, Xiao-Dong; Sun, Jian-Jun

    2018-04-01

    A highly sensitive and rapid method of in-situ surface-enhanced Raman spectroscopy (SERS) combining with electrochemical preconcentration (EP) in detecting malachite green (MG) in aquaculture water was established. Ag nanoparticles (AgNPs) were synthesized and spread onto the surface of gold electrodes after centrifuging to produce SERS-active substrates. After optimizing the pH values, preconcentration potentials and times, in-situ EP-SERS detection was carried out. A sensitive and rapid analysis of the low-concentration MG was accomplished within 200s and the limit of detection was 2.4 × 10 -16 M. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    M. N. Brahmbhatt

    2013-06-01

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

  17. Toxicological impacts of antibiotics on aquatic micro-organisms: A mini-review.

    Science.gov (United States)

    Välitalo, Pia; Kruglova, Antonina; Mikola, Anna; Vahala, Riku

    2017-05-01

    Antibiotics are found globally in the environment at trace levels due to their extensive consumption, which raises concerns about the effects they can have on non-target organisms, especially environmental micro-organisms. So far the majority of studies have focused on different aspects of antibiotic resistance or on analyzing the occurrence, fate, and removal of antibiotics from hospital and municipal wastewaters. Little attention has been paid to ecotoxicological effects of antibiotics on aquatic micro-organisms although they play a critical role in most ecosystems and they are potentially sensitive to these substances. Here we review the current state of research on the toxicological impacts of antibiotics to aquatic micro-organisms, including proteobacteria, cyanobacteria, algae and bacteria commonly present in biological wastewater treatment processes. We focus on antibiotics that are poorly removed during wastewater treatment and thus end up in surface waters. We critically discuss and compare the available analytical methods and test organisms based on effect concentrations and identify the knowledge gaps and future challenges. We conclude that, in general, cyanobacteria and ammonium oxidizing bacteria are the most sensitive micro-organisms to antibiotics. It is important to include chronic tests in ecotoxicological assessment, because acute tests are not always appropriate in case of low sensitivity (for example for proteobacteria). However, the issue of rapid development of antibiotic resistance should be regarded in chronic testing. Furthermore, the application of other species of bacteria and endpoints should be considered in the future, not forgetting the mixture effect and bacterial community studies. Due to differences in the sensitivity of different test organisms to individual antibiotic substances, the application of several bioassays with varying test organisms would provide more comprehensive data for the risk assessment of antibiotics

  18. Simrank: Rapid and sensitive general-purpose k-mer search tool

    Energy Technology Data Exchange (ETDEWEB)

    DeSantis, T.Z.; Keller, K.; Karaoz, U.; Alekseyenko, A.V; Singh, N.N.S.; Brodie, E.L; Pei, Z.; Andersen, G.L; Larsen, N.

    2011-04-01

    Terabyte-scale collections of string-encoded data are expected from consortia efforts such as the Human Microbiome Project (http://nihroadmap.nih.gov/hmp). Intra- and inter-project data similarity searches are enabled by rapid k-mer matching strategies. Software applications for sequence database partitioning, guide tree estimation, molecular classification and alignment acceleration have benefited from embedded k-mer searches as sub-routines. However, a rapid, general-purpose, open-source, flexible, stand-alone k-mer tool has not been available. Here we present a stand-alone utility, Simrank, which allows users to rapidly identify database strings the most similar to query strings. Performance testing of Simrank and related tools against DNA, RNA, protein and human-languages found Simrank 10X to 928X faster depending on the dataset. Simrank provides molecular ecologists with a high-throughput, open source choice for comparing large sequence sets to find similarity.

  19. Combining magnetic nanoparticle with biotinylated nanobodies for rapid and sensitive detection of influenza H3N2

    Science.gov (United States)

    Zhu, Min; Hu, Yonghong; Li, Guirong; Ou, Weijun; Mao, Panyong; Xin, Shaojie; Wan, Yakun

    2014-09-01

    Our objective is to develop a rapid and sensitive assay based on magnetic beads to detect the concentration of influenza H3N2. The possibility of using variable domain heavy-chain antibodies (nanobody) as diagnostic tools for influenza H3N2 was investigated. A healthy camel was immunized with inactivated influenza H3N2. A nanobody library of 8 × 108 clones was constructed and phage displayed. After three successive biopanning steps, H3N2-specific nanobodies were successfully isolated, expressed in Escherichia coli, and purified. Sequence analysis of the nanobodies revealed that we possessed four classes of nanobodies against H3N2. Two nanobodies were further used to prepare our rapid diagnostic kit. Biotinylated nanobody was effectively immobilized onto the surface of streptavidin magnetic beads. The modified magnetic beads with nanobody capture specifically influenza H3N2 and can still be recognized by nanobodies conjugated to horseradish peroxidase (HRP) conjugates. Under optimized conditions, the present immunoassay exhibited a relatively high sensitive detection with a limit of 50 ng/mL. In conclusion, by combining magnetic beads with specific nanobodies, this assay provides a promising influenza detection assay to develop a potential rapid, sensitive, and low-cost diagnostic tool to screen for influenza infections.

  20. Time-Resolved Fluorescent Immunochromatography of Aflatoxin B1 in Soybean Sauce: A Rapid and Sensitive Quantitative Analysis.

    Science.gov (United States)

    Wang, Du; Zhang, Zhaowei; Li, Peiwu; Zhang, Qi; Zhang, Wen

    2016-07-14

    Rapid and quantitative sensing of aflatoxin B1 with high sensitivity and specificity has drawn increased attention of studies investigating soybean sauce. A sensitive and rapid quantitative immunochromatographic sensing method was developed for the detection of aflatoxin B1 based on time-resolved fluorescence. It combines the advantages of time-resolved fluorescent sensing and immunochromatography. The dynamic range of a competitive and portable immunoassay was 0.3-10.0 µg·kg(-1), with a limit of detection (LOD) of 0.1 µg·kg(-1) and recoveries of 87.2%-114.3%, within 10 min. The results showed good correlation (R² > 0.99) between time-resolved fluorescent immunochromatographic strip test and high performance liquid chromatography (HPLC). Soybean sauce samples analyzed using time-resolved fluorescent immunochromatographic strip test revealed that 64.2% of samples contained aflatoxin B1 at levels ranging from 0.31 to 12.5 µg·kg(-1). The strip test is a rapid, sensitive, quantitative, and cost-effective on-site screening technique in food safety analysis.

  1. Bacterial cheating limits antibiotic resistance

    Science.gov (United States)

    Xiao Chao, Hui; Yurtsev, Eugene; Datta, Manoshi; Artemova, Tanya; Gore, Jeff

    2012-02-01

    The widespread use of antibiotics has led to the evolution of resistance in bacteria. Bacteria can gain resistance to the antibiotic ampicillin by acquiring a plasmid carrying the gene beta-lactamase, which inactivates the antibiotic. This inactivation may represent a cooperative behavior, as the entire bacterial population benefits from removing the antibiotic. The cooperative nature of this growth suggests that a cheater strain---which does not contribute to breaking down the antibiotic---may be able to take advantage of cells cooperatively inactivating the antibiotic. Here we find experimentally that a ``sensitive'' bacterial strain lacking the plasmid conferring resistance can invade a population of resistant bacteria, even in antibiotic concentrations that should kill the sensitive strain. We observe stable coexistence between the two strains and find that a simple model successfully explains the behavior as a function of antibiotic concentration and cell density. We anticipate that our results will provide insight into the evolutionary origin of phenotypic diversity and cooperative behaviors.

  2. The comparison of printed resources bacterial contamination in libraries of Al-Zahra Hospital and Sciences Faculty of Isfahan University and the determination of their antibiotic sensitivity pattern.

    Science.gov (United States)

    Rafiei, Hosein; Chadeganipour, Mostafa; Ojaghi, Rezvan; Maracy, Mohammad Reza; Nouri, Rasool

    2017-01-01

    During the library loan process, the printed resources can be a carrier of pathogenic bacteria. In this study, it was tried to compare the Bacterial Contamination Rates and their antibiotic sensitivity pattern in printed resources of a hospital and a non-hospital library. This is a cross-sectional study. Returning books from the Al-Zahra hospital library and library of Sciences faculty of Isfahan University provides the research community. The sample size, 96 cases, was calculated using quota sampling. For sampling sterile swab dipped in trypticase soy broth medium and transfer trypticase soy broth medium were used. To identify different type of isolated bacteria from Gram-staining test and biochemical tests such as; TSI, IMViC and etc., were used. 76 (79.2%) and 20 (20.8%) of cultured samples were negative and positive, the respectively. Of 20 positive samples, 11 samples (55%) belong to the family Enterobacteriaceae that after detecting by Differential teste identified all 11 samples of Enterobacter that all of them were sensitive to Gentamicin and Ofloxacin. Also the most resistance to Nitrofurantoin and Amikacin was observed. 9 cases remained (45%) were coagulase-negative Staphylococcus that all of them were sensitive to the Trimethoprim-sulfamethoxazole and Cephalexin antibiotics also the most resistance to Cefixime was observed. Considering that the Enterobacter sp and coagulase-negative Staphylococcus were separated from the books, the books as well as other hospital and medical equipment can transmit the infection to librarians, library users, patients and hospital staff, and also it can produce serious infections in patients with immune deficiency.

  3. A nanoparticle label/immunochromatographic electrochemical biosensor for rapid and sensitive detection of prostate-specific antigen

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Ying-Ying; Wang, Jun; Liu, Guodong; Wu, Hong; Wai, Chien M.; Lin, Yuehe

    2008-06-15

    We present a nanoparticle (NP) label/immunochromatographic electrochemical biosensor (IEB) for rapid and sensitive detection of prostate-specific antigen (PSA) in human serum. This IEB integrates the immunochromatographic strip with the electrochemical detector for transducing quantitative signals. The NP label, made of CdSe@ZnS, serves as a signal-amplifier vehicle. A sandwich immunoreaction was performed on the immunochromatographic strip. The captured NP labels in the test zone were determined by highly sensitive stripping voltammetric measurement of the dissolved metallic component (cadmium) with a disposable-screen-printed electrode, which is embedded underneath the membrane of the test zone. Experimental parameters (e.g., immunoreaction time, the amount of anti-PSA-NP conjugations applied) and electrochemical detection conditions (e.g., preconcentration potential and time) were optimized using this biosensor for PSA detection. The analytical performance of this biosensor was evaluated with serum PSA samples according to the “figure-of-merits” (e.g., dynamic range, reproducibility, and detection limit). The results were validated with enzyme-linked immunosorbent assay (ELISA) and show high consistency. It is found that this biosensor is very sensitive with the detection limit of 0.02 ng/mL PSA and is quite reproducible. This method is rapid, clinically accurate, and less expensive than other diagnosis tools for PSA; therefore, this IEB coupled with a portable electrochemical analyzer shows great promise for simple, sensitive, quantitative point-of-care testing of disease-related protein biomarkers.

  4. A High-Sensitivity Potentiometric 65-nm CMOS ISFET Sensor for Rapid E. coli Screening.

    Science.gov (United States)

    Jiang, Yu; Liu, Xu; Dang, Tran Chien; Huang, Xiwei; Feng, Hao; Zhang, Qing; Yu, Hao

    2018-04-01

    Foodborne bacteria, inducing outbreaks of infection or poisoning, have posed great threats to food safety. Potentiometric sensors can identify bacteria levels in food by measuring medium's pH changes. However, most of these sensors face the limitation of low sensitivity and high cost. In this paper, we developed a high-sensitivity ion-sensitive field-effect transistor sensor. It is small sized, cost-efficient, and can be massively fabricated in a standard 65-nm complementary metal-oxide-semiconductor process. A subthreshold pH-to-time-to-voltage conversion scheme was proposed to improve the sensitivity. Furthermore, design parameters, such as chemical sensing area, transistor size, and discharging time, were optimized to enhance the performance. The intrinsic sensitivity of passivation membrane was calculated as 33.2 mV/pH. It was amplified to 123.8 mV/pH with a 0.01-pH resolution, which greatly exceeded 6.3 mV/pH observed in a traditional source-follower based readout structure. The sensing system was applied to Escherichia coli (E. coli) detection with densities ranging from 14 to 140 cfu/mL. Compared to the conventional direct plate counting method (24 h), more efficient sixfold smaller screening time (4 h) was achieved to differentiate samples' E. coli levels. The demonstrated portable, time-saving, and low-cost prescreen system has great potential for food safety detection.

  5. A Rapid and Sensitive Assay for the Detection of Benzylpenicillin (PenG in Milk.

    Directory of Open Access Journals (Sweden)

    Anna Pennacchio

    Full Text Available Antibiotics, such as benzyl-penicillin (PenG and cephalosporin, are the most common compounds used in animal therapy. Their massive and illegal use in animal therapy and prophylaxis inevitably causes the presence of traces in foods of animal origin (milk and meat, which creates several problems for human health. With the aim to prevent the negative impact of β-lactam and, in particular, PenG residues present in the milk on customer health, many countries have established maximum residue limits (MRLs. To cope with this problem here, we propose an effective alternative, compared to the analytical methods actually employed, to quantify the presence of penicillin G using the surface plasmon resonance (SPR method. In particular, the PenG molecule was conjugated to a protein carrier to immunize a rabbit and produce polyclonal antibodies (anti-PenG. The produced antibodies were used as molecular recognition elements for the design of a competitive immune-assay for the detection of PenG by SPR experiments. The detection limit of the developed assay was found to be 8.0 pM, a value much lower than the MRL of the EU regulation limit that is fixed at 12 nM. Thus, our results clearly show that this system could be successfully suitable for the accurate and easy determination of PenG.

  6. Molecular Detection and Sensitivity to Antibiotics and Bacteriocins of Pathogens Isolated from Bovine Mastitis in Family Dairy Herds of Central Mexico

    Directory of Open Access Journals (Sweden)

    Ma. Fabiola León-Galván

    2015-01-01

    Full Text Available Thirty-two farms (n=535 cows located in the state of Guanajuato, Mexico, were sampled. Pathogens from bovine subclinical mastitis (SCM and clinical mastitis (CLM were identified by 16S rDNA and the sensitivity to both antibiotics and bacteriocins of Bacillus thuringiensis was tested. Forty-six milk samples were selected for their positive California Mastitis Test (CMT (≥3 and any abnormality in the udder or milk. The frequency of SCM and CLM was 39.1% and 9.3%, respectively. Averages for test day milk yield (MY, lactation number (LN, herd size (HS, and number of days in milk (DM were 20.6 kg, 2.8 lactations, 16.7 animals, and 164.1 days, respectively. MY was dependent on dairy herd (DH, LN, HS, and DM P<0.01, and correlations between udder quarters from the CMT were around 0.49 P<0.01. Coagulase-negative staphylococci were mainly identified, as well as Staphylococcus aureus, Streptococcus uberis, Brevibacterium stationis, B. conglomeratum, and Staphylococcus agnetis. Bacterial isolates were resistant to penicillin, clindamycin, ampicillin, and cefotaxime. Bacteriocins synthesized by Bacillus thuringiensis inhibited the growth of multiantibiotic resistance bacteria such as S. agnetis, S. equorum, Streptococcus uberis, Brevibacterium stationis, and Brachybacterium conglomeratum, but they were not active against S. sciuri, a microorganism that showed an 84% resistance to antibiotics tested in this study.

  7. A simple, rapid, cost-effective and sensitive method for detection of Salmonella in environmental and pecan samples.

    Science.gov (United States)

    Dobhal, S; Zhang, G; Rohla, C; Smith, M W; Ma, L M

    2014-10-01

    PCR is widely used in the routine detection of foodborne human pathogens; however, challenges remain in overcoming PCR inhibitors present in some sample matrices. The objective of this study was to develop a simple, sensitive, cost-effective and rapid method for processing large numbers of environmental and pecan samples for Salmonella detection. This study was also aimed at validation of a new protocol for the detection of Salmonella from in-shell pecans. Different DNA template preparation methods, including direct boiling, prespin, multiple washing and commercial DNA extraction kits, were evaluated with pure cultures of Salmonella Typhimurium and with enriched soil, cattle feces and in-shell pecan each spiked individually with Salmonella Typhimurium. PCR detection of Salmonella was conducted using invA and 16S rRNA gene (internal amplification control) specific primers. The effect of amplification facilitators, including bovine serum albumin (BSA), polyvinylpyrrolidone (PVP), polyethylene glycol (PEG) and gelatin on PCR sensitivity, was also evaluated. Conducting a prespin of sample matrices in combination with the addition of 0·4% (w/v) BSA and 1% (w/v) PVP in PCR mix was the simplest, most rapid, cost-effective and sensitive method for PCR detection of Salmonella, with up to 40 CFU Salmonella per reaction detectable in the presence of over 10(9 ) CFU ml(-1) of background micro-organisms from enriched feces soil or pecan samples. The developed method is rapid, cost-effective and sensitive for detection of Salmonella from different matrices. This study provides a method with broad applicability for PCR detection of Salmonella in complex sample matrices. This method has a potential for its application in different research arenas and diagnostic laboratories. © 2014 The Society for Applied Microbiology.

  8. Biotunable Nanoplasmonic Filter on Few-Layer MoS2 for Rapid and Highly Sensitive Cytokine Optoelectronic Immunosensing.

    Science.gov (United States)

    Park, Younggeun; Ryu, Byunghoon; Oh, Bo-Ram; Song, Yujing; Liang, Xiaogan; Kurabayashi, Katsuo

    2017-06-27

    Monitoring of the time-varying immune status of a diseased host often requires rapid and sensitive detection of cytokines. Metallic nanoparticle-based localized surface plasmon resonance (LSPR) biosensors hold promise to meet this clinical need by permitting label-free detection of target biomolecules. These biosensors, however, continue to suffer from relatively low sensitivity as compared to conventional immunoassay methods that involve labeling processes. Their response speeds also need to be further improved to enable rapid cytokine quantification for critical care in a timely manner. In this paper, we report an immunobiosensing device integrating a biotunable nanoplasmonic optical filter and a highly sensitive few-layer molybdenum disulfide (MoS 2 ) photoconductive component, which can serve as a generic device platform to meet the need of rapid cytokine detection with high sensitivity. The nanoplasmonic filter consists of anticytokine antibody-conjugated gold nanoparticles on a SiO 2 thin layer that is placed 170 μm above a few-layer MoS 2 photoconductive flake device. The principle of the biosensor operation is based on tuning the delivery of incident light to the few-layer MoS 2 photoconductive flake thorough the nanoplasmonic filter by means of biomolecular surface binding-induced LSPR shifts. The tuning is dependent on cytokine concentration on the nanoplasmonic filter and optoelectronically detected by the few-layer MoS 2 device. Using the developed optoelectronic biosensor, we have demonstrated label-free detection of IL-1β, a pro-inflammatory cytokine, with a detection limit as low as 250 fg/mL (14 fM), a large dynamic range of 10 6 , and a short assay time of 10 min. The presented biosensing approach could be further developed and generalized for point-of-care diagnosis, wearable bio/chemical sensing, and environmental monitoring.

  9. Rapidly progressive effusive constrictive pericarditis caused by methicillin sensitive Staphylococcus aureus (MSSA). samraakhtar@hotmail.com.

    Science.gov (United States)

    Akhtar, Naveed; Khalid, Ayesha; Ahmed, Waqas; Rasheed, Khalid

    2010-04-01

    Effusive-constrictive pericarditis is a clinical syndrome characterized by concurrent pericardial effusion and pericardial constriction, where constrictive hemodynamics are persistent after effusion is drained. It may present at any point along the clinical course, from the occurrence of an effusion to the development of chronic pericardial constriction. We refer an unusual case of effusive constrictive pericarditis developing rapidly within days, following purulent pericarditis secondary to chest trauma.

  10. Rapid and sensitive detection of Bordetella bronchiseptica by loop-mediated isothermal amplification (LAMP

    Directory of Open Access Journals (Sweden)

    Hui Zhang

    2013-10-01

    Full Text Available Bordetella bronchiseptica causes acute and chronic respiratory infections in diverse animal species and occasionally in humans. In this study, we described the establishment of a simple, sensitive and cost-efficient loop-mediated isothermal amplification (LAMP assay for the detection of B. bronchiseptica. A set of primers towards a 235 bp region within the flagellum gene of B. bronchiseptica was designed with online software.. The specificity of the LAMP assay was examined by using 6 porcine pathogens and 100 nasal swabs collected from healthy pigs and suspect infected pigs. The results indicated that positive reactions were confirmed for all B. bronchiseptica and no cross-reactivity was observed from other non-B. bronchiseptica. In sensitivity evaluations, the technique successfully detected a serial dilutions of extracted B. bronchiseptica DNA with a detection limit of 9 copies, which was 10 times more sensitive than that of PCR. Compared with conventional PCR, the higher sensitivity of LAMP method and no need for the complex instrumentation make this LAMP assay a promising alternative for the diagnosis of B. bronchiseptica in rural areas and developing countries where there lacks of complex laboratory services.

  11. The Prevalence of Antibiotic and Toothpaste Sensitivity found in Oral Streptococcal Isolates in Healthy Individuals in the Okada Community of Nigeria

    Directory of Open Access Journals (Sweden)

    Maureen U Okwu

    2017-04-01

    Full Text Available Background: This study aimed to determine the prevalence, antibiotic, and toothpaste sensitivity of oral streptococcal isolates in healthy individuals in the Okada community of Nigeria. Methods: Oral samples were collected from 230 volunteers and were subjected to standard microbiological tests. Antibacterial sensitivity tests were carried out on the streptococcal isolates that were obtained using a disk diffusion technique, and eight kinds of toothpaste (A-H were screened for their antibacterial effects on Streptococcus mutans (S. mutans. Results: The prevalence of oral streptococci found in this study was 26.1% and the predominant species was S. salivarius (13.9%. S. salivarius was highly resistant to cloxacillin (100% and Augmentin (96.9%, whilst resistance to gentamicin and erythromycin was low at 21.9% and 3.1% respectively. S. mutans were completely sensitive to gentamicin whilst resistance to erythromycin was 33.3%. The entire Streptococcus species showed the lowest resistance to erythromycin (20.0%, followed by gentamicin (31.7%. At 100 mg/mL all toothpaste samples had antibacterial effects on S. mutans. At 50 mg/mL all samples except toothpastes G and H inhibited the bacterium. Toothpastes A and E had the lowest minimum inhibitory concentration of 25 mg/mL. Conclusions: Toothpastes A and E were the most effective toothpastes of the eight assessed in this study.

  12. Development of a new, rapid and sensitive HPTLC method for estimation of Milnacipran in bulk, formulation and compatibility study

    Directory of Open Access Journals (Sweden)

    Gautam Singhvi

    2017-05-01

    Full Text Available A simple, sensitive and rapid high performance thin layer chromatographic (HPTLC method has been developed and validated for quantitative determination of Milnacipran Hydrochloride (MIL in bulk and formulations. The chromatographic development was carried out on HPTLC plates precoated with silica gel 60 F254 using a mixture of acetonitrile, water and ammonia (6:0.6:1.6 (v/v/v as mobile phase. Detection was carried out densitometrically at 220 nm. The Rf value of drug was found to be 0.63 ± 0.02. The method was validated as per ICH guideline with respect to linearity, accuracy, precision, robustness etc. The calibration curve was found to be linear over a range of 100–1000 ng μL−1 with a regression coefficient of 0.999. The accuracy was found to be very high (99.12–100.87%. %RSD values for intra-day and inter-day variation were not more than 1.43. The method has demonstrated high sensitivity and specificity. The method was applied for compatibility studies also. The method is new, simple and economic for routine estimation of MIL in bulk, preformulation studies and pharmaceutical formulation to help the industries as well as researchers for their sensitive determination of MIL rapidly at low cost in routine analysis.

  13. Iron oxyhydroxide nanorods with high electrochemical reactivity as a sensitive and rapid determination platform for 4-chlorophenol

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yuanyuan [Key Laboratory for Material Chemistry of Energy Conversion and Storage, Ministry of Education, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Britton Chance Center for Biomedical Photonics at Wuhan, National Laboratory for Optoelectronics-Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Cheng, Qin; Zheng, Meng [Key Laboratory for Material Chemistry of Energy Conversion and Storage, Ministry of Education, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Liu, Xin [Britton Chance Center for Biomedical Photonics at Wuhan, National Laboratory for Optoelectronics-Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Wu, Kangbing, E-mail: kbwu@hust.edu.cn [Key Laboratory for Material Chemistry of Energy Conversion and Storage, Ministry of Education, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2016-04-15

    Highlights: • Prepared FeOOH nanorods exhibited high reactivity toward the oxidation of 4-CP. • Response signals and detection sensitivity of 4-CP increased greatly by FeOOH. • Highly-sensitive and rapid determination platform was developed for 4-CP. • Practical application in water samples was studied, and the accuracy was good. - Abstract: Iron oxyhydroxide (FeOOH) nanorods were prepared through solvothermal reaction, and characterized using Raman spectroscopy, X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy and scanning electron microscopy. Thereafter, the prepared FeOOH nanorods were used as sensing material to construct a novel detection platform for 4-chlorophenol (4-CP). The electrochemical behaviors of 4-CP were studied, and the oxidation peak currents increased greatly on the surface of FeOOH nanorods. The signal enhancement mechanism was studied for 4-CP, and it was found that the prepared FeOOH nanorods remarkably improved the electron transfer ability and surface adsorption efficiency of 4-CP. The influences of pH value, amount of FeOOH nanorods and accumulation time were examined. As a result, a highly-sensitive electrochemical method was developed for the rapid determination of 4-CP. The linear range was from 10 to 500 nM, and the detection limit was 3.2 nM. It was used in different water samples, and the results consisted with the values that obtained by high-performance liquid chromatography.

  14. Bead-based competitive fluorescence immunoassay for sensitive and rapid diagnosis of cyanotoxin risk in drinking water.

    Science.gov (United States)

    Yu, Hye-Weon; Jang, Am; Kim, Lan Hee; Kim, Sung-Jo; Kim, In S

    2011-09-15

    Due to the increased occurrence of cyanobacterial blooms and their toxins in drinking water sources, effective management based on a sensitive and rapid analytical method is in high demand for security of safe water sources and environmental human health. Here, a competitive fluorescence immunoassay of microcystin-LR (MCYST-LR) is developed in an attempt to improve the sensitivity, analysis time, and ease-of-manipulation of analysis. To serve this aim, a bead-based suspension assay was introduced based on two major sensing elements: an antibody-conjugated quantum dot (QD) detection probe and an antigen-immobilized magnetic bead (MB) competitor. The assay was composed of three steps: the competitive immunological reaction of QD detection probes against analytes and MB competitors, magnetic separation and washing, and the optical signal generation of QDs. The fluorescence intensity was found to be inversely proportional to the MCYST-LR concentration. Under optimized conditions, the proposed assay performed well for the identification and quantitative analysis of MCYST-LR (within 30 min in the range of 0.42-25 μg/L, with a limit of detection of 0.03 μg/L). It is thus expected that this enhanced assay can contribute both to the sensitive and rapid diagnosis of cyanotoxin risk in drinking water and effective management procedures.

  15. Rapid and sensitive multiplex single-tube nested PCR for the identification of five human Plasmodium species.

    Science.gov (United States)

    Saito, Takahiro; Kikuchi, Aoi; Kaneko, Akira; Isozumi, Rie; Teramoto, Isao; Kimura, Masatsugu; Hirasawa, Noriyasu; Hiratsuka, Masahiro

    2018-06-01

    Malaria is caused by five species of Plasmodium in humans. Microscopy is currently used for pathogen detection, requiring considerable training and technical expertise as the parasites are often difficult to differentiate morphologically. Rapid diagnostic tests are as reliable as microscopy and offer faster diagnoses but possess lower detection limits and are incapable of distinguishing among the parasitic species. To improve global health efforts towards malaria control, a rapid, sensitive, species-specific, and economically viable diagnostic method is needed. In this study, we designed a malaria diagnostic method involving a multiplex single-tube nested PCR targeting Plasmodium mitochondrial cytochrome c oxidase III and single-stranded tag hybridization chromatographic printed-array strip. The detection sensitivity was found to be at least 40 times higher than that of agarose gel electrophoresis with ethidium bromide. This system also enables the identification of both single- and mixed-species malaria infections. The assay was validated with 152 Kenyan samples; using nested PCR as the standard, the assay's sensitivity and specificity were 88.7% and 100.0%, respectively. The turnaround time required, from PCR preparation to signal detection, is 90min. Our method should improve the diagnostic speed, treatment efficacy, and control of malaria, in addition to facilitating surveillance within global malaria eradication programs. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. Rapid, sensitive and cost effective method for isolation of viral DNA from feacal samples of dogs

    Directory of Open Access Journals (Sweden)

    Savi.

    2010-06-01

    Full Text Available A simple method for viral DNA extraction using chelex resin was developed. The method used was eco-friendly and cost effective compared to other methods such as phenol chloroform method which use health hazardous organic reagents. Further, a polymerase chain reaction (PCR based detection of canine parvovirus (CPV using primers from conserved region of VP2 gene was developed. To increase the sensitivity and specificity of reaction, nested PCR was designed. PCR reaction was optimized to amplify 747bp product of VP2 gene. The assay can be completed in few hours and doesn’t need hazardous chemicals. Thus, the sample preparation using chelating resin along with nested PCR seems to be a sensitive, specific and practical method for the detection of CPV in diarrhoeal feacal samples. [Vet. World 2010; 3(3.000: 105-106

  17. Viral infection causes rapid sensitization to lipopolysaccharide: central role of IFN-alpha beta

    DEFF Research Database (Denmark)

    Nansen, A; Randrup Thomsen, A

    2001-01-01

    LPS is the major active agent in the pathogenesis of Gram-negative septic shock. In this report we have studied the influence of concurrent viral infection on the outcome of LPS-induced shock. We find that infection with vesicular stomatitis virus sensitizes mice to LPS at an early time point...... following infection. Treatment of mice with the chemical IFN inducer, polyinosinic:polycytidylic acid, has a similar effect. This hypersensitivity to LPS correlated with hyperproduction of TNF-alpha in vivo. The cellular and molecular mechanisms underlying this phenomenon were investigated using Ab......-depleted and gene-targeted mice. Our results revealed that while NK cell depletion and elimination of IFN-gamma partially protected against the sensitizing effects of vesicular stomatitis virus and polyinosinic:polycytidylic acid, the most striking effect was observed in IFN-alphabetaR-deficient mice. Thus...

  18. 1,6-hexanediol diacrylate: a rapid and potent sensitizer in the printing industry.

    Science.gov (United States)

    Morgan, V A; Fewings, J M

    2000-08-01

    Printers are exposed to a wide variety of irritants and sensitizers. Allergy developing from a single exposure to any compound is rare. We report two cases of workers in the printing industry who developed allergic contact dermatitis to 1,6-hexanediol diacrylate (HDDA) within a short period of exposure. The first developed within weeks of exposure to a plastic sheet primed with HDDA. The second developed after a single accidental exposure.

  19. Rapid, Sensitive, and Reusable Detection of Glucose by a Robust Radiofrequency Integrated Passive Device Biosensor Chip

    Science.gov (United States)

    Kim, Nam-Young; Adhikari, Kishor Kumar; Dhakal, Rajendra; Chuluunbaatar, Zorigt; Wang, Cong; Kim, Eun-Soo

    2015-01-01

    Tremendous demands for sensitive and reliable label-free biosensors have stimulated intensive research into developing miniaturized radiofrequency resonators for a wide range of biomedical applications. Here, we report the development of a robust, reusable radiofrequency resonator based integrated passive device biosensor chip fabricated on a gallium arsenide substrate for the detection of glucose in water-glucose solutions and sera. As a result of the highly concentrated electromagnetic energy between the two divisions of an intertwined spiral inductor coupled with an interdigital capacitor, the proposed glucose biosensor chip exhibits linear detection ranges with high sensitivity at center frequency. This biosensor, which has a sensitivity of up to 199 MHz/mgmL−1 and a short response time of less than 2 sec, exhibited an ultralow detection limit of 0.033 μM and a reproducibility of 0.61% relative standard deviation. In addition, the quantities derived from the measured S-parameters, such as the propagation constant (γ), impedance (Z), resistance (R), inductance (L), conductance (G) and capacitance (C), enabled the effective multi-dimensional detection of glucose. PMID:25588958

  20. Rapid and sensitive detection of Yersinia pestis using amplification of plague diagnostic bacteriophages monitored by real-time PCR.

    Directory of Open Access Journals (Sweden)

    Kirill V Sergueev

    Full Text Available BACKGROUND: Yersinia pestis, the agent of plague, has caused many millions of human deaths and still poses a serious threat to global public health. Timely and reliable detection of such a dangerous pathogen is of critical importance. Lysis by specific bacteriophages remains an essential method of Y. pestis detection and plague diagnostics. METHODOLOGY/PRINCIPAL FINDINGS: The objective of this work was to develop an alternative to conventional phage lysis tests--a rapid and highly sensitive method of indirect detection of live Y. pestis cells based on quantitative real-time PCR (qPCR monitoring of amplification of reporter Y. pestis-specific bacteriophages. Plague diagnostic phages phiA1122 and L-413C were shown to be highly effective diagnostic tools for the detection and identification of Y. pestis by using qPCR with primers specific for phage DNA. The template DNA extraction step that usually precedes qPCR was omitted. phiA1122-specific qPCR enabled the detection of an initial bacterial concentration of 10(3 CFU/ml (equivalent to as few as one Y. pestis cell per 1-microl sample in four hours. L-413C-mediated detection of Y. pestis was less sensitive (up to 100 bacteria per sample but more specific, and thus we propose parallel qPCR for the two phages as a rapid and reliable method of Y. pestis identification. Importantly, phiA1122 propagated in simulated clinical blood specimens containing EDTA and its titer rise was detected by both a standard plating test and qPCR. CONCLUSIONS/SIGNIFICANCE: Thus, we developed a novel assay for detection and identification of Y. pestis using amplification of specific phages monitored by qPCR. The method is simple, rapid, highly sensitive, and specific and allows the detection of only live bacteria.

  1. Analytical sensitivity of rapid isotopic analysis of water by refractometry for monitoring D2O concentration in nuclear reactor

    International Nuclear Information System (INIS)

    Dhole, K.; Tripathy, M.K.; Ghadigaonkar, R.D.; Datta, A.; Bose, H.; Roy, M.

    2011-01-01

    The feasibility of refractometry for rapid measurement of D 2 O (heavy water) concentration has been studied. Refractometry has been utilised to be an excellent analytical technique to quickly and non-invasively determine D 2 O concentration in water samples without using any chemical reagents. The measurement of refractive index property of water samples with use of temperature control has been utilized for the purpose of their quantitative analysis. The calibration performance provided a reasonable analytical sensitivity of this technique in the 1-100% D 2 O range. (author)

  2. EU-approved rapid tests for bovine spongiform encephalopathy detect atypical forms: a study for their sensitivities.

    Directory of Open Access Journals (Sweden)

    Daniela Meloni

    Full Text Available Since 2004 it become clear that atypical bovine spongiform encephalopthies (BSEs exist in cattle. Whenever their detection has relied on active surveillance plans implemented in Europe since 2001 by rapid tests, the overall and inter-laboratory performance of these diagnostic systems in the detection of the atypical strains has not been studied thoroughly to date. To fill this gap, the present study reports on the analytical sensitivity of the EU-approved rapid tests for atypical L- and H-type and classical BSE in parallel. Each test was challenged with two dilution series, one created from a positive pool of the three BSE forms according to the EURL standard method of homogenate preparation (50% w/v and the other as per the test kit manufacturer's instructions. Multilevel logistic models and simple logistic models with the rapid test as the only covariate were fitted for each BSE form analyzed as directed by the test manufacturer's dilution protocol. The same schemes, but excluding the BSE type, were then applied to compare test performance under the manufacturer's versus the water protocol. The IDEXX HerdChek ® BSE-scrapie short protocol test showed the highest sensitivity for all BSE forms. The IDEXX® HerdChek BSE-scrapie ultra short protocol, the Prionics®--Check WESTERN and the AJ Roboscreen® BetaPrion tests showed similar sensitivities, followed by the Roche® PrionScreen, the Bio-Rad® TeSeE™ SAP and the Prionics®--Check PrioSTRIP in descending order of analytical sensitivity. Despite these differences, the limit of detection of all seven rapid tests against the different classes of material set within a 2 log(10 range of the best-performing test, thus meeting the European Food Safety Authority requirement for BSE surveillance purposes. These findings indicate that not many atypical cases would have been missed surveillance since 2001 which is important for further epidemiological interpretations of the sporadic character of

  3. Rapid label-free identification of Klebsiella pneumoniae antibiotic resistant strains by the drop-coating deposition surface-enhanced Raman scattering method

    Science.gov (United States)

    Cheong, Youjin; Kim, Young Jin; Kang, Heeyoon; Choi, Samjin; Lee, Hee Joo

    2017-08-01

    Although many methodologies have been developed to identify unknown bacteria, bacterial identification in clinical microbiology remains a complex and time-consuming procedure. To address this problem, we developed a label-free method for rapidly identifying clinically relevant multilocus sequencing typing-verified quinolone-resistant Klebsiella pneumoniae strains. We also applied the method to identify three strains from colony samples, ATCC70063 (control), ST11 and ST15; these are the prevalent quinolone-resistant K. pneumoniae strains in East Asia. The colonies were identified using a drop-coating deposition surface-enhanced Raman scattering (DCD-SERS) procedure coupled with a multivariate statistical method. Our workflow exhibited an enhancement factor of 11.3 × 106 to Raman intensities, high reproducibility (relative standard deviation of 7.4%), and a sensitive limit of detection (100 pM rhodamine 6G), with a correlation coefficient of 0.98. All quinolone-resistant K. pneumoniae strains showed similar spectral Raman shifts (high correlations) regardless of bacterial type, as well as different Raman vibrational modes compared to Escherichia coli strains. Our proposed DCD-SERS procedure coupled with the multivariate statistics-based identification method achieved excellent performance in discriminating similar microbes from one another and also in subtyping of K. pneumoniae strains. Therefore, our label-free DCD-SERS procedure coupled with the computational decision supporting method is a potentially useful method for the rapid identification of clinically relevant K. pneumoniae strains.

  4. Rapid and sensitive detection of canine parvovirus type 2 by recombinase polymerase amplification.

    Science.gov (United States)

    Wang, Jianchang; Liu, Libing; Li, Ruiwen; Wang, Jinfeng; Fu, Qi; Yuan, Wanzhe

    2016-04-01

    A novel recombinase polymerase amplification (RPA)-based method for detection of canine parvovirus type 2 (CPV-2) was developed. Sensitivity analysis showed that the detection limit of RPA was 10 copies of CPV-2 genomic DNA. RPA amplified both CPV-2a and -2b DNA but did not amplify the template of other important dog viruses (CCoV, PRV or CDV), demonstrating high specificity. The method was further validated with 57 canine fecal samples. An outstanding advantage of RPA is that it is an isothermal reaction and can be performed in a water bath, making RPA a potential alternative method for CPV-2 detection in resource-limited settings.

  5. Evaluation of the sensitizing potential of antibiotics in vitro using the human cell lines THP-1 and MUTZ-LC and primary monocyte‐derived dendritic cells

    International Nuclear Information System (INIS)

    Sebastian, Katrin; Ott, Hagen; Zwadlo-Klarwasser, Gabriele; Skazik-Voogt, Claudia; Marquardt, Yvonne; Czaja, Katharina; Merk, Hans F.; Baron, Jens Malte

    2012-01-01

    Since the 7th amendment to the EU cosmetics directive foresees a complete ban on animal testing, alternative in vitro methods have been established to evaluate the sensitizing potential of small molecular weight compounds. To find out whether these novel in vitro assays are also capable to predict the sensitizing potential of small molecular weight drugs, model compounds such as beta-lactams and sulfonamides – which are the most frequent cause of adverse drug reactions – were co-incubated with THP-1, MUTZ-LC, or primary monocyte‐derived dendritic cells for 48 h and subsequent expression of selected marker genes (IL-8, IL-1β, CES1, NQO1, GCLM, PIR and TRIM16) was studied by real time PCR. Benzylpenicillin and phenoxymethylpenicillin were recognized as sensitizing compounds because they are capable to induce the mRNA expression of these genes in moDCs and, except for IL-8, in THP-1 cells but not in MUTZ-LC. Ampicillin stimulated the expression of some marker genes in moDCs and THP-1 cells. SMX did not affect the expression of these genes in THP-1, however, in moDCs, at least PIR was enhanced and there was an increase of the release of IL-8. These data reveal that novel in vitro DC based assays might play a role in the evaluation of the allergenic potential of novel drug compounds, but these systems seem to lack the ability to detect the sensitizing potential of prohaptens that require metabolic activation prior to sensitization and moDCs seem to be superior with regard to the sensitivity compared with THP-1 and MUTZ-3 cell lines. -- Highlights: ► We tested the sensitizing potential of small molecular weight drugs in vitro. ► In vitro assays were performed with moDCs and THP-1 cells. ► Beta-lactam antibiotics can be recognized as sensitizing compounds. ► They affect the expression of metabolic enzymes, cytokines and transcription factors. ► Sulfamethoxazole has no measurable effect on THP-1 cells and moDCs.

  6. Evaluation of the sensitizing potential of antibiotics in vitro using the human cell lines THP-1 and MUTZ-LC and primary monocyte‐derived dendritic cells

    Energy Technology Data Exchange (ETDEWEB)

    Sebastian, Katrin, E-mail: ksebastian@ukaachen.de [Department of Dermatology and Allergology, RWTH Aachen University Hospital, D-52074 Aachen (Germany); Ott, Hagen [Department of Dermatology and Allergology, RWTH Aachen University Hospital, D-52074 Aachen (Germany); Zwadlo-Klarwasser, Gabriele [IZKF (BIOMAT), RWTH Aachen University Hospital, D-52074 Aachen (Germany); Skazik-Voogt, Claudia; Marquardt, Yvonne; Czaja, Katharina; Merk, Hans F.; Baron, Jens Malte [Department of Dermatology and Allergology, RWTH Aachen University Hospital, D-52074 Aachen (Germany)

    2012-08-01

    Since the 7th amendment to the EU cosmetics directive foresees a complete ban on animal testing, alternative in vitro methods have been established to evaluate the sensitizing potential of small molecular weight compounds. To find out whether these novel in vitro assays are also capable to predict the sensitizing potential of small molecular weight drugs, model compounds such as beta-lactams and sulfonamides – which are the most frequent cause of adverse drug reactions – were co-incubated with THP-1, MUTZ-LC, or primary monocyte‐derived dendritic cells for 48 h and subsequent expression of selected marker genes (IL-8, IL-1β, CES1, NQO1, GCLM, PIR and TRIM16) was studied by real time PCR. Benzylpenicillin and phenoxymethylpenicillin were recognized as sensitizing compounds because they are capable to induce the mRNA expression of these genes in moDCs and, except for IL-8, in THP-1 cells but not in MUTZ-LC. Ampicillin stimulated the expression of some marker genes in moDCs and THP-1 cells. SMX did not affect the expression of these genes in THP-1, however, in moDCs, at least PIR was enhanced and there was an increase of the release of IL-8. These data reveal that novel in vitro DC based assays might play a role in the evaluation of the allergenic potential of novel drug compounds, but these systems seem to lack the ability to detect the sensitizing potential of prohaptens that require metabolic activation prior to sensitization and moDCs seem to be superior with regard to the sensitivity compared with THP-1 and MUTZ-3 cell lines. -- Highlights: ► We tested the sensitizing potential of small molecular weight drugs in vitro. ► In vitro assays were performed with moDCs and THP-1 cells. ► Beta-lactam antibiotics can be recognized as sensitizing compounds. ► They affect the expression of metabolic enzymes, cytokines and transcription factors. ► Sulfamethoxazole has no measurable effect on THP-1 cells and moDCs.

  7. Rapid and sensitive detection of synthetic cannabinoids AMB-FUBINACA and α-PVP using surface enhanced Raman scattering (SERS)

    Science.gov (United States)

    Islam, Syed K.; Cheng, Yin Pak; Birke, Ronald L.; Green, Omar; Kubic, Thomas; Lombardi, John R.

    2018-04-01

    The application of surface enhanced Raman scattering (SERS) has been reported as a fast and sensitive analytical method in the trace detection of the two most commonly known synthetic cannabinoids AMB-FUBINACA and alpha-pyrrolidinovalerophenone (α-PVP). FUBINACA and α-PVP are two of the most dangerous synthetic cannabinoids which have been reported to cause numerous deaths in the United States. While instruments such as GC-MS, LC-MS have been traditionally recognized as analytical tools for the detection of these synthetic drugs, SERS has been recently gaining ground in the analysis of these synthetic drugs due to its sensitivity in trace analysis and its effectiveness as a rapid method of detection. This present study shows the limit of detection of a concentration as low as picomolar for AMB-FUBINACA while for α-PVP, the limit of detection is in nanomolar concentration using SERS.

  8. Rapid and Sensitive Determination of Lipid Oxidation Using the Reagent Kit Based on Spectrophotometry (FOODLABfat System

    Directory of Open Access Journals (Sweden)

    Chang Woo Kwon

    2016-01-01

    Full Text Available The reliability and availability of FOODLABfat system for determining acid value (AV and peroxide value (POV were assessed during the hydrolytic rancidification and lipid oxidation of edible oils. This reagent kit based on spectrophotometry was compared to the official methods (ISO 660 and 3960 protocols based on manual titration employing the standard mixture for the simulated oxidation models and edible oils during the thermally induced oxidation at 180°C. The linear regression line of standard mixture and the significant difference of thermally oxidized time course study determined between them showed high correlations (R2=0.998 and p<0.05 in both AVs and POVs. Considering ISO protocols with a probability of human error in manual titration, the rapidness and simplicity of the reagent kit based on spectrophotometry make it a promising alternative to monitor the lipid oxidation of edible oils and lipid-containing foods.

  9. A simple, rapid, and sensitive system for the evaluation of anti-viral drugs in rats

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiaoguang [Tohoku University Graduate School of Medicine, Department of Internal Medicine/Division of Emerging Infectious Diseases, Sendai 980-8575 (Japan); Department of Medical Microbiology, Harbin Medical University, Harbin 150086 (China); Center for AIDS Research, Kumamoto University, 2-2-1 Honjo, Kumamoto 860-0811 (Japan); Qian, Hua [Tohoku University Graduate School of Medicine, Department of Internal Medicine/Division of Emerging Infectious Diseases, Sendai 980-8575 (Japan); Center for AIDS Research, Kumamoto University, 2-2-1 Honjo, Kumamoto 860-0811 (Japan); Miyamoto, Fusako [Tohoku University Graduate School of Medicine, Department of Internal Medicine/Division of Emerging Infectious Diseases, Sendai 980-8575 (Japan); Naito, Takeshi [Laboratory of Virus Control, Institute for Virus Research, Kyoto University, 53 Kawaramachi, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Kawaji, Kumi [Tohoku University Graduate School of Medicine, Department of Internal Medicine/Division of Emerging Infectious Diseases, Sendai 980-8575 (Japan); Kajiwara, Kazumi [Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan); JST Innovation Plaza Kyoto, Japan Science and Technology Agency, Nishigyo-ku, Kyoto 615-8245 (Japan); Hattori, Toshio [Tohoku University Graduate School of Medicine, Department of Internal Medicine/Division of Emerging Infectious Diseases, Sendai 980-8575 (Japan); Matsuoka, Masao [Laboratory of Virus Control, Institute for Virus Research, Kyoto University, 53 Kawaramachi, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Watanabe, Kentaro; Oishi, Shinya; Fujii, Nobutaka [Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan); and others

    2012-07-27

    Highlights: Black-Right-Pointing-Pointer We established a novel, simple and rapid in vivo system for evaluation of anti-HIV-1 drugs with rats. Black-Right-Pointing-Pointer The system may be applicable for other antiviral drugs, and/or useful for initial screening in vivo. Black-Right-Pointing-Pointer In this system, TRI-1144 displayed the most potent anti-HIV-1 activity in vivo. -- Abstract: The lack of small animal models for the evaluation of anti-human immunodeficiency virus type 1 (HIV-1) agents hampers drug development. Here, we describe the establishment of a simple and rapid evaluation system in a rat model without animal infection facilities. After intraperitoneal administration of test drugs to rats, antiviral activity in the sera was examined by the MAGI assay. Recently developed inhibitors for HIV-1 entry, two CXCR4 antagonists, TF14016 and FC131, and four fusion inhibitors, T-20, T-20EK, SC29EK, and TRI-1144, were evaluated using HIV-1{sub IIIB} and HIV-1{sub BaL} as representative CXCR4- and CCR5-tropic HIV-1 strains, respectively. CXCR4 antagonists were shown to only possess anti-HIV-1{sub IIIB} activity, whereas fusion inhibitors showed both anti-HIV-1{sub IIIB} and anti-HIV-1{sub BaL} activities in rat sera. These results indicate that test drugs were successfully processed into the rat sera and could be detected by the MAGI assay. In this system, TRI-1144 showed the most potent and sustained antiviral activity. Sera from animals not administered drugs showed substantial anti-HIV-1 activity, indicating that relatively high dose or activity of the test drugs might be needed. In conclusion, the novel rat system established here, 'phenotypic drug evaluation', may be applicable for the evaluation of various antiviral drugs in vivo.

  10. A simple, rapid, and sensitive system for the evaluation of anti-viral drugs in rats

    International Nuclear Information System (INIS)

    Li, Xiaoguang; Qian, Hua; Miyamoto, Fusako; Naito, Takeshi; Kawaji, Kumi; Kajiwara, Kazumi; Hattori, Toshio; Matsuoka, Masao; Watanabe, Kentaro; Oishi, Shinya; Fujii, Nobutaka

    2012-01-01

    Highlights: ► We established a novel, simple and rapid in vivo system for evaluation of anti-HIV-1 drugs with rats. ► The system may be applicable for other antiviral drugs, and/or useful for initial screening in vivo. ► In this system, TRI-1144 displayed the most potent anti-HIV-1 activity in vivo. -- Abstract: The lack of small animal models for the evaluation of anti-human immunodeficiency virus type 1 (HIV-1) agents hampers drug development. Here, we describe the establishment of a simple and rapid evaluation system in a rat model without animal infection facilities. After intraperitoneal administration of test drugs to rats, antiviral activity in the sera was examined by the MAGI assay. Recently developed inhibitors for HIV-1 entry, two CXCR4 antagonists, TF14016 and FC131, and four fusion inhibitors, T-20, T-20EK, SC29EK, and TRI-1144, were evaluated using HIV-1 IIIB and HIV-1 BaL as representative CXCR4- and CCR5-tropic HIV-1 strains, respectively. CXCR4 antagonists were shown to only possess anti-HIV-1 IIIB activity, whereas fusion inhibitors showed both anti-HIV-1 IIIB and anti-HIV-1 BaL activities in rat sera. These results indicate that test drugs were successfully processed into the rat sera and could be detected by the MAGI assay. In this system, TRI-1144 showed the most potent and sustained antiviral activity. Sera from animals not administered drugs showed substantial anti-HIV-1 activity, indicating that relatively high dose or activity of the test drugs might be needed. In conclusion, the novel rat system established here, “phenotypic drug evaluation”, may be applicable for the evaluation of various antiviral drugs in vivo.

  11. A rapid detection method for policy-sensitive amines real-time supervision.

    Science.gov (United States)

    Zhang, Haixu; Shu, Jinian; Yang, Bo; Zhang, Peng; Ma, Pengkun

    2018-02-01

    Many organic amines that comprise a benzene ring are policy-sensitive because of their toxicity and links to social harm. However, to date, detection of such compounds mainly relies on offline methods. This study proposes an online pptv (parts per trillion by volume) level of detection method for amines, using the recently-built vacuum ultraviolet photoionization mass spectrometer (VUV-PIMS) combined with a new doping technique. Thus, the dichloromethane doping-assisted photoionization mass spectra of aniline, benzylamine, phenethylamine, amphetamine, and their structural isomers were recorded. The dominant characteristic mass peaks for all amines are those afforded by protonated amines and the amino radical-loss. The signal intensities of the amines were enhanced by 60-130 times compared to those recorded without doping assistance. Under 10s detection time, the sensitivities of aniline and benzylamine in the gas phase were determined as 4.0 and 2.7 countspptv -1 , with limits of detection (LODs) of 36 and 22 pptv, respectively. Notably, the detection efficiency of this method can be tenfold better in future applications since the ion transmission efficiency of the mass spectrometer was intentionally reduced to ~ 10% in this study. Therefore, dichloromethane doping-assisted photoionization mass spectrometry has proven to be a highly promising on-line approach to amine detection in environmental and judicial supervision and shows great potential for application in the biological field. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Informing Antibiotic Treatment Decisions: Evaluating Rapid Molecular Diagnostics To Identify Susceptibility and Resistance to Carbapenems against Acinetobacter spp. in PRIMERS III.

    Science.gov (United States)

    Evans, Scott R; Hujer, Andrea M; Jiang, Hongyu; Hill, Carol B; Hujer, Kristine M; Mediavilla, Jose R; Manca, Claudia; Tran, Thuy Tien T; Domitrovic, T Nicholas; Higgins, Paul G; Seifert, Harald; Kreiswirth, Barry N; Patel, Robin; Jacobs, Michael R; Chen, Liang; Sampath, Rangarajan; Hall, Thomas; Marzan, Christine; Fowler, Vance G; Chambers, Henry F; Bonomo, Robert A

    2017-01-01

    The widespread dissemination of carbapenem-resistant Acinetobacter spp. has created significant therapeutic challenges. At present, rapid molecular diagnostics (RMDs) that can identify this phenotype are not commercially available. Two RMD platforms, PCR combined with electrospray ionization mass spectrometry (PCR/ESI-MS) and molecular beacons (MB), for detecting genes conferring resistance/susceptibility to carbapenems in Acinetobacter spp. were evaluated. An archived collection of 200 clinical Acinetobacter sp. isolates was tested. Predictive values for susceptibility and resistance were estimated as a function of susceptibility prevalence and were based on the absence or presence of beta-lactamase (bla) NDM, VIM, IMP, KPC, and OXA carbapenemase genes (e.g., bla OXA-23 , bla OXA-24/40 , and bla OXA-58 found in this study) against the reference standard of MIC determinations. According to the interpretation of MICs, 49% (n = 98) of the isolates were carbapenem resistant (as defined by either resistance or intermediate resistance to imipenem). The susceptibility sensitivities (95% confidence interval [CI]) for imipenem were 82% (74%, 89%) and 92% (85%, 97%) for PCR/ESI-MS and MB, respectively. Resistance sensitivities (95% CI) for imipenem were 95% (88%, 98%) and 88% (80%, 94%) for PCR/ESI-MS and MB, respectively. PRIMERS III establishes that RMDs can discriminate between carbapenem resistance and susceptibility in Acinetobacter spp. In the context of a known prevalence of resistance, SPVs and RPVs can inform clinicians regarding the best choice for empiric antimicrobial therapy against this multidrug-resistant pathogen. Copyright © 2016 American Society for Microbiology.

  13. Rapid, highly sensitive detection of herpes simplex virus-1 using multiple antigenic peptide-coated superparamagnetic beads.

    Science.gov (United States)

    Ran, Ying-Fen; Fields, Conor; Muzard, Julien; Liauchuk, Viktoryia; Carr, Michael; Hall, William; Lee, Gil U

    2014-12-07

    A sensitive, rapid, and label free magnetic bead aggregation (MBA) assay has been developed that employs superparamagnetic (SPM) beads to capture, purify, and detect model proteins and the herpes simplex virus (HSV). The MBA assay is based on monitoring the aggregation state of a population of SPM beads using light scattering of individual aggregates. A biotin-streptavidin MBA assay had a femtomolar (fM) level sensitivity for analysis times less than 10 minutes, but the response of the assay becomes nonlinear at high analyte concentrations. A MBA assay for the detection of HSV-1 based on a novel peptide probe resulted in the selective detection of the virus at concentrations as low as 200 viral particles (vp) per mL in less than 30 min. We define the parameters that determine the sensitivity and response of the MBA assay, and the mechanism of enhanced sensitivity of the assay for HSV. The speed, relatively low cost, and ease of application of the MBA assay promise to make it useful for the identification of viral load in resource-limited and point-of-care settings where molecular diagnostics cannot be easily implemented.

  14. A simple and rapid Hepatitis A Virus (HAV titration assay based on antibiotic resistance of infected cells: evaluation of the HAV neutralization potency of human immune globulin preparations

    Directory of Open Access Journals (Sweden)

    Kaplan Gerardo G

    2008-12-01

    Full Text Available Abstract Background Hepatitis A virus (HAV, the causative agent of acute hepatitis in humans, is an atypical Picornaviridae that grows poorly in cell culture. HAV titrations are laborious and time-consuming because the virus in general does not cause cytopathic effect and is detected by immunochemical or molecular probes. Simple HAV titration assays could be developed using currently available viral construct containing selectable markers. Results We developed an antibiotic resistance titration assay (ARTA based on the infection of human hepatoma cells with a wild type HAV construct containing a blasticidin (Bsd resistance gene. Human hepatoma cells infected with the HAV-Bsd construct survived selection with 2 μg/ml of blasticidin whereas uninfected cells died within a few days. At 8 days postinfection, the color of the pH indicator phenol red in cell culture media correlated with the presence of HAV-Bsd-infected blasticidin-resistant cells: an orange-to-yellow color indicated the presence of growing cells whereas a pink-to-purple color indicated that the cells were dead. HAV-Bsd titers were determined by an endpoint dilution assay based on the color of the cell culture medium scoring orange-to-yellow wells as positive and pink-to-purple wells as negative for HAV. As a proof-of-concept, we used the ARTA to evaluate the HAV neutralization potency of two commercially available human immune globulin (IG preparations and a WHO International Standard for anti-HAV. The three IG preparations contained comparable levels of anti-HAV antibodies that neutralized approximately 1.5 log of HAV-Bsd. Similar neutralization results were obtained in the absence of blasticidin by an endpoint dilution ELISA at 2 weeks postinfection. Conclusion The ARTA is a simple and rapid method to determine HAV titers without using HAV-specific probes. We determined the HAV neutralization potency of human IG preparations in 8 days by ARTA compared to the 14 days required by the

  15. A Lateral Flow Protein Microarray for Rapid and Sensitive Antibody Assays

    Directory of Open Access Journals (Sweden)

    Helene Andersson-Svahn

    2011-11-01

    Full Text Available Protein microarrays are useful tools for highly multiplexed determination of presence or levels of clinically relevant biomarkers in human tissues and biofluids. However, such tools have thus far been restricted to laboratory environments. Here, we present a novel 384-plexed easy to use lateral flow protein microarray device capable of sensitive (< 30 ng/mL determination of antigen-specific antibodies in ten minutes of total assay time. Results were developed with gold nanobeads and could be recorded by a cell-phone camera or table top scanner. Excellent accuracy with an area under curve (AUC of 98% was achieved in comparison with an established glass microarray assay for 26 antigen-specific antibodies. We propose that the presented framework could find use in convenient and cost-efficient quality control of antibody production, as well as in providing a platform for multiplexed affinity-based assays in low-resource or mobile settings.

  16. A competitive chemiluminescence enzyme immunoassay for rapid and sensitive determination of enrofloxacin

    Science.gov (United States)

    Yu, Fei; Wu, Yongjun; Yu, Songcheng; Zhang, Huili; Zhang, Hongquan; Qu, Lingbo; Harrington, Peter de B.

    With alkaline phosphatase (ALP)-adamantane (AMPPD) system as the chemiluminescence (CL) detection system, a highly sensitive, specific and simple competitive chemiluminescence enzyme immunoassay (CLEIA) was developed for the measurement of enrofloxacin (ENR). The physicochemical parameters, such as the chemiluminescent assay mediums, the dilution buffer of ENR-McAb, the volume of dilution buffer, the monoclonal antibody concentration, the incubation time, and other relevant variables of the immunoassay have been optimized. Under the optimal conditions, the detection linear range of 350-1000 pg/mL and the detection limit of 0.24 ng/mL were provided by the proposed method. The relative standard deviations were less than 15% for both intra and inter-assay precision. This method has been successfully applied to determine ENR in spiked samples with the recovery of 103%-96%. It showed that CLEIA was a good potential method in the analysis of residues of veterinary drugs after treatment of related diseases.

  17. Automated microfluidically controlled electrochemical biosensor for the rapid and highly sensitive detection of Francisella tularensis.

    Science.gov (United States)

    Dulay, Samuel B; Gransee, Rainer; Julich, Sandra; Tomaso, Herbert; O'Sullivan, Ciara K

    2014-09-15

    Tularemia is a highly infectious zoonotic disease caused by a Gram-negative coccoid rod bacterium, Francisella tularensis. Tularemia is considered as a life-threatening potential biological warfare agent due to its high virulence, transmission, mortality and simplicity of cultivation. In the work reported here, different electrochemical immunosensor formats for the detection of whole F. tularensis bacteria were developed and their performance compared. An anti-Francisella antibody (FB11) was used for the detection that recognises the lipopolysaccharide found in the outer membrane of the bacteria. In the first approach, gold-supported self-assembled monolayers of a carboxyl terminated bipodal alkanethiol were used to covalently cross-link with the FB11 antibody. In an alternative second approach F(ab) fragments of the FB11 antibody were generated and directly chemisorbed onto the gold electrode surface. The second approach resulted in an increased capture efficiency and higher sensitivity. Detection limits of 4.5 ng/mL for the lipopolysaccharide antigen and 31 bacteria/mL for the F. tularensis bacteria were achieved. Having demonstrated the functionality of the immunosensor, an electrode array was functionalised with the antibody fragment and integrated with microfluidics and housed in a tester set-up that facilitated complete automation of the assay. The only end-user intervention is sample addition, requiring less than one-minute hands-on time. The use of the automated microfluidic set-up not only required much lower reagent volumes but also the required incubation time was considerably reduced and a notable increase of 3-fold in assay sensitivity was achieved with a total assay time from sample addition to read-out of less than 20 min. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Sensitivity analysis

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003741.htm Sensitivity analysis To use the sharing features on this page, please enable JavaScript. Sensitivity analysis determines the effectiveness of antibiotics against microorganisms (germs) ...

  19. Highly reproducible and sensitive silver nanorod array for the rapid detection of Allura Red in candy

    Science.gov (United States)

    Yao, Yue; Wang, Wen; Tian, Kangzhen; Ingram, Whitney Marvella; Cheng, Jie; Qu, Lulu; Li, Haitao; Han, Caiqin

    2018-04-01

    Allura Red (AR) is a highly stable synthetic red azo dye, which is widely used in the food industry to dye food and increase its attraction to consumers. However, the excessive consumption of AR can result in adverse health effects to humans. Therefore, a highly reproducible silver nanorod (AgNR) array was developed for surface enhanced Raman scattering (SERS) detection of AR in candy. The relative standard deviation (RSD) of AgNR substrate obtained from the same batch and different batches were 5.7% and 11.0%, respectively, demonstrating the high reproducibility. Using these highly reproducible AgNR arrays as the SERS substrates, AR was detected successfully, and its characteristic peaks were assigned by the density function theory (DFT) calculation. The limit of detection (LOD) of AR was determined to be 0.05 mg/L with a wide linear range of 0.8-100 mg/L. Furthermore, the AgNR SERS arrays can detect AR directly in different candy samples within 3 min without any complicated pretreatment. These results suggest the AgNR array can be used for rapid and qualitative SERS detection of AR, holding a great promise for expanding SERS application in food safety control field.

  20. Spectroscopic sensitivity of real-time, rapidly induced phytochemical change in response to damage.

    Science.gov (United States)

    Couture, John J; Serbin, Shawn P; Townsend, Philip A

    2013-04-01

    An ecological consequence of plant-herbivore interactions is the phytochemical induction of defenses in response to insect damage. Here, we used reflectance spectroscopy to characterize the foliar induction profile of cardenolides in Asclepias syriaca in response to damage, tracked in vivo changes and examined the influence of multiple plant traits on cardenolide concentrations. Foliar cardenolide concentrations were measured at specific time points following damage to capture their induction profile. Partial least-squares regression (PLSR) modeling was employed to calibrate cardenolide concentrations to reflectance spectroscopy. In addition, subsets of plants were either repeatedly sampled to track in vivo changes or modified to reduce latex flow to damaged areas. Cardenolide concentrations and the induction profile of A. syriaca were well predicted using models derived from reflectance spectroscopy, and this held true for repeatedly sampled plants. Correlations between cardenolides and other foliar-related variables were weak or not significant. Plant modification for latex reduction inhibited an induced cardenolide response. Our findings show that reflectance spectroscopy can characterize rapid phytochemical changes in vivo. We used reflectance spectroscopy to identify the mechanisms behind the production of plant secondary metabolites, simultaneously characterizing multiple foliar constituents. In this case, cardenolide induction appears to be largely driven by enhanced latex delivery to leaves following damage. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  1. Frequency Modulation of Transcriptional Bursting Enables Sensitive and Rapid Gene Regulation.

    Science.gov (United States)

    Li, Congxin; Cesbron, François; Oehler, Michael; Brunner, Michael; Höfer, Thomas

    2018-04-25

    Gene regulation is a complex non-equilibrium process. Here, we show that quantitating the temporal regulation of key gene states (transcriptionally inactive, active, and refractory) provides a parsimonious framework for analyzing gene regulation. Our theory makes two non-intuitive predictions. First, for transcription factors (TFs) that regulate transcription burst frequency, as opposed to amplitude or duration, weak TF binding is sufficient to elicit strong transcriptional responses. Second, refractoriness of a gene after a transcription burst enables rapid responses to stimuli. We validate both predictions experimentally by exploiting the natural, optogenetic-like responsiveness of the Neurospora GATA-type TF White Collar Complex (WCC) to blue light. Further, we demonstrate that differential regulation of WCC target genes is caused by different gene activation rates, not different TF occupancy, and that these rates are tuned by both the core promoter and the distance between TF-binding site and core promoter. In total, our work demonstrates the relevance of a kinetic, non-equilibrium framework for understanding transcriptional regulation. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  2. Sensitivity of human auditory cortex to rapid frequency modulation revealed by multivariate representational similarity analysis.

    Science.gov (United States)

    Joanisse, Marc F; DeSouza, Diedre D

    2014-01-01

    Functional Magnetic Resonance Imaging (fMRI) was used to investigate the extent, magnitude, and pattern of brain activity in response to rapid frequency-modulated sounds. We examined this by manipulating the direction (rise vs. fall) and the rate (fast vs. slow) of the apparent pitch of iterated rippled noise (IRN) bursts. Acoustic parameters were selected to capture features used in phoneme contrasts, however the stimuli themselves were not perceived as speech per se. Participants were scanned as they passively listened to sounds in an event-related paradigm. Univariate analyses revealed a greater level and extent of activation in bilateral auditory cortex in response to frequency-modulated sweeps compared to steady-state sounds. This effect was stronger in the left hemisphere. However, no regions showed selectivity for either rate or direction of frequency modulation. In contrast, multivoxel pattern analysis (MVPA) revealed feature-specific encoding for direction of modulation in auditory cortex bilaterally. Moreover, this effect was strongest when analyses were restricted to anatomical regions lying outside Heschl's gyrus. We found no support for feature-specific encoding of frequency modulation rate. Differential findings of modulation rate and direction of modulation are discussed with respect to their relevance to phonetic discrimination.

  3. A vertically aligned carbon nanotube-based impedance sensing biosensor for rapid and high sensitive detection of cancer cells.

    Science.gov (United States)

    Abdolahad, Mohammad; Taghinejad, Mohammad; Taghinejad, Hossein; Janmaleki, Mohsen; Mohajerzadeh, Shams

    2012-03-21

    A novel vertically aligned carbon nanotube based electrical cell impedance sensing biosensor (CNT-ECIS) was demonstrated for the first time as a more rapid, sensitive and specific device for the detection of cancer cells. This biosensor is based on the fast entrapment of cancer cells on vertically aligned carbon nanotube arrays and leads to mechanical and electrical interactions between CNT tips and entrapped cell membranes, changing the impedance of the biosensor. CNT-ECIS was fabricated through a photolithography process on Ni/SiO(2)/Si layers. Carbon nanotube arrays have been grown on 9 nm thick patterned Ni microelectrodes by DC-PECVD. SW48 colon cancer cells were passed over the surface of CNT covered electrodes to be specifically entrapped on elastic nanotube beams. CNT arrays act as both adhesive and conductive agents and impedance changes occurred as fast as 30 s (for whole entrapment and signaling processes). CNT-ECIS detected the cancer cells with the concentration as low as 4000 cells cm(-2) on its surface and a sensitivity of 1.7 × 10(-3)Ω cm(2). Time and cell efficiency factor (TEF and CEF) parameters were defined which describe the sensor's rapidness and resolution, respectively. TEF and CEF of CNT-ECIS were much higher than other cell based electrical biosensors which are compared in this paper.

  4. Rapid and sensitive detection of Plesiomonas shigelloides by loop-mediated isothermal amplification of the hugA gene.

    Directory of Open Access Journals (Sweden)

    Shuang Meng

    Full Text Available Plesiomonas shigelloides is one of the causative agents of human gastroenteritis, with increasing number of reports describing such infections in recent years. In this study, the hugA gene was chosen as the target to design loop-mediated isothermal amplification (LAMP assays for the rapid, specific, and sensitive detection of P. shigelloides. The performance of the assay with reference plasmids and spiked human stools as samples was evaluated and compared with those of quantitative PCR (qPCR. No false-positive results were observed for the 32 non-P. shigelloides strains used to evaluate assay specificity. The limit of detection for P. shigelloides was approximately 20 copies per reaction in reference plasmids and 5×10(3 CFU per gram in spiked human stool, which were more sensitive than the results of qPCR. When applied in human stool samples spiked with 2 low levels of P. shigelloides, the LAMP assays achieved accurate detection after 6-h enrichment. In conclusion, the LAMP assay developed in this study is a valuable method for rapid, cost-effective, and simple detection of P. shigelloides in basic clinical and field laboratories in the rural areas of China.

  5. Luminol-based electrochemiluminescent biosensors for highly sensitive medical diagnosis and rapid antioxidant detection

    Science.gov (United States)

    Tamiya, Eiichi; Inoue, Yuki; Saito, Masato

    2018-03-01

    We present a review of luminol-based electrochemiluminescence (ECL) biosensors that perform enzymatic reactions and bioanalysis using antioxidant molecules by controlling the spatiotemporal production of a luminescent substrate, catalase activity, and glycated albumin (GA). The ECL intensity depends on the antioxidant capacity because radicals are neutralized by the antioxidants, which suppresses the luminescence. The antioxidant capacities of 22 types beverages were evaluated by comparison with a standard curve of Trolox. The time necessary for the ECL measurement of the antioxidant capacity is only 2 min with screen-printed electrodes and a portable ECL measurement system. Our system was also used to monitor reactive oxygen species released from neutrophils, which play an important role in the immune system, defending against viral and bacterial infections. The quenching of ECL imaging by catalase reaction localized in the multichamber electrode using the electrogenerated substrate was examined as a potential candidate for a sensitive reporting system. The substrate was successfully generated at applied potentials between -1 and -0.4 V in multichamber electrodes and the substrate confinement within the chamber was observed within 60 s of generation. The microchamber electrode system demonstrated a detection limit of 90 fM catalase. We also demonstrated a detection limit of 0.1 µM GA in human serum albumin, which is an improvement of about 70 times over colorimetric methods.

  6. Rapid and Sensitive Isothermal Detection of Nucleic-acid Sequence by Multiple Cross Displacement Amplification.

    Science.gov (United States)

    Wang, Yi; Wang, Yan; Ma, Ai-Jing; Li, Dong-Xun; Luo, Li-Juan; Liu, Dong-Xin; Jin, Dong; Liu, Kai; Ye, Chang-Yun

    2015-07-08

    We have devised a novel amplification strategy based on isothermal strand-displacement polymerization reaction, which was termed multiple cross displacement amplification (MCDA). The approach employed a set of ten specially designed primers spanning ten distinct regions of target sequence and was preceded at a constant temperature (61-65 °C). At the assay temperature, the double-stranded DNAs were at dynamic reaction environment of primer-template hybrid, thus the high concentration of primers annealed to the template strands without a denaturing step to initiate the synthesis. For the subsequent isothermal amplification step, a series of primer binding and extension events yielded several single-stranded DNAs and single-stranded single stem-loop DNA structures. Then, these DNA products enabled the strand-displacement reaction to enter into the exponential amplification. Three mainstream methods, including colorimetric indicators, agarose gel electrophoresis and real-time turbidity, were selected for monitoring the MCDA reaction. Moreover, the practical application of the MCDA assay was successfully evaluated by detecting the target pathogen nucleic acid in pork samples, which offered advantages on quick results, modest equipment requirements, easiness in operation, and high specificity and sensitivity. Here we expounded the basic MCDA mechanism and also provided details on an alternative (Single-MCDA assay, S-MCDA) to MCDA technique.

  7. Leptin rapidly improves glucose homeostasis in obese mice by increasing hypothalamic insulin sensitivity.

    Science.gov (United States)

    Koch, Christiane; Augustine, Rachael A; Steger, Juliane; Ganjam, Goutham K; Benzler, Jonas; Pracht, Corinna; Lowe, Chrishanthi; Schwartz, Michael W; Shepherd, Peter R; Anderson, Greg M; Grattan, David R; Tups, Alexander

    2010-12-01

    Obesity is associated with resistance to the actions of both leptin and insulin via mechanisms that remain incompletely understood. To investigate whether leptin resistance per se contributes to insulin resistance and impaired glucose homeostasis, we investigated the effect of acute leptin administration on glucose homeostasis in normal as well as leptin- or leptin receptor-deficient mice. In hyperglycemic, leptin-deficient Lep(ob/ob) mice, leptin acutely and potently improved glucose metabolism, before any change of body fat mass, via a mechanism involving the p110α and β isoforms of phosphatidylinositol-3-kinase (PI3K). Unlike insulin, however, the anti-diabetic effect of leptin occurred independently of phospho-AKT, a major downstream target of PI3K, and instead involved enhanced sensitivity of the hypothalamus to insulin action upstream of PI3K, through modulation of IRS1 (insulin receptor substrate 1) phosphorylation. These data suggest that leptin resistance, as occurs in obesity, reduces the hypothalamic response to insulin and thereby impairs peripheral glucose homeostasis, contributing to the development of type 2 diabetes.

  8. Simple, rapid and sensitive detection of Orientia tsutsugamushi by loop-isothermal DNA amplification.

    Science.gov (United States)

    Paris, Daniel H; Blacksell, Stuart D; Newton, Paul N; Day, Nicholas P J

    2008-12-01

    We present a loop-mediated isothermal PCR assay (LAMP) targeting the groEL gene, which encodes the 60kDa heat shock protein of Orientia tsutsugamushi. Evaluation included testing of 63 samples of contemporary in vitro isolates, buffy coats and whole blood samples from patients with fever. Detection limits for LAMP were assessed by serial dilutions and quantitation by real-time PCR assay based on the same target gene: three copies/microl for linearized plasmids, 26 copies/microl for VERO cell culture isolates, 14 copies/microl for full blood samples and 41 copies/microl for clinical buffy coats. Based on a limited sample number, the LAMP assay is comparable in sensitivity with conventional nested PCR (56kDa gene), with limits of detection well below the range of known admission bacterial loads of patients with scrub typhus. This inexpensive method requires no sophisticated equipment or sample preparation, and may prove useful as a diagnostic assay in financially poor settings; however, it requires further prospective validation in the field setting.

  9. Rapid DNA Synthesis During Early Drosophila Embryogenesis Is Sensitive to Maternal Humpty Dumpty Protein Function.

    Science.gov (United States)

    Lesly, Shera; Bandura, Jennifer L; Calvi, Brian R

    2017-11-01

    Problems with DNA replication cause cancer and developmental malformations. It is not fully understood how DNA replication is coordinated with development and perturbed in disease. We had previously identified the Drosophila gene humpty dumpty ( hd ), and showed that null alleles cause incomplete DNA replication, tissue undergrowth, and lethality. Animals homozygous for the missense allele, hd 272-9 , were viable, but adult females had impaired amplification of eggshell protein genes in the ovary, resulting in the maternal effects of thin eggshells and embryonic lethality. Here, we show that expression of an hd transgene in somatic cells of the ovary rescues amplification and eggshell synthesis but not embryo viability. The germline of these mothers remain mutant for the hd 272-9 allele, resulting in reduced maternal Hd protein and embryonic arrest during mitosis of the first few S/M nuclear cleavage cycles with chromosome instability and chromosome bridges. Epistasis analysis of hd with the rereplication mutation plutonium indicates that the chromosome bridges of hd embryos are the result of a failed attempt to segregate incompletely replicated sister chromatids. This study reveals that maternally encoded Humpty dumpty protein is essential for DNA replication and genome integrity during the little-understood embryonic S/M cycles. Moreover, the two hd 272-9 maternal-effect phenotypes suggest that ovarian gene amplification and embryonic cleavage are two time periods in development that are particularly sensitive to mild deficits in DNA replication function. This last observation has broader relevance for interpreting why mild mutations in the human ortholog of humpty dumpty and other DNA replication genes cause tissue-specific malformations of microcephalic dwarfisms. Copyright © 2017 by the Genetics Society of America.

  10. Rapid T1 quantification based on 3D phase sensitive inversion recovery

    Directory of Open Access Journals (Sweden)

    Warntjes Marcel JB

    2010-08-01

    Full Text Available Abstract Background In Contrast Enhanced Magnetic Resonance Imaging fibrotic myocardium can be distinguished from healthy tissue using the difference in the longitudinal T1 relaxation after administration of Gadolinium, the so-called Late Gd Enhancement. The purpose of this work was to measure the myocardial absolute T1 post-Gd from a single breath-hold 3D Phase Sensitivity Inversion Recovery sequence (PSIR. Equations were derived to take the acquisition and saturation effects on the magnetization into account. Methods The accuracy of the method was investigated on phantoms and using simulations. The method was applied to a group of patients with suspected myocardial infarction where the absolute difference in relaxation of healthy and fibrotic myocardium was measured at about 15 minutes post-contrast. The evolution of the absolute R1 relaxation rate (1/T1 over time after contrast injection was followed for one patient and compared to T1 mapping using Look-Locker. Based on the T1 maps synthetic LGE images were reconstructed and compared to the conventional LGE images. Results The fitting algorithm is robust against variation in acquisition flip angle, the inversion delay time and cardiac arrhythmia. The observed relaxation rate of the myocardium is 1.2 s-1, increasing to 6 - 7 s-1 after contrast injection and decreasing to 2 - 2.5 s-1 for healthy myocardium and to 3.5 - 4 s-1 for fibrotic myocardium. Synthesized images based on the T1 maps correspond very well to actual LGE images. Conclusions The method provides a robust quantification of post-Gd T1 relaxation for a complete cardiac volume within a single breath-hold.

  11. A simple and sensitive biosensor for rapid detection of nanoparticles in water

    Science.gov (United States)

    Bhomkar, Prasanna; Goss, Greg; Wishart, David S.

    2014-02-01

    Advances in nanoscience have led to a greater use of engineered nanoparticles (ENPs) in numerous applications. Due to their small size and unique surface properties, ENPs have many desirable features. However, they also interact with living cells in potentially undesirable manners highlighting the need to develop improved detection systems to manage risks associated with their accidental occupational exposure or environmental release. However, the routine detection of ENPs has not yet been demonstrated, especially for aquatic environments. Using standard protein engineering techniques, we generated a protein-based biosensor that can sensitively detect negatively charged ENPs in aquatic matrices. In particular, we genetically engineered a green fluorescent protein with a poly-lysine tag (His-GFP-LYS) to facilitate its electrostatic interaction with commercially available negatively charged NPs. These 5-6-nm-sized NPs have metallic cores comprising gold, iron oxide, cerium oxide, and zinc oxide and are stabilized via poly-acrylic acid (PAA) coating. The interaction between the recombinant positively charged GFP and the PAA coating of the negatively charged NPs resulted in visually observable turbidity changes that were quantified using a portable spectrophotometer (NANODROP). These interactions were confirmed using dynamic light scattering and visualized using agarose native gel electrophoresis. This simple and portable system could detect ENPs resuspended in pure aqueous buffer (0.08 mg/L) and those resuspended in environmental matrices, such as pond water (0.6 mg/L). This detection system also sensed ENPs in the presence of moderate concentrations of natural organic matter that is ubiquitously present in surface waters. These results suggest that this biosensor system could be used for the routine, portable, and affordable detection of negatively-charged ENPs under environmentally relevant aquatic conditions.

  12. History of Antibiotics Research.

    Science.gov (United States)

    Mohr, Kathrin I

    2016-01-01

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

  13. Functional paper-based SERS substrate for rapid and sensitive detection of Sudan dyes in herbal medicine

    Science.gov (United States)

    Wu, Mianmian; Li, Pan; Zhu, Qingxia; Wu, Meiran; Li, Hao; Lu, Feng

    2018-05-01

    There has been an increasing demand for rapid and sensitive techniques for the identification of Sudan compounds that emerged as the most often illegally added fat-soluble dyes in herbal medicine. In this report, we have designed and fabricated a functionalized filter paper consisting of gold nanorods (GNRs) and mono-6-thio-cyclodextrin (HS-β-CD) as a surface-enhanced Raman spectroscopy (SERS) substrate, in which the GNR provides sufficient SERS enhancement, and the HS-β-CD with strong chemical affinity toward GNR provides the inclusion compound to capture hydrophobic molecules. Moreover, the CD-GNR were uniformly assembled on filter paper cellulose through the electrostatic adsorption and hydrogen bond, so that the CD-GNR paper-based SERS substrate (CD-GNR-paper) demonstrated higher sensitivity for the determination of Sudan III (0.1 μM) and Sudan IV (0.5 μM) than GNRs paper-based SERS substrate (GNR-paper), with high stability after the storage in the open air for 90 days. Importantly, CD-GNR-paper can effectively collect the Sudan dyes from illegally adulterated onto samples of Resina Draconis with a simple operation, further open up new exciting opportunity for SERS detection of more compounds illegally added with high sensitivity and fast signal responses.

  14. The development of a loop-mediated isothermal amplification assay for rapid and sensitive detection of abalone herpesvirus DNA.

    Science.gov (United States)

    Chen, M H; Kuo, S T; Renault, T; Chang, P H

    2014-02-01

    A loop-mediated isothermal amplification (LAMP) assay was developed for the detection of abalone herpesvirus DNA. Two pairs of primers were designed, based on the sequence of the DNA polymerase gene of abalone herpesvirus. The reaction temperature and time were optimized to 63°C and 60min, respectively. LAMP amplicons were analyzed by 2% agarose gel electrophoresis or by visual inspection of a colour change emitted by fluorescent dye. The method developed was specific for the detection of abalone herpesvirus, without cross-reactions with other tested herpesviruses including ostreid herpesvirus 1 (OsHV-1), European eel herpesvirus, koi herpesvirus (KHV) and an avian herpesvirus. The LAMP assay was 100 folds more sensitive than a conventional PCR and 10 folds less sensitive than a SYBR Green PCR. These results indicate that the developed LAMP assay is a simple, rapid, sensitive, specific and reliable technique for the detection of abalone herpesvirus. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Rapid, sensitive and effective diagnostic tools for foot-and-mouth disease virus in Africa

    Directory of Open Access Journals (Sweden)

    Christopher J. Kasanga

    2014-04-01

    Full Text Available Speed is paramount in the diagnosis of highly infectious diseases, such as foot-and-mouth disease (FMD, as well as for emerging diseases; however, simplicity is required if a test is to be deployed in the field. Recent developments in molecular biology have enabled the specific detection of FMD virus (FMDV by reverse-transcription loop-mediated isothermal amplification (RT-LAMP, real-time  reverse-transcription polymerase chain reaction (RT-qPCR and sequencing. RT-LAMP enables amplification of the FMDV RNA-dependent RNA polymerase 3D(pol gene at 63 °C (in the presence of a primer mixture and both reverse transcriptase and Bst DNA polymerase for 1 h, whilst RT-qPCR amplifies the same gene in approximately 2 h 30 min. In this study, we compared the sensitivity and effectiveness of RT-LAMP against RT-qPCR for the detection of the FMDV 3D(pol gene in 179 oesophageal-pharyngeal scraping samples (collected by probang obtained from clinically healthy cattle and buffalo in Malawi, Mozambique and Tanzania in 2010. The FMDV detection rate was higher with RT-LAMP (30.2%; n = 54 than with RT-qPCR (17.3%; n = 31. All samples positive by RT-qPCR (Cq ≤ 32.0 were also positive for the RT-LAMP assay; and both assays proved to be highly specific for the FMDV target sequence. In addition, the VP1 sequences of 10 viruses isolated from positive samples corresponded to the respective FMDV serotypes and genotypes. Our findings indicate that the performance of RT-LAMP is superior to RT-qPCR. Accordingly, we consider this test to have great potential with regard to the specific detection and surveillance of infectious diseases of humans and animals in resource-compromised developing countries.

  16. Assessment of antibiotic susceptibilities, genotypic characteristics ...

    African Journals Online (AJOL)

    Jane

    2011-09-28

    Sep 28, 2011 ... Staphylococcus aureus and Salmonella Typhimurium ... This study was designed to evaluate the antibiotic susceptibilities, genotypic characteristics and ..... Distribution of reference and virulence genes among antibiotic-sensitive S. aureus (SAS), .... environmental factors such as temperature, water activity,.

  17. Multi-bacteria multi-antibiotic testing using surface enhanced Raman spectroscopy (SERS) for urinary tract infection (UTI) diagnosis

    Science.gov (United States)

    Hadjigeorgiou, Katerina; Kastanos, Evdokia; Pitris, Costas

    2013-06-01

    The inappropriate use of antibiotics leads to antibiotic resistance, which is a major health care problem. The current method for determination of bacterial susceptibility to antibiotics requires overnight cultures. However most of the infections cannot wait for the results to receive treatment, so physicians administer general spectrum antibiotics. This results in ineffective treatments and aggravates the rising problem of antibiotic resistance. In this work, a rapid method for diagnosis and antibiogram for a bacterial infection was developed using Surface Enhanced Raman Spectroscopy (SERS) with silver nanoparticles. The advantages of this novel method include its rapidness and efficiency which will potentially allow doctors to prescribe the most appropriate antibiotic for an infection. SERS spectra of three species of gram negative bacteria, Escherichia coli, Proteus spp., and Klebsiella spp. were obtained after 0 and 4 hour exposure to the seven different antibiotics. Bacterial strains were diluted in order to reach the concentration of (2x105 cfu/ml), cells/ml which is equivalent to the minimum concentration found in urine samples from UTIs. Even though the concentration of bacteria was low, species classification was achieved with 94% accuracy using spectra obtained at 0 hours. Sensitivity or resistance to antibiotics was predicted with 81%-100% accuracy from spectra obtained after 4 hours of exposure to the different antibiotics. This technique can be applied directly to urine samples, and with the enhancement provided by SERS, this method has the potential to be developed into a rapid method for same day UTI diagnosis and antibiogram.

  18. Rapid and sensitive approach to simultaneous detection of genomes of hepatitis A, B, C, D and E viruses.

    Science.gov (United States)

    Kodani, Maja; Mixson-Hayden, Tonya; Drobeniuc, Jan; Kamili, Saleem

    2014-10-01

    Five viruses have been etiologically associated with viral hepatitis. Nucleic acid testing (NAT) remains the gold standard for diagnosis of viremic stages of infection. NAT methodologies have been developed for all hepatitis viruses; however, a NAT-based assay that can simultaneously detect all five viruses is not available. We designed TaqMan card-based assays for detection of HAV RNA, HBV DNA, HCV RNA, HDV RNA and HEV RNA. The performances of individual assays were evaluated on TaqMan Array Cards (TAC) for detecting five viral genomes simultaneously. Sensitivity and specificity were determined by testing 329 NAT-tested clinical specimens. All NAT-positive samples for HCV (n = 32), HDV (n = 28) and HEV (n = 14) were also found positive in TAC (sensitivity, 100%). Forty-three of 46 HAV-NAT positive samples were also positive in TAC (sensitivity, 94%), while 36 of 39 HBV-NAT positive samples were positive (sensitivity, 92%). No false-positives were detected for HBV (n = 32), HCV (n = 36), HDV (n = 30), and HEV (n = 31) NAT-negative samples (specificity 100%), while 38 of 41 HAV-NAT negative samples were negative by TAC (specificity 93%). TAC assay was concordant with corresponding individual NATs for hepatitis A-E viral genomes and can be used for their detection simultaneously. The TAC assay has potential for use in hepatitis surveillance, for screening of donor specimens and in outbreak situations. Wider availability of TAC-ready assays may allow for customized assays, for improving acute jaundice surveillance and for other purposes for which there is need to identify multiple pathogens rapidly. Published by Elsevier B.V.

  19. Determination of fluoroquinolone antibiotics by microchip capillary electrophoresis along with time-resolved sensitized luminescence of their terbium(III) complexes

    International Nuclear Information System (INIS)

    Sierra-Rodero, Marina; Fernández -Romero, Juan Manuel; Gómez -Hens, Agustina

    2014-01-01

    We report on the time-resolved detection of the three fluoroquinolone (FQs) antibiotics ciprofloxacin (CIP), enrofloxacin (ENR) and flumequine (FLU). On addition of terbium(III) ions, the terbium(III)-FQs chelates are formed in-situ in an on-capillary derivatization reaction of a microfluidic system. The laser-induced terbium(III)-sensitized luminescence of the chelates is measured at excitation/emission wavelengths of 337/545 nm. The analytes can be separated and quantified within less than 4 min. A solid phase extraction step for analyte preconcentration can be included prior to chelation and microchip capillary electrophoresis. The analytical ranges of the calibration graphs for CIP, ENR and FLU are from 10.6 to 60.0, 10.3 to 51.0, and 11.5 to 58.8 ng mL −1 , respectively, and the detection limits are 3.2, 3.1 and 3.6 ng mL −1 , respectively. The precision was established at two concentration levels of each analyte and revealed relative standard deviations in the range from 3.0 to 10.2 %. The method was applied to the analysis of FQ-spiked water samples. (author)

  20. Development of loop-mediated isothermal amplification (LAMP assay for rapid and sensitive identification of ostrich meat.

    Directory of Open Access Journals (Sweden)

    Amir Abdulmawjood

    Full Text Available Animal species identification is one of the primary duties of official food control. Since ostrich meat is difficult to be differentiated macroscopically from beef, therefore new analytical methods are needed. To enforce labeling regulations for the authentication of ostrich meat, it might be of importance to develop and evaluate a rapid and reliable assay. In the present study, a loop-mediated isothermal amplification (LAMP assay based on the cytochrome b gene of the mitochondrial DNA of the species Struthio camelus was developed. The LAMP assay was used in combination with a real-time fluorometer. The developed system allowed the detection of 0.01% ostrich meat products. In parallel, a direct swab method without nucleic acid extraction using the HYPLEX LPTV buffer was also evaluated. This rapid processing method allowed detection of ostrich meat without major incubation steps. In summary, the LAMP assay had excellent sensitivity and specificity for detecting ostrich meat and could provide a sampling-to-result identification-time of 15 to 20 minutes.

  1. Rapid and sensitive method to identify Mycobacterium avium subsp. paratuberculosis in cow's milk by DNA methylase genotyping.

    Science.gov (United States)

    Mundo, Silvia Leonor; Gilardoni, Liliana Rosa; Hoffman, Federico José; Lopez, Osvaldo Jorge

    2013-03-01

    Paratuberculosis is an infectious, chronic, and incurable disease that affects ruminants, caused by Mycobacterium avium subsp. paratuberculosis. This bacterium is shed primarily through feces of infected cows but can be also excreted in colostrum and milk and might survive pasteurization. Since an association of genomic sequences of M. avium subsp. paratuberculosis in patients with Crohn's disease has been described; it is of interest to rapidly detect M. avium subsp. paratuberculosis in milk for human consumption. IS900 insertion is used as a target for PCR amplification to identify the presence of M. avium subsp. paratuberculosis in biological samples. Two target sequences were selected: IS1 (155 bp) and IS2 (94 bp). These fragments have a 100% identity among all M. avium subsp. paratuberculosis strains sequenced. M. avium subsp. paratuberculosis was specifically concentrated from milk samples by immunomagnetic separation prior to performing PCR. The amplicons were characterized using DNA methylase Genotyping, i.e., the amplicons were methylated with 6-methyl-adenine and digested with restriction enzymes to confirm their identity. The methylated amplicons from 100 CFU of M. avium subsp. paratuberculosis can be visualized in a Western blot format using an anti-6-methyl-adenine monoclonal antibody. The use of DNA methyltransferase genotyping coupled to a scintillation proximity assay allows for the detection of up to 10 CFU of M. avium subsp. paratuberculosis per ml of milk. This test is rapid and sensitive and allows for automation and thus multiple samples can be tested at the same time.

  2. Rapid quantification of live/dead lactic acid bacteria in probiotic products using high-sensitivity flow cytometry

    Science.gov (United States)

    He, Shengbin; Hong, Xinyi; Huang, Tianxun; Zhang, Wenqiang; Zhou, Yingxing; Wu, Lina; Yan, Xiaomei

    2017-06-01

    A laboratory-built high-sensitivity flow cytometer (HSFCM) was employed for the rapid and accurate detection of lactic acid bacteria (LAB) and their viability in probiotic products. LAB were stained with both the cell membrane-permeable SYTO 9 green-fluorescent nucleic acid stain and the red-fluorescent nucleic acid stain, propidium iodide, which penetrates only bacteria with compromised membranes. The side scatter and dual-color fluorescence signals of single bacteria were detected simultaneously by the HSFCM. Ultra-high temperature processing milk and skim milk spiked with Lactobacillus casei were used as the model systems for the optimization of sample pretreatment and staining. The viable LAB counts measured by the HSFCM were in good agreement with those of the plate count method, and the measured ratios between the live and dead LAB matched well with the theoretical ratios. The established method was successfully applied to the rapid quantification of live/dead LAB in yogurts and fermented milk beverages of different brands. Moreover, the concentration and viability status of LAB in ambient yogurt, a relatively new yet popular milk product in China, are also reported.

  3. Rapid, Sensitive, Enzyme-Immunodotting Assay for Detecting Cow Milk Adulteration in Sheep Milk: A Modern Laboratory Project

    Science.gov (United States)

    Inda, Luis A.; Razquín, Pedro; Lampreave, Fermín; Alava, María A.; Calvo, Miguel

    1998-12-01

    Specificity, sensitivity, and experimental simplicity make the immunoenzymatic assay suitable for a variety of laboratories dedicated to diverse activities such as research, quality control in food analysis, or clinical biochemistry. In these assays, the antibody that specifically recognizes the antigen is covalently attached to an enzyme. Once the antigen-antibody immunocomplex is formed, the enzymatic reaction gives a colored product that allows the detection of the initial antigen. The aim of this work was the design of a new laboratory project appropriate for use in courses of biochemistry, immunochemistry, or analytical chemistry. The assay described here detects the presence of cow milk in milk of other species. The main application is the detection of cow milk in sheep milk and cheese. Specific proteins, immunoglobulins (IgG) of the fraudulent bovine milk, are specifically recognized and retained by antibodies immobilized on a membrane. The binding of a second antibody covalently attached to horseradish peroxidase (HRP) allows the development of a visible signal. Thus, students can rapidly detect milk adulterations using a specific, sensitive, and safe experimental approach. The experiment allows students to apply their theoretical knowledge, resulting in a stimulating experience of solving a real problem during a 4-hour laboratory period.

  4. Development of a polymerase chain reaction applicable to rapid and sensitive detection of Clonorchis sinensis eggs in human stool samples

    Science.gov (United States)

    Cho, Pyo Yun; Na, Byoung-Kuk; Mi Choi, Kyung; Kim, Jin Su; Cho, Shin-Hyeong; Lee, Won-Ja; Lim, Sung-Bin; Cha, Seok Ho; Park, Yun-Kyu; Pak, Jhang Ho; Lee, Hyeong-Woo; Hong, Sung-Jong; Kim, Tong-Soo

    2013-01-01

    Microscopic examination of eggs of parasitic helminths in stool samples has been the most widely used classical diagnostic method for infections, but tiny and low numbers of eggs in stool samples often hamper diagnosis of helminthic infections with classical microscopic examination. Moreover, it is also difficult to differentiate parasite eggs by the classical method, if they have similar morphological characteristics. In this study, we developed a rapid and sensitive polymerase chain reaction (PCR)-based molecular diagnostic method for detection of Clonorchis sinensis eggs in stool samples. Nine primers were designed based on the long-terminal repeat (LTR) of C. sinensis retrotransposon1 (CsRn1) gene, and seven PCR primer sets were paired. Polymerase chain reaction with each primer pair produced specific amplicons for C. sinensis, but not for other trematodes including Metagonimus yokogawai and Paragonimus westermani. Particularly, three primer sets were able to detect 10 C. sinensis eggs and were applicable to amplify specific amplicons from DNA samples purified from stool of C. sinensis-infected patients. This PCR method could be useful for diagnosis of C. sinensis infections in human stool samples with a high level of specificity and sensitivity. PMID:23916334

  5. Early life exposure to antibiotics and the subsequent development of eczema, wheeze, and allergic sensitization in the first 2 years of life: the KOALA Birth Cohort Study

    NARCIS (Netherlands)

    Kummeling, Ischa; Stelma, Foekje F.; Dagnelie, Pieter C.; Snijders, Bianca E. P.; Penders, John; Huber, Machteld; van Ree, Ronald; van den Brandt, Piet A.

    2007-01-01

    OBJECTIVES: Antibiotic exposure in early life may be associated with atopic disease development either by interfering with bacterial commensal flora or by modifying the course of bacterial infections. We evaluated early life exposure to antibiotics and the subsequent development of eczema, wheeze,

  6. Uncomplicated E Coli Urinary Tract Infection in College Women: A Follow-Up Study of E Coli Sensitivities to Commonly Prescribed Antibiotics

    Science.gov (United States)

    Ansbach, Robert K.; Dybus, Karen; Bergeson, Rachel

    2005-01-01

    Treatment of uncomplicated urinary tract infections (UTIs) has changed in the past few years with researchers advocating empiric treatment for shorter periods of time without the use of cultures. Researchers report that antibiotic resistance of Escherichia coli (E coli) to commonly prescribed antibiotics in uncomplicated UTIs has been increasing.…

  7. Rapid, simple and sensitive detection of Q fever by loop-mediated isothermal amplification of the htpAB gene.

    Directory of Open Access Journals (Sweden)

    Lei Pan

    Full Text Available BACKGROUND: Q fever is the most widespread zoonosis, and domestic animals are the most common sources of transmission. It is not only difficult to distinguish from other febrile diseases because of the lack of specific clinical manifestations in humans, but it is also difficult to identify the disease in C. burnetii-carrying animals because of the lack of identifiable features. Conventional serodiagnosis requires sera from the acute and convalescent stages of infection, which are unavailable at early diagnosis. Nested PCR and real-time PCR require equipment. In this study, we developed a Loop-Mediated Isothermal Amplification (LAMP assay to identify C. burnetii rapidly and sensitively. METHODS: A universal LAMP primer set was designed to detect the repeated sequence IS1111a of the htpAB gene of C. burnetii using PrimerExplorer V4 software. The sensitivity of the LAMP assay was evaluated using known quantities of recombined reference plasmids containing the targeted genes. The specificity of the developed LAMP assay was determined using 26 members of order Rickettsiae and 18 other common pathogens. The utility of the LAMP assay was further compared with real time PCR by the examination 24 blood samples including 6 confirmed and 18 probable Q fever cases, which diagnosed by IFA serological assessment and real time PCR. In addition, 126 animal samples from 4 provinces including 97 goats, 7 cattle, 18 horses, 3 marmots and 1 deer were compared by these two methods. RESULTS: The limits of detection of the LAMP assay for the htpAB gene were 1 copy per reaction. The specificity of the LAMP assay was 100%, and no cross-reaction was observed among the bacteria used in the study. The positive rate of unknown febrile patients was 33.3%(95%CI 30.2%-36.4% for the LAMP assay and 8.3%(95%CI 7.4%-9.2% for the real time PCR(P<0.05. Similarly, the total positive rate of animals was 7.9%(95%CI 7.1%-8.7% for the LAMP assay and 0.8%(95%CI 0.7%-0.9%for the real time

  8. Real-time detection of antibiotic activity by measuring nanometer-scale bacterial deformation

    Science.gov (United States)

    Iriya, Rafael; Syal, Karan; Jing, Wenwen; Mo, Manni; Yu, Hui; Haydel, Shelley E.; Wang, Shaopeng; Tao, Nongjian

    2017-12-01

    Diagnosing antibiotic-resistant bacteria currently requires sensitive detection of phenotypic changes associated with antibiotic action on bacteria. Here, we present an optical imaging-based approach to quantify bacterial membrane deformation as a phenotypic feature in real-time with a nanometer scale (˜9 nm) detection limit. Using this approach, we found two types of antibiotic-induced membrane deformations in different bacterial strains: polymyxin B induced relatively uniform spatial deformation of Escherichia coli O157:H7 cells leading to change in cellular volume and ampicillin-induced localized spatial deformation leading to the formation of bulges or protrusions on uropathogenic E. coli CFT073 cells. We anticipate that the approach will contribute to understanding of antibiotic phenotypic effects on bacteria with a potential for applications in rapid antibiotic susceptibility testing.

  9. Forgotten antibiotics

    DEFF Research Database (Denmark)

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

    2012-01-01

    In view of the alarming spread of antimicrobial resistance in the absence of new antibiotics, this study aimed at assessing the availability of potentially useful older antibiotics. A survey was performed in 38 countries among experts including hospital pharmacists, microbiologists, and infectious...

  10. Multiple strategies to improve sensitivity, speed and robustness of isothermal nucleic acid amplification for rapid pathogen detection

    Directory of Open Access Journals (Sweden)

    Lemieux Bertrand

    2011-05-01

    Full Text Available Abstract Background In the past decades the rapid growth of molecular diagnostics (based on either traditional PCR or isothermal amplification technologies meet the demand for fast and accurate testing. Although isothermal amplification technologies have the advantages of low cost requirements for instruments, the further improvement on sensitivity, speed and robustness is a prerequisite for the applications in rapid pathogen detection, especially at point-of-care diagnostics. Here, we describe and explore several strategies to improve one of the isothermal technologies, helicase-dependent amplification (HDA. Results Multiple strategies were approached to improve the overall performance of the isothermal amplification: the restriction endonuclease-mediated DNA helicase homing, macromolecular crowding agents, and the optimization of reaction enzyme mix. The effect of combing all strategies was compared with that of the individual strategy. With all of above methods, we are able to detect 50 copies of Neisseria gonorrhoeae DNA in just 20 minutes of amplification using a nearly instrument-free detection platform (BESt™ cassette. Conclusions The strategies addressed in this proof-of-concept study are independent of expensive equipments, and are not limited to particular primers, targets or detection format. However, they make a large difference in assay performance. Some of them can be adjusted and applied to other formats of nucleic acid amplification. Furthermore, the strategies to improve the in vitro assays by maximally simulating the nature conditions may be useful in the general field of developing molecular assays. A new fast molecular assay for Neisseria gonorrhoeae has also been developed which has great potential to be used at point-of-care diagnostics.

  11. Medical-grade honey enriched with antimicrobial peptides has enhanced activity against antibiotic-resistant pathogens

    NARCIS (Netherlands)

    Kwakman, P. H. S.; de Boer, L.; Ruyter-Spira, C. P.; Creemers-Molenaar, T.; Helsper, J. P. F. G.; Vandenbroucke-Grauls, C. M. J. E.; Zaat, S. A. J.; te Velde, A. A.

    2011-01-01

    Honey has potent activity against both antibiotic-sensitive and -resistant bacteria, and is an interesting agent for topical antimicrobial application to wounds. As honey is diluted by wound exudate, rapid bactericidal activity up to high dilution is a prerequisite for its successful application. We

  12. Bacterial clonal diagnostics as a tool for evidence-based empiric antibiotic selection.

    Directory of Open Access Journals (Sweden)

    Veronika Tchesnokova

    Full Text Available Despite the known clonal distribution of antibiotic resistance in many bacteria, empiric (pre-culture antibiotic selection still relies heavily on species-level cumulative antibiograms, resulting in overuse of broad-spectrum agents and excessive antibiotic/pathogen mismatch. Urinary tract infections (UTIs, which account for a large share of antibiotic use, are caused predominantly by Escherichia coli, a highly clonal pathogen. In an observational clinical cohort study of urgent care patients with suspected UTI, we assessed the potential for E. coli clonal-level antibiograms to improve empiric antibiotic selection. A novel PCR-based clonotyping assay was applied to fresh urine samples to rapidly detect E. coli and the urine strain's clonotype. Based on a database of clonotype-specific antibiograms, the acceptability of various antibiotics for empiric therapy was inferred using a 20%, 10%, and 30% allowed resistance threshold. The test's performance characteristics and possible effects on prescribing were assessed. The rapid test identified E. coli clonotypes directly in patients' urine within 25-35 minutes, with high specificity and sensitivity compared to culture. Antibiotic selection based on a clonotype-specific antibiogram could reduce the relative likelihood of antibiotic/pathogen mismatch by ≥ 60%. Compared to observed prescribing patterns, clonal diagnostics-guided antibiotic selection could safely double the use of trimethoprim/sulfamethoxazole and minimize fluoroquinolone use. In summary, a rapid clonotyping test showed promise for improving empiric antibiotic prescribing for E. coli UTI, including reversing preferential use of fluoroquinolones over trimethoprim/sulfamethoxazole. The clonal diagnostics approach merges epidemiologic surveillance, antimicrobial stewardship, and molecular diagnostics to bring evidence-based medicine directly to the point of care.

  13. Bacterial clonal diagnostics as a tool for evidence-based empiric antibiotic selection.

    Science.gov (United States)

    Tchesnokova, Veronika; Avagyan, Hovhannes; Rechkina, Elena; Chan, Diana; Muradova, Mariya; Haile, Helen Ghirmai; Radey, Matthew; Weissman, Scott; Riddell, Kim; Scholes, Delia; Johnson, James R; Sokurenko, Evgeni V

    2017-01-01

    Despite the known clonal distribution of antibiotic resistance in many bacteria, empiric (pre-culture) antibiotic selection still relies heavily on species-level cumulative antibiograms, resulting in overuse of broad-spectrum agents and excessive antibiotic/pathogen mismatch. Urinary tract infections (UTIs), which account for a large share of antibiotic use, are caused predominantly by Escherichia coli, a highly clonal pathogen. In an observational clinical cohort study of urgent care patients with suspected UTI, we assessed the potential for E. coli clonal-level antibiograms to improve empiric antibiotic selection. A novel PCR-based clonotyping assay was applied to fresh urine samples to rapidly detect E. coli and the urine strain's clonotype. Based on a database of clonotype-specific antibiograms, the acceptability of various antibiotics for empiric therapy was inferred using a 20%, 10%, and 30% allowed resistance threshold. The test's performance characteristics and possible effects on prescribing were assessed. The rapid test identified E. coli clonotypes directly in patients' urine within 25-35 minutes, with high specificity and sensitivity compared to culture. Antibiotic selection based on a clonotype-specific antibiogram could reduce the relative likelihood of antibiotic/pathogen mismatch by ≥ 60%. Compared to observed prescribing patterns, clonal diagnostics-guided antibiotic selection could safely double the use of trimethoprim/sulfamethoxazole and minimize fluoroquinolone use. In summary, a rapid clonotyping test showed promise for improving empiric antibiotic prescribing for E. coli UTI, including reversing preferential use of fluoroquinolones over trimethoprim/sulfamethoxazole. The clonal diagnostics approach merges epidemiologic surveillance, antimicrobial stewardship, and molecular diagnostics to bring evidence-based medicine directly to the point of care.

  14. bacterial flora and antibiotic sensitivity

    African Journals Online (AJOL)

    Purulent pelvic collections are common pathologies observed in contemporary gynaecological practice. They may originate from chronic pelvic inflammatory disease, from abortions or following normal deliveries. This study was designed to compare the bacterial flora in purulent pelvic collections obtained from HIV infected ...

  15. Magnetic Beads-Based Sensor with Tailored Sensitivity for Rapid and Single-Step Amperometric Determination of miRNAs

    Directory of Open Access Journals (Sweden)

    Eva Vargas

    2017-11-01

    Full Text Available This work describes a sensitive amperometric magneto-biosensor for single-step and rapid determination of microRNAs (miRNAs. The developed strategy involves the use of direct hybridization of the target miRNA (miRNA-21 with a specific biotinylated DNA probe immobilized on streptavidin-modified magnetic beads (MBs, and labeling of the resulting heteroduplexes with a specific DNA–RNA antibody and the bacterial protein A (ProtA conjugated with an horseradish peroxidase (HRP homopolymer (Poly-HRP40 as an enzymatic label for signal amplification. Amperometric detection is performed upon magnetic capture of the modified MBs onto the working electrode surface of disposable screen-printed carbon electrodes (SPCEs using the H2O2/hydroquinone (HQ system. The magnitude of the cathodic signal obtained at −0.20 V (vs. the Ag pseudo-reference electrode demonstrated linear dependence with the concentration of the synthetic target miRNA over the 1.0 to 100 pM range. The method provided a detection limit (LOD of 10 attomoles (in a 25 μL sample without any target miRNA amplification in just 30 min (once the DNA capture probe-MBs were prepared. This approach shows improved sensitivity compared with that of biosensors constructed with the same anti-DNA–RNA Ab as capture instead of a detector antibody and further labeling with a Strep-HRP conjugate instead of the Poly-HRP40 homopolymer. The developed strategy involves a single step working protocol, as well as the possibility to tailor the sensitivity by enlarging the length of the DNA/miRNA heteroduplexes using additional probes and/or performing the labelling with ProtA conjugated with homopolymers prepared with different numbers of HRP molecules. The practical usefulness was demonstrated by determination of the endogenous levels of the mature target miRNA in 250 ng raw total RNA (RNAt extracted from human mammary epithelial normal (MCF-10A and cancer (MCF-7 cells and tumor tissues.

  16. Antibiotic sensitivity of bacterial strains isolated from newborn infants Sensibilidad a los antibióticos de bacterias aisladas de neonatos hospitalizados

    Directory of Open Access Journals (Sweden)

    Alvaro Uribe

    1990-02-01

    Full Text Available

    Eighty nine bacterial strains isolated from newborn infants hospitalized at a Special Care Unit in Medellin, Colombia, were studied. The sensitivity of each one was determined by the Minimallnhibitory Concentration method against 21 antibiotics; a high frequency of resistance was found toward gentamycin, netilmycin, oxacillin, penicillin G and ampicillin, that are often employed as initial therapy in newborn infants; on the other hand both Gram positive and Gram negative bacteria exhibited high percentages of sensitivity against quinolones; aztreonam and third generation cephalosporins were also highly effective against Gram negative bacilli. On the basis of this new information the need to restate therapeutic conducts in the case of serious bacterial neonatal infections is emphasized.

    Se estudiaron 89 cepas bacterianas aisladas de neonatos hospitalizados en la sala de cuidados especiales de la Fundación Hospitalaria San Vicente de Paúl, de Medellín; a cada una se le determinó la sensibilidad frente a 21 antibióticos por el método de la concentración inhibitoria mínima (CIM; se halló una alta frecuencia de resistencia hacia la gentamicina, la netilmicina, la oxacilina y la ampicilina que se usan a menudo en esta institución como terapia inicial en las infecciones del recién nacido; por otra parte se demostraron altos porcentajes de sensibilidad hacia las quinolonas tanto de las bacterias gram positivas como de las gram negativas; contra estas últimas también fueron muy efectivos el aztreonam y las cefalosporinas de tercera generación. A la luz de esta nueva información se llama la atención hacia la necesidad de revaluar las normas de la antibioterapia en las infecciones graves del recién nacido.

  17. Rapid and Sensitive Determination of Timosaponin AIII in Rat Plasma by LC-MS/MS and Its Pharmacokinetic Application

    Directory of Open Access Journals (Sweden)

    Zhenzhen Cai

    2013-02-01

    Full Text Available A rapid sensitive and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS method was developed for determination of timosaponin AIII (TA-III in rat plasma, using ginsenoside Re as an internal standard (IS. TA-III and the IS were detected in MRM mode with a negative ionization electrospray mass spectrometer. The calibration curves were linear over the concentration ranges from 11.14 to 1114 ng/mL and the lower limit of quantification (LLOQ was 11.14 ng/mL. Intra-day and inter-day precisions (RSD were within 10%, and accuracy ranged from 6.4% to 9.1%. The extraction recovery at three concentrations ranged from 92.3% to 95.5%. The validated method was successfully applied to monitor the concentrations of TA-III in rat plasma after intragastric administration. The best fit pharmacokinetic model to estimate the pharmacokinetic parameters was a single compartment model with weight of 1/x2 for oral administration groups of rats for TA-III.

  18. A highly selective and sensitive fluorescent chemosensor and its application for rapid on-site detection of Al3 +

    Science.gov (United States)

    Yue, Xiao-li; Wang, Zhao-qing; Li, Chao-rui; Yang, Zheng-yin

    2018-03-01

    In this paper, a simple naphthalene-based derivative (HL) has been designed and synthesized as a Al3 +-selective fluorescent chemosensor based on the PET mechanism. HL exhibited high selectivity and sensitivity towards Al3 + over other commonly coexisting metal ions in ethanol with a detection limit of 2.72 nM. The 1:1 binding stoichiometry of the complex (HL-Al3 +) was determined from the Job's plot based on fluorescence titrations and the ESI-MS spectrum data. Moreover, the binding site of HL with Al3 + was assured by the 1H NMR titration experiment. The binding constant (Ka) of the complex (HL-Al3 +) was calculated to be 5.06 × 104 M- 1 according to the Benesi-Hildebrand equation. In addition, the recognizing process of HL towards Al3 + was chemically reversible by adding Na2EDTA. Importantly, HL could directly and rapidly detect aluminum ion through the filter paper without resorting to additional instrumental analysis.

  19. Rapid and Sensitive Detection of sFAT-1 Transgenic Pigs by Visual Loop-Mediated Isothermal Amplification.

    Science.gov (United States)

    Tao, Chenyu; Yang, Yalan; Li, Xunbi; Zheng, Xinmin; Ren, Hongyan; Li, Kui; Zhou, Rong

    2016-07-01

    Genetically modified (GM) livestock have the potential to contribute to improving the environment and human health, with consumption of fewer resources and reduced waste production. However, the transgene process also poses risks. The safety assessment and control of transgenic animal products have drawn wide attention, and the relevant regulations and technology are being developed. Quick testing technology plays a significant role in on-site and customs sampling. Nowadays, loop-mediated isothermal amplification (LAMP) was widely applied in nucleic acid analysis because of its simplicity, rapidity, high efficiency and specificity. In this study, a specific, sensitive detection system for detecting sFAT-1 transgenic pigs was designed. A set of six primers including two loop primers was designed for the target sequence. The DNA samples were amplified in less than 1 h at the optimized temperature and detecting by both Nephelometer LA-320c and unaided eyes directly adding calcein. The detection limit of sFAT-1 LAMP was as low as 1.26 ng/μL. Furthermore, blind tests of transgenic and non-transgenic DNA samples were all correctly detected. Hence, the results in this study demonstrated that LAMP is a very useful tool for transgenic detection.

  20. Immunochromatographic strip assay for the rapid and sensitive detection of Salmonella Typhimurium in artificially contaminated tomato samples.

    Science.gov (United States)

    Shukla, Shruti; Leem, Hyerim; Lee, Jong-Suk; Kim, Myunghee

    2014-06-01

    This study was designed to confirm the applicability of a liposome-based immunochromatographic assay for the rapid detection of Salmonella enterica subsp. enterica serovar Typhimurium (Salmonella Typhimurium) in artificially contaminated tomato samples. To determine the detection limit and pre-enrichment incubation time (10, 12, and 18 h pre-enrichment in 1% buffered peptone water), the tests were performed with different cell numbers of Salmonella Typhimurium (3 × 10(0), 3 × 10(1), 3 × 10(2), and 3 × 10(3) CFU·mL(-1)) inoculated into 25 g of crushed tomato samples. The assay was able to detect as few as 30 Salmonella Typhimurium cells per 25 g of tomato samples (1.2 cells·g(-1)) after 12 h pre-enrichment incubation. Moreover, when the developed assay was compared with traditional morphological and biochemical culture-based methods as well as colloidal gold nanoparticle-based commercial test strips, the developed assay yielded positive results for the detection of Salmonella Typhimurium within a shorter period time. These findings confirm that the developed assay may have practical application for the sensitive detection of Salmonella Typhimurium in various food samples, including raw vegetables, with a relatively low detection limit and shorter analysis time.

  1. Barcoding melting curve analysis for rapid, sensitive, and discriminating authentication of saffron (Crocus sativus L.) from its adulterants.

    Science.gov (United States)

    Jiang, Chao; Cao, Liang; Yuan, Yuan; Chen, Min; Jin, Yan; Huang, Luqi

    2014-01-01

    Saffron (Crocus sativus L.) is one of the most important and expensive medicinal spice products in the world. Because of its high market value and premium price, saffron is often adulterated through the incorporation of other materials, such as Carthamus tinctorius L. and Calendula officinalis L. flowers, Hemerocallis L. petals, Daucus carota L. fleshy root, Curcuma longa L. rhizomes, Zea may L., and Nelumbo nucifera Gaertn. stigmas. To develop a straightforward, nonsequencing method for rapid, sensitive, and discriminating detection of these adulterants in traded saffron, we report here the application of a barcoding melting curve analysis method (Bar-MCA) that uses the universal chloroplast plant DNA barcoding region trnH-psbA to identify adulterants. When amplified at DNA concentrations and annealing temperatures optimized for the curve analysis, peaks were formed at specific locations for saffron (81.92°C) and the adulterants: D. carota (81.60°C), C. tinctorius (80.10°C), C. officinalis (79.92°C), Dendranthema morifolium (Ramat.) Tzvel. (79.62°C), N. nucifera (80.58°C), Hemerocallis fulva (L.) L. (84.78°C), and Z. mays (84.33°C). The constructed melting curves for saffron and its adulterants have significantly different peak locations or shapes. In conclusion, Bar-MCA could be a faster and more cost-effective method to authenticate saffron and detect its adulterants.

  2. Barcoding Melting Curve Analysis for Rapid, Sensitive, and Discriminating Authentication of Saffron (Crocus sativus L. from Its Adulterants

    Directory of Open Access Journals (Sweden)

    Chao Jiang

    2014-01-01

    Full Text Available Saffron (Crocus sativus L. is one of the most important and expensive medicinal spice products in the world. Because of its high market value and premium price, saffron is often adulterated through the incorporation of other materials, such as Carthamus tinctorius L. and Calendula officinalis L. flowers, Hemerocallis L. petals, Daucus carota L. fleshy root, Curcuma longa L. rhizomes, Zea may L., and Nelumbo nucifera Gaertn. stigmas. To develop a straightforward, nonsequencing method for rapid, sensitive, and discriminating detection of these adulterants in traded saffron, we report here the application of a barcoding melting curve analysis method (Bar-MCA that uses the universal chloroplast plant DNA barcoding region trnH-psbA to identify adulterants. When amplified at DNA concentrations and annealing temperatures optimized for the curve analysis, peaks were formed at specific locations for saffron (81.92°C and the adulterants: D. carota (81.60°C, C. tinctorius (80.10°C, C. officinalis (79.92°C, Dendranthema morifolium (Ramat. Tzvel. (79.62°C, N. nucifera (80.58°C, Hemerocallis fulva (L. L. (84.78°C, and Z. mays (84.33°C. The constructed melting curves for saffron and its adulterants have significantly different peak locations or shapes. In conclusion, Bar-MCA could be a faster and more cost-effective method to authenticate saffron and detect its adulterants.

  3. Rapid fabrication of mesoporous TiO2 thin films by pulsed fibre laser for dye sensitized solar cells

    Science.gov (United States)

    Hadi, Aseel; Alhabradi, Mansour; Chen, Qian; Liu, Hong; Guo, Wei; Curioni, Michele; Cernik, Robert; Liu, Zhu

    2018-01-01

    In this paper we demonstrate for the first time that a fibre laser with a wavelength of 1070 nm and a pulse width of milliseconds can be applied to generate mesoporous nanocrystalline (nc) TiO2 thin films on ITO coated glass in ambient atmosphere, by complete vaporisation of organic binder and inter-connection of TiO2 nanoparticles, without thermally damaging the ITO layer and the glass substrate. The fabrication of the mesoporous TiO2 thin films was achieved by stationary laser beam irradiation of 1 min. The dye sensitized solar cell (DSSC) with the laser-sintered TiO2 photoanode reached higher power conversion efficiency (PCE) of 3.20% for the TiO2 film thickness of 6 μm compared with 2.99% for the furnace-sintered. Electrochemical impedance spectroscopy studies revealed that the laser sintering under the optimised condition effectively decreased charge transfer resistance and increased electron lifetime of the TiO2 thin films. The use of the fibre laser with over 40% wall-plug efficiency offers an economically-feasible, industrial viable solution to the major challenge of rapid fabrication of large scale, mass production of mesoporous metal oxide thin film based solar energy systems, potentially for perovskite and monolithic tandem solar cells, in the future.

  4. Rapid and sensitive analysis of cyclobenzaprine by LC–MS/MS: Application to a pharmacokinetic study of cyclobenzaprine in dog

    Directory of Open Access Journals (Sweden)

    Wenhong Yu

    2014-04-01

    Full Text Available A rapid and sensitive liquid chromatography–tandem mass spectrometry method was developed and validated for the quantification of cyclobenzaprine in dog plasma. After extracted with organic solvent, post-treatment samples were separated on an Agela C18 column interfaced with a triple quadrupole tandem mass spectrometer in positive electrospray ionization mode. Multiple reaction monitoring was performed using the transitions of m/z 276.2 → 216.1 and m/z 325.1 → 109.0 to quantify cyclobenzaprine and escitalopram (internal standard, respectively. The mobile phase consisted of acetonitrile: 5 mM ammonium acetate: formic acid (90:10:0.01, v/v/v at a flow rate of 0.3 ml/min. The total analysis time was 2.4 min. The method was linear over the concentration range of 0.0200–10.0 ng/ml. The intra- and inter-day precision was within 12.8% in terms of relative standard deviation (RSD% and the accuracy within 5.6% in terms of relative error. This method was successfully applied in a pharmacokinetic study of extended-release cyclobenzaprine in dogs.

  5. Rapid and sensitive analysis of melatonin by LC-MS/MS and its application to pharmacokinetic study in dogs

    Directory of Open Access Journals (Sweden)

    Huimin Zhao

    2016-04-01

    Full Text Available A rapid and sensitive liquid chromatography tandem mass spectrometry method was established and validated for determination of melatonin in dog plasma using desvenlafaxine as an internal standard (IS. Plasma samples were pretreated by liquid–liquid extraction with ethyl acetate. Chromatographic separation was carried out on a C18 column at a flow rate of 0.2 ml/min by an isocratic mobile phase of methanol : 5 mM ammonium acetate : formic acid (40:60:0.1, v/v/v. Positive ion mode detection was performed using multiple reaction monitoring (MRM at m/z 233.2→174.2 for melatonin and m/z 264.2→58.2 for desvenlafaxine. The method was linear in the concentration range of 0.020–10 ng/ml with a correlation coefficient ≥0.996. The intra- and inter-assay precision (%RSD values were within 12.6% (LLOQ 15.2%, and accuracy (%RE ranged from −1.8% to 5.0% (LLOQ ±16.5%. The total analysis time was 3.0 min. The method was fully validated and successfully applied to a pharmacokinetic study of melatonin prolonged-release tablet in Beagle dogs. The values of half-life and Tmax were similar to the corresponding data reported before.

  6. Multiplex-PCR As a Rapid and Sensitive Method for Identification of Meat Species in Halal-Meat Products.

    Science.gov (United States)

    Alikord, Mahsa; Keramat, Javad; Kadivar, Mahdi; Momtaz, Hassan; Eshtiaghi, Mohammad N; Homayouni-Rad, Aziz

    2017-01-01

    Species identification and authentication in meat products are important subjects for ensuring the health of consumers. The multiplex-PCR amplification and species- specific primer set were used for the identification of horse, donkey, pig and other ruminants in raw and processed meat products. Oligonucleotid primers were designed and patented for amplification of species-specific mitochondrial DNA sequences of each species and samples were prepared from binary meat mixtures. The results showed that meat species were accurately determined in all combinations by multiplex-PCR, and the sensitivity of this method was 0.001 ng, rendering this technique open to and suitable for use in industrial meat products. It is concluded that more fraud is seen in lower percentage industrial meat products than in higher percentage ones. There was also more fraud found in processed products than in raw ones. This rapid and useful test is recommended for quality control firms for applying more rigorous controls over industrial meat products, for the benefit of target consumers. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  7. Correlation of Frequency of Pseudomonas Aeruginosa and Exos & Exou Genes and Their Antibiotic Sensitivity Pattern in Specimen Isolated from ICU Ward

    Directory of Open Access Journals (Sweden)

    Mahsa Joodzadeh

    2016-06-01

    Full Text Available Pseudomonas aeruginosa is a cause of nosocomial infections that can be destroyer by antibiotic-resistant strains. This study conducted to determine the antibiotic susceptibility pattern and distribution of exoU and exoS among clinical isolates of P. aeruginosa. Fifty three specimens of tracheal tube were collected from patients who were hospitalized in ICU wards and P. aeruginosa were isolated and identified by phenotypic and molecular methods. Antibiotic resistance performs by disk diffusion and analyzed their virulence factors genes by PCR method. Susceptibility pattern of 53 isolates of P. aeruginosa showed that majority and minority of resistance belong to cefepime (55.4%,and Meropenem (50% Respectively. Twenty four (45.2% isolates were not susceptible to three or more different groups of antibiotics. Forty (71.4% of isolated have had exoSand1(1.8% exoU, 8(15%both of exoS and exoU and the rest being negative for exoS or exoU. Distribution of MDR(resistance to three or more group of antibiotics exoenzymes were shown: exoU(7.5%and exoS(90.5%. According to statistically analysis there were not significant relationship between presence of exo SandexoU and antibiotic resistance.

  8. Magnetic separation of antibiotics by electrochemical magnetic seeding

    Energy Technology Data Exchange (ETDEWEB)

    Ihara, I; Toyoda, K [Department of Agricultural Engineering and Socio Economics, Kobe University, Nada, Kobe 657-8501 (Japan); Beneragama, N; Umetsu, K [Department of Animal Science, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555 (Japan)

    2009-03-01

    Magnetic separation of several classes of antibiotics was investigated using electrochemical magnetic seeding. Electrocoagulation with a sacrificial anode followed by addition of magnetite particles was applied for the magnetic seeding of antibiotics. With electrochemical magnetic seeding using an iron anode, tetracycline antibiotics (oxytetracycline, chlortetracycline, doxycycline and tetracycline) and cephalosporin antibiotic (cefdinir) were rapidly removed from synthetic wastewater by magnetic separation using a neodymium magnet. Iron and aluminium anodes were suitable for magnetic seeding of the antibiotics. The results indicated that the ability of antibiotics to form strong complex with iron and aluminium allowed the higher removal by magnetic separation. This method would be appropriate for rapid treatment of antibiotics in wastewater.

  9. Magnetic separation of antibiotics by electrochemical magnetic seeding

    International Nuclear Information System (INIS)

    Ihara, I; Toyoda, K; Beneragama, N; Umetsu, K

    2009-01-01

    Magnetic separation of several classes of antibiotics was investigated using electrochemical magnetic seeding. Electrocoagulation with a sacrificial anode followed by addition of magnetite particles was applied for the magnetic seeding of antibiotics. With electrochemical magnetic seeding using an iron anode, tetracycline antibiotics (oxytetracycline, chlortetracycline, doxycycline and tetracycline) and cephalosporin antibiotic (cefdinir) were rapidly removed from synthetic wastewater by magnetic separation using a neodymium magnet. Iron and aluminium anodes were suitable for magnetic seeding of the antibiotics. The results indicated that the ability of antibiotics to form strong complex with iron and aluminium allowed the higher removal by magnetic separation. This method would be appropriate for rapid treatment of antibiotics in wastewater.

  10. Low-Cost and Rapid Fabrication of Metallic Nanostructures for Sensitive Biosensors Using Hot-Embossing and Dielectric-Heating Nanoimprint Methods

    Directory of Open Access Journals (Sweden)

    Kuang-Li Lee

    2017-07-01

    Full Text Available We propose two approaches—hot-embossing and dielectric-heating nanoimprinting methods—for low-cost and rapid fabrication of periodic nanostructures. Each nanofabrication process for the imprinted plastic nanostructures is completed within several seconds without the use of release agents and epoxy. Low-cost, large-area, and highly sensitive aluminum nanostructures on A4 size plastic films are fabricated by evaporating aluminum film on hot-embossing nanostructures. The narrowest bandwidth of the Fano resonance is only 2.7 nm in the visible light region. The periodic aluminum nanostructure achieves a figure of merit of 150, and an intensity sensitivity of 29,345%/RIU (refractive index unit. The rapid fabrication is also achieved by using radio-frequency (RF sensitive plastic films and a commercial RF welding machine. The dielectric-heating, using RF power, takes advantage of the rapid heating/cooling process and lower electric power consumption. The fabricated capped aluminum nanoslit array has a 5 nm Fano linewidth and 490.46 nm/RIU wavelength sensitivity. The biosensing capabilities of the metallic nanostructures are further verified by measuring antigen–antibody interactions using bovine serum albumin (BSA and anti-BSA. These rapid and high-throughput fabrication methods can benefit low-cost, highly sensitive biosensors and other sensing applications.

  11. Antibiotic resistance

    Directory of Open Access Journals (Sweden)

    Marianne Frieri

    2017-07-01

    Full Text Available Summary: Antimicrobial resistance in bacterial pathogens is a challenge that is associated with high morbidity and mortality. Multidrug resistance patterns in Gram-positive and -negative bacteria are difficult to treat and may even be untreatable with conventional antibiotics. There is currently a shortage of effective therapies, lack of successful prevention measures, and only a few new antibiotics, which require development of novel treatment options and alternative antimicrobial therapies. Biofilms are involved in multidrug resistance and can present challenges for infection control. Virulence, Staphylococcus aureus, Clostridium difficile infection, vancomycin-resistant enterococci, and control in the Emergency Department are also discussed. Keywords: Antibiotic resistance, Biofilms, Infections, Public health, Emergency Department

  12. Rapid and sensitive electrochemiluminescence detection of rotavirus by magnetic primer based reverse transcription-polymerase chain reaction

    International Nuclear Information System (INIS)

    Zhan Fangfang; Zhou Xiaoming; Xing Da

    2013-01-01

    Graphical abstract: In this work, we have developed and demonstrated a magnetic primer based RT-PCR assay for ECL detection of rotavirus. In the presence of two functional primers (magnetic primer and TBR-primer) and PCR reagents, cDNA from RT was amplified directly onto MPs during PCR cycles of denaturation, annealing and extension. The resulting MPs–TBR complexes were easily loaded on the electrode surface and produced a concentrated ECL signal. The figure shows the schematic illustration of magnetic primer RT-PCR based ECL assay for rotavirus detection. Highlights: ► A novel method for detection of rotavirus has been developed. ► In the presence of magnetic primer, TBR-primer and PCR reagents, cDNA form RT was amplified directly onto MPs. ► To obtain the best sensing and efficient performance, important parameters associated with the efficiency were investigated carefully. ► The proposed method will find numerous applications in food safety field and clinical diagnosis. - Abstract: A novel method for detection of rotavirus has been developed by integrating magnetic primer based reverse transcription-polymerase chain reaction (RT-PCR) with electrochemiluminescence (ECL) detection. This is realized by accomplishing RT of rotavirus RNA in traditional way and performing PCR of the resulting cDNA fragment on the surface of magnetic particles (MPs). In order to implement PCR on MPs and achieve rapid ECL detection, forward and reverse primers are bounded to MPs and tris-(2,2′-bipyridyl) ruthenium (TBR), respectively. After RT-PCR amplification, the TBR labels are directly enriched onto the surface of MPs. Then the MPs–TBR complexes can be loaded on the electrode surface and analyzed by magnetic ECL platform without any post-modification or post-incubation process. So some laborious manual operations can be avoided to achieve rapid yet sensitive detection. In this study, rotavirus in fecal specimens was successfully detected within 1.5 h. Experimental

  13. Rapid and sensitive electrochemiluminescence detection of rotavirus by magnetic primer based reverse transcription-polymerase chain reaction

    Energy Technology Data Exchange (ETDEWEB)

    Zhan Fangfang; Zhou Xiaoming [MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631 (China); Xing Da, E-mail: xingda@scnu.edu.cn [MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631 (China)

    2013-01-25

    Graphical abstract: In this work, we have developed and demonstrated a magnetic primer based RT-PCR assay for ECL detection of rotavirus. In the presence of two functional primers (magnetic primer and TBR-primer) and PCR reagents, cDNA from RT was amplified directly onto MPs during PCR cycles of denaturation, annealing and extension. The resulting MPs-TBR complexes were easily loaded on the electrode surface and produced a concentrated ECL signal. The figure shows the schematic illustration of magnetic primer RT-PCR based ECL assay for rotavirus detection. Highlights: Black-Right-Pointing-Pointer A novel method for detection of rotavirus has been developed. Black-Right-Pointing-Pointer In the presence of magnetic primer, TBR-primer and PCR reagents, cDNA form RT was amplified directly onto MPs. Black-Right-Pointing-Pointer To obtain the best sensing and efficient performance, important parameters associated with the efficiency were investigated carefully. Black-Right-Pointing-Pointer The proposed method will find numerous applications in food safety field and clinical diagnosis. - Abstract: A novel method for detection of rotavirus has been developed by integrating magnetic primer based reverse transcription-polymerase chain reaction (RT-PCR) with electrochemiluminescence (ECL) detection. This is realized by accomplishing RT of rotavirus RNA in traditional way and performing PCR of the resulting cDNA fragment on the surface of magnetic particles (MPs). In order to implement PCR on MPs and achieve rapid ECL detection, forward and reverse primers are bounded to MPs and tris-(2,2 Prime -bipyridyl) ruthenium (TBR), respectively. After RT-PCR amplification, the TBR labels are directly enriched onto the surface of MPs. Then the MPs-TBR complexes can be loaded on the electrode surface and analyzed by magnetic ECL platform without any post-modification or post-incubation process. So some laborious manual operations can be avoided to achieve rapid yet sensitive detection

  14. Sensitivity to Antibiotics of Bacteria Exposed to Gamma Radiation Emitted from Hot Soils of the High Background Radiation Areas of Ramsar, Northern Iran.

    Science.gov (United States)

    Mortazavi, Seyed Mohammad Javad; Zarei, Samira; Taheri, Mohammad; Tajbakhsh, Saeed; Mortazavi, Seyed Alireza; Ranjbar, Sahar; Momeni, Fatemeh; Masoomi, Samaneh; Ansari, Leila; Movahedi, Mohammad Mehdi; Taeb, Shahram; Zarei, Sina; Haghani, Masood

    2017-04-01

    Over the past several years our laboratories have investigated different aspects of the challenging issue of the alterations in bacterial susceptibility to antibiotics induced by physical stresses. To explore the bacterial susceptibility to antibiotics in samples of Salmonella enterica subsp. enterica serovar Typhimurium ( S. typhimurium ), Staphylococcus aureus , and Klebsiella pneumoniae after exposure to gamma radiation emitted from the soil samples taken from the high background radiation areas of Ramsar, northern Iran. Standard Kirby-Bauer test, which evaluates the size of the zone of inhibition as an indicator of the susceptibility of different bacteria to antibiotics, was used in this study. The maximum alteration of the diameter of inhibition zone was found for K. pneumoniae when tested for ciprofloxacin. In this case, the mean diameter of no growth zone in non-irradiated control samples of K. pneumoniae was 20.3 (SD 0.6) mm; it was 14.7 (SD 0.6) mm in irradiated samples. On the other hand, the minimum changes in the diameter of inhibition zone were found for S. typhimurium and S. aureus when these bacteria were tested for nitrofurantoin and cephalexin, respectively. Gamma rays were capable of making significant alterations in bacterial susceptibility to antibiotics. It can be hypothesized that high levels of natural background radiation can induce adaptive phenomena that help microorganisms better cope with lethal effects of antibiotics.

  15. Sensitivity to Antibiotics of Bacteria Exposed to Gamma Radiation Emitted from Hot Soils of the High Background Radiation Areas of Ramsar, Northern Iran

    Directory of Open Access Journals (Sweden)

    Seyed Mohammad Javad Mortazavi

    2017-04-01

    Full Text Available Background: Over the past several years our laboratories have investigated different aspects of the challenging issue of the alterations in bacterial susceptibility to antibiotics induced by physical stresses. Objective: To explore the bacterial susceptibility to antibiotics in samples of Salmonella enterica subsp. enterica serovar Typhimurium (S. typhimurium, Staphylococcus aureus, and Klebsiella pneumoniae after exposure to gamma radiation emitted from the soil samples taken from the high background radiation areas of Ramsar, northern Iran. Methods: Standard Kirby-Bauer test, which evaluates the size of the zone of inhibition as an indicator of the susceptibility of different bacteria to antibiotics, was used in this study. Results: The maximum alteration of the diameter of inhibition zone was found for K. pneumoniae when tested for ciprofloxacin. In this case, the mean diameter of no growth zone in non-irradiated control samples of K. pneumoniae was 20.3 (SD 0.6 mm; it was 14.7 (SD 0.6 mm in irradiated samples. On the other hand, the minimum changes in the diameter of inhibition zone were found for S. typhimurium and S. aureus when these bacteria were tested for nitrofurantoin and cephalexin, respectively. Conclusion: Gamma rays were capable of making significant alterations in bacterial susceptibility to antibiotics. It can be hypothesized that high levels of natural background radiation can induce adaptive phenomena that help microorganisms better cope with lethal effects of antibiotics.

  16. Rapid, simple and highly sensitive LC-ESI-MS/MS method for the quantification of tamsulosin in human plasma.

    Science.gov (United States)

    Ramakrishna, N V S; Vishwottam, K N; Manoj, S; Koteshwara, M; Wishu, S; Varma, D P

    2005-12-01

    A simple, rapid, sensitive and specific liquid chromatography-tandem mass spectrometry method was developed and validated for quantification of tamsulosin (I), a highly selective alpha1-adrenoceptor antagonist used for the treatment of patients with symptomatic benign prostatic hyperplasia. The analyte and internal standard, mosapride (II) were extracted by liquid-liquid extraction with diethyl ether-dichloromethane (70:30, v/v) using a Glas-Col Multi-Pulse Vortexer. The chromatographic separation was performed on a reverse phase Waters symmetry C18 column with a mobile phase of 0.03% formic acid-acetonitrile (30:70, v/v). The protonated analyte was quantitated in positive ionization by multiple reaction monitoring with a mass spectrometer. The mass transitions m/z 409.1 solidus in circle 228.1 and m/z 422.3 solidus in circle 198.3 were used to measure I and II, respectively. The assay exhibited a linear dynamic range of 0.1-50.0 ng/mL for tamsulosin in human plasma. The lower limit of quantitation was 100 pg/mL with a relative standard deviation of less than 10%. Acceptable precision and accuracy were obtained for concentrations over the standard curve ranges. A run time of 2.0 min for each sample made it possible to analyze a throughput of more than 400 human plasma samples per day. The validated method has been successfully used to analyze human plasma samples for application in pharmacokinetic, bioavailability or bioequivalence studies. (c) 2005 John Wiley & Sons, Ltd.

  17. Simultaneous quantitative detection of multiple tumor markers with a rapid and sensitive multicolor quantum dots based immunochromatographic test strip.

    Science.gov (United States)

    Wang, Chunying; Hou, Fei; Ma, Yicai

    2015-06-15

    A novel multicolor quantum dots (QDs) based immunochromatographic test strip (ICTS) was developed for simultaneous quantitative detection of multiple tumor markers, by utilizing alpha fetoprotein (AFP) and carcinoembryonic antigen (CEA) as models. The immunosensor could realize simultaneous quantitative detection of tumor markers with only one test line and one control line on the nitrocellulose membrane (NC membrane) due to the introduction of multicolor QDs. In this method, a mixture of mouse anti-AFP McAb and mouse anti-CEA McAb was coated on NC membrane as test line and goat anti-mouse IgG antibody was coated as control line. Anti-AFP McAb-QDs546 conjugates and anti-CEA McAb-QDs620 conjugates were mixed and applied to the conjugate pad. Simultaneous quantitative detection of multiple tumor markers was achieved by detecting the fluorescence intensity of captured QDs labels on test line and control line using a test strip reader. Under the optimum conditions, AFP and CEA could be detected as low as 3 ng/mL and 2 ng/mL in 15 min with a sample volume of 80 μL, and no obvious cross-reactivity was observed. The immunosensor was validated with 130 clinical samples and in which it exhibited high sensitivity (93% for AFP and 87% for CEA) and specificity (94% for AFP and 97% for CEA). The immunosensor also demonstrated high recoveries (87.5-113% for AFP and 90-97.3% for CEA) and low relative standard deviations (RSDs) (2.8-6.2% for AFP and 4.9-9.6% for CEA) when testing spiked human serum. This novel multicolor QDs based ICTS provides an easy and rapid, simultaneous quantitative detecting strategy for point-of-care testing of tumor markers. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Rapid and sensitive detection of canine distemper virus by real-time reverse transcription recombinase polymerase amplification.

    Science.gov (United States)

    Wang, Jianchang; Wang, Jinfeng; Li, Ruiwen; Liu, Libing; Yuan, Wanzhe

    2017-08-15

    Canine distemper, caused by Canine distemper virus (CDV), is a highly contagious and fatal systemic disease in free-living and captive carnivores worldwide. Recombinase polymerase amplification (RPA), as an isothermal gene amplification technique, has been explored for the molecular detection of diverse pathogens. A real-time reverse transcription RPA (RT-RPA) assay for the detection of canine distemper virus (CDV) using primers and exo probe targeting the CDV nucleocapsid protein gene was developed. A series of other viruses were tested by the RT-RPA.Thirty-two field samples were further tested by RT-RPA, and the resuts were compared with those obtained by the real-time RT-PCR. The RT-RPA assay was performed successfully at 40 °C, and the results were obtained within 3 min-12 min. The assay could detect CDV, but did not show cross-detection of canine parvovirus-2 (CPV-2), canine coronavirus (CCoV), canine parainfluenza virus (CPIV), pseudorabies virus (PRV) or Newcastle disease virus (NDV), demonstrating high specificity. The analytical sensitivity of RT-RPA was 31.8 copies in vitro transcribed CDV RNA, which is 10 times lower than the real-time RT-PCR. The assay performance was validated by testing 32 field samples and compared to real-time RT-PCR. The results indicated an excellent correlation between RT-RPA and a reference real-time RT-PCR method. Both assays provided the same results, and R 2 value of the positive results was 0.947. The results demonstrated that the RT-RPA assay offers an alternative tool for simple, rapid, and reliable detection of CDV both in the laboratory and point-of-care facility, especially in the resource-limited settings.

  19. Antibiotic prescribing for acute bronchitis

    DEFF Research Database (Denmark)

    Llor, Carl; Bjerrum, Lars

    2016-01-01

    INTRODUCTION: Acute bronchitis is a self-limiting infectious disease characterized by acute cough with or without sputum but without signs of pneumonia. About 90% of cases are caused by viruses. AREAS COVERED: Antibiotics for acute bronchitis have been associated with an approximately half......-day reduction in duration of cough. However, at follow-up there are no significant differences in overall clinical improvement inpatients treated with antibiotics compared with those receiving placebo. Despite this, antibiotics are administered to approximately two thirds of these patients. This review...... discusses the reason for this antibiotic overprescription. Other therapies targeted to control symptoms have also demonstrated a marginal or no effect. EXPERT COMMENTARY: Clinicians should be aware of the marginal effectiveness of antibiotic therapy. Some strategies like the use of rapid tests, delayed...

  20. Comparative study of isolates from community-acquired and catheter-associated urinary tract infections with reference to biofilm-producing property, antibiotic sensitivity and multi-drug resistance.

    Science.gov (United States)

    Bardoloi, Vishwajeet; Yogeesha Babu, K V

    2017-07-01

    Urinary tract infection (UTI) can be community-acquired (Com-UTI) or catheter-associated (CAUTI) and may be associated with biofilm-producing organisms. A comparative analysis of biofilm-producing property (BPP), antibiotic-sensitivity and multi-drug resistance (MDR) and their relation with the BPP of isolates from Com-UTI and CAUTI has not yet been performed and necessitated this study. (1) isolation of bacteria from CAUTI and Com-UTI and identification of their BPP, antibiotic-sensitivity and MDR status; (2) comparison of the isolates from CAUTI and Com-UTI as regards BPP, MDR status and their relation with BPP. isolates from 100 cases each of Com-UTI and CAUTI were subjected to Congo redagar (CRA) and Safranin tube tests. Antibiotic susceptibility was investigated using the disc diffusion method. Both groups were compared regarding BPP, drug sensitivity and MDR status. Statistical analyses were performed using χ2 and Fisher's exact tests. 76.19 % of isolates from Com-UTI and 60.72 % from CAUTI had BPP (P=0.0252; significant). The Safranin tube test detected more isolates with BPP than the CRA test. MDR is greater in CAUTI than Com-UTI (83.33 % versus 64.76 %; P=0.0039; significant). MDR is greater in isolates with BPP in both Com-UTI and CAUTI (76.47 and 62.35 %; non-significant). BPP was found in both Com-UTI and CAUTI. When used together, the Safranin tube test and the CRA test increased the sensitivity of detecting BPP. MDR was higher in CAUTI than Com-UTI. MDR and BPP are not interrelated or associated, especially in settings where it is not certain that isolates were obtained from a well-formed biofilm. However, this does not rule out a higher incidence or prevalence of MDR in isolates with BPP taken directly from the biofilms.

  1. Subinhibitory concentrations of antibiotics affect stress and virulence gene expression in Listeria monocytogenes and cause enhanced stress sensitivity but do not affect Caco‐2 cell invasion

    DEFF Research Database (Denmark)

    Knudsen, Gitte Maegaard; Holch, Anne; Gram, Lone

    2012-01-01

    with promoter fusions, 14 of 16 antibiotics induced or repressed expression of one or more stress and/or virulence genes. Despite ampicillin‐induced up‐regulation of PinlA‐lacZ expression, Caco‐2 cell invasion was not affected. Subinhibitory concentrations of ampicillin and tetracycline caused up‐ and down...

  2. Antibiotic Resistance

    DEFF Research Database (Denmark)

    Munck, Christian

    morbidity and mortality as well as an increase in the cost of treatment. Understanding how bacteria respond to antibiotic exposure gives the foundations for a rational approach to counteract antimicrobial resistance. In the work presented in this thesis, I explore the two fundamental sources...... of antimicrobial resistance: (1) adaptive mutations and (2) horizontal acquisition of resistance genes from antibiotic gene reservoirs. By studying the geno- and phenotypic changes of E. coli in response to single and drug-pair exposures, I uncover the evolutionary trajectories leading to adaptive resistance. I...... to rationally design drug combinations that limit the evolution of antibiotic resistance due to counteracting evolutionary trajectories. My results highlight that an in-depth knowledge about the genetic responses to the individual antimicrobial compounds enables the prediction of responses to drug combinations...

  3. Simple and rapid quantification of vancomycin in serum, urine and peritoneal/pleural effusion via UHPLC-MS/MS applicable to personalized antibiotic dosing research.

    Science.gov (United States)

    Javorska, Lenka; Krcmova, Lenka Kujovska; Solich, Petr; Kaska, Milan

    2017-08-05

    Management of the therapy of life-threatening bacterial infection is extremely based on an optimal antibiotic treatment. Achieving the correct vancomycin dosage in blood and target tissues can be complicated in special situations, e.g., where large fluid sequestration and/or acute renal failure occur. A UHPLC-MS/MS method operating in electrospray (ESI) positive ion mode was applied for the determination of vancomycin in serum, urine and peritoneal/pleural effusion. Sample pretreatment was composed of dilution and simple protein precipitation where only a small volume (50μL) of serum, urine or peritoneal/pleural effusion was required. The separation of vancomycin was performed on a Meteoric Core C18 BIO column (100×4.6mm, 2.7μm) by gradient elution with 0.1% formic acid in water and acetonitrile. The total time of analysis was 4.5min. The method was found to be linear in the range of 2-60μM (or 0.5-10μM) for serum, 0.27-10μM (or 2-60μM) for peritoneal/pleural effusion and 25-300μM for urine, which was adequate for the determination of vancomycin in patient samples. The intra- and inter-day precision was below 8% RSD, and accuracy was from 89 to 104%. The UHPLC/MS-MS method offers a fast and reliable approach to determine vancomycin concentrations in three different human body fluid samples (serum, urine and peritoneal/pleural effusion) with a simple sample pretreatment that was the same for all selected specimens. This method should be applicable to large sample series in clinical (pharmacokinetic/pharmacodynamic) studies. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. ELISA-PLA: A novel hybrid platform for the rapid, highly sensitive and specific quantification of proteins and post-translational modifications.

    Science.gov (United States)

    Tong, Qing-He; Tao, Tao; Xie, Li-Qi; Lu, Hao-Jie

    2016-06-15

    Detection of low-abundance proteins and their post-translational modifications (PTMs) remains a great challenge. A conventional enzyme-linked immunosorbent assay (ELISA) is not sensitive enough to detect low-abundance PTMs and suffers from nonspecific detection. Herein, a rapid, highly sensitive and specific platform integrating ELISA with a proximity ligation assay (PLA), termed ELISA-PLA, was developed. Using ELISA-PLA, the specificity was improved by the simultaneous and proximate recognition of targets through multiple probes, and the sensitivity was significantly improved by rolling circle amplification (RCA). For GFP, the limit of detection (LOD) was decreased by two orders of magnitude compared to that of ELISA. Using site-specific phospho-antibody and pan-specific phospho-antibody, ELISA-PLA was successfully applied to quantify the phosphorylation dynamics of ERK1/2 and the overall tyrosine phosphorylation level of ERK1/2, respectively. ELISA-PLA was also used to quantify the O-GlcNAcylation of AKT, c-Fos, CREB and STAT3, which is faster and more sensitive than the conventional immunoprecipitation and western blotting (IP-WB) method. As a result, the sample consumption of ELISA-PLA was reduced 40-fold compared to IP-WB. Therefore, ELISA-PLA could be a promising platform for the rapid, sensitive and specific detection of proteins and PTMs. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Combating Antibiotic Resistance

    Science.gov (United States)

    ... Bacteria Phasing Out Certain Antibiotic Use in Farm Animals FDA: Cutting-Edge Technology Sheds Light on Antibiotic Resistance For More Information Antibiotics and Antibiotic Resistance Antimicrobial Resistance Information for Consumers and Health Professionals CDC: ...

  6. Loop-mediated isothermal amplification assay for rapid and sensitive detection of sheep pox and goat pox viruses in clinical samples.

    Science.gov (United States)

    Venkatesan, G; Balamurugan, V; Bhanuprakash, V; Singh, R K; Pandey, A B

    2016-06-01

    A Loop-mediated isothermal amplification (LAMP) assay targeting the highly conserved DNA polymerase gene of capripox virus genome was developed and evaluated for rapid detection of sheep pox and goat pox viruses. The optimized LAMP assay is found specific and sensitive for amplification of target DNA with a diagnostic sensitivity and specificity of 96.6% and 100% respectively compared to quantitative PCR. The detection rate of LAMP, PCR and Q-PCR assays is found to be 81.5%, 67% and 83% respectively. This LAMP assay has the potential for rapid clinical diagnosis and surveillance of sheep pox and goat pox in field diagnostic laboratories. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Bacterial Contamination of Adult House Flies (Musca domestica) and Sensitivity of these Bacteria to Various Antibiotics, Captured from Hamadan City, Iran.

    Science.gov (United States)

    Nazari, Mansour; Mehrabi, Tahereh; Hosseini, Seyed Mostafa; Alikhani, Mohammad Yousef

    2017-04-01

    House flies ( Musca domestica ) have been known as a mechanical vector in spreading infectious diseases such as cholera, shigellosis, salmonellosis and skin infections. To investigate the bacterial contaminations of house flies and determine the resistance of these bacteria against various antibiotics. An analytical descriptive cross- sectional study was conducted. The study was performed from July to September 2015 in Hamadan University of Medical Sciences, Hamadan, Iran. A total number of 300 house flies were collected from four places, 75 flies from each place, including two educational hospitals belonging to Hamadan University of Medical Sciences, a fruit and vegetables center, and a livestock slaughter. The body surface of house flies was washed using the physiological sterile serum and the obtained solution was centrifuged at 2000 rpm for five minutes. The identification of bacteria was carried out using the phenotypic methods. The resistance of bacteria against various antibiotics was determined using the disk diffusion approach. Data were analysed by the employment of SPSS software package version 20.0. A total number of 394 bacterial strains were isolated from 275 house flies. The most prevalent type of bacteria was Bacillus spp which was detected in 31.1% of house flies. Moreover, Staphylococcus s pp. (22.9%), Escherichia coli (11.6%) were other prevalent species, whereas, Enterococcus s pp. was the least prevalent type of bacteria in the collected house flies. In terms of resistance to antibiotics, it was identified that bacteria extracted from house flies which were collected from hospital environments were more resistant to antibiotics compared with the resistance of bacteria extracted from house flies which were collected from non hospital environments. The maximum bacterial isolation was found in houseflies from hospital No.1 environment from around the accumulation of garbage. It is a well-known fact that house flies are a source of bacterial

  8. Quantification of rifampicin in human plasma and cerebrospinal fluid by a highly sensitive and rapid liquid chromatographic–tandem mass spectrometric method

    OpenAIRE

    Srivastava, Abhishek; Waterhouse, David; Ardrey, Alison; Ward, Stephen A.

    2012-01-01

    A highly sensitive and rapid liquid chromatography tandem mass spectrometry (LC–MS/MS) method has been developed to measure the levels of the antitubercular drug rifampicin (RIF) in human plasma and cerebrospinal fluid (CSF). The analyte and internal standard (IS) were isolated from plasma and CSF by a simple organic solvent based precipitation of proteins followed by centrifugation. Detection was carried out by electrospray positive ionization mass spectrometry in the multiple-reaction monit...

  9. A highly sensitive and specific capacitive aptasensor for rapid and label-free trace analysis of Bisphenol A (BPA) in canned foods.

    Science.gov (United States)

    Mirzajani, Hadi; Cheng, Cheng; Wu, Jayne; Chen, Jiangang; Eda, Shigotoshi; Najafi Aghdam, Esmaeil; Badri Ghavifekr, Habib

    2017-03-15

    A rapid, highly sensitive, specific and low-cost capacitive affinity biosensor is presented here for label-free and single step detection of Bisphenol A (BPA). The sensor design allows rapid prototyping at low-cost using printed circuit board material by benchtop equipment. High sensitivity detection is achieved through the use of a BPA-specific aptamer as probe molecule and large electrodes to enhance AC-electroelectrothermal effect for long-range transport of BPA molecules toward electrode surface. Capacitive sensing technique is used to determine the bounded BPA level by measuring the sample/electrode interfacial capacitance of the sensor. The developed biosensor can detect BPA level in 20s and exhibits a large linear range from 1 fM to 10 pM, with a limit of detection (LOD) of 152.93 aM. This biosensor was applied to test BPA in canned food samples and could successfully recover the levels of spiked BPA. This sensor technology is demonstrated to be highly promising and reliable for rapid, sensitive and on-site monitoring of BPA in food samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. A novel gold nanoparticle-DNA aptamer-based plasmonic chip for rapid and sensitive detection of bacterial pathogens

    DEFF Research Database (Denmark)

    Sun, Yi; Phuoc Long, Truong; Wolff, Anders

    2016-01-01

    Gold nanoparticles (AuNPs)-based biosensors are emerging technologies for rapid detection of pathogens. However, it is very challenging to develop chip-based AuNP-biosensors for whole cells. This paper describes a novel AuNPs-DNA aptamer-based plasmonic assay which allows DNA aptamers...

  11. Rapid and sensitive trace gas detection with continuous wave Optical Parametric Oscillator-based Wavelength Modulation Spectroscopy

    NARCIS (Netherlands)

    Arslanov, D.D.; Spunei, M.; Ngai, A.K.Y.; Cristescu, S.M.; Lindsay, I.D.; Lindsay, I.D.; Boller, Klaus J.; Persijn, S.T.; Harren, F.J.M.

    2011-01-01

    A fiber-amplified Distributed Bragg Reflector diode laser is used to pump a continuous wave, singly resonant Optical Parametric Oscillator (OPO). The output radiation covers the 3–4 μm with ability of rapid (100 THz/s) and broad mode-hop-free tuning (5 cm−1). Wavelength Modulation Spectroscopy is

  12. Reconventionalization following antibiotic decontamination in man and animals

    NARCIS (Netherlands)

    Waaij, D. van der; Vossen, J.M.; Korthals Altes, C.; Hartgrink, C.

    1977-01-01

    Antibiotic decontamination of the digestive tract can suppress or eliminate all microorganisms in this tract that are sensitive to the antibiotics used for decontamination. Experimental work in animals has indicated that colonization resistance (CR) decreases to extremely low values during

  13. Prevalence of bovine mastitis and multi-antibiotic resistant ...

    African Journals Online (AJOL)

    Prevalence of bovine mastitis and multi-antibiotic resistant Staphylococcus and ... Bulletin of Animal Health and Production in Africa ... their antibiotic sensitivities and management practices of sahiwal and dairy cattle kept at a centre of Kenya ...

  14. Prescribing Antibiotics

    DEFF Research Database (Denmark)

    Pedersen, Inge Kryger; Jepsen, Kim Sune

    2018-01-01

    The medical professions will lose an indispensable tool in clinical practice if even simple infections cannot be cured because antibiotics have lost effectiveness. This article presents results from an exploratory enquiry into “good doctoring” in the case of antibiotic prescribing at a time when...... the knowledge base in the healthcare field is shifting. Drawing on in-depth interviews about diagnosing and prescribing, the article demonstrates how the problem of antimicrobial resistance is understood and engaged with by Danish general practitioners. When general practitioners speak of managing “non......-medical issues,” they refer to routines, clinical expertise, experiences with their patients, and decision-making based more on contextual circumstances than molecular conditions—and on the fact that such conditions can be hard to assess. This article’s contribution to knowledge about how new and global health...

  15. Increasing biopsy number and sampling from gastric body improve the sensitivity of rapid urease test in patients with peptic ulcer bleeding.

    Science.gov (United States)

    Lee, Tzong-Hsi; Lin, Chien-Chu; Chung, Chen-Shuan; Lin, Cheng-Kuan; Liang, Cheng-Chao; Tsai, Kuang-Chau

    2015-02-01

    Previous studies demonstrated that the sensitivity of rapid urease test (RUT) for diagnosis of Helicobacter pylori infection decreased during peptic ulcer bleeding. We designed this study and tried to find a better method to improve the detection rate of H. pylori infection at the same session of endoscopic diagnosis of peptic ulcer bleeding. We prospectively enrolled 116 patients with peptic ulcer bleeding. These patients received intravenous proton pump inhibitor and then received upper gastrointestinal endoscopy within 24 h after arrival. We took one piece of biopsy from gastric antrum (Group 1), four pieces from gastric antrum (Group 2), and one piece from the gastric body (Group 3) for three separate RUTs, respectively. (13)C-urease breath test was used as gold standard for diagnosis of H. pylori infection. There were 74 patients (64 %) with positive (13)C-urease breath test. Among these 74 patients, 45 patients had positive RUT (sensitivity: 61 %) in Group 1; 55 patients had positive RUT (sensitivity: 74 %) in Group 2; 54 patients had positive RUT (sensitivity: 73 %) in Group 3. There were significant differences between Group 1 and Group 2 (p = 0.02) and between Group 1 and Group 3 (p = 0.022). The sensitivity of RUT was 61 % during peptic ulcer bleeding. The sensitivity of RUT can be increased significantly by increased biopsy number from gastric antrum or biopsy from gastric body.

  16. First Report of a Case of Pneumococcal Meningitis Which Did Not Respond to the Ceftriaxone Therapy despite the Isolated Organism Being Sensitive to This Antibiotic In Vitro

    Directory of Open Access Journals (Sweden)

    Maryam Mojtabavi

    2011-01-01

    Full Text Available A 60-year-old man presented with pneumococcal meningitis which did not respond to the ceftriaxone therapy, in spite of in-vitro susceptibility (minimal inhibitory concentration of 0.016 μg/dLit of the isolated organism to this antibacterial agent, although ceftriaxone is still the drug of choice for such pneumococcal meningitis. Review of published articles revealed no report of clinical resistance in organisms which were susceptible to the same antimicrobial agent in vitro. This alarming emergence of isolates with in vivo resistance should be considered and even could lead to a shift in the empirical antibiotic therapy for pneumococcal infections.

  17. Detection of residues antibiotics in food using a microbiological method

    International Nuclear Information System (INIS)

    Ben Ali, Ahmed

    2007-01-01

    Antibiotics are effective therapeutic agents because of their property of selective bacterial toxicity which helps controlling infections. Animals, just like humans, can be treated with antibiotics. This use of antibiotics can lead to the development of resistance. Resistant strains may cause severe infections in humans and animals. In addition, antibiotic residues might represent a problem for human health. Our objective is to develop a microbiological method for the detection of antibiotic residues in poultry(muscle, liver,...). For this purpose, antibiotic sensitive bacteria and selective agar media were used. An inhibition growth zone surrounds each of the food samples containing antibiotic residues after a prescribed incubation time. (Author). 23 refs

  18. Bistable Bacterial Growth Rate in Response to Antibiotics with Low Membrane Permeability

    Science.gov (United States)

    Elf, Johan; Nilsson, Karin; Tenson, Tanel; Ehrenberg, Måns

    2006-12-01

    We demonstrate that growth rate bistability for bacterial cells growing exponentially at a fixed external antibiotic concentration can emerge when the cell wall permeability for the drug is low and the growth rate sensitivity to the intracellular drug concentration is high. Under such conditions, an initially high growth rate can remain high, due to dilution of the intracellular drug concentration by rapid cell volume increase, while an initially low growth rate can remain low, due to slow cell volume increase and insignificant drug dilution. Our findings have implications for the testing of novel antibiotics on growing bacterial strains.

  19. Urinary tract infection (UTI) multi-bacteria multi-antibiotic testing using surface enhanced Raman spectroscopy (SERS)

    Science.gov (United States)

    Hadjigeorgiou, Katerina; Kastanos, Evdokia; Pitris, Costas

    2013-02-01

    Antibiotic resistance is a major health care problem mostly caused by the inappropriate use of antibiotics. At the root of the problem lies the current method for determination of bacterial susceptibility to antibiotics which requires overnight cultures. Physicians suspecting an infection usually prescribe an antibiotic without waiting for the results. This practice aggravates the problem of bacterial resistance. In this work, a rapid method of diagnosis and antibiogram for a bacterial infection was developed using Surface Enhanced Raman Spectroscopy (SERS) with silver nanoparticles. SERS spectra of three species of gram negative bacteria, Escherichia coli, Proteus spp., and Klebsiella spp. were obtained after 0 and 4 hour exposure to the seven different antibiotics. Even though the concentration of bacteria was low (2x105 cfu/ml), species classification was achieved with 94% accuracy using spectra obtained at 0 hours. Sensitivity or resistance to antibiotics was predicted with 81%-100% accuracy from spectra obtained after 4 hours of exposure to the different antibiotics. With the enhancement provided by SERS, the technique can be applied directly to urine or blood samples, bypassing the need for overnight cultures. This technology can lead to the development of rapid methods of diagnosis and antibiogram for a variety of bacterial infections.

  20. A simple, rapid and green method based on pulsed potentiostatic electrodeposition of reduced graphene oxide on glass carbon electrode for sensitive voltammetric detection of sophoridine

    International Nuclear Information System (INIS)

    Wang, Fei; Wu, Yanju; Lu, Kui; Gao, Lin; Ye, Baoxian

    2014-01-01

    Graphical abstract: A simple, rapid and green method, based on graphene nanosheets directly deposited onto a glassy carbon electrode by pulsed potentiostatic reduction of a graphene oxide colloidal solution, to build sensitive voltammetric sensor for the determination of sophoridine was presented. - Highlights: • A simple, rapid and green method to build sensitive voltammetric sensor was presented. • The proposed sensor has a high electrochemical sensitivity for determination of sophoridine. • The proposed sensor exhibited an excellent selectivity. - Abstract: A simple, rapid and green method was described for sensitive voltammetric detection of sophoridine based on graphene nanosheets directly deposited onto a glassy carbon electrode (GCE) by pulsed potentiostatic reduction of a graphene oxide (GO) colloidal solution. The resulting electrodes (PP-ERGO/GCE) were characterized by electrochemical methods and scanning electron microscopy. Moreover, the electrochemical behaviors of sophoridine at the modified electrode were investigated in detail by cyclic voltammetry (CV), chronoamperometry (CA) and chronocoulometry (CC). Compared with the bare GCE and the preparation of reduced graphene oxide (RGO) films by potentiostatic method (PM) modified GCE, PP-ERGO/GCE could intensively enhance the oxidation peak currents and decrease the overpotential of sophoridine. Under the selected conditions, the modified electrode showed a linear voltammetric response to sophoridine within the concentration range of 8.0 × 10 −7 ∼ 1.0 × 10 −4 mol L −11 , with the detection limit of 2.0 × 10 −7 mol L −1 . And, the method was also applied to detect sophoridine in spiked human urine with wonderful satisfactory

  1. Rapid screening of oxytetracycline residue in catfish muscle by dispersive liquid-liquid microextraction and europium-sensitized luminescence

    Science.gov (United States)

    Oxytetracycline (OTC) residue in catfish muscle was screened by dispersive liquid-liquid microextraction (DLLME) and europium-sensitized luminescence (ESL). After extraction in EDTA, HCl, and acetonitrile, cleanup was carried out by DLLME, and ESL was measured at microgram = 385 nm and wavelength = ...

  2. Antibiotic Resistance of Bacteria: A Global Challenge

    Indian Academy of Sciences (India)

    protein that functions as an elctroneutral antiport system. The .... isolates, obtained from north Bengal, and over the counter sale of the same antibiotics in and around .... biology is being applied to rapidly explore and optimize the interactions ...

  3. Synthesis of molecularly imprinted dye-silica nanocomposites with high selectivity and sensitivity: Fluorescent imprinted sensor for rapid and efficient detection of τ-fluvalinate in vodka.

    Science.gov (United States)

    Wang, Yunyun; Wang, Jixiang; Cheng, Rujia; Sun, Lin; Dai, Xiaohui; Yan, Yongsheng

    2018-04-01

    An imprinted fluorescent sensor was fabricated based on SiO 2 nanoparticles encapsulated with a molecularly imprinted polymer containing allyl fluorescein. High fluorine cypermethirin as template molecules, methyl methacrylate as functional monomer, and allyl fluorescein as optical materials synthesized a core-shell fluorescent molecular imprinted sensor, which showed a high and rapid sensitivity and selectivity for the detection of τ-fluvalinate. The sensor presented appreciable sensitivity with a limit of 13.251 nM, rapid detection that reached to equilibrium within 3 min, great linear relationship in the relevant concentration range from 0 to 150 nM, and excellent selectivity over structural analogues. In addition, the fluorescent sensor demonstrated desirable regeneration ability (eight cycling operations). The molecularly imprinted polymers ensured specificity, while the fluorescent dyes provided the stabile sensitivity. Finally, an effective application of the sensor was implemented by the detection of τ-fluvalinate in real samples from vodka. The molecularly imprinted fluorescent sensor showed a promising potential in environmental monitoring and food safety. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Rapid test for lung maturity, based on spectroscopy of gastric aspirate, predicted respiratory distress syndrome with high sensitivity

    DEFF Research Database (Denmark)

    Verder, Henrik; Heiring, Christian; Clark, Howard

    2017-01-01

    AIM: Respiratory distress syndrome (RDS) is a major cause of mortality and morbidity in premature infants. By the time symptoms appear, it may already be too late to prevent a severe course, with bronchopulmonary dysplasia or mortality. We aimed to develop a rapid test of lung maturity...... for targeting surfactant supplementation. METHODS: Concentrations of the most surface-active lung phospholipid dipalmitoylphosphatidylcholine and sphingomyelin in gastric aspirates from premature infants were measured by mass spectrometry and expressed as the lecithin/sphingomyelin ratio (L/S). The same...

  5. Design and synthesis of new fluorescent probe for rapid and highly sensitive detection of proteins via electrophoretic gel stain.

    Science.gov (United States)

    Suzuki, Yoshio; Takagi, Nobuyuki; Chimuro, Tomoyuki; Shinohara, Atsushi; Sakaguchi, Nao; Hiratsuka, Atsunori; Yokoyama, Kenji

    2011-06-01

    A new fluorescent molecular probe, 2,2'-(1E,1'E)-2,2'-(4-(dicyanomethylene)-4H-pyrane-2,6-diyl)bis(ethene-2,1-diyl)bis(sodium benzenesulfonate) salt (1), possessing the cyanopyranyl moieties and two benzene sulfonic acid groups was designed and synthesized to detect proteins in solution and for high-throughput SDS-PAGE. Compound 1 exhibited no fluorescence in the absence of proteins; however, it exhibited strong fluorescence on the addition of bovine serum albumin as a result of intramolecular charge transfer. Compared with the conventional protocols for in-gel protein staining, such as SYPRO Ruby and silver staining, 1 achieves higher sensitivity, even though it offers a simplified, higher throughput protocol. In fact, the total time required for protein staining was 60-90 min under optimum conditions much shorter than that required by the less-sensitive silver staining or SYPRO Ruby staining protocols. Moreover, 1 was successfully applied to protein identification by mass spectrometry via in-gel tryptic digestion, Western blotting, and native PAGE together with protein staining by 1, which is a modified protocol of blue native PAGE (BN-PAGE). Thus, 1 may facilitate high-sensitivity protein detection, and it may be widely applicable as a convenient tool in various scientific and medical fields. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Re-sensitizing Multidrug Resistant Bacteria to Antibiotics by Targeting Bacterial Response Regulators: Characterization and Comparison of Interactions between 2-Aminoimidazoles and the Response Regulators BfmR from Acinetobacter baumannii and QseB from Francisella spp.

    Directory of Open Access Journals (Sweden)

    Morgan E. Milton

    2018-02-01

    Full Text Available 2-aminoimidazole (2-AI compounds inhibit the formation of bacterial biofilms, disperse preformed biofilms, and re-sensitize multidrug resistant bacteria to antibiotics. 2-AIs have previously been shown to interact with bacterial response regulators, but the mechanism of interaction is still unknown. Response regulators are one part of two-component systems (TCS. TCSs allow cells to respond to changes in their environment, and are used to trigger quorum sensing, virulence factors, and antibiotic resistance. Drugs that target the TCS signaling process can inhibit pathogenic behavior, making this a potent new therapeutic approach that has not yet been fully exploited. We previously laid the groundwork for the interaction of the Acinetobacter baumannii response regulator BfmR with an early 2-AI derivative. Here, we further investigate the response regulator/2-AI interaction and look at a wider library of 2-AI compounds. By combining molecular modeling with biochemical and cellular studies, we expand on a potential mechanism for interaction between response regulators and 2-AIs. We also establish that Francisella tularensis/novicida, encoding for only three known response regulators, can be a model system to study the interaction between 2-AIs and response regulators. We show that knowledge gained from studying Francisella can be applied to the more complex A. baumannii system, which contains over 50 response regulators. Understanding the impact of 2-AIs on response regulators and their mechanism of interaction will lead to the development of more potent compounds that will serve as adjuvant therapies to broad-range antibiotics.

  7. Sensitive and rapid detection of endogenous hydrogen sulfide distributing in different mouse viscera via a two-photon fluorescent probe

    International Nuclear Information System (INIS)

    Chen, Qian; Yang, Jinfeng; Li, Yinhui; Zheng, Jing; Yang, Ronghua

    2015-01-01

    Development of efficient methods for detection of endogenous H 2 S in living cells and tissues is of considerable significance for better understanding the biological and pathological functions of H 2 S. Two-photon (TP) fluorescent probes are favorable as powerful molecular tools for studying physiological process due to its non-invasiveness, high spatiotemporal resolution and deep-tissues imaging. Up to date, several TP probes for intracellular H 2 S imaging have been designed, but real-time imaging of endogenous H 2 S-related biological processes in tissues is hampered due to low sensitivity, long response time and interference from other biothiols. To address this issue, we herein report a novel two-photon fluorescent probe (TPP-H 2 S) for highly sensitive and fast monitoring and imaging H 2 S levels in living cells and tissues. In the presence of H 2 S, it exhibits obviously improved sensitivity (LOD: 0.12 μM) and fast response time (about 2 min) compared with the reported two-photon H 2 S probes. With two-photon excitation, TPP-H 2 S displays high signal-to-noise ratio and sensitivity even no interference in cell growth media. As further application, TPP-H 2 S is applied for fast imaging of H 2 S in living cells and different fresh tissues by two-photon confocal microscope. Most importantly we first measured the endogenous H 2 S level in different viscera by vivisection and found that the distribution of endogenous H 2 S mostly in brain, liver and lung. The excellent sensing properties of TPP-H 2 S make it a practically useful tool for further studying biological roles of H 2 S. - Highlights: • This two-photon probe exhibits an improved sensitivity and response time to H 2 S. • This probe shows excellent membrane permeability and fast visualization of H 2 S in living cells and tissues. • This probe is successfully applied to measure the endogenously produced H 2 S levels in different viscera of mouse.

  8. MASTITE BOVINA: SENSIBILIDADE DE AGENTES ETIOLÓGICOS A ANTIBIÓTICOS E QUIMIOTERÁPICOS BOVINE MASTITIS: SENSITIVITY OF ETIOLOGICAL AGENTS TO ANTIBIOTICS AND CHEMOTHERAPICS

    Directory of Open Access Journals (Sweden)

    Roberval Rodrigues da Costa

    2007-09-01

    Full Text Available

    Foram analisadas 590 amostras de leite procedentes de 701 vacas da bacia leiteira de Goiânia, que apresentaram ao teste de Whiteside/CMT resultado suspeito ou positivo. Foi feito o teste de sensibilidade bacteriana “in vitro” a antibióticos e quimioterápicos dos agentes etiológicos isolados das lactoculturas. Os antibióticos e quimioterápicos testados foram: trimetropim-sulfametazole, tetraciclina, streptomicina cloranfenicol, kanamicina, penicilina G, furadantina, neomicina, eritromicina e novobiocina. As drogas que mostraram a maior ação foram: trimetropim-sulfametazole, cloranfenicol e furadantina; por outro lado, maior resistência foi observada para a penicilina G, streptomicina e eritromicina.

    590 samples of mi1k collected from 701 cows in the milk area around Goiânia were submitted to the Whiteside/CMT test and all suspect or positive. It was also done the bacterial sensibility test “in vitro” to antibiotics and chemotherapics of the aetiological agents isolated from the lactocultures. The antibiotics and chemioterapics tested were as follow: trimetropim-sulfametazole, tetracicline, streptomicine, chloranfenicol, kanamicine, penicilin G, furadantine, neomicine, eritromicine and novobiocine. The drugs which had better action were: trimetropim-sulfametazole, chloranfenicol and furadantine; on the other side, a higher resistance was observed for penicilin G, streptomicine and eritromicine.

  9. Valuing reduced antibiotic use for pediatric acute otitis media.

    Science.gov (United States)

    Meropol, Sharon B

    2008-04-01

    The 2004 American Academy of Pediatrics acute otitis media guidelines urge parents to weigh the benefits of reduced antibiotic use, adverse drug events, and future resistance versus risks of extra costs and sick days resulting from guideline use. The value of decreased antibiotic resistance has not been quantified. The objective was to perform cost-utility analysis, estimating the resistance value of implementing the guidelines for acute otitis media treatment for children life-day units. The minimum resistance benefit value, where the benefits of the American Academy of Pediatrics guidelines would at least balance their costs, was defined as the guidelines' incremental costs minus their other benefits. For a child 2 to benefit at 0.77 quality-adjusted life-days per antibiotic prescription avoided for the guidelines' benefits to balance their costs. For the 6- to life-days per prescription avoided. Results were sensitive to the dollar cost utility; when willingness to pay ranged from $20,000 to $200,000 per quality-adjusted life-year, results ranged from 0.36 and 0.30 quality-adjusted life-days up to 4.10 and 3.57 quality-adjusted life-days for the 2- to work days. From a societal perspective, trading 0.30 to 4 quality-adjusted life-days to avoid 1 antibiotic course might be desirable; from a parental perspective, this may not be as desirable. Parent demand for antibiotics may be rational when driven by the value of parent time. Other approaches that have the potential to reduce antibiotic use, such as wider use of influenza vaccine and improved rapid viral diagnostic techniques, might be more successful.

  10. ASP Strategies and Appropriate Antibiotic Use

    Science.gov (United States)

    Lee, Brian R; Tribble, Alison; Handy, Lori; Gerber, Jeffrey S; Hersh, Adam L; Kronman, Matthew; Terrill, Cindy; Newland, Jason

    2017-01-01

    Abstract Background The Infectious Diseases Society of America (IDSA) recommends hospitals implement antimicrobial stewardship programs (ASP) in order to decrease inappropriate antibiotic use due to the rise in antibiotic-resistant infections. Data are limited on the extent to which different ASP strategies influence appropriate antibiotic use. Methods We conducted an online survey in 2016 of U.S. Children’s Hospitals to collect hospital-level information on dedicated ASP effort, ASP monitoring activities, use of audit-feedback, formulary restrictions, rapid diagnostics, etc. During the same period the ASP teams at these hospitals completed 3 point prevalence surveys that documented details on all admitted patients 0–17 years receiving any antibiotics, determined what ASP modifications could be made, and if the antibiotic was appropriate. We employed hierarchical, multivariable logit models to examine which ASP-related, hospital-level strategies were associated with appropriate antibiotic use. Results Thirty hospitals participated. A total of 6,921 patients were included, representing 10,068 total antibiotics. Of these orders, 8,554 (85.0%) were categorized as appropriate, though this varied across sites (range: 68-92%). Additionally, 78.2% of antibiotics did not have recommended modifications. Appropriate antibiotic use was significantly higher for hospitals that relied on rapid diagnostics (aOR: 1.6; P Terrill, Merck: Grant Investigator, Research grant Allergan: Grant Investigator, Research grant. J. Newland, Merck: Grant Investigator, Research grant. Allergan: Grant Investigator, Research grant

  11. Generic antibiotics in Japan.

    Science.gov (United States)

    Fujimura, Shigeru; Watanabe, Akira

    2012-08-01

    Generic drugs have been used extensively in many developed countries, although their use in Japan has been limited. Generic drugs reduce drug expenses and thereby national medical expenditure. Because generic drugs provide advantages for both public administration and consumers, it is expected that they will be more widely used in the future. However, the diffusion rate of generic drugs in Japan is quite low compared with that of other developed countries. An investigation on generic drugs conducted by the Ministry of Health, Labour and Welfare in Japan revealed that 17.2 % of doctors and 37.2 % of patients had not used generic drugs. The major reasons for this low use rate included distrust of off-patent products and lower drug price margin compared with the brand name drug. The generic drugs available in the market include external drugs such as wet packs, antihypertensive agents, analgesics, anticancer drugs, and antibiotics. Among them, antibiotics are frequently used in cases of acute infectious diseases. When the treatment of these infections is delayed, the infection might be aggravated rapidly. The pharmacokinetics-pharmacodynamics (PK-PD) theory has been adopted in recent chemotherapy, and in many cases, the most appropriate dosage and administration of antibiotics are determined for individual patients considering renal function; high-dosage antibiotics are used preferably for a short duration. Therefore, a highly detailed antimicrobial agent is necessary. However, some of the generic antibiotics have less antibacterial potency or solubility than the brand name products. We showed that the potency of the generic products of vancomycin and teicoplanin is lower than that of the branded drugs by 14.6 % and 17.3 %, respectively. Furthermore, we confirmed that a generic meropenem drug for injection required about 82 s to solubilize in saline, whereas the brand product required only about 21 s. It was thought that the cause may be the difference in size of bulk

  12. Rapid, simple, and highly sensitive analysis of drugs in biological samples using thin-layer chromatography coupled with matrix-assisted laser desorption/ionization mass spectrometry.

    Science.gov (United States)

    Kuwayama, Kenji; Tsujikawa, Kenji; Miyaguchi, Hajime; Kanamori, Tatsuyuki; Iwata, Yuko T; Inoue, Hiroyuki

    2012-01-01

    Rapid and precise identification of toxic substances is necessary for urgent diagnosis and treatment of poisoning cases and for establishing the cause of death in postmortem examinations. However, identification of compounds in biological samples using gas chromatography and liquid chromatography coupled with mass spectrometry entails time-consuming and labor-intensive sample preparations. In this study, we examined a simple preparation and highly sensitive analysis of drugs in biological samples such as urine, plasma, and organs using thin-layer chromatography coupled with matrix-assisted laser desorption/ionization mass spectrometry (TLC/MALDI/MS). When the urine containing 3,4-methylenedioxymethamphetamine (MDMA) without sample dilution was spotted on a thin-layer chromatography (TLC) plate and was analyzed by TLC/MALDI/MS, the detection limit of the MDMA spot was 0.05 ng/spot. The value was the same as that in aqueous solution spotted on a stainless steel plate. All the 11 psychotropic compounds tested (MDMA, 4-hydroxy-3-methoxymethamphetamine, 3,4-methylenedioxyamphetamine, methamphetamine, p-hydroxymethamphetamine, amphetamine, ketamine, caffeine, chlorpromazine, triazolam, and morphine) on a TLC plate were detected at levels of 0.05-5 ng, and the type (layer thickness and fluorescence) of TLC plate did not affect detection sensitivity. In addition, when rat liver homogenate obtained after MDMA administration (10 mg/kg) was spotted on a TLC plate, MDMA and its main metabolites were identified using TLC/MALDI/MS, and the spots on a TLC plate were visualized by MALDI/imaging MS. The total analytical time from spotting of intact biological samples to the output of analytical results was within 30 min. TLC/MALDI/MS enabled rapid, simple, and highly sensitive analysis of drugs from intact biological samples and crude extracts. Accordingly, this method could be applied to rapid drug screening and precise identification of toxic substances in poisoning cases and

  13. Alleviation of rapid, futile ammonium cycling at the plasma membrane by potassium reveals K+-sensitive and -insensitive components of NH4+ transport.

    Science.gov (United States)

    Szczerba, Mark W; Britto, Dev T; Balkos, Konstantine D; Kronzucker, Herbert J

    2008-01-01

    Futile plasma membrane cycling of ammonium (NH4+) is characteristic of low-affinity NH4+ transport, and has been proposed to be a critical factor in NH4+ toxicity. Using unidirectional flux analysis with the positron-emitting tracer 13N in intact seedlings of barley (Hordeum vulgare L.), it is shown that rapid, futile NH4+ cycling is alleviated by elevated K+ supply, and that low-affinity NH4+ transport is mediated by a K+-sensitive component, and by a second component that is independent of K+. At low external [K+] (0.1 mM), NH4+ influx (at an external [NH4+] of 10 mM) of 92 micromol g(-1) h(-1) was observed, with an efflux:influx ratio of 0.75, indicative of rapid, futile NH4+ cycling. Elevating K+ supply into the low-affinity K+ transport range (1.5-40 mM) reduced both influx and efflux of NH4+ by as much as 75%, and substantially reduced the efflux:influx ratio. The reduction of NH4+ fluxes was achieved rapidly upon exposure to elevated K+, within 1 min for influx and within 5 min for efflux. The channel inhibitor La3+ decreased high-capacity NH4+ influx only at low K+ concentrations, suggesting that the K+-sensitive component of NH4+ influx may be mediated by non-selective cation channels. Using respiratory measurements and current models of ion flux energetics, the energy cost of concomitant NH4+ and K+ transport at the root plasma membrane, and its consequences for plant growth are discussed. The study presents the first demonstration of the parallel operation of K+-sensitive and -insensitive NH4+ flux mechanisms in plants.

  14. Rapid Estrogen Receptor-Mediated Mechanisms Determine the Sexually Dimorphic Sensitivity of Ventricular Myocytes to 17β-Estradiol and the Environmental Endocrine Disruptor Bisphenol A

    Science.gov (United States)

    Belcher, Scott M.; Chen, Yamei; Yan, Sujuan

    2012-01-01

    Previously we showed that 17β-estradiol (E2) and/or the xenoestrogen bisphenol A (BPA) alter ventricular myocyte Ca2+ handing, resulting in increased cardiac arrhythmias in a female-specific manner. In the present study, the roles of estrogen receptors (ER) in mediating the rapid contractile and arrhythmogenic effects of estrogens were examined. Contractility was used as an index to assess the impact of E2 or BPA on Ca2+ handling in rodent ventricular myocytes. The concentration-response curve for the stimulatory effects of BPA and E2 on female myocyte was inverted-U shaped. Detectable effects for each compound were observed at 10−12 m, and the most efficacious concentrations for each were at 10−9 m. Sensitivity to E2 and BPA was not observed in male myocytes and was abolished in myocytes from ovariectomized females. Analysis using protein-conjugated E2 suggests that these rapid actions are induced by membrane-associated receptors. Analysis using selective ER agonists and antagonists and a genetic ERβ knockout mouse model showed that ERα and ERβ have opposing actions in myocytes and that the balance between ERβ and ERα signaling is the prime regulator of the sex-specific sensitivity toward estrogens. The response of female myocytes to E2 and BPA is dominated by the stimulatory ERβ-mediated signaling, and the absence of BPA and E2 responsiveness in males is due to a counterbalancing-suppressive action of ERα. We conclude that the sex-specific sensitivity of myocytes to estrogens and the rapid arrhythmogenic effects of BPA and estradiol in the female heart are regulated by the balance between ERα and ERβ signaling. PMID:22166976

  15. Antibiotics as CECs: An Overview of the Hazards Posed by Antibiotics and Antibiotic Resistance

    Directory of Open Access Journals (Sweden)

    Geoffrey Ivan Scott

    2016-04-01

    Full Text Available ABSTRACTMonitoring programs have traditionally monitored legacy contaminants but are shifting focus to Contaminants of Emerging Concern (CECs. CECs present many challenges for monitoring and assessment, because measurement methods don't always exist nor have toxicological studies been fully conducted to place results in proper context. Also some CECs affect metabolic pathways to produce adverse outcomes that are not assessed through traditional toxicological evaluations. Antibiotics are CECs that pose significant environmental risks including development of both toxic effects at high doses and antibiotic resistance at doses well below the Minimum Inhibitory Concentration (MIC which kill bacteria and have been found in nearly half of all sites monitored in the US. Antimicrobial resistance has generally been attributed to the use of antibiotics in medicine for humans and livestock as well as aquaculture operations. The objective of this study was to assess the extent and magnitude of antibiotics in the environment and estimate their potential hazards in the environment. Antibiotics concentrations were measured in a number of monitoring studies which included Waste Water Treatment Plants (WWTP effluent, surface waters, sediments and biota. A number of studies reported levels of Antibiotic Resistant Microbes (ARM in surface waters and some studies found specific ARM genes (e.g. the blaM-1 gene in E. coli which may pose additional environmental risk. High levels of this gene were found to survive WWTP disinfection and accumulated in sediment at levels 100-1000 times higher than in the sewerage effluent, posing potential risks for gene transfer to other bacteria.in aquatic and marine ecosystems. Antibiotic risk assessment approaches were developed based on the use of MICs and MIC Ratios [High (Antibiotic Resistant/Low (Antibiotic Sensitive MIC] for each antibiotic indicating the range of bacterial adaptability to each antibiotic to help define the No

  16. Synthetic membrane-targeted antibiotics.

    Science.gov (United States)

    Vooturi, S K; Firestine, S M

    2010-01-01

    Antimicrobial resistance continues to evolve and presents serious challenges in the therapy of both nosocomial and community-acquired infections. The rise of resistant strains like methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Staphylococcus aureus (VRSA) and vancomycin-resistant enterococci (VRE) suggests that antimicrobial resistance is an inevitable evolutionary response to antimicrobial use. This highlights the tremendous need for antibiotics against new bacterial targets. Agents that target the integrity of bacterial membrane are relatively novel in the clinical armamentarium. Daptomycin, a lipopeptide is a classical example of membrane-bound antibiotic. Nature has also utilized this tactic. Antimicrobial peptides (AMPs), which are found in all kingdoms, function primarily by permeabilizing the bacterial membrane. AMPs have several advantages over existing antibiotics including a broad spectrum of activity, rapid bactericidal activity, no cross-resistance with the existing antibiotics and a low probability for developing resistance. Currently, a small number of peptides have been developed for clinical use but therapeutic applications are limited because of poor bioavailability and high manufacturing cost. However, their broad specificity, potent activity and lower probability for resistance have spurred the search for synthetic mimetics of antimicrobial peptides as membrane-active antibiotics. In this review, we will discuss the different classes of synthetic membrane-bound antibiotics published since 2004.

  17. Incidence and antibiotic susceptibility pattern of Staphylococcus ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-06-03

    Jun 3, 2008 ... antibiotic sensitivity test results of suspected cases of urinary tract infection (UTI) of the University of ... (4.4%), Pseudomonas aeruginosa (2.0%) and Candida albican (1.0%). ... and oxfloxacin could be the drug of choice in the treatment of S. aureus. ... appropriate empirical antibiotics that could be of use.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    The human pathogenic bacterium Listeria monocytogenes is exposed to antibiotics both during clinical treatment and in its saprophytic lifestyle. As one of the keys to successful treatment is continued antibiotic sensitivity, the purpose of this study was to determine if exposure to sublethal...... antibiotic concentrations would affect the bacterial physiology and induce antibiotic tolerance. Transcriptomic analyses demonstrated that each of the four antibiotics tested caused an antibiotic-specific gene expression pattern related to mode-of-action of the particular antibiotic. All four antibiotics...... in Imo1179 (eutE) encoding an aldehyde oxidoreductase where rerouting caused increased ethanol production was tolerant to three of four antibiotics tested. This shift in metabolism could be a survival strategy in response to antibiotics to avoid generation of ROS production from respiration by oxidation...

  19. Development of a rapid, simple and sensitive HPLC-FLD method for determination of rhodamine B in chili-containing products.

    Science.gov (United States)

    Qi, Ping; Lin, Zhihao; Li, Jiaxu; Wang, ChengLong; Meng, WeiWei; Hong, Hong; Zhang, Xuewu

    2014-12-01

    In this work, a simple, rapid and sensitive analytical method for the determination of rhodamine B in chili-containing foodstuffs is described. The dye is extracted from samples with methanol and analysed without further cleanup procedure by high-performance liquid chromatography (HPLC) coupled to fluorescence detection (FLD). The influence of matrix fluorescent compounds (capsaicin and dihydrocapsaicin) on the analysis was overcome by the optimisation of mobile-phase composition. The limit of determination (LOD) and limit of quantification (LOQ) were 3.7 and 10 μg/kg, respectively. Validation data show a good repeatability and within-lab reproducibility with relative standard deviations rhodamine B in foodstuffs. This method is suitable for the routine analysis of rhodamine B due to its sensitivity, simplicity, reasonable time and cost. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Rapid and sensitive detection of canine distemper virus by one-tube reverse transcription-insulated isothermal polymerase chain reaction.

    Science.gov (United States)

    Wilkes, Rebecca P; Tsai, Yun-Long; Lee, Pei-Yu; Lee, Fu-Chun; Chang, Hsiao-Fen Grace; Wang, Hwa-Tang Thomas

    2014-09-09

    Canine distemper virus (CDV) has been associated with outbreaks of canine infectious respiratory disease in shelters and boarding kennel environments. POCKITTM Nucleic Acid Analyzer is a field-deployable device capable of generating automatically interpreted insulated isothermal polymerase chain reaction (iiPCR) results from extracted nucleic acid within one hour. In this study, reverse transcription iiPCR (RT-iiPCR) was developed to facilitate point-of-need diagnosis of CDV infection. Analytical sensitivity (limit of detection 95%) of the established CDV RT-iiPCR was about 11 copies of in vitro transcribed RNA per reaction. CDV RT-iiPCR generated positive signals from CDV, but not Bordetella bronchiseptica, canine parvovirus, canine herpesvirus, canine adenovirus 2, canine influenza virus (subtype H3N8), canine parainfluenza virus, and canine respiratory coronavirus. To evaluate accuracy of the established reaction in canine distemper clinical diagnosis, 110 specimens from dogs, raccoons, and foxes suspected with CDV infection were tested simultaneously by CDV RT-iiPCR and real-time RT-PCR. CDV RT-iiPCR demonstrated excellent sensitivity (100%) and specificity (100%), compared to real-time RT-PCR. The results indicated an excellent correlation between RT-iiPCR and a reference real time RT-PCR method. Working in a lyophilized format, the established method has great potential to be used for point-of-care diagnosis of canine distemper in animals, especially in resource-limited facilities.

  1. A highly sensitive and selective aptamer-based colorimetric sensor for the rapid detection of PCB 77.

    Science.gov (United States)

    Cheng, Ruojie; Liu, Siyao; Shi, Huijie; Zhao, Guohua

    2018-01-05

    A highly sensitive, specific and simple colorimetric sensor based on aptamer was established for the detection of polychlorinated biphenyls (PCB 77). The use of unmodified gold nanoparticles as a colorimetric probe for aptamer sensors enabled the highly sensitive and selective detection of polychlorinated biphenyls (PCB 77). A linear range of 0.5nM to 900nM was obtained for the colorimetric assay with a minimum detection limit of 0.05nM. In addition, by the methods of circular dichroism, UV and naked eyes, we found that the 35 base fragments retained after cutting 5 bases from the 5 'end of aptamer plays the most significant role in the PCB 77 specific recognition process. We found a novel way to truncated nucleotides to optimize the detection of PCB 77, and the selected nucleotides also could achieve high affinity with PCB 77. At the same time, the efficient detection of the PCB 77 by our colorimetric sensor in the complex environmental water samples was realized, which shows a good application prospect. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Rapid and Sensitive Detection of Lung Cancer Biomarker Using Nanoporous Biosensor Based on Localized Surface Plasmon Resonance Coupled with Interferometry

    Directory of Open Access Journals (Sweden)

    Jae-Sung Lee

    2015-01-01

    Full Text Available We propose a nanobiosensor to evaluate a lung cancer-specific biomarker. The nanobiosensor is based on an anodic aluminum oxide (AAO chip and functions on the principles of localized surface plasmon resonance (LSPR and interferometry. The pore-depth of the fabricated nanoporous AAO chip was 1 µm and was obtained using a two-step electrochemical anodization process. The sensor chip is sensitive to the refractive index (RI changes of the surrounding medium and also provides simple and label-free detection when specific antibodies are immobilized on the gold-deposited surface of the AAO chip. In order to confirm the effectiveness of the sensor, the antibodies were immobilized on the surface of the AAO chip, and the lung cancer-specific biomarker was applied atop of the immobilized-antibody layer using the self-assembled monolayer method. The nanoporous AAO chip was used as a sensor system to detect serum amyloid A1, which is a lung cancer-specific biomarker. The specific reaction of the antigen-antibody contributes to the change in the RI. This in turn causes a shift in the resonance spectrum in the refractive interference pattern. The limit of detection (LOD was found to be 100 ag/mL and the biosensor had high sensitivity over a wide concentration range.

  3. Antibiotic resistance of Helicobacter pylori in Mashhad, Iran

    International Nuclear Information System (INIS)

    Zendedel, A.; Almasi, V.; Moradimoghadam, F.; Zivarifar, H.

    2013-01-01

    Objective: To evaluate Helicobacter pylori resistance to amoxicillin, clarithromycin, metronidazole and tetracycline in Mashhad, Iran. Methods: The cross-sectional study was done from January to May 2008 in Mashhad, involving 185 patients who had been indicated for endoscopy and lesions had been found. Biopsy samples were assessed with histological evaluation, rapid urease test, and culture. Antibiotic resistance was assessed by the disc diffusion method. Data was analysed with SPSS 11.5 using chi-square and Fisher exact test. P values of < 0.05 were regarded as statistically significant. Results: Of the total patients, histological evaluations were positive in 124 (67%). Compared with histology, sensitivity and specificity of rapid urease test were 96.7% and 100%, respectively. In 82 (66.1%) patients with positive cultures, antibiotic resistance was found in 14 (17.1%) for clarithromycin; 53 (64.6%) for metronidazole; and 8 (9.8%) for amoxicillin. No resistance was observed for tetracycline. Moreover, 9 (64%) patients with resistance to clarithromycin had co-resistance to metronidazole. Conclusion: Metronidazole is not recommended for treatment of Helicobacter pylori as a first-line drug. Also, considering the sensitivity and specificity of rapid urease test, we suggest this method as a suitable alternative for histology. (author)

  4. A rapid and highly sensitive protocol for the detection of Escherichia coli O157:H7 based on immunochromatography assay combined with the enrichment technique of immunomagnetic nanoparticles

    Directory of Open Access Journals (Sweden)

    Qi H

    2011-11-01

    Full Text Available Hui Qi1, Zhen Zhong1, Han-Xin Zhou1, Chun-Yan Deng1, Hai Zhu2, Jin-Feng Li2, Xi-Li Wang2, Fu-Rong Li1,31Clinical Medical Research Center, The Second Clinical Medical College (Shenzhen People's Hospital, Jinan University, 2Shenzhen Bioeasy Biotechnologies Co, Ltd, 3Shenzhen Institute of Gerontology, Shenzhen, People's Republic of ChinaBackground: Escherichia coli O157:H7 (E. coli O157:H7 is an important pathogenic bacterium that threatens human health. A rapid, simple, highly sensitive, and specific method for the detection of E. coli O157:H7 is necessary.Methods: In the present study, immunomagnetic nanoparticles (IMPs were prepared with nanopure iron as the core, coated with E. coli O157:H7 polyclonal antibodies. These IMPs were used in combination with immunochromatographic assay (ICA and used to establish highly sensitive and rapid kits (IMPs+ICA to detect E. coli O157:H7. The kits were then used to detect E. coli O157:H7 in 150 food samples and were compared with conventional ICA to evaluate their efficacy.Results: The average diameter of IMPs was 56 nm and the amount of adsorbed antibodies was 106.0 µg/mg. The sensitivity of ICA and IMPs+ICA was 105 colony-forming units/mL and 103 CFUs/mL, respectively, for purified E. coli O157:H7 solution. The sensitivity of IMPs+ICA was increased by two orders, and its specificity was similar to ICA.Conclusion: The kits have the potential to offer important social and economic benefits in the screening, monitoring, and control of food safety.Keywords: colloidal gold, immunomagnetic nanoparticles, Escherichia coli O157:H7, immunochromatographic assay

  5. An insulated isothermal PCR method on a field-deployable device for rapid and sensitive detection of canine parvovirus type 2 at points of need.

    Science.gov (United States)

    Wilkes, Rebecca P; Lee, Pei-Yu A; Tsai, Yun-Long; Tsai, Chuan-Fu; Chang, Hsiu-Hui; Chang, Hsiao-Fen G; Wang, Hwa-Tang T

    2015-08-01

    Canine parvovirus type 2 (CPV-2), including subtypes 2a, 2b and 2c, causes an acute enteric disease in both domestic and wild animals. Rapid and sensitive diagnosis aids effective disease management at points of need (PON). A commercially available, field-deployable and user-friendly system, designed with insulated isothermal PCR (iiPCR) technology, displays excellent sensitivity and specificity for nucleic acid detection. An iiPCR method was developed for on-site detection of all circulating CPV-2 strains. Limit of detection was determined using plasmid DNA. CPV-2a, 2b and 2c strains, a feline panleukopenia virus (FPV) strain, and nine canine pathogens were tested to evaluate assay specificity. Reaction sensitivity and performance were compared with an in-house real-time PCR using serial dilutions of a CPV-2b strain and 100 canine fecal clinical samples collected from 2010 to 2014, respectively. The 95% limit of detection of the iiPCR method was 13 copies of standard DNA and detection limits for CPV-2b DNA were equivalent for iiPCR and real-time PCR. The iiPCR reaction detected CPV-2a, 2b and 2c and FPV. Non-targeted pathogens were not detected. Test results of real-time PCR and iiPCR from 99 fecal samples agreed with each other, while one real-time PCR-positive sample tested negative by iiPCR. Therefore, excellent agreement (k = 0.98) with sensitivity of 98.41% and specificity of 100% in detecting CPV-2 in feces was found between the two methods. In conclusion, the iiPCR system has potential to serve as a useful tool for rapid and accurate PON, molecular detection of CPV-2. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  6. A review of analytical procedures for the simultaneous determination of medically important veterinary antibiotics in environmental water: Sample preparation, liquid chromatography, and mass spectrometry.

    Science.gov (United States)

    Kim, Chansik; Ryu, Hong-Duck; Chung, Eu Gene; Kim, Yongseok; Lee, Jae-Kwan

    2018-07-01

    Medically important (MI) antibiotics are defined by the United States Food and Drug Administration as drugs containing certain active antimicrobial ingredients that are used for the treatment of human diseases or enteric pathogens causing food-borne diseases. The presence of MI antibiotic residues in environmental water is a major concern for both aquatic ecosystems and public health, particularly because of their potential to contribute to the development of antimicrobial-resistant microorganisms. In this article, we present a review of global trends in the sales of veterinary MI antibiotics and the analytical methodologies used for the simultaneous determination of antibiotic residues in environmental water. According to recently published government reports, sales volumes have increased steadily, despite many countries having adopted strategies for reducing the consumption of antibiotics. Global attention needs to be directed urgently at establishing new management strategies for reducing the use of MI antimicrobial products in the livestock industry. The development of standardized analytical methods for the detection of multiple residues is required to monitor and understand the fate of antibiotics in the environment. Simultaneous analyses of antibiotics have mostly been conducted using high-performance liquid chromatography-tandem mass spectrometry with a solid-phase extraction (SPE) pretreatment step. Currently, on-line SPE protocols are used for the rapid and sensitive detection of antibiotics in water samples. On-line detection protocols must be established for the monitoring and screening of unknown metabolites and transformation products of antibiotics in environmental water. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Studies on mycobacterium tuberculosis sensitivity test by using the method of rapid radiometry with appendixes of clinical results

    International Nuclear Information System (INIS)

    Yang Yongqing; Jiang Yimin; Lu Wendong; Zhu Rongen

    1987-01-01

    Three standard strains of mycobacterium tuberculosis (H 37 RV-fully sensitive, SM-R1000 μg/ml, RFP-R 100 μg/ml) were tested with 10 concentration of 5 antitubercular agent, INH, SM, PAS, RFP and EB. 114 isolates of mycobacterium tuberculosis taken from patients were tested with INH, PAS, SM and RFP. They were agreed with the results of standard Lowenstein-Jensen method in 81.7%. 82% of the isolate test were completed within 5 days. The method may be used in routine clinical work. The liquid media prepared by authors do not require human serum albumin and it is less expensive and readily available

  8. Highly sensitive capillary electrophoresis-mass spectrometry for rapid screening and accurate quantitation of drugs of abuse in urine.

    Science.gov (United States)

    Kohler, Isabelle; Schappler, Julie; Rudaz, Serge

    2013-05-30

    The combination of capillary electrophoresis (CE) and mass spectrometry (MS) is particularly well adapted to bioanalysis due to its high separation efficiency, selectivity, and sensitivity; its short analytical time; and its low solvent and sample consumption. For clinical and forensic toxicology, a two-step analysis is usually performed: first, a screening step for compound identification, and second, confirmation and/or accurate quantitation in cases of presumed positive results. In this study, a fast and sensitive CE-MS workflow was developed for the screening and quantitation of drugs of abuse in urine samples. A CE with a time-of-flight MS (CE-TOF/MS) screening method was developed using a simple urine dilution and on-line sample preconcentration with pH-mediated stacking. The sample stacking allowed for a high loading capacity (20.5% of the capillary length), leading to limits of detection as low as 2 ng mL(-1) for drugs of abuse. Compound quantitation of positive samples was performed by CE-MS/MS with a triple quadrupole MS equipped with an adapted triple-tube sprayer and an electrospray ionization (ESI) source. The CE-ESI-MS/MS method was validated for two model compounds, cocaine (COC) and methadone (MTD), according to the Guidance of the Food and Drug Administration. The quantitative performance was evaluated for selectivity, response function, the lower limit of quantitation, trueness, precision, and accuracy. COC and MTD detection in urine samples was determined to be accurate over the range of 10-1000 ng mL(-1) and 21-1000 ng mL(-1), respectively. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Prophylactic antibiotic therapy for chronic obstructive pulmonary disease (COPD).

    Science.gov (United States)

    Herath, Samantha C; Poole, Phillippa

    2013-11-28

    an exacerbation was reduced (odds ratio (OR) 0.55; 95% confidence interval (CI) 0.39 to 0.77, 3 studies, 1262 participants, high quality). This represented a reduction from 69% of participants in the control group compared to 54% in the treatment group (95% CI 46% to 63%) and the number needed to treat to prevent one exacerbation (NNTb) was therefore 8 (95% CI 5 to 18). The frequency of exacerbations was also reduced with continuous prophylactic antibiotic treatment (rate ratio 0.73; 95% CI 0.58 to 0.91).Use of pulsed antibiotic treatment showed a non-significant reduction in the number of people with exacerbations (OR 0.87; 95% CI 0.69 to 1.09, 1 study, 1149 participants, moderate quality) and the test for interaction showed that this result was significantly different from the effect on exacerbations with continuous antibiotics.There was a statistically significant improvement in quality of life with both continuous and pulsed antibiotic treatment but this was smaller than the four unit improvement that is regarded as being clinically significant (MD -1.78; 95% CI -2.95 to -0.61, 2 studies, 1962 participants, moderate quality).Neither pulsed nor continuous antibiotics showed a significant effect on the secondary outcomes of frequency of hospital admissions, change in lung function, serious adverse events or all-cause mortality (moderate quality evidence).The adverse events that were recorded varied among the trials depending on the different antibiotics used. Azithromycin was associated with a significant hearing loss in the treatment group. The moxifloxacin pulsed study reported a significantly higher number of adverse events in the treatment arm due to the marked increase in gastrointestinal adverse events (P antibiotic resistance in the community is of major concern. One study found newly colonised patients to have higher rates of antibiotic resistance. Patients colonised with moxifloxacin-sensitive pseudomonas at initiation of therapy rapidly became resistant

  10. Antibiotic Resistance

    DEFF Research Database (Denmark)

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

    2015-01-01

    hygiene, and possibly vaccination and exercise, may be effective. Also, a large range of complementary and alternative medicines (e.g. zinc, vitamin C and probiotics) are proposed for preventing and treating ARIs, but evidence for efficacy is scarce. General practitioners' (GPs) attitudes towards...... wrong. Shared decision making might be a solution, as it enables clinician and patient to participate jointly in making a health decision, having discussed the options together with the evidence for their harms as well as benefits. Furthermore, GPs' diagnostic uncertainty - often leading...... will greatly improve the use of antibiotics for ARIs. However, used in concert, combinations are likely to enable clinicians and health care systems to implement the strategies that will reduce antimicrobial resistance in the future....

  11. Rapid and Sensitive Detection of Breast Cancer Cells in Patient Blood with Nuclease-Activated Probe Technology

    Directory of Open Access Journals (Sweden)

    Sven Kruspe

    2017-09-01

    Full Text Available A challenge for circulating tumor cell (CTC-based diagnostics is the development of simple and inexpensive methods that reliably detect the diverse cells that make up CTCs. CTC-derived nucleases are one category of proteins that could be exploited to meet this challenge. Advantages of nucleases as CTC biomarkers include: (1 their elevated expression in many cancer cells, including cells implicated in metastasis that have undergone epithelial-to-mesenchymal transition; and (2 their enzymatic activity, which can be exploited for signal amplification in detection methods. Here, we describe a diagnostic assay based on quenched fluorescent nucleic acid probes that detect breast cancer CTCs via their nuclease activity. This assay exhibited robust performance in distinguishing breast cancer patients from healthy controls, and it is rapid, inexpensive, and easy to implement in most clinical labs. Given its broad applicability, this technology has the potential to have a substantive impact on the diagnosis and treatment of many cancers. Keywords: cancer, circulating tumor cells, diagnostic nucleic acids, nucleases, diagnostic markers, breast cancer, liquid biopsy

  12. Rapid and sensitive lateral flow immunoassay method for determining alpha fetoprotein in serum using europium (III) chelate microparticles-based lateral flow test strips

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Rong-Liang; Xu, Xu-Ping; Liu, Tian-Cai; Zhou, Jian-Wei; Wang, Xian-Guo; Ren, Zhi-Qi [Institute of Antibody Engineering, School of Biotechnology, Southern Medical University, Guangzhou 510515, Guangdong (China); Hao, Fen [DaAn Gene Co. Ltd. of Sun Yat-sen University, 19 Xiangshan Road, Guangzhou 510515 (China); Wu, Ying-Song, E-mail: wg@smu.edu.cn [Institute of Antibody Engineering, School of Biotechnology, Southern Medical University, Guangzhou 510515, Guangdong (China)

    2015-09-03

    Alpha-fetoprotein (AFP), a primary marker for many diseases including various cancers, is important in clinical tumor diagnosis and antenatal screening. Most immunoassays provide high sensitivity and accuracy for determining AFP, but they are expensive, often complex, time-consuming procedures. A simple and rapid point-of-care system that integrates Eu (III) chelate microparticles with lateral flow immunoassay (LFIA) has been developed to determine AFP in serum with an assay time of 15 min. The approach is based on a sandwich immunoassay performed on lateral flow test strips. A fluorescence strip reader was used to measure the fluorescence peak heights of the test line (H{sub T}) and the control line (H{sub C}); the H{sub T}/H{sub C} ratio was used for quantitation. The Eu (III) chelate microparticles-based LFIA assay exhibited a wide linear range (1.0–1000 IU mL{sup −1}) for AFP with a low limit of detection (0.1 IU mL{sup −1}) based on 5ul of serum. Satisfactory specificity and accuracy were demonstrated and the intra- and inter-assay coefficients of variation (CV) for AFP were both <10%. Furthermore, in the analysis of human serum samples, excellent correlation (n = 284, r = 0.9860, p < 0.0001) was obtained between the proposed method and a commercially available CLIA kit. Results indicated that the Eu (III) chelate microparticles-based LFIA system provided a rapid, sensitive and reliable method for determining AFP in serum, indicating that it would be suitable for development in point-of-care testing. - Highlights: • Europium (III) chelate microparticles was used as a label for LIFA. • Quantitative detection by using H{sub T}/H{sub C} ratio was achieved. • LIFA for simple and rapid AFP detection in human serum. • The sensitivity and linearity was more excellent compared with QD-based ICTS. • This method could be developed for rapid point-of-care screening.

  13. Effects of antibiotics on protected specimen brush sampling in ventilator-associated pneumonia.

    Science.gov (United States)

    Prats, E; Dorca, J; Pujol, M; Garcia, L; Barreiro, B; Verdaguer, R; Gudiol, F; Manresa, F

    2002-05-01

    The effects of antibiotic treatment on the results of protected specimen brushing (PSB) in ventilator-associated pneumonia were prospectively assessed by performing this procedure before antibiotic treatment, and 12, 24, 48 and 72 h after initiation of antibiotic treatment, in 35 ventilated patients who developed pneumonia during mechanical ventilation. The number of micro-organisms isolated, their concentration (colony-forming units (cfu) mL(-1)), and the number of cases with a positive PSB (> or =10(3) cfu x mL(-1)) were evaluated. Within 12 h of the initiation of effective antibiotic treatment a rapid, significant decrease in the numbers of organisms isolated, their individual concentrations and the percentage of positive PSB results were observed. Certain bacterial species (Streptococcus pneumoniae, Haemophilus influenzee) appeared to be more vulnerable to antibiotics than others (Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumanni). This data confirms that prior antibiotic treatment, even after only a few hours of activity, significantly decreases the sensitivity of protected brush specimen; this effect appears to be particularly marked among the species involved in early ventilator associated pneumonia.

  14. Antibiotic Resistance Pattern and Molecular Epidemiology of ...

    African Journals Online (AJOL)

    2099 ... Veterinary Medicine, Seoul National University 151-742, Korea, 3Institute of Basic Medical Sciences, Khyber Medical University, .... Culture sensitivity data for 16 antibiotics were recorded .... occupancy and cross-transmission of MRSA.

  15. tration on Phenotypic Antibiotic Susceptibility and Resistance

    African Journals Online (AJOL)

    resistance in bacteria of food animal origin (Van den Bogaard and Stobberingh, ... however, the effect of antimicrobial drug use in companion animals like dogs or ...... Antibiotic sensitivity of bacterial isolates from cases of canine dermatitis.

  16. Antibiotics Susceptibility Pattern of Pseudomonas aeruginosa ...

    African Journals Online (AJOL)

    ABSTRACT: This work investigated the prevalence and antibiotics sensitivity of Pseudomonas aeruginosa isolated from ... skin triggers coagulation and an acute inflammatory response ... agents with anti-pseudomonal activity, life-threatening.

  17. Field-Deployable Reverse Transcription-Insulated Isothermal PCR (RT-iiPCR) Assay for Rapid and Sensitive Detection of Foot-and-Mouth Disease Virus.

    Science.gov (United States)

    Ambagala, A; Fisher, M; Goolia, M; Nfon, C; Furukawa-Stoffer, T; Ortega Polo, R; Lung, O

    2017-10-01

    Foot-and-mouth disease (FMD) is a highly contagious viral disease of cloven-hoofed animals, which can decimate the livestock industry and economy of countries previously free of this disease. Rapid detection of foot-and-mouth disease virus (FMDV) is critical to containing an FMD outbreak. Availability of a rapid, highly sensitive and specific, yet simple and field-deployable assay would support local decision-making during an FMDV outbreak. Here we report validation of a novel reverse transcription-insulated isothermal PCR (RT-iiPCR) assay that can be performed on a commercially available, compact and portable POCKIT ™ analyser that automatically analyses data and displays '+' or '-' results. The FMDV RT-iiPCR assay targets the 3D region of the FMDV genome and was capable of detecting 9 copies of in vitro-transcribed RNA standard with 95% confidence. It accurately identified 63 FMDV strains belonging to all seven serotypes and showed no cross-reactivity with viruses causing similar clinical diseases in cloven-hoofed animals. The assay was able to identify FMDV RNA in multiple sample types including oral, nasal and lesion swabs, epithelial tissue suspensions, vesicular and oral fluid samples, even before the appearance of clinical signs. Clinical sensitivity of the assay was comparable or slightly higher than the laboratory-based real-time RT-PCR assay in use. The assay was able to detect FMDV RNA in vesicular fluid samples without nucleic acid extraction. For RNA extraction from more complex sample types, a commercially available taco ™ mini transportable magnetic bead-based, automated extraction system was used. This assay provides a potentially useful field-deployable diagnostic tool for rapid detection of FMDV in an outbreak in FMD-free countries or for routine diagnostics in endemic countries with less structured laboratory systems. © 2016 Her Majesty the Queen in Right of Canada.

  18. Multiplex Biosensing Based on Highly Sensitive Magnetic Nanolabel Quantification: Rapid Detection of Botulinum Neurotoxins A, B, and E in Liquids.

    Science.gov (United States)

    Orlov, Alexey V; Znoyko, Sergey L; Cherkasov, Vladimir R; Nikitin, Maxim P; Nikitin, Petr I

    2016-11-01

    We present a multiplex quantitative lateral flow (LF) assay for simultaneous on-site detection of botulinum neurotoxin (BoNT) types A, B, and E in complex matrixes, which is innovative by virtually no sacrifice in performance while transition from the single-plex assays and by characteristics on the level of laboratory quantitative methods. The novel approach to easy multiplexing is realized via joining an on-demand set of single-plex LF strips, which employ magnetic nanolabels, into a miniature cylinder cartridge that mimics LF strip during all assay stages. The cartridge is read out by an original portable multichannel reader based on the magnetic particle quantification technique. The developed reader offers the unmatched 60 zmol detection limit and 7-order linear dynamic range for volumetric registration of magnetic labels inside a cartridge of several millimeters in diameter regardless of its optical transparency. Each of the test strips, developed here as building blocks for the multiplex assay, can be used "as is" for autonomous quantitative single-plex detection with the same measuring setup, exhibiting the limits of detection (LOD) of 0.22, 0.11, and 0.32 ng/mL for BoNT-A, -B, and -E, respectively. The proposed multiplex assay has demonstrated the remarkably similar LOD values of 0.20, 0.12, 0.35 ng/mL under the same conditions. The multiplex assay performance was successfully validated by BoNT detection in milk and apple and orange juices. The developed methods can be extended to other proteins and used for rapid multianalyte tests for point-of-care in vitro diagnostics, food analysis, biosafety and environmental monitoring, forensics, and security, etc.

  19. Microbial resistance to antibiotics | Chinedum | African Journal of ...

    African Journals Online (AJOL)

    Organisms that are normally sensitive to the action of an antibiotic may sometimes develop resistance or insensitivity to it. This, they may do through destroying the antibiotic or by retaining their growth even in the presence of the drug. Microbial resistance to antibiotics is now widespread and poses a serious clinical threat.

  20. A non-polyene antifungal antibiotic from Streptomyces albidoflavus ...

    Indian Academy of Sciences (India)

    Unknown

    One promising strain, Streptomyces albidoflavus PU 23 with strong anti- fungal activity against pathogenic fungi was selected for further studies. Antibiotic was extracted and purified from the isolate. Aspergillus spp. was most sensitive to the antibiotic followed by other molds and yeasts. The antibiotic was stable at different ...

  1. Rapid and sensitive quantification of C3- and C6-phosphoesters in starch by fluorescence-assisted capillary electrophoresis.

    Science.gov (United States)

    Verbeke, Jeremy; Penverne, Christophe; D'Hulst, Christophe; Rolando, Christian; Szydlowski, Nicolas

    2016-11-05

    Phosphate groups are naturally present in starch at C3- or C6-position of the glucose residues and impact the structure of starch granules. Their precise quantification is necessary for understanding starch physicochemical properties and metabolism. Nevertheless, reliable quantification of Glc-3-P remains laborious and time consuming. Here we describe a capillary electrophoresis method for simultaneous measurement of both Glc-6-P and Glc-3-P after acid hydrolysis of starch. The sensitivity threshold was estimated at the fg scale, which is compatible with the analysis of less than a μg of sample. The method was validated by analyzing antisense potato lines deficient in SBEs, GWD or GBSS. We show that Glc-3-P content is altered in the latter and that these variations do not correlate with modifications in Glc-6-P content. We anticipate the method reported here to be an efficient tool for high throughput study of starch phosphorylation at both C3- and C6-position. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Rapid and sensitive spectrofluorimetric determination of enrofloxacin, levofloxacin and ofloxacin with 2,3,5,6-tetrachloro- p-benzoquinone

    Science.gov (United States)

    Ulu, Sevgi Tatar

    2009-06-01

    A highly sensitive spectrofluorimetric method was developed for the first time, for the analysis of three fluoroquinolones (FQ) antibacterials, namely enrofloxacin (ENR), levofloxacin (LEV) and ofloxacin (OFL) in pharmaceutical preparations through charge transfer (CT) complex formation with 2,3,5,6-tetrachloro- p-benzoquinone (chloranil,CLA). At the optimum reaction conditions, the FQ-CLA complexes showed excitation maxima ranging from 359 to 363 nm and emission maxima ranging from 442 to 488 nm. Rectilinear calibration graphs were obtained in the concentration range of 50-1000, 50-1000 and 25-500 ng mL -1 for ENR, LEV and OFL, respectively. The detection limit was found to be 17 ng mL -1 for ENR, 17 ng mL -1 for LEV, 8 ng mL -1 for OFL, respectively. Excipients used as additive in commercial formulations did not interfere in the analysis. The method was validated according to the ICH guidelines with respect to specificity, linearity, accuracy, precision and robustness. The proposed method was successfully applied to the analysis of pharmaceutical preparations. The results obtained were in good agreement with those obtained using the official method; no significant difference in the accuracy and precision as revealed by the accepted values of t- and F-tests, respectively.

  3. A portable smart-phone device for rapid and sensitive detection of E. coli O157:H7 in Yoghurt and Egg.

    Science.gov (United States)

    Zeinhom, Mohamed Maarouf Ali; Wang, Yijia; Song, Yang; Zhu, Mei-Jun; Lin, Yuehe; Du, Dan

    2018-01-15

    The detection of E. coli O157:H7 in foods has held the attention of many researchers because of the seriousness attributed to this pathogen. In this study, we present a simple, sensitive, rapid and portable smartphone based fluorescence device for E. coli O157:H7 detection. This field-portable fluorescent imager on the smartphone involves a compact laser-diode-based photosource, a long-pass (LP) thin-film interference filter and a high-quality insert lenses. The design of the device provided a low noise to background imaging system. Based on a sandwich ELISA and the specific recognition of antibody to E. coli O157:H7, the sensitive detection of E. coli O157:H7 were realized both in standard samples and real matrix in yoghurt and egg on our device. The detection limit are 1 CFU/mL and 10 CFU/mL correspondingly. Recovery percentages of spiked yogurt and egg samples with 10 3 , 10 4 and 10 5 CFU/mL E. coli O157:H7 were 106.98, 96.52 and 102.65 (in yogurt) and 107.37, 105.64 and 93.84 (in egg) samples using our device, respectively. Most importantly, the entire process could be quickly completed within two hours. This smartphone based device provides a simple, rapid, sensitive detection platform for fluorescent imaging which applied in pathogen detection for food safety monitoring. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Alternative Evolutionary Paths to Bacterial Antibiotic Resistance Cause Distinct Collateral Effects.

    Science.gov (United States)

    Barbosa, Camilo; Trebosc, Vincent; Kemmer, Christian; Rosenstiel, Philip; Beardmore, Robert; Schulenburg, Hinrich; Jansen, Gunther

    2017-09-01

    When bacteria evolve resistance against a particular antibiotic, they may simultaneously gain increased sensitivity against a second one. Such collateral sensitivity may be exploited to develop novel, sustainable antibiotic treatment strategies aimed at containing the current, dramatic spread of drug resistance. To date, the presence and molecular basis of collateral sensitivity has only been studied in few bacterial species and is unknown for opportunistic human pathogens such as Pseudomonas aeruginosa. In the present study, we assessed patterns of collateral effects by experimentally evolving 160 independent populations of P. aeruginosa to high levels of resistance against eight commonly used antibiotics. The bacteria evolved resistance rapidly and expressed both collateral sensitivity and cross-resistance. The pattern of such collateral effects differed to those previously reported for other bacterial species, suggesting interspecific differences in the underlying evolutionary trade-offs. Intriguingly, we also identified contrasting patterns of collateral sensitivity and cross-resistance among the replicate populations adapted to the same drug. Whole-genome sequencing of 81 independently evolved populations revealed distinct evolutionary paths of resistance to the selective drug, which determined whether bacteria became cross-resistant or collaterally sensitive towards others. Based on genomic and functional genetic analysis, we demonstrate that collateral sensitivity can result from resistance mutations in regulatory genes such as nalC or mexZ, which mediate aminoglycoside sensitivity in β-lactam-adapted populations, or the two-component regulatory system gene pmrB, which enhances penicillin sensitivity in gentamicin-resistant populations. Our findings highlight substantial variation in the evolved collateral effects among replicates, which in turn determine their potential in antibiotic therapy. © The Author 2017. Published by Oxford University Press on

  5. A rapid, sensitive, reproducible and cost-effective method for mutation profiling of colon cancer and metastatic lymph nodes

    International Nuclear Information System (INIS)

    Fumagalli, Debora; Gavin, Patrick G; Taniyama, Yusuke; Kim, Seung-Il; Choi, Hyun-Joo; Paik, Soonmyung; Pogue-Geile, Katherine L

    2010-01-01

    Carta panel may provide a mechanism for rapid screening of mutations in clinically relevant genes like KRAS, PIK3CA, and BRAF. ClinicalTrials.gov: NSABP C-07: NCT00004931

  6. Gene expression at each stage of the life cycle of spore-forming bacteria: different sensitivity of transcription to antibiotics which act on DNA gyrase.

    Science.gov (United States)

    Matsuda, M; Kameyama, T

    1985-01-01

    Effects of antibiotics acting on DNA gyrase, novobiocin and nalidixic acid on RNA synthesis during germination, vegetative growth and sporulation of Bacillus subtilis were examined. These drugs were relatively ineffective in inhibiting RNA synthesis of phase Gm 1 (5-15 min) during germination but effective in those of Gm 2 (15-40 min) and Gm 3 (40-60 min) during germination (Matsuda and Kameyama 1980). No distinguishable inhibitory effects of RNA synthesis in B. subtilis NOVr1TT mutant could be detected by novobiocin. RNA synthesis of Gm 2 and Gm 3 of this mutant was inhibited by nalidixic acid. When novobiocin was added to exponential vegetative cell or sporulating cell culture at T0 and T1 stage, the rate of RNA synthesis was inhibited by 80% for 5 min following addition of the drug. However, RNA synthesis after T2 of sporulation became resistant toward novobiocin, as was the case at an early stage of germination. RNA profiles from transcripts synthesized on administration of NOV suggested that the suppression of the synthesis of 23S and 16S rRNA is relatively greater than 4 to 5S RNA at the middle stage of germination and at vegetative growth stage in the presence of NOV. Our present data suggest that DNA gyrase is involved in the regulation of gene transcription during middle and late phases of germination, vegetative growth and T0 and T1 of sporulation. The transcription during early phase of germination and sporulation after T2 may proceed independently of this enzyme.

  7. Tandem mass spectrometry-based newborn screening strategy could be used to facilitate rapid and sensitive lung cancer diagnosis

    Directory of Open Access Journals (Sweden)

    Huang T

    2016-04-01

    Full Text Available Ting Huang,1,* Yunfeng Cao,1,* Jia Zeng,1 Jun Dong,2 Xiaoyu Sun,2 Jianxing Chen,1 Peng Gao2,3 1Key Laboratory of Contraceptives and Devices Research (NPFPC, Shanghai Engineer and Technology Research Center of Reproductive Health Drug and Devices, Shanghai Institute of Planned Parenthood Research, Shanghai, 2Clinical Laboratory, Dalian Sixth People’s Hospital, 3CASKey Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, People’s Republic of China *These authors contributed equally to this work Objective: Newborn screening (NBS helps in the early detection of inborn errors of metabolism (IEM. The most effective NBS strategy prevailing in clinics is tandem mass spectrometry (MS/MS analysis using dried blood spot (DBS samples. Taking lung cancer (LC as an example, this study tried to explore if this technique could be of any assistance for the discovery of tumor metabolite markers.Materials and methods: Twenty-six acylcarnitines and 23 amino acids, which are commonly used in IEM screening, were quantified using DBS samples from 222 LC patients, 118 benign lung disease (LD patients, and 96 healthy volunteers (CONT. Forty-four calculated ratios based on the abovementioned metabolites were also included using MS/MS quantification results.Results: This pilot study led to the findings of 65 significantly changed amino acids, acylcarnitines, and some of their ratios for the LC, LD, and CONT groups. Among the differential parameters, 12 items showed reverse changing trends between the LC and LD groups compared to the CONT group. Regression analysis demonstrated that six of them – Arg, Pro, C10:1, Arg/Orn, Cit/Arg, and C5-OH/C0 – could be used to diagnose LC with a sensitivity of 91.3% and a specificity of 92.7%.Conclusion: This study demonstrated the DBS-based MS/MS strategy was a promising tool for the discovery of tumor metabolite markers. Remarkably, this MS

  8. Performance of a High-Sensitivity Rapid Diagnostic Test for Plasmodium falciparum Malaria in Asymptomatic Individuals from Uganda and Myanmar and Naive Human Challenge Infections.

    Science.gov (United States)

    Das, Smita; Jang, Ihn Kyung; Barney, Becky; Peck, Roger; Rek, John C; Arinaitwe, Emmanuel; Adrama, Harriet; Murphy, Maxwell; Imwong, Mallika; Ling, Clare L; Proux, Stephane; Haohankhunnatham, Warat; Rist, Melissa; Seilie, Annette M; Hanron, Amelia; Daza, Glenda; Chang, Ming; Nakamura, Tomoka; Kalnoky, Michael; Labarre, Paul; Murphy, Sean C; McCarthy, James S; Nosten, Francois; Greenhouse, Bryan; Allauzen, Sophie; Domingo, Gonzalo J

    2017-11-01

    Sensitive field-deployable diagnostic tests can assist malaria programs in achieving elimination. The performance of a new Alere™ Malaria Ag P.f Ultra Sensitive rapid diagnostic test (uRDT) was compared with the currently available SD Bioline Malaria Ag P.f RDT in blood specimens from asymptomatic individuals in Nagongera, Uganda, and in a Karen Village, Myanmar, representative of high- and low-transmission areas, respectively, as well as in pretreatment specimens from study participants from four Plasmodium falciparum -induced blood-stage malaria (IBSM) studies. A quantitative reverse transcription PCR (qRT-PCR) and a highly sensitive enzyme-linked immunosorbent assay (ELISA) test for histidine-rich protein II (HRP2) were used as reference assays. The uRDT showed a greater than 10-fold lower limit of detection for HRP2 compared with the RDT. The sensitivity of the uRDT was 84% and 44% against qRT-PCR in Uganda and Myanmar, respectively, and that of the RDT was 62% and 0% for the same two sites. The specificities of the uRDT were 92% and 99.8% against qRT-PCR for Uganda and Myanmar, respectively, and 99% and 99.8% against the HRP2 reference ELISA. The RDT had specificities of 95% and 100% against qRT-PCR for Uganda and Myanmar, respectively, and 96% and 100% against the HRP2 reference ELISA. The uRDT detected new infections in IBSM study participants 1.5 days sooner than the RDT. The uRDT has the same workflow as currently available RDTs, but improved performance characteristics to identify asymptomatic malaria infections. The uRDT may be a useful tool for malaria elimination strategies.

  9. Demographics of antibiotic persistence

    DEFF Research Database (Denmark)

    Kollerova, Silvia; Jouvet, Lionel; Steiner, Ulrich

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

  10. Quantification of rifampicin in human plasma and cerebrospinal fluid by a highly sensitive and rapid liquid chromatographic-tandem mass spectrometric method.

    Science.gov (United States)

    Srivastava, Abhishek; Waterhouse, David; Ardrey, Alison; Ward, Stephen A

    2012-11-01

    A highly sensitive and rapid liquid chromatography tandem mass spectrometry (LC-MS/MS) method has been developed to measure the levels of the antitubercular drug rifampicin (RIF) in human plasma and cerebrospinal fluid (CSF). The analyte and internal standard (IS) were isolated from plasma and CSF by a simple organic solvent based precipitation of proteins followed by centrifugation. Detection was carried out by electrospray positive ionization mass spectrometry in the multiple-reaction monitoring (MRM) mode. The assay was linear in the concentration range 25-6400 ng/mL with intra- and inter-day precision of <7% and <8%, respectively. The validated method was applied to the study of RIF pharmacokinetics in human CSF and plasma over 25 h period after a 10 mg/kg oral dose. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. A sensitive, rapid, and simple DR-EcoScreen bioassay for the determination of PCDD/Fs and dioxin-like PCBs in environmental and food samples.

    Science.gov (United States)

    Kojima, Hiroyuki; Takeuchi, Shinji; Iida, Mitsuru; Nakayama, Shoji F; Shiozaki, Takuya

    2018-03-01

    In developing countries in Asia, such as China, Vietnam, and Thailand, there is a strong need for the development of relatively rapid and low-cost bioassays for the determination of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (DL-PCBs) in environmental and food samples. These compounds are known to induce a variety of toxic and biological effects through their ligand-specific binding of the aryl hydrocarbon receptor (AhR). Indeed, several AhR-mediated reporter gene assays are widely used as prescreening tools for high-resolution gas chromatography/high-resolution mass spectrometry (HRGC-HRMS) analysis, which individually measures 17 PCDD/Fs and 12 DL-PCBs. In 2008, we have developed a new sensitive and rapid reporter gene assay using a genetically engineered stable cell line, designated DR-EcoScreen cells. The DR-EcoScreen assay using these cells has a number of great advantages of its sensitivity to 2,3,7,8-tetrachlorodibenzo-p-dioxin and its simple procedure, which shows little variance in the data (within CV 10 %) compared to other reporter gene assays. In this review, we summarize the application of the DR-EcoScreen assay to the determination of PCDD/Fs and DL-PCBs in ambient air samples, in fish and shellfish samples, and in flue gas samples from incinerators and provide potential usefulness of this bioassay for the determination of PCDD/Fs and DL-PCBs in various matrices.

  12. Evaluation of antibiotic susceptibility in wound infections: A pilot study from Bangladesh

    Science.gov (United States)

    Roy, Sushmita; Ahmed, Mejbah Uddin; Uddin, Bhuiyan Mohammad Mahtab; Ratan, Zubair Ahmed; Rajawat, Monali; Mehta, Varshil; Zaman, Sojib Bin

    2017-01-01

    Introduction: Infections due to antibiotic resistant bacteria have increased alarmingly in both developed and developing countries. Unrestrained and rapidly spreading bacterial growth has turned the management of wound infections into a serious challenge. This study aimed to determine the prevalence of different bacterial pathogens and their antibiotic susceptibility in various types of wound infections. Methods:  A cross-sectional study was conducted to collect 105 wound swabs. All isolated bacteria were identified based on colony characteristics, gram stain and standard biochemical tests, and antibiotic susceptibility testing (AST) with the disc diffusion method. Descriptive statistics were used to present the study findings, and all analyses were performed using Stata Version 13. Results:  The rate of isolation of bacteria was 92.3%. Staphylococcus aureus was found to be the most frequent isolate (55.7%), followed by Escherichia coli (23.7%), Pseudomonas spp. (8.2%), and Streptococcus pyogenes (7.2%). Gram-positive bacteria were mostly (60%) found sensitive to vancomycin, azithromycin, gentamicin, imipenem, cefixime, and ceftriaxone in this study. Among the Gram-negative bacteria, Escherichia coli (>60%) showed sensitivity to cefixime, azithromycin, cefuroxime, ceftriaxone, cefotaxime, gentamycin, and ceftazidime. Conclusions: The diversity of isolated bacteria and their susceptibility patterns signify a need to implement a proper infection control strategy, which can be achieved by carrying out antibiotic sensitivity tests of the isolates. PMID:29527295

  13. Measurement of Rapid Amiloride-Dependent pH Changes at the Cell Surface Using a Proton-Sensitive Field-Effect Transistor.

    Science.gov (United States)

    Schaffhauser, Daniel; Fine, Michael; Tabata, Miyuki; Goda, Tatsuro; Miyahara, Yuji

    2016-03-30

    We present a novel method for the rapid measurement of pH fluxes at close proximity to the surface of the plasma membrane in mammalian cells using an ion-sensitive field-effect transistor (ISFET). In conjuction with an efficient continuous superfusion system, the ISFET sensor was capable of recording rapid changes in pH at the cells' surface induced by intervals of ammonia loading and unloading, even when using highly buffered solutions. Furthermore, the system was able to isolate physiologically relevant signals by not only detecting the transients caused by ammonia loading and unloading, but display steady-state signals as would be expected by a proton transport-mediated influence on the extracellular proton-gradient. Proof of concept was demonstrated through the use of 5-(N-ethyl-N-isopropyl)amiloride (EIPA), a small molecule inhibitor of sodium/hydrogen exchangers (NHE). As the primary transporter responsible for proton balance during cellular regulation of pH, non-electrogenic NHE transport is notoriously difficult to detect with traditional methods. Using the NHE positive cell lines, Chinese hamster ovary (CHO) cells and NHE3-reconstituted mouse skin fibroblasts (MSF), the sensor exhibited a significant response to EIPA inhibition, whereas NHE-deficient MSF cells were unaffected by application of the inhibitor.

  14. A rapid and sensitive loop-mediated isothermal amplification procedure (LAMP) for Mycoplasma hyopneumoniae detection based on the p36 gene.

    Science.gov (United States)

    Liu, M J; Du, G M; Bai, F F; Wu, Y Z; Xiong, Q Y; Feng, Z X; Li, B; Shao, G Q

    2015-05-04

    The aim of this study was to establish a method for sensitive and rapid diagnosis of Mycoplasma hyopneumoniae in clinical specimens. To this effect, we employed three sets of primers specifically designed for amplification of nucleic acids under isothermal conditions. After optimization of reaction conditions, M. hyopneumoniae could be successfully detected at 63°C in 45 min through use of the loop-mediated isothermal amplification (LAMP) assay. A positive reaction was identified visually as white precipitate and confirmed by gel electrophoresis. The detection limit for this assay was 10 copies/μL, as observed by electrophoretic analysis. The accuracy of the LAMP reaction was confirmed by restriction endonuclease digestion as well as by direct sequencing of the amplified product. This method can specifically detect M. hyopneumoniae; other species with high homology and other bacterial and virus strains gave negative results. To test the utility of this procedure, the LAMP assay was applied to 40 clinical samples collected from swine lung tissues experimentally challenged with M. hyopneumoniae isolates, and compared to the results from a real-time polymerase chain reaction (PCR) assay. A concordance of 100% was observed between the two assays. In conclusion, the results from our study demonstrated that the LAMP assay provided a rapid reaction and was inexpensive to perform, with no need of complex instruments or systems such as Geneamp PCR. The LAMP assay may therefore be applied in routine diagnosis in the clinical laboratory and for in-field detection of M. hyopneumoniae infection.

  15. Rapid, sensitive and reproducible method for point-of-collection screening of liquid milk for adulterants using a portable Raman spectrometer with novel optimized sample well

    Science.gov (United States)

    Nieuwoudt, Michel K.; Holroyd, Steve E.; McGoverin, Cushla M.; Simpson, M. Cather; Williams, David E.

    2017-02-01

    Point-of-care diagnostics are of interest in the medical, security and food industry, the latter particularly for screening food adulterated for economic gain. Milk adulteration continues to be a major problem worldwide and different methods to detect fraudulent additives have been investigated for over a century. Laboratory based methods are limited in their application to point-of-collection diagnosis and also require expensive instrumentation, chemicals and skilled technicians. This has encouraged exploration of spectroscopic methods as more rapid and inexpensive alternatives. Raman spectroscopy has excellent potential for screening of milk because of the rich complexity inherent in its signals. The rapid advances in photonic technologies and fabrication methods are enabling increasingly sensitive portable mini-Raman systems to be placed on the market that are both affordable and feasible for both point-of-care and point-of-collection applications. We have developed a powerful spectroscopic method for rapidly screening liquid milk for sucrose and four nitrogen-rich adulterants (dicyandiamide (DCD), ammonium sulphate, melamine, urea), using a combined system: a small, portable Raman spectrometer with focusing fibre optic probe and optimized reflective focusing wells, simply fabricated in aluminium. The reliable sample presentation of this system enabled high reproducibility of 8% RSD (residual standard deviation) within four minutes. Limit of detection intervals for PLS calibrations ranged between 140 - 520 ppm for the four N-rich compounds and between 0.7 - 3.6 % for sucrose. The portability of the system and reliability and reproducibility of this technique opens opportunities for general, reagentless adulteration screening of biological fluids as well as milk, at point-of-collection.

  16. Gold Nanorods as Surface-Enhanced Raman Spectroscopy Substrates for Rapid and Sensitive Analysis of Allura Red and Sunset Yellow in Beverages.

    Science.gov (United States)

    Ou, Yiming; Wang, Xiaohui; Lai, Keqiang; Huang, Yiqun; Rasco, Barbara A; Fan, Yuxia

    2018-03-21

    Synthetic colorants in food can be a potential threat to human health. In this study, surface-enhanced Raman spectroscopy (SERS) coupled with gold nanorods as substrates is proposed to analyze allura red and sunset yellow in beverages. The gold nanorods with different aspect ratios were synthesized, and their long-term stability, SERS activity, and the effect of the different salts on the SERS signal were investigated. The results demonstrate that gold nanorods have a satisfactory stability (stored up to 28 days). SERS coupled with gold nanorods exhibit stronger sensitivity. MgSO 4 was chosen to improve the SERS signal of sunset yellow, and no salts could enhance the SERS signal of allura red. The lowest concentration was 0.10 mg/L for both colorant standard solutions. The successful prediction results using SERS were much closer to those obtained by high-performance liquid chromatography for the sample in beverages. SERS combined with gold nanorods shows potential for analyzing food colorants and other food additives as a rapid, convenient, and sensitive method.

  17. A rapid, ratiometric, enzyme-free, and sensitive single-step miRNA detection using three-way junction based FRET probes

    Science.gov (United States)

    Luo, Qingying; Liu, Lin; Yang, Cai; Yuan, Jing; Feng, Hongtao; Chen, Yan; Zhao, Peng; Yu, Zhiqiang; Jin, Zongwen

    2018-03-01

    MicroRNAs (miRNAs) are single stranded endogenous molecules composed of only 18-24 nucleotides which are critical for gene expression regulating the translation of messenger RNAs. Conventional methods based on enzyme-assisted nucleic acid amplification techniques have many problems, such as easy contamination, high cost, susceptibility to false amplification, and tendency to have sequence mismatches. Here we report a rapid, ratiometric, enzyme-free, sensitive, and highly selective single-step miRNA detection using three-way junction assembled (or self-assembled) FRET probes. The developed strategy can be operated within the linear range from subnanomolar to hundred nanomolar concentrations of miRNAs. In comparison with the traditional approaches, our method showed high sensitivity for the miRNA detection and extreme selectivity for the efficient discrimination of single-base mismatches. The results reveal that the strategy paved a new avenue for the design of novel highly specific probes applicable in diagnostics and potentially in microscopic imaging of miRNAs in real biological environments.

  18. A simple, sensitive and rapid isocratic reversed-phase high-performance liquid chromatography method for determination and stability study of curcumin in pharmaceutical samples

    Science.gov (United States)

    Amanolahi, Farjad; Mohammadi, Ali; Kazemi Oskuee, Reza; Nassirli, Hooriyeh; Malaekeh-Nikouei, Bizhan

    2017-01-01

    Objective: This study was designed to develop and validate a new reversed-phase high-performance liquid chromatography (RP-HPLC) method based on Q2 (R1) International Conference on Harmonization (ICH) guideline for determination of curcumin in pharmaceutical samples. Materials and Methods: The HPLC instrument method was optimized with isocratic elution with acetonitrile: ammonium acetate (45:55, v/v, pH 3.5), C18 column (150 mm×4.6 mm×5 µm particle size) and a flow rate of 1 ml/min in ambient condition and total retention time of 17 min. The volume of injection was set at 20 µl and detection was recorded at 425 nm. The robustness of the method was examined by changing the mobile phase composition, mobile phase pH, and flow rate. Results: The method was validated with respect to precision, accuracy and linearity in a concentration range of 2-100 µg/ml. The limit of detection (LOD) and limit of quantification (LOQ) were 0.25 and 0.5 µg/ml, respectively. The percentage of recovery was 98.9 to 100.5 with relative standard deviation (RSD) < 0.638%. Conclusion: The method was found to be simple, sensitive and rapid for determination of curcumin in pharmaceutical samples and had enough sensitivity to detect degradation product of curcumin produced under photolysis and hydrolysis stress condition. PMID:29062806

  19. Combined rapid (TUBEX test for typhoid-paratyphoid A fever based on strong anti-O12 response: design and critical assessment of sensitivity.

    Directory of Open Access Journals (Sweden)

    Meiying Yan

    Full Text Available Rapid diagnostics can be accurate but, often, those based on antibody detection for infectious diseases are unwittingly underrated for various reasons. Herein, we described the development of a combined rapid test for two clinically-indistinguishable bacterial diseases, typhoid and paratyphoid A fever, the latter fast emerging as a global threat. By using monoclonal antibodies (mAbs to bacterial antigens of known chemical structures as probes, we were able to dissect the antibody response in patients at the level of monosaccharides. Thus, a mAb specific for a common lipopolysaccharide antigen (O12 found in both the causative organisms was employed to semi-quantify the amounts of anti-O12 antibodies present in both types of patients in an epitope-inhibition particle-based (TUBEX immunoassay. This colorimetric assay detected not only anti-O12 antibodies that were abundantly produced, but also, by steric hindrance, antibodies to an adjoining epitope (O9 or O2 in the typhoid or paratyphoid bacillus, respectively. Sensitivity and, particularly, reaction intensities, were significantly better than those obtained using an anti-O9 or anti-O2 mAb-probe in the examination of paired sera from 22 culture-confirmed typhoid patients (sensitivity, 81.8% vs 75.0% or single sera from 36 culture-confirmed paratyphoid patients (52.8% vs 28.6, respectively. Importantly, sensitivity was better (97.1% for typhoid, 75.0% for paratyphoid if allowance was made for the absence of relevant antibodies in certain specimens as determined by an independent, objective assay (ELISA--such specimens might have been storage-denatured (especially the older paratyphoid samples or procured from non-responders. Benchmarking against ELISA, which revealed high concordance between the two tests, was useful and more appropriate than comparing with culture methods as traditionally done, since antibody tests and culture target slightly different stages of these diseases. Paired sera

  20. An immuno-wall microdevice exhibits rapid and sensitive detection of IDH1-R132H mutation specific to grade II and III gliomas

    Science.gov (United States)

    Yamamichi, Akane; Kasama, Toshihiro; Ohka, Fumiharu; Suzuki, Hiromichi; Kato, Akira; Motomura, Kazuya; Hirano, Masaki; Ranjit, Melissa; Chalise, Lushun; Kurimoto, Michihiro; Kondo, Goro; Aoki, Kosuke; Kaji, Noritada; Tokeshi, Manabu; Matsubara, Toshio; Senga, Takeshi; Kaneko, Mika K.; Suzuki, Hidenori; Hara, Masahito; Wakabayashi, Toshihiko; Baba, Yoshinobu; Kato, Yukinari; Natsume, Atsushi

    2016-01-01

    World Health Organization grade II and III gliomas most frequently occur in the central nervous system (CNS) in adults. Gliomas are not circumscribed; tumor edges are irregular and consist of tumor cells, normal brain tissue, and hyperplastic reactive glial cells. Therefore, the tumors are not fully resectable, resulting in recurrence, malignant progression, and eventual death. Approximately 69-80% of grade II and III gliomas harbor mutations in the isocitrate dehydrogenase 1 gene (IDH1), of which 83-90% are found to be the IDH1-R132H mutation. Detection of the IDH1-R132H mutation should help in the differential diagnosis of grade II and III gliomas from other types of CNS tumors and help determine the boundary between the tumor and normal brain tissue. In this study, we established a highly sensitive antibody-based device, referred to as the immuno-wall, to detect the IDH1-R132H mutation in gliomas. The immuno-wall causes an immunoreaction in microchannels fabricated using a photo-polymerizing polymer. This microdevice enables the analysis of the IDH1 status with a small sample within 15 min with substantially high sensitivity. Our results suggested that 10% content of the IDH1-R132H mutation in a sample of 0.33 μl volume, with 500 ng protein, or from 500 cells is theoretically sufficient for the analysis. The immuno-wall device will enable the rapid and highly sensitive detection of the IDH1-R132H mutation in routine clinical practice.

  1. Genetic architecture of intrinsic antibiotic susceptibility.

    Directory of Open Access Journals (Sweden)

    Hany S Girgis

    2009-05-01

    Full Text Available Antibiotic exposure rapidly selects for more resistant bacterial strains, and both a drug's chemical structure and a bacterium's cellular network affect the types of mutations acquired.To better characterize the genetic determinants of antibiotic susceptibility, we exposed a transposon-mutagenized library of Escherichia coli to each of 17 antibiotics that encompass a wide range of drug classes and mechanisms of action. Propagating the library for multiple generations with drug concentrations that moderately inhibited the growth of the isogenic parental strain caused the abundance of strains with even minor fitness advantages or disadvantages to change measurably and reproducibly. Using a microarray-based genetic footprinting strategy, we then determined the quantitative contribution of each gene to E. coli's intrinsic antibiotic susceptibility. We found both loci whose removal increased general antibiotic tolerance as well as pathways whose down-regulation increased tolerance to specific drugs and drug classes. The beneficial mutations identified span multiple pathways, and we identified pairs of mutations that individually provide only minor decreases in antibiotic susceptibility but that combine to provide higher tolerance.Our results illustrate that a wide-range of mutations can modulate the activity of many cellular resistance processes and demonstrate that E. coli has a large mutational target size for increasing antibiotic tolerance. Furthermore, the work suggests that clinical levels of antibiotic resistance might develop through the sequential accumulation of chromosomal mutations of small individual effect.

  2. Antibiotics: Precious Goods in Changing Times.

    Science.gov (United States)

    Sass, Peter

    2017-01-01

    Antibiotics represent a first line of defense of diverse microorganisms, which produce and use antibiotics to counteract natural enemies or competitors for nutritional resources in their nearby environment. For antimicrobial activity, nature has invented a great variety of mechanisms of antibiotic action that involve the perturbation of essential bacterial structures or biosynthesis pathways of macromolecules such as the bacterial cell wall, DNA, RNA, or proteins, thereby threatening the specific microbial lifestyle and eventually even survival. However, along with highly inventive modes of antibiotic action, nature also developed a comparable set of resistance mechanisms that help the bacteria to circumvent antibiotic action. Microorganisms have evolved specific adaptive responses that allow appropriately reacting to the presence of antimicrobial agents, ensuring survival during antimicrobial stress. In times of rapid development and spread of antibiotic (multi-)resistance, we need to explore new, resistance-breaking strategies to counteract bacterial infections. This chapter intends to give an overview of common antibiotics and their target pathways. It will also discuss recent advances in finding new antibiotics with novel modes of action, illustrating that nature's repertoire of innovative new antimicrobial agents has not been fully exploited yet, and we still might find new drugs that help to evade established antimicrobial resistance strategies.

  3. Ad Hoc Constitution of Topical Antibiotics Solution for Ear Dressing ...

    African Journals Online (AJOL)

    Background/ Purpose: In the management of chronic suppurative otitis media and otitis externa there are few cases where although an organism is cultured and isolated from the ear, there are either no antibiotic sensitive to the microbiological flora or the sensitive antibiotic is not available in the form of an ear drop, limiting ...

  4. Antibiotic resistant Staphylococcus aureus in Abia State of Nigeria ...

    African Journals Online (AJOL)

    The S. aureus. isolates varied in their antibiotic susceptibility pattern when tested for their sensitivity to 16 antibiotics. Eighty percent of the isolates were resistant to more than one antimicrobial agent. All the isolates showed resistance to nalidixic acid and 100% sensitivity to rifampicin. Key words: Staphylococcus aureus, ...

  5. Bacterial Cheating Limits the Evolution of Antibiotic Resistance

    Science.gov (United States)

    Yurtsev, Eugene; Xiao Chao, Hui; Datta, Manoshi; Artemova, Tatiana; Gore, Jeff

    2012-02-01

    The emergence of antibiotic resistance in bacteria is a significant health concern. Bacteria can gain resistance to the antibiotic ampicillin by acquiring a plasmid carrying the gene beta-lactamase, which inactivates the antibiotic. This inactivation may represent a cooperative behavior, as the entire bacterial population benefits from removal of the antibiotic. The presence of a cooperative mechanism of resistance suggests that a cheater strain - which does not contribute to breaking down the antibiotic - may be able to take advantage of resistant cells. We find experimentally that a ``sensitive'' bacterial strain lacking the plasmid conferring resistance can invade a population of resistant bacteria, even in antibiotic concentrations that should kill the sensitive strain. We use a simple model in conjunction with difference equations to explain the observed population dynamics as a function of cell density and antibiotic concentration. Our experimental difference equations resemble the logistic map, raising the possibility of oscillations or even chaotic dynamics.

  6. Impact of the rapid antigen detection test in diagnosis and treatment of acute pharyngotonsillitis in a pediatric emergency room.

    Science.gov (United States)

    Cardoso, Débora Morais; Gilio, Alfredo Elias; Hsin, Shieh Huei; Machado, Beatriz Marcondes; de Paulis, Milena; Lotufo, João Paulo B; Martinez, Marina Baquerizo; Grisi, Sandra Josefina E

    2013-01-01

    To evaluate the impact of the routine use of rapid antigen detection test in the diagnosis and treatment of acute pharyngotonsillitis in children. This is a prospective and observational study, with a protocol compliance design established at the Emergency Unit of the University Hospital of Universidade de São Paulo for the care of children and adolescents diagnosed with acute pharyngitis. 650 children and adolescents were enrolled. Based on clinical findings, antibiotics would be prescribed for 389 patients (59.8%); using the rapid antigen detection test, they were prescribed for 286 patients (44.0%). Among the 261 children who would not have received antibiotics based on the clinical evaluation, 111 (42.5%) had positive rapid antigen detection test. The diagnosis based only on clinical evaluation showed 61.1% sensitivity, 47.7% specificity, 44.9% positive predictive value, and 57.5% negative predictive value. The clinical diagnosis of streptococcal pharyngotonsillitis had low sensitivity and specificity. The routine use of rapid antigen detection test led to the reduction of antibiotic use and the identification of a risk group for complications of streptococcal infection, since 42.5% positive rapid antigen detection test patients would not have received antibiotics based only on clinical diagnosis.

  7. Bioluminescent human breast cancer cell lines that permit rapid and sensitive in vivo detection of mammary tumors and multiple metastases in immune deficient mice

    International Nuclear Information System (INIS)

    Jenkins, Darlene E; Hornig, Yvette S; Oei, Yoko; Dusich, Joan; Purchio, Tony

    2005-01-01

    Our goal was to generate xenograft mouse models of human breast cancer based on luciferase-expressing MDA-MB-231 tumor cells that would provide rapid mammary tumor growth; produce metastasis to clinically relevant tissues such as lymph nodes, lung, and bone; and permit sensitive in vivo detection of both primary and secondary tumor sites by bioluminescent imaging. Two clonal cell sublines of human MDA-MB-231 cells that stably expressed firefly luciferase were isolated following transfection of the parental cells with luciferase cDNA. Each subline was passaged once or twice in vivo to enhance primary tumor growth and to increase metastasis. The resulting luciferase-expressing D3H1 and D3H2LN cells were analyzed for long-term bioluminescent stability, primary tumor growth, and distal metastasis to lymph nodes, lungs, bone and soft tissues by bioluminescent imaging. Cells were injected into the mammary fat pad of nude and nude-beige mice or were delivered systemically via intracardiac injection. Metastasis was also evaluated by ex vivo imaging and histologic analysis postmortem. The D3H1 and D3H2LN cell lines exhibited long-term stable luciferase expression for up to 4–6 months of accumulative tumor growth time in vivo. Bioluminescent imaging quantified primary mammary fat pad tumor development and detected early spontaneous lymph node metastasis in vivo. Increased frequency of spontaneous lymph node metastasis was observed with D3H2LN tumors as compared with D3H1 tumors. With postmortem ex vivo imaging, we detected additional lung micrometastasis in mice with D3H2LN mammary tumors. Subsequent histologic evaluation of tissue sections from lymph nodes and lung lobes confirmed spontaneous tumor metastasis at these sites. Following intracardiac injection of the MDA-MB-231-luc tumor cells, early metastasis to skeletal tissues, lymph nodes, brain and various visceral organs was detected. Weekly in vivo imaging data permitted longitudinal analysis of metastasis at

  8. Streptavidin-biotin-based directional double Nanobody sandwich ELISA for clinical rapid and sensitive detection of influenza H5N1.

    Science.gov (United States)

    Zhu, Min; Gong, Xue; Hu, Yonghong; Ou, Weijun; Wan, Yakun

    2014-12-20

    Influenza H5N1 is one subtype of the influenza A virus which can infect human bodies and lead to death. Timely diagnosis before its breakout is vital to the human health. The current clinical biochemical diagnosis for influenza virus are still flawed, and the diagnostic kits of H5N1 are mainly based on traditional monoclonal antibodies that hardly meet the requirements for clinical applications. Nanobody is a promising tool for diagnostics and treatment due to its smallest size, high specificity and stability. In this study, a novel Nanobody-based bioassay was developed for rapid, low-cost and sensitive detection of the influenza H5N1 virus. Nanobodies specific to H5N1 virus were selected from a VHH library by phage display technology. In this system, the biotinylated Nanobody was directionally captured by streptavidin coated on ELISA plate, which can specifically capture the H5N1 virus. Another Nanobody conjugated with HRP was used as a detector. A novel directional enzyme-linked immunosorbent assay for H5N1 using specific Nanobodies was established and compared to the conventional undirected ELISA assay. We have successfully constructed a high quality phage display Nanobody library and isolated two Nanobodies against H5N1 with high affinity and specificity. These two Nanobodies were further used to prepare the biosensor detection system. This streptavidin-biotin-based directional double Nanobodies sandwich ELISA for H5N1 detection showed superiority over the commonly undirectional ELISA protocol. The linear range of detection for standards in this immunoassay was approximately 50-1000 ng/mL and the detection limit was 14.1 ng/mL. The average recoveries of H5N1 virus from human serum samples were in the range from 94.58% to 114.51%, with a coefficient of variation less than 6.5%. Collectively, these results demonstrated that the proposed detection system is an alternative diagnostic tool that enables a rapid, inexpensive, sensitive and specific detection of the

  9. Sensitivity and Specificity of a Prototype Rapid Diagnostic Test for the Detection of Trypanosoma brucei gambiense Infection: A Multi-centric Prospective Study.

    Science.gov (United States)

    Bisser, Sylvie; Lumbala, Crispin; Nguertoum, Etienne; Kande, Victor; Flevaud, Laurence; Vatunga, Gedeao; Boelaert, Marleen; Büscher, Philippe; Josenando, Theophile; Bessell, Paul R; Biéler, Sylvain; Ndung'u, Joseph M

    2016-04-01

    A major challenge in the control of human African trypanosomiasis (HAT) is lack of reliable diagnostic tests that are rapid and easy to use in remote areas where the disease occurs. In Trypanosoma brucei gambiense HAT, the Card Agglutination Test for Trypanosomiasis (CATT) has been the reference screening test since 1978, usually on whole blood, but also in a 1/8 dilution (CATT 1/8) to enhance specificity. However, the CATT is not available in a single format, requires a cold chain for storage, and uses equipment that requires electricity. A solution to these challenges has been provided by rapid diagnostic tests (RDT), which have recently become available. A prototype immunochromatographic test, the SD BIOLINE HAT, based on two native trypanos