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Sample records for affects beta-lactam resistance

  1. Comprehensive identification of single nucleotide polymorphisms associated with beta-lactam resistance within pneumococcal mosaic genes.

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    Claire Chewapreecha

    2014-08-01

    Full Text Available Traditional genetic association studies are very difficult in bacteria, as the generally limited recombination leads to large linked haplotype blocks, confounding the identification of causative variants. Beta-lactam antibiotic resistance in Streptococcus pneumoniae arises readily as the bacteria can quickly incorporate DNA fragments encompassing variants that make the transformed strains resistant. However, the causative mutations themselves are embedded within larger recombined blocks, and previous studies have only analysed a limited number of isolates, leading to the description of "mosaic genes" as being responsible for resistance. By comparing a large number of genomes of beta-lactam susceptible and non-susceptible strains, the high frequency of recombination should break up these haplotype blocks and allow the use of genetic association approaches to identify individual causative variants. Here, we performed a genome-wide association study to identify single nucleotide polymorphisms (SNPs and indels that could confer beta-lactam non-susceptibility using 3,085 Thai and 616 USA pneumococcal isolates as independent datasets for the variant discovery. The large sample sizes allowed us to narrow the source of beta-lactam non-susceptibility from long recombinant fragments down to much smaller loci comprised of discrete or linked SNPs. While some loci appear to be universal resistance determinants, contributing equally to non-susceptibility for at least two classes of beta-lactam antibiotics, some play a larger role in resistance to particular antibiotics. All of the identified loci have a highly non-uniform distribution in the populations. They are enriched not only in vaccine-targeted, but also non-vaccine-targeted lineages, which may raise clinical concerns. Identification of single nucleotide polymorphisms underlying resistance will be essential for future use of genome sequencing to predict antibiotic sensitivity in clinical microbiology.

  2. Evolution of beta-lactam : Resistance in Klebsiella pneumoniae

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    Hæggman, Sara

    2010-01-01

    K. pneumoniae is recognized as a common opportunistic pathogen. Numerous reports have been published worldwide on outbreaks in different healthcare settings. K. pneumoniae is inherently resistant to penicillins, including semisynthetic broad-spectrum penicillins. The drug of choice for empirical treatment is often a cephalosporin. However, the use of cephalosporins is known to select for extended-spectrum beta-lactamase (ESBL)-producing strains. The focus of this thesis ...

  3. CesRK, a two-component signal transduction system in Listeria monocytogenes, responds to the presence of cell wall-acting antibiotics and affects beta-lactam resistance

    DEFF Research Database (Denmark)

    Kallipolitis, Birgitte H; Ingmer, Hanne; Gahan, Cormac G;

    2003-01-01

    Listeria monocytogenes is a food-borne pathogen that can cause a variety of illnesses ranging from gastroenteritis to life-threatening septicemia. The beta-lactam antibiotic ampicillin remains the drug of choice for the treatment of listeriosis. We have previously identified a response regulator of...

  4. Efficacy of ciprofloxacin in experimental aortic valve endocarditis caused by a multiply beta-lactam-resistant variant of Pseudomonas aeruginosa stably derepressed for beta-lactamase production.

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    Bayer, A S; Lindsay, P.; Yih, J; Hirano, L; Lee, D.; Blomquist, I K

    1986-01-01

    The emergence of multi-beta-lactam resistance is a limiting factor in treating invasive Pseudomonas infections with newer cephalosporins. The in vivo efficacy of ciprofloxacin, a new carboxy-quinolone, was evaluated in experimental aortic valve endocarditis caused by a strain of Pseudomonas aeruginosa which is stably derepressed for beta-lactamase production and is resistant to ceftazidime and multiple other beta-lactam agents. A total of 51 catheterized rabbits with aortic catheters in place...

  5. Metallo-beta-lactamases of Pseudomonas aeruginosa--a novel mechanism resistance to beta-lactam antibiotics.

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    Dorota Olszańska

    2008-06-01

    Full Text Available Since about twenty years, following the introduction into therapeutic of news beta-lactam antibiotics (broad-spectrum cephalosporins, monobactams and carbapenems, a very significant number of new beta-lactamases appeared. These enzymes confer to the bacteria which put them, the means of resisting new molecules. The genetic events involved in this evolution are of two types: evolution of old enzymes by mutation and especially appearance of new genes coming for some, from bacteria of the environment. Numerous mechanisms of enzymatic resistance to the carbapenems have been described in Pseudomonas aeruginosa. The important mechanism of inactivation carbapenems is production variety of b-lactam hydrolysing enzymes associated to carbapenemases. The metallo-beta-enzymes (IMP, VIM, SPM, GIM types are the most clinically significant carbapenemases. P. aeruginosa posses MBLs and seem to have acquired them through transmissible genetic elements (plasmids or transposons associated with integron and can be transmission to other bacteria. They have reported worldwide but mostly from South East Asia and Europe. The enzymes, belonging to the molecular class B family, are the most worrisome of all beta-lactamases because they confer resistance to carbapenems and all the beta-lactams (with the exception of aztreonam and usually to aminoglycosides and quinolones. The dissemination of MBLs genes is thought to be driven by regional consumption of extended--spectrum antibiotics (e.g. cephalosporins and carbapenems, and therefore care must be taken that these drugs are not used unnecessarily.

  6. Antibodies against Pseudomonas aeruginosa chromosomal beta-lactamase inpatients with cystic fibrosis are markers of the development of resistance of P. aeruginosa to beta-lactams

    DEFF Research Database (Denmark)

    Ciofu, O; Giwercman, B; Walter-Rasmussen, J; Pressler, T; Pedersen, S S; Høiby, N

    1995-01-01

    Chromosomal beta-lactamase production is considered to be the most important resistance mechanism of Pseudomonas aeruginosa against beta-lactams. Recently we have detected serum and sputum antibodies against P. aeruginosa chromosomal beta-lactamase (a beta ab), using immunoblotting techniques. In...

  7. In vitro selection of one-step mutants of Streptococcus pneumoniae resistant to different oral beta-lactam antibiotics is associated with alterations of PBP2x.

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    Sifaoui, F; Kitzis, M D; Gutmann, L

    1996-01-01

    Many oral penicillins and cephalosporins are used to treat clinical infections caused by Streptococcus pneumoniae. Therefore, using different beta-lactams as selectors, we estimated the frequencies of one-step mutations leading to resistance. Resistant mutants were obtained from penicillin-susceptible, intermediately resistant, and penicillin resistant strains. For cefixime, cefuroxime, cefpodoxime, cefotaxime, and ceftriaxone, the frequencies of mutation ranged from 10(-6) to 10(-8) when res...

  8. An Investigation of beta-lactam antibiotics resistance in Escherichia coli isolates and molecular detection of Escherichia coli O157:H7 in cage birds from Shahrekord, Iran

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    Hossein Tahmasby; Sara Barati; Hassan Momtaz; Mohammad Rafiee Dolatabadi; Mohammad Ghasemi; Seied Vahid Ahmadi Salianeh; Samaneh Mehrabiyan

    2014-01-01

    Introduction: Cage birds can harbor human pathogens and contribute to the transmission and spread of drug resistant infectious agents to human. Since many people are interested in keeping cage birds, present study was conducted in cage birds from Shahrekord to investigate the beta-lactam antibiotics resistant E. coli and molecular detection of E. coli O157:H7 that is responsible for outbreaks of human intestinal diseases and fatal haemolytic-uraemic syndrome worldwide. Materials and metho...

  9. Amoxicillin treatment of experimental acute otitis media caused by Haemophilus influenzae with non-beta-lactamase-mediated resistance to beta-lactams: aspects of virulence and treatment.

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    Melhus, A; Janson, H; Westman, E.; Hermansson, A.; Forsgren, A; Prellner, K

    1997-01-01

    Through alterations primarily in the penicillin-binding proteins, a non-beta-lactamase-mediated resistance to beta-lactams has evolved in Haemophilus influenzae. The virulence of these chromosomally changed strains has been questioned. To ascertain whether these alterations involve a reduction in virulence of H. influenzae and whether they could be advantageous for the bacterium during amoxicillin treatment of acute otitis media, a total of 70 Sprague-Dawley rats were challenged with a suscep...

  10. Detection and reporting beta-lactam resistance phenotypes in Escherichia coli and Klebsiella pneumoniae: a multicenter proficiency study in Spain.

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    Conejo, M Carmen; Mata, C; Navarro, F; Pascual, A

    2008-11-01

    The ability of 57 Spanish microbiology laboratories in detecting and reporting beta-lactam resistance phenotypes in Escherichia coli and Klebsiella pneumoniae was evaluated. Laboratories received 6 well-characterized isolates expressing the most widespread extended-spectrum beta-lactamases (ESBLs) in Spain (4 CTX-M type, 1 TEM type, and 1 SHV type), 3 isolates producing AmpC-type enzymes (2 plasmid mediated and 1 E. coli hyperproducing its chromosomal AmpC), and 3 quality control strains. Ninety-one percent of laboratories recognized all ESBL producers correctly, and therefore, low error rates were observed when testing cephalosporins and aztreonam. The highest error rates were observed with combinations of penicillin plus beta-lactamase inhibitor, although more than 60% of cases were due to the interpretation made by the microbiologists. Correct recognition of all AmpC beta-lactamase-producing strains occurred in only 47.4% of laboratories. These isolates were wrongly reported as ESBL producers and penicillinase hyperproducers in 7.6 % and 5.8% of cases, respectively. Detection of the AmpC-type phenotype by Spanish laboratories needs to be improved. PMID:18692340

  11. The Survey of Genes Encoding Beta-Lactamases, in Escherichia Coli Resistant to Beta-Lactam and Non-Beta-Lactam Antibiotics

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    Fereshteh Shahcheraghi

    2010-01-01

    Full Text Available Resistance to the new generation of cephalosporins which is mediated by Extended-Spectrum beta-lactamases (ESBLs has been found amongEscherichia coli isolates throughout the world. These resistance genes and their producers, the micro-organisms carrying beta-lactamases, are responsible for serious clinical and therapeutic problems among inpatients and it is necessary to pay more attention to detection of ESBLs producing organisms.Materiasl and MethodsCollectively 260 isolates of E. coli were obtained from 6 hospitals in Tehran (Iran during April-2006 to April-2007. The antibiotic susceptibility patterns of isolates were determined by disk diffusion method. phenotypic confirmatory test (PCT was carried out for screening of ESBLs. Microbroth dilution assay was used to determine the minimum inhibitory concentration (MIC of ceftazidime. Isolates showing MIC≥2 μg/ml were subjected to polymerase chain reaction (PCR targeting blaTEM, blaSHV, blaCTX and blaPER genes. ResultsThe PCT showed that 48.08% of isolates are ESBL producers (125 of 260. The majority of cefotaxime resistant (90.8% and ceftazidime resistant (92.5% isolates were ESBL producers. The obtained results by PCR revealed that 5.77% (n=15 of 260 and 24.23 (n=63 of isolates can produce SHV and TEM type enzymes respectively. blaCTX was detected in 20.38% of isolates (n=53 and none of them could produce blaPER type beta-lactamases. ConclusionThe results of our study showed that the ESBL genes have high prevalence among clinical isolates of E. coli. Such high dissemination of ESBLs is a serious problem for public health and therefore, it's necessary to seek a program for monitoring ESBLs in hospitals.

  12. Replicon typing of plasmids encoding resistance to newer beta-lactams.

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    Carattoli, Alessandra; Miriagou, Vivi; Bertini, Alessia; Loli, Alexandra; Colinon, Celine; Villa, Laura; Whichard, Jean M; Rossolini, Gian Maria

    2006-07-01

    Polymerase chain reaction-based replicon typing represents a novel method to describe the dissemination and follow the evolution of resistance plasmids. We used this approach to study 26 epidemiologically unrelated Enterobacteriaceae and demonstrate the dominance of incompatibility (Inc) A/C or Inc N-related plasmids carrying some emerging resistance determinants to extended-spectrum cephalosporins and carbapenems. PMID:16836838

  13. Peptidoglycan biosynthesis in Neisseria gonorrhoeae strains sensitive and intrinsically resistant to beta-lactam antibiotics.

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    Dougherty, T J

    1983-01-01

    Treatment of penicillin-sensitive and intrinsically resistant Neisseria gonorrhoeae strains with their respective inhibitory concentrations of penicillin caused rapid cell death. When the peptidoglycan syntheses of these two strains were examined in the presence of penicillin, the sensitive strain continued to make this cell wall polymer for an extended time, whereas the resistant strain underwent a rapid and marked depression in synthesis. Examination of the labeled sodium dodecyl sulfate-in...

  14. Characterization of Beta-lactam Resistance in the Gastric Pathogen Helicobacter pylori

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    Qureshi, Nadia Naeem

    2010-01-01

    Helicobacter pylori is a major cause of peptic ulcer disease and potentially stomach cancer. Treatment of patients with gastritis is warranted and normally done with a combination of antibiotics (such as amoxicillin, clarithromycin or others) and a proton pump inhibitor. Resistance to most of these antibiotics in H. pylori has been seen worldwide and is constantly increasing. The purpose of this thesis was to more systematically characterize the mechanisms of amoxicillin resistance in H. py...

  15. Partial characterization of an endemic strain of a methicillin- and aminoglycoside-resistant Staphylococcus aureus (MARSA) homogeneously resistant to beta-lactam antibiotics.

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    Jacob, J; Meers, P D

    1992-06-01

    Selected strains of methicillin- and aminoglycoside-resistant Staphylococcus aureus (MARSA) were subjected to a preliminary examination. They were representative of a larger group collected in a routine clinical microbiology laboratory over a period of 2 years. MARSA was endemic in the associated hospital. The characteristics investigated were antimicrobial resistance, the production of beta-lactamase, free and bound coagulase, protein A, DNA-ase, urease, lipase and pigment. The MARSA strains were generally indistinguishable, other than in their antimicrobial resistances. The resistance to methicillin was completely homogeneous. Except with imipenem, growth extended to the edge of discs containing methicillin and the other beta-lactam antibiotics tested when the strains were cultured at 37 degrees C on media without added salt. Homogeneous resistance may confer an epidemiological advantage on strains of this phenotype. PMID:1353087

  16. An Investigation of beta-lactam antibiotics resistance in Escherichia coli isolates and molecular detection of Escherichia coli O157:H7 in cage birds from Shahrekord, Iran

    Directory of Open Access Journals (Sweden)

    Hossein Tahmasby

    2014-04-01

    Full Text Available Introduction: Cage birds can harbor human pathogens and contribute to the transmission and spread of drug resistant infectious agents to human. Since many people are interested in keeping cage birds, present study was conducted in cage birds from Shahrekord to investigate the beta-lactam antibiotics resistant E. coli and molecular detection of E. coli O157:H7 that is responsible for outbreaks of human intestinal diseases and fatal haemolytic-uraemic syndrome worldwide. Materials and methods: Altogether 256 samples of cage birds (lovebirds, quails, nightingales, parrots, mynahs, goldfinchs, finches, kingbirds, peacocks, and pheasants faeces were collected with sterile cotton swabs from different areas of Shahrekord, Iran. Swabs were placed directly into Tryptone Soya Broth (TSB. In the laboratory, samples were streaked onto MacConkey agar and also Sorbitol MacConkey agar as selective plating media. Then, antibiogram tests were performed using disc diffusion method. Suspected colonies to E. coli O157:H7 were tested by polymerase chain reaction (PCR. Results: E. coli was isolated from 31 (12.1% out of 256 the samples. Resistance of isolates to Imipenem, Cefotaxime, Cefixime, Cefalexin, Amoxicillin, Penicillin G and Oxacillin was 0, 3.2, 16.1, 90.3, 100, 100 and 100% respectively. E. coli O157:H7 was not found in any samples. Discussion and conclusion: Although cage birds were not sourcee or carriers of E. coli O157:H7 in the studied region, they harbored beta-lactam antibiotics resistant E. coli and could be an important component of drug-resistant infections transmission from cage-birds to human, especially to kids and can pose a potential risk to human health. For this reason, it is recommended to make pet birds owners and general public aware of potential dangers of cage bird keeping.

  17. Meropenem in cystic fibrosis patients infected with resistant Pseudomonas aeruginosa or Burkholderia cepacia and with hypersensitivity to beta-lactam antibiotics

    DEFF Research Database (Denmark)

    Ciofu, Oana; Jensen, Tim; Pressler, Tacjana;

    1996-01-01

    OBJECTIVE: To assess the efficacy and safety of meropenem, administered on a compassionate basis to 62 cystic fibrosis (CF) patients (age: 24plus minus6 years) with hypersensitivity reactions to beta-lactam antibiotics and/or infection by bacteria resistant to other antibiotics. METHODS: Fifty......-seven patients were chronically infected with Pseudomonas aeruginosa and 5 with Burkholderia cepacia. In total, 124 courses (1 to 6/patient) of meropenem, 2 g three times a day by intravenous infusion (10 to 15 min) for 14 days, were administered. RESULTS: During treatment for P. aeruginosa the mean increase in...... chronic infection with B. cepacia the post treatment FEV1 and FVC values were higher than the pre-treatment values, and all the inflammatory parameters decreased. The geometric means of minimal inhibitory concentration (MICs) (microg/mL) for P. aeruginosa (B. cepacia) were: tobramycin 6 (59...

  18. Meropenem in cystic fibrosis patients infected with resistant Pseudomonas aeruginosa or Burkholderia cepacia and with hypersensitivity to beta-lactam antibiotics.

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    Ciofu, Oana; Jensen, Tim; Pressler, Tacjana; Johansen, Helle Krogh; Koch, Christian; Høiby, Niels

    1996-01-01

    OBJECTIVE: To assess the efficacy and safety of meropenem, administered on a compassionate basis to 62 cystic fibrosis (CF) patients (age: 24plus minus6 years) with hypersensitivity reactions to beta-lactam antibiotics and/or infection by bacteria resistant to other antibiotics. METHODS: Fifty-seven patients were chronically infected with Pseudomonas aeruginosa and 5 with Burkholderia cepacia. In total, 124 courses (1 to 6/patient) of meropenem, 2 g three times a day by intravenous infusion (10 to 15 min) for 14 days, were administered. RESULTS: During treatment for P. aeruginosa the mean increase in pulmonary function (as a percentage of the predictive values) was 5.6% for FEV1 (forced expiratory volume in the first second) and 8.6% for FVC (forced vital capacity). C-reactive protein and erythrocyte sedimentation rate (ESR) and leukocyte count decreased significantly. In courses administered for chronic infection with B. cepacia the post treatment FEV1 and FVC values were higher than the pre-treatment values, and all the inflammatory parameters decreased. The geometric means of minimal inhibitory concentration (MICs) (microg/mL) for P. aeruginosa (B. cepacia) were: tobramycin 6 (59), ciprofloxacin 1.2 (9.7), piperacillin 49 (16.3), ceftazidime 26 (23), aztreonam 26 (35), imipenem 6.4 (not determined) and meropenem 5.1 (4.8). No statistically significant increase in the MICs of meropenem for either pathogen occurred during therapy. Of the 124 courses, 115 were tolerated without any clinical complaint. The following side effects were observed: nausea (0.8%), itching (4%), rash (3.2%), drug fever (1.6%). CONCLUSIONS: Meropenem proved to be a valuable drug in the treatment of CF patients with chronic pulmonary infection with multiresistant P. aeruginosa and B. cepacia and with hypersensitivity reactions to other beta-lactam drugs. PMID:11866824

  19. Synthesis and anti Methicillin resistant Staphylococcus aureus activity of substituted chalcones alone and in combination with non-beta-lactam antibiotics.

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    Tran, Thanh-Dao; Do, Tuong-Ha; Tran, Ngoc-Chau; Ngo, Trieu-Du; Huynh, Thi-Ngoc-Phuong; Tran, Cat-Dong; Thai, Khac-Minh

    2012-07-15

    A total of 30 chalcone analogues was synthesized via a base catalyzed Claisen Schmidt condensation and screened for their in vitro antibacterial activity against Methicillin-sensitive Staphylococcus aureus (MSSA) and Methicillin-resistant Staphylococcus aureus (MRSA) alone or in combination with non beta-lactam antibiotics namely ciprofloxacin, chloramphenicol, erythromycin, vancomycin, doxycycline and gentamicin. In the checkerboard technique, fractional inhibitory concentration indices (FICI) show that the following combinations like ciprofloxacin with 25 (4'-bromo-2-hydroxychalcone); doxycycline with 21 (4-hydroxychalcone); doxycycline with 25; and doxycycline with 4 (2',2-dihydroxychalcone) were synergistic against MRSA. In term SAR study, the relationship between chalcone structure and their antibacterial activity against S. aureus and synergy with tested antibiotics were discussed. Possible mechanisms for antibacterial activity of chalcones alone as well as the synergistic effect in combinations were proposed by molecular modeling studies, respectively. Combinations of chalcones with conventional antibiotics could be an effective alternative in the treatment of infection caused by MRSA. PMID:22727643

  20. Effects of reducing beta-lactam antibiotic pressure on intestinal colonization of antibiotic-resistant gram-negative bacteria

    NARCIS (Netherlands)

    S. Nijssen (Saskia); A.C. Fluit (Ad); D.A.M.C. van de Vijver (David); J. Top (Janetta); R.J.L. Willems (Rob); M.J.M. Bonten (Marc)

    2010-01-01

    textabstractBackground: We determined the effects of two antibiotic policies (predominance of either β-lactam antibiotics or fluroquinolones) on acquisition with third-generation cephalosporin-resistant Enterobacteriaceae (CRE) and fluoroquinolone-resistant CRE (FCRE) in two ICUs, with monitoring of

  1. Occurrence of quinolone- and beta-lactam-resistant Escherichia coli in danish broiler flocks

    DEFF Research Database (Denmark)

    Bortolaia, Valeria; Guardabassi, Luca; Bisgaard, Magne;

    An increased concern for the possible transfer of resistant bacteria or mobile resistance elements from food animals to humans has resulted in rigorous legislation preventing i.e. practical use of fluoroquinolones in the Danish broiler industry (Olesen et al., 2004; Petersen et al., 2006). In...... F. M. Aarestrup. 2004. Prevalence of ß-lactamases among ampicillin-resistant Escherichia coli and Salmonella isolated from food animals in Denmark. Micr. Drug Res. 10:334-340. Petersen, A., J. P. Christensen, P. Kuhnert, M. Bisgaard, J. E. Olsen. 2006. Vertical transmission of a fluoroquinolone...

  2. In vitro susceptibility of cephalothin-resistant Enterobacteriaceae and Pseudomonas aeruginosa to Amikacin and selected new beta-lactam agents.

    OpenAIRE

    McNamara, B T; Meyer, R D; Pasiecznik, K A

    1982-01-01

    Amikacin was evaluated in vitro by agar dilution testing against 148 different clinical isolates of cephalothin-resistant Enterobacteriaceae and Pseudomonas aeruginosa in parallel with cephalothin, cefoxitin, moxalactam, N-formimidoyl thienamycin, ceftriaxone, and cefmenoxime. Cefsulodin was also evaluated against 39 isolates of P. aeruginosa. More than 80% of all isolates tested were also gentamicin resistant, as determined by disk testing. Moxalactam and amikacin had comparable high activit...

  3. Differential fate of erythromycin and beta-lactam resistance genes from swine lagoon waste under different aquatic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, Charles W., E-mail: charles.knapp@strath.ac.u [David Livingstone Centre for Sustainability, Department of Civil Engineering, University of Strathclyde, 50 Richmond Street, Glasgow, G1 1XN (United Kingdom); School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, NE1 7RU (United Kingdom); Zhang, Wen; Sturm, Belinda S.M. [Department of Civil, Environmental and Architectural Engineering, University of Kansas, Lawrence, KS 66045 (United States); Graham, David W. [School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, NE1 7RU (United Kingdom); Department of Civil, Environmental and Architectural Engineering, University of Kansas, Lawrence, KS 66045 (United States)

    2010-05-15

    The attenuation and fate of erythromycin-resistance-methylase (erm) and extended-spectrum beta-lactamse (bla) genes were quantified over time in aquatic systems by adding 20-L swine waste to 11,300-L outdoor mesocosms that simulated receiving water conditions below intensive agricultural operations. The units were prepared with two different light-exposure scenarios and included artificial substrates to assess gene movement into biofilms. Of eleven genes tested, only erm(B), erm(F), bla{sub SHV} and bla{sub TEM} were found in sufficient quantity for monitoring. The genes disappeared rapidly from the water column and first-order water-column disappearance coefficients were calculated. However, detected gene levels became elevated in the biofilms within 2 days, but then disappeared over time. Differences were observed between sunlight and dark treatments and among individual genes, suggesting that ecological and gene-specific factors play roles in the fate of these genes after release into the environment. Ultimately, this information will aid in generating better predictive models for gene fate. - The disappearance and fate of erythromycin-resistance-methylase and beta-lactamase genes were monitored in outdoor mesocosms under different light conditions.

  4. Differential fate of erythromycin and beta-lactam resistance genes from swine lagoon waste under different aquatic conditions

    International Nuclear Information System (INIS)

    The attenuation and fate of erythromycin-resistance-methylase (erm) and extended-spectrum beta-lactamse (bla) genes were quantified over time in aquatic systems by adding 20-L swine waste to 11,300-L outdoor mesocosms that simulated receiving water conditions below intensive agricultural operations. The units were prepared with two different light-exposure scenarios and included artificial substrates to assess gene movement into biofilms. Of eleven genes tested, only erm(B), erm(F), blaSHV and blaTEM were found in sufficient quantity for monitoring. The genes disappeared rapidly from the water column and first-order water-column disappearance coefficients were calculated. However, detected gene levels became elevated in the biofilms within 2 days, but then disappeared over time. Differences were observed between sunlight and dark treatments and among individual genes, suggesting that ecological and gene-specific factors play roles in the fate of these genes after release into the environment. Ultimately, this information will aid in generating better predictive models for gene fate. - The disappearance and fate of erythromycin-resistance-methylase and beta-lactamase genes were monitored in outdoor mesocosms under different light conditions.

  5. Energetic, Structural, and Antimicrobial Analyses of [beta]-Lactam Side Chain Recognition by [beta]-Lactamases

    Energy Technology Data Exchange (ETDEWEB)

    Caselli, E.; Powers, R.A.; Blaszczak, L.C.; Wu, C.Y.E.; Prati, F.; Shoichet, B.K. (NWU)

    2010-03-05

    Penicillins and cephalosporins are among the most widely used and successful antibiotics. The emergence of resistance to these {beta}-lactams, most often through bacterial expression of {beta}-lactamases, threatens public health. To understand how {beta}-lactamases recognize their substrates, it would be helpful to know their binding energies. Unfortunately, these have been difficult to measure because {beta}-lactams form covalent adducts with {beta}-lactamases. This has complicated functional analyses and inhibitor design. To investigate the contribution to interaction energy of the key amide (R1) side chain of {beta}-lactam antibiotics, eight acylglycineboronic acids that bear the side chains of characteristic penicillins and cephalosporins, as well as four other analogs, were synthesized. These transition-state analogs form reversible adducts with serine {beta}-lactamases. Therefore, binding energies can be calculated directly from K{sub i} values. The K{sub i} values measured span four orders of magnitude against the Group I {beta}-lactamase AmpC and three orders of magnitude against the Group II {beta}-lactamase TEM-1. The acylglycineboronic acids have K{sub i} values as low as 20 nM against AmpC and as low as 390 nM against TEM-1. The inhibitors showed little activity against serine proteases, such as chymotrypsin. R1 side chains characteristic of {beta}-lactam inhibitors did not have better affinity for AmpC than did side chains characteristic of {beta}-lactam substrates. Two of the inhibitors reversed the resistance of pathogenic bacteria to {beta}-lactams in cell culture. Structures of two inhibitors in their complexes with AmpC were determined by X-ray crystallography to 1.90 {angstrom} and 1.75 {angstrom} resolution; these structures suggest interactions that are important to the affinity of the inhibitors. Acylglycineboronic acids allow us to begin to dissect interaction energies between {beta}-lactam side chains and {beta}-lactamases. Surprisingly

  6. Lysine N[superscript zeta]-Decarboxylation Switch and Activation of the [beta]-Lactam Sensor Domain of BlaR1 Protein of Methicillin-resistant Staphylococcus aureus

    Energy Technology Data Exchange (ETDEWEB)

    Borbulevych, Oleg; Kumarasiri, Malika; Wilson, Brian; Llarrull1, Leticia I.; Lee, Mijoon; Hesek, Dusan; Shi, Qicun; Peng, Jeffrey; Baker, Brian M.; Mobashery, Shahriar (Notre)

    2012-10-29

    The integral membrane protein BlaR1 of methicillin-resistant Staphylococcus aureus senses the presence of {beta}-lactam antibiotics in the milieu and transduces the information to the cytoplasm, where the biochemical events that unleash induction of antibiotic resistance mechanisms take place. We report herein by two-dimensional and three-dimensional NMR experiments of the sensor domain of BlaR1 in solution and by determination of an x-ray structure for the apo protein that Lys-392 of the antibiotic-binding site is posttranslationally modified by N{sup {zeta}}-carboxylation. Additional crystallographic and NMR data reveal that on acylation of Ser-389 by antibiotics, Lys-392 experiences N{sup {zeta}}-decarboxylation. This unique process, termed the lysine N{sup {zeta}}-decarboxylation switch, arrests the sensor domain in the activated ('on') state, necessary for signal transduction and all the subsequent biochemical processes. We present structural information on how this receptor activation process takes place, imparting longevity to the antibiotic-receptor complex that is needed for the induction of the antibiotic-resistant phenotype in methicillin-resistant S. aureus.

  7. Endopeptidase-Mediated Beta Lactam Tolerance

    OpenAIRE

    Dörr, Tobias; Davis, Brigid M.; Waldor, Matthew K.

    2015-01-01

    In many bacteria, inhibition of cell wall synthesis leads to cell death and lysis. The pathways and enzymes that mediate cell lysis after exposure to cell wall-acting antibiotics (e.g. beta lactams) are incompletely understood, but the activities of enzymes that degrade the cell wall (‘autolysins’) are thought to be critical. Here, we report that Vibrio cholerae, the cholera pathogen, is tolerant to antibiotics targeting cell wall synthesis. In response to a wide variety of cell wall- acting ...

  8. [Survey of the antibiotic sensitivity of Pseudomonas aeruginosa in France and the distribution of beta-lactam resistance mechanisms: the GERPB 1999 study].

    Science.gov (United States)

    Cavallo, J D; Leblanc, F; Fabre, R; Fourticq-Esqueöute, A

    2001-09-01

    A prospective survey was carried out in october 1999 in 15 french teaching hospitals. Average susceptibility rates, determined by minimal inhibitory concentrations, for the 738 non-repetitive strains of P. aeruginosa isolated were: ticarcillin, 58%, ticarcillin + clavulanic acid, 56%, piperacillin, 73%, piperacillin + tazobactam, 82%, ceftazidime, 76%, cefepime, 53%, cefpirome, 36%, aztreonam, 58%, imipenem, 81%, amikacin, 62%, tobramycine, 71% and, ciprofloxacin, 60%. Among the 75% serotypable strains, the most frequent serotypes were: O:6 (15.3%), O:11 (14.5%), O:1 (10.4%), O:3 (7.9%), O:4 (6.1%) and O:12 (6.1%). The serotype O:12 was the most resistant to antibiotics. Forty-two percent of the strains were resistant or presented an intermediate susceptibility to ticarcillin. Mechanisms were as follow: 14.5% non enzymatic mechanism, 12.5% overproduction of the constitutive cephalosporinase, 7.1% transferable betalactamase and, 6.9% combination of these mechanisms. Among the 67 transferable betalactamases: 48 (71.6%) were PSE-1, 12 (19.4%) TEM-2 and 6 (7.5%) oxacillinases. One extended spectrum betalactamase was characterized. Among the cephalosporines tested, cefepime was less affected by the overproduction of constitutive cephalosporinase. Ceftazidime, remained the best cephalosporin except against the strains overexpressing the chromosomal type 1 beta-lactamase. Resistance to tobramycin was mainly due to enzymatic mechanisms with a high level of resistance. Decreased susceptibility was more frequent for amikacin than for tobramycin. This was probably related with non enzymatic mechanisms. PMID:11642015

  9. beta-Lactam and glycopeptide antibiotics: first and last line of defense?

    NARCIS (Netherlands)

    Jovetic, S.; Yang Zhu, Yang; Marcone, G.L.; Marinelli, F.; Tramper, J.

    2010-01-01

    Most infections are caused by bacteria, many of which are ever-evolving and resistant to nearly all available antibiotics beta-Lactams and glycopeptides are used to combat these infections by inhibiting bacterial cell-wall synthesis This mechanism remains an interesting target in the search for new

  10. New molecules from old classes: revisiting the development of beta-lactams.

    Science.gov (United States)

    Page, Malcolm G P; Heim, Jutta

    2009-09-01

    Beta-lactams are among the most successful classes of antibiotics, both medically and commercially. However, more than 60 years of extensive, and sometimes inappropriate, use has enabled bacteria to develop a broad range of resistance mechanisms. Nevertheless, the versatility of the beta-lactam core structure, combined with the innovation of medicinal chemists, has repeatedly led to the development of new generations of beta-lactam antibiotics that are capable of overcoming the problems caused by mounting bacterial resistance. In particular, two cephalosporin derivatives, ceftobiprole and ceftaroline (Forest Laboratories Inc/AstraZeneca plc), as well as the carbapenem razupenem (Novartis AG/Dainippon Sumitomo Pharma Co Ltd), have demonstrated potent activity against the gram-positive 'superbug' MRSA. CXA-101 (Calixa Therapeutics Inc) is a new member of the series of cephalosporins that are effective against gram-negative bacteria such as Pseudomonas aeruginosa. The compound has been demonstrated to be particularly stable to degradation by the class C beta-lactamases in P. aeruginosa. Furthermore, siderophore-containing monobactams such as BAL-30072 (Basilea Pharmaceutica International Ltd) are inherently stable to hydrolysis by metallo-beta-lactamases, and act as 'Trojan horses' by being transported into gram-negative cells using endogenous bacterial iron-uptake systems. Considering the significant medical need for novel antibiotics that are active against resistant strains of bacteria, it is hoped several of the new generation of beta-lactam compounds that are in clinical development will soon reach the market. PMID:19697275

  11. Abundances of tetracycline, sulphonamide and beta-lactam antibiotic resistance genes in conventional wastewater treatment plants (WWTPs) with different waste load

    DEFF Research Database (Denmark)

    Laht, Mailis; Karkman, Antti; Voolaid, Veiko;

    2014-01-01

    Antibiotics and antibiotic resistant bacteria enter wastewater treatment plants (WWTPs), an environment where resistance genes can potentially spread and exchange between microbes. Several antibiotic resistance genes (ARGs) were quantified using qPCR in three WWTPs of decreasing capacity located in...... abundances with 16S rRNA gene abundances while assessing if the respective genes increased or decreased during treatment. ARGs were detected in most samples; sul1, sul2, and tetM were detected in all samples. Statistically significant differences (adjusted p<0.01) between the inflow and effluent were...... detected in only four cases. Effluent values for blaoxa-58 and tetC decreased in the two larger plants while tetM decreased in the medium-sized plant. Only blashv-34 increased in the effluent from the medium-sized plant. In all other cases the purification process caused no significant change in the...

  12. Beta-Lactam-beta-lactamase-inhibitor combinations are active in experimental endocarditis caused by beta-lactamase-producing oxacillin-resistant staphylococci.

    OpenAIRE

    Hirano, L; Bayer, A S

    1991-01-01

    Optimal therapeutic strategies for serious infections caused by borderline and heterotypic oxacillin-resistant Staphylococcus aureus (BORSA and ORSA) strains have not been fully characterized. Recent evidence suggests that the dominant penicillin-binding protein of ORSA strains (PBP 2a) shows good affinity for ampicillin and that these strains commonly produce beta-lactamase. Therefore, we compared the in vivo efficacy of the combination of ampicillin plus sulbactam with that of vancomycin ag...

  13. Treatment of Gram-negative pneumonia in the critical care setting: is the beta-lactam antibiotic backbone broken beyond repair?

    Science.gov (United States)

    Bassetti, Matteo; Welte, Tobias; Wunderink, Richard G

    2016-01-01

    Beta-lactam antibiotics form the backbone of treatment for Gram-negative pneumonia in mechanically ventilated patients in the intensive care unit. However, this beta-lactam antibiotic backbone is increasingly under pressure from emerging resistance across all geographical regions, and health-care professionals in many countries are rapidly running out of effective treatment options. Even in regions that currently have only low levels of resistance, the effects of globalization are likely to increase local pressures on the beta-lactam antibiotic backbone in the near future. Therefore, clinicians are increasingly faced with a difficult balancing act: the need to prescribe adequate and appropriate antibiotic therapy while reducing the emergence of resistance and the overuse of antibiotics. In this review, we explore the burden of Gram-negative pneumonia in the critical care setting and the pressure that antibiotic resistance places on current empiric therapy regimens (and the beta-lactam antibiotic backbone) in this patient population. New treatment approaches, such as systemic and inhaled antibiotic alternatives, are on the horizon and are likely to help tackle the rising levels of beta-lactam antibiotic resistance. In the meantime, it is imperative that the beta-lactam antibiotic backbone of currently available antibiotics be supported through stringent antibiotic stewardship programs. PMID:26821535

  14. In vitro activities of 15 oral beta-lactams against Klebsiella pneumoniae harboring new extended-spectrum beta-lactamases.

    OpenAIRE

    Kitzis, M D; Liassine, N; Ferré, B.; Gutmann, L; Acar, J F; Goldstein, F.

    1990-01-01

    The activities of 15 oral beta-lactams against Klebsiella pneumoniae harboring new extended-spectrum beta-lactamases were studied. All compounds were affected by these enzymes, especially by the SHV derivatives. Except for ceftibuten, the compounds with the greatest intrinsic activity were more affected by the presence of these enzymes than were older compounds with moderate intrinsic activity.

  15. Noncovalent Interaction Energies in Covalent Complexes: TEM-1 beta-Lactamase and beta-Lactams

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaojun; Minasov, George; Shoichet, Brian K. (NWU)

    2010-03-08

    The class A {beta}-lactamase TEM-1 is a key bacterial resistance enzyme against {beta}-lactam antibiotics, but little is known about the energetic bases for complementarity between TEM-1 and its inhibitors. Most inhibitors form a covalent adduct with the catalytic Ser70, making the measurement of equilibriumconstants, and hence interaction energies, technically difficult. This study evaluates noncovalent interactions withincovalent complexes by examining the differential stability of TEM-1 and its inhibitor adducts. The thermal denaturation of TEM-1 follows a two-state, reversible model with a melting temperature (T{sub m}) of 51.6 C and a van't Hoff enthalpy of unfolding ({Delta}H{sub VH}) of 146.2 kcal/mol at pH 7.0. The stability of the enzyme changes on forming an inhibitor adduct. As expected, some inhibitors stabilize TEM-1; transition-state analogues increase the T{sub m} by up to 3.7 C(1.7 kcal/mol). Surprisingly, all {beta}-lactam covalent acyl-enzyme complexes tested destabilize TEM-1 significantly relative to the apoenzyme. For instance, the clinically used inhibitor clavulanic acid and the {beta}-lactamase-resistant {beta}-lactams moxalactam and imipenem destabilize TEM-1 by over 2.6 C (1.2 kcal/mol) in their covalent adducts. Based on the structure of the TEM-1/imipenem complex (Maveyraud et al., J Am Chem Soc 1998;120:9748-52), destabilization by moxalactam and imipenem is thought to be caused by a steric clash between the side-chain of Asn132 and the 6(7)-{alpha} group of these {beta}-lactams. To test this hypothesis, the mutant enzyme N132A was made. In contrast with wild-type, the covalent complexes between N132A and both imipenem and moxalactam stabilize the enzyme, consistent with the hypothesis. To investigate the structural bases of this dramatic change instability, the structure of N132A/imipenem was determined by X-ray crystallography. In the complex with N132A, imipenemadopts a very different conformation from that observed in the wild

  16. Thin Layer Chromatographic Analysis of Beta-Lactam Antibiotics

    Directory of Open Access Journals (Sweden)

    Gabriel Hancu

    2013-08-01

    Full Text Available Purpose: The paper describes some thin layer chromatographic procedures that allow simple and rapid separation and identification of penicillins and cephalosporins from complex mixtures. Methods: Using silicagel GF254 as stationary phase and selecting different mobile phases we succeeded in the separation of the studied beta-lactamins. Our aim was not only to develop a simple, rapid and efficient method for their separation but also the optimization of the analytical conditions. Results: No system will separate all the beta-lactams, but they could be identified when supplementary information is used from color reactions and/or by using additional chromatographic systems. Conclusions: The right combination of solvent system and detection method allows the identification of the studied penicillins and cephalosporins and can be successfully used in the preliminary analysis beta-lactam antibiotics.

  17. 76 FR 14024 - Draft Guidance for Industry on Non-Penicillin Beta-Lactam Risk Assessment: A CGMP Framework...

    Science.gov (United States)

    2011-03-15

    ... HUMAN SERVICES Food and Drug Administration Draft Guidance for Industry on Non-Penicillin Beta-Lactam... guidance for industry entitled ``Non-Penicillin Beta-Lactam Risk Assessment: A CGMP Framework.'' This... non- penicillin beta-lactam antibiotics. The draft guidance is intended to assist manufacturers...

  18. Activities of beta-lactam antibiotics against Escherichia coli strains producing extended-spectrum beta-lactamases.

    OpenAIRE

    Jacoby, G A; Carreras, I

    1990-01-01

    Seven extended-spectrum beta-lactamases related to TEM and four enzymes derived from SHV-1 were transferred to a common Escherichia coli host so that the activity of a variety of beta-lactams could be tested in a uniform genetic environment. For most derivatives, penicillinase activity was 10% or less than that of strains making TEM-1, TEM-2, or SHV-1 beta-lactamase, suggesting that reduced catalytic efficiency accompanied the broader substrate spectrum. Despite this deficit, resistance to az...

  19. Detection of Aspergillus Galactomannan Antigenemia To Determine Biological and Clinical Implications of Beta-Lactam Treatments

    OpenAIRE

    Bart-Delabesse, Emmanuelle; Basile, Maria; Al Jijakli, Ahmad; Souville, Didier; Gay, Frédérick; Philippe, Bruno; Bossi, Philippe; Danis, Martin; Vernant, Jean-Paul; Datry, Annick

    2005-01-01

    Detection of Aspergillus galactomannan (GM) in serum with the Platelia Aspergillus enzyme immunoassay (EIA) is useful for diagnosing invasive aspergillosis. From May 2003 to November 2004, 65 patients who did not develop aspergillosis had at least two positive sera while receiving a beta-lactam treatment (GM index [GMI], ≥0.5). Of the 69 treatment episodes scored, 41 consisted of a beta-lactam other than piperacillin-tazobactam (n = 29), namely, amoxicillin-clavulanate (n = 25), amoxicillin (...

  20. Prevalencia y perfil de resistencia a betalactámicos en estafilococos de perros y gatos Prevalence and resistance profile to beta-lactam antibiotics in staphylococci from dogs and cats

    Directory of Open Access Journals (Sweden)

    G Denamiel

    2009-12-01

    Full Text Available El objetivo de este trabajo fue conocer la prevalencia de especies y perfil de resistencia a betalactámicos en estafilococos aislados de infecciones en caninos y felinos. En perros, de 207 aislamientos, el porcentaje de las especies identificadas fue: S. intermedius 29,5%, S. aureus y S. simulans 20,8%, S. saprophyticus 12,6%, S. chromogenes 10,6%, S. haemolyticus 3,9% y S. epidermidis 1,9%. De 63 aislamientos en gatos: S. simulans 33,3%, S. intermedius y S. aureus 15,4%, S. saprophyticus 11,1%, S. haemolyticus 6,34%, S. chromogenes y S. epidermidis 3,5%. En perros, el porcentaje de resistencia a penicilina fue: S. intermedius 47,5%, S. aureus 34,8% y S. saprophyticus 7,7%. Los aislamientos que expresaron meticilina resistencia correspondieron: S. intermedius 9,8% y S. saprophyticus 3,8%. En gatos los estafilococos resistentes a penicilina fueron S. saprophyticus 42,8%, S. aureus y S. intermedius 15,4% y S. simulans 9,5%. No se hallaron especies de estafilococos meticilino resistentes.The purpose of this study was to characterize the prevalence and resistance profile to betalactam antibiotics of staphylococci isolated from canine and feline infections. Staphylococci were isolated from 207 dog samples. The species frequency for identified staphylococci were: S. intermedius 29.5%, S. aureus and S. simulans 20.8%, S. saprophyticus 12.6%, S. chromogenes 10.6%, S. haemolyticus 3.9% and S. epidermidis 1.9%. Sixty three staphylococci isolates were from cats: S. simulans 33.3%, S. intermedius and S. aureus 15.4%, S. saprophyticus 11.1%, S. haemolyticus 6.34%, S. chromogenes and S. epidermidis 3.5%. Resistance to penicillin in samples from dogs were: S. intermedius 47.5%, S. aureus 34.8% and S. saprophyticus 7.7%. Methicillin-resistance was evidenced in S. intermedius 9.8% and S. saprophyticus 3.8%. In samples from cats, penicillin-resistant staphylococci were: S. saprophyticus 42.8%, S. aureus and S. intermedius 15.4% and S. simulans 9

  1. Bactericidal interactions of a beta-lactam and beta-lactamase inhibitors in experimental Pseudomonas aeruginosa endocarditis caused by a constitutive overproducer of type Id beta-lactamase.

    OpenAIRE

    Bayer, A S; Selecky, M; Babel, K; Hirano, L; Yih, J; Parr, T R

    1987-01-01

    We investigated the in vitro and in vivo effects of a combination of a beta-lactam (ceftazidime) and a beta-lactamase inhibitor (dicloxacillin) to synergistically kill a ceftazidime-resistant variant, Pseudomonas aeruginosa PA-48, which overproduces type Id cephalosporinase constitutively. In vitro, dicloxacillin plus ceftazidime exerted bactericidal synergy at approximately 10(5) CFU/ml of inoculum (but not at approximately 10(7)-CFU inoculum), whereas other beta-lactamase inhibitors (sulbac...

  2. In vitro antimicrobial activity of piperacillin/tazobactam in comparison with other broad-spectrum beta-lactams.

    Science.gov (United States)

    Roland, R K; Mendes, R E; Silbert, S; Bolsoni, A P; Sader, H S

    2000-10-01

    Combining tazobactam, a beta-lactamase inhibitor, with the ureidopenicillin, piperacillin, successfully restores the activity of piperacillin against beta-lactamase producing bacteria. Thus, piperacillin/tazobactam is highly active against most clinically important species of Gram-negative and Gram-positive bacteria, including anaerobes. We evaluated the in vitro activity of piperacillin/tazobactam against clinical isolates from a tertiary university hospital located in Sao Paulo, Brazil. Its activity was compared to that of ticarcillin/clavulanic acid, ampicillin/sulbactam, ceftazidime, ceftriaxone, cefotaxime, cefoxitin, aztreonam, and imipenem against 820 isolates (608 Gram-negative and 212 Gram-positive) collected from hospitalized patients in 1999. The most frequent species tested were Pseudomonas aeruginosa (168/20%), Escherichia coli (139/17%), Acinetobacter spp. (131/16%), and Staphylococcus aureus (76/9%). Of the isolates studied, 30% were from the bloodstream, 16% from the lower respiratory tract, and 11% from surgical wounds or soft tissue. The isolates were susceptibility tested by the broth microdilution method according to NCCLS procedures. The isolates tested were highly resistant to most antimicrobial agents evaluated. Imipenem resistance was not verified among Enterobacteriaceae, and piperacillin/tazobactam was the second most active beta-lactams against this group of bacteria (80.0% susceptibility). Extended-spectrum beta-lactamase production was very high among E. coli (approximately 20%) and Klebsiella pneumoniae (approximately 40%). Imipenem was uniformly active against these species (100% susceptibility) and piperacillin/tazobactam was the second most active compound inhibiting 84.4% of isolates. Pseudomonas aeruginosa was highly resistant to all beta-lactams evaluated and piperacillin/tazobactam was the most active compound against this species. Our results demonstrate an extremely high level of antimicrobial resistance in the hospital

  3. High beta-Lactamase Levels Change the Pharmacodynamics of beta-Lactam Antibiotics in Pseudomonas aeruginosa Biofilms

    DEFF Research Database (Denmark)

    Wang, Hengzhuang; Ciofu, Oana; Yang, Liang;

    2013-01-01

    , microtiter plates, and on alginate beads were treated with different concentrations of ceftazidime and imipenem. The kinetics of antibiotics on the biofilms was investigated in vitro by time-kill methods. Time-dependent killing of ceftazidime was observed in PAO1 biofilms, but concentration-dependent killing......Resistance to beta-lactam antibiotics is a frequent problem in Pseudomonas aeruginosa lung infection of cystic fibrosis (CF) patients. This resistance is mainly due to the hyperproduction of chromosomally encoded beta-lactamase and biofilm formation. The purpose of this study was to investigate the...... activity of ceftazidime was observed for beta-lactamase-overproducing biofilms of P. aeruginosa in all three models. Ceftazidime showed time-dependent killing on planktonic PAO1 and PA Delta DDh2Dh3. This difference is probably due to the special distribution and accumulation in the biofilm matrix of beta...

  4. In vitro synergistic activities of tobramycin and selected beta-lactams against 75 gram-negative clinical isolates.

    OpenAIRE

    Owens, R C; Banevicius, M A; Nicolau, D. P.; Nightingale, C H; Quintiliani, R

    1997-01-01

    The microdilution checkerboard technique was utilized to distinguish synergistic activity between tobramycin and four beta-lactams: piperacillin-tazobactam, ticarcillin-clavulanate, ceftazidime, and ceftriaxone. Beta-lactam-aminoglycoside combinations were tested against 75 clinical isolates of Pseudomonas aeruginosa, Acinetobacter baumanii, Citrobacterfreundii, Serratia marcescens, and Enterobacter cloacae. Despite in vitro susceptibilities, all isolates demonstrated either synergism or indi...

  5. Activities of beta-lactam antibiotics against Escherichia coli strains producing extended-spectrum beta-lactamases.

    Science.gov (United States)

    Jacoby, G A; Carreras, I

    1990-05-01

    Seven extended-spectrum beta-lactamases related to TEM and four enzymes derived from SHV-1 were transferred to a common Escherichia coli host so that the activity of a variety of beta-lactams could be tested in a uniform genetic environment. For most derivatives, penicillinase activity was 10% or less than that of strains making TEM-1, TEM-2, or SHV-1 beta-lactamase, suggesting that reduced catalytic efficiency accompanied the broader substrate spectrum. Despite this deficit, resistance to aztreonam, carumonam, cefdinir, cefepime, cefixime, cefmenoxime, cefotaxime, cefotiam, cefpirome, cefpodoxime, ceftazidime, ceftibuten, ceftizoxime, ceftriaxone, cefuroxime, and E1040 was enhanced. For strains producing TEM-type enzymes, however, MICs of carumonam, cefepime, cefmenoxime, cefotiam, cefpirome, and ceftibuten were 8 micrograms/ml or less. Susceptibilities of cefmetazole, cefotetan, cefoxitin, flomoxef, imipenem, meropenem, moxalactam, temocillin, FCE 22101, and Sch 34343 were unaffected. FCE 22101, imipenem, meropenem, and Sch 34343 were inhibitory for all strains at 1 microgram/ml or less. In E. coli an OmpF- porin mutation in combination with an extended-spectrum beta-lactamase enhanced resistance to many of these agents, but generally by only fourfold. Hyperproduction of chromosomal AmpC beta-lactamase increased resistance to 7-alpha-methoxy beta-lactams but not that to temocillin. When tested at 8 micrograms/ml, clavulanate was more potent than sulbactam or tazobactam in overcoming resistance to ampicillin, while cefoperazone-sulbactam was more active than ticarcillin-clavulanate or piperacillin-tazobactam, especially against TEM-type extended-spectrum beta-lactamases. PMID:2193623

  6. The non-enzymatic inactivation of thirteen beta-lactam antibiotics in human faeces

    NARCIS (Netherlands)

    Jansen, G; Weissing, F; de Vries-Hospers, H; Tonk, R; van der Waaij, D

    1992-01-01

    In order to obtain a method that could predict the in vitro inactivation of an antibiotic in the digestive tract, the non-enzymatic inactivation of 13 beta-lactam antibiotics by human faeces was investigated. Benzylpenicillin, amoxicillin, amoxicillin/clavulanate, cloxacillin, piperacillin, temocill

  7. 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

  8. NADPH-dependent glutamate dehydrogenase in Penicillium chrysogenum is involved in regulation of beta-lactam production

    DEFF Research Database (Denmark)

    Thykær, Jette; Kildegaard, Kanchana Rueksomtawin; Noorman, H.; Nielsen, Jens

    2008-01-01

    The interactions between the ammonium assimilatory pathways and beta-lactam production were investigated by disruption of the NADPH-dependent glutamate dehydrogenase gene (gdhA) in two industrial beta-lactam-producing strains of Penicillium chrysogenum. The strains used were an adipoyl-7-ADCA- an...... results indicate that the NADPH-dependent glutamate dehydrogenase may be directly or indirectly involved in the regulation of beta-lactann production in industrial strains of P. chrysogenum....

  9. Correlation of pharmacodynamic parameters of five beta-lactam antibiotics with therapeutic efficacies in an animal model.

    OpenAIRE

    Soriano, F; García-Corbeira, P; Ponte, C; Fernández-Roblas, R.; Gadea, I.

    1996-01-01

    The MIC is the main microbiologic parameter used to predict the efficacies of antibiotics. However, it is well known that MICs may vary according to the inoculum size used (inoculum effect), especially with some beta-lactam antibiotics. In order to correlate the pharmacologic and microbiologic properties of some beta-lactams, an experimental model of intraperitoneal infection caused by Escherichia coli in nonneutropenic and neutro-penic mice was developed. The animals were treated with three ...

  10. Susceptibility of Nocardia asteroides to 46 antibiotics, including 22 beta-lactams.

    OpenAIRE

    Gutmann, L; Goldstein, F W; Kitzis, M D; Hautefort, B; Darmon, C; Acar, J F

    1983-01-01

    Twelve Nocardia asteroides isolates were tested for their susceptibility to 46 antibiotics by the agar dilution method. N-Formimidoyl thienamycin was the most active of 22 beta-lactam antibiotics, inhibiting 11 of the 12 strains at 1 microgram/ml. Penicillins, including ureidopenicillins, showed poor activity. Cefotaxime, ceftriaxone, and especially cefuroxime had the best activities of the cephalosporins tested. Among the other antibiotics, amikacin and minocycline, respectively, inhibited a...

  11. Activity of beta-lactam beta-lactamase inhibitor combinations against extended spectrum beta-lactamase producing enterobacteriaceae in urinary isolates

    International Nuclear Information System (INIS)

    Objective: To determine the susceptibility pattern of beta-lactam beta-lactamase inhibitor combinations against extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae in urinary isolates. Study Design: Observational study. Place and Duration of Study: Ziauddin University Hospital, Karachi, from February to October 2008. Methodology: A total of 190 consecutive non-duplicate isolates of ESBL producing Enterobacteriaceae from urine samples of in-patients were included in the study. Urinary samples from out-patients, repeat samples and non-ESBL producing isolates were excluded. Detection of ESBL was carried out by double disk diffusion technique. Antimicrobial susceptibility testing was performed using modified Kirby Bauer's disk diffusion method according to CLSI guidelines. Statistical analysis was performed by SPSS version 10. Results: Of the 190 ESBL isolates tested, 88 cases (46.31%) were sensitive and 6 cases (3.15%) were resistant to all three combinations, the rest 96 cases (50.52%) were resistant to at least one of the combinations. Susceptibility pattern of cefoperazone/sulbactam, piperacillin/tazobactam, and amoxicillin/clavulanic acid was 95.26, 92.10, and 44.31 percent respectively. Conclusion: Cefoperazone/sulbactam exhibited the best activity against ESBL producing Enterobacteriaceae followed by piperacillin/tazobactam. Hospital antibiotic policies should be reviewed periodically to reduce the usage of extended spectrum cephalosporins and replace them with beta-lactam beta-lactamase inhibitor combinations agent for treating urinary tract infections. (author)

  12. [Strict anaerobic bacteria: comparative study of various beta-lactam antibiotics in combination with tazobactam or sulbactam].

    Science.gov (United States)

    Dubreuil, L; Sedallian, A

    1991-05-01

    The minimal inhibitory concentrations of piperacillin (PIP) or cefotaxime (CTX) alone or in combination with tazobactam (TAZ) were determined against 168 anaerobes. All the strains were inhibited by PIP + TAZ, but certain strains resistant to CTX + TAZ were found among B. fragilis, Eubacterium and Peptostreptococcus. The second investigations included 30 strains of Bacteroides fragilis. Concentrations of 2, 4 and 8 mg/l of TAZ and sulbactam (SUL) were combined with piperacillin or cefotaxime. The two beta-lactamase-inhibitors had similar activities when used at 2 or 4 mg/l, but at 8 mg/l TAZ was more active than SUL. All B. fragilis strains were inhibited by PIP + TAZ or PIP + SUL, whereas resistance was observed with CTX + SUL or CTX + TAZ. On the same strains the activities of 6 beta-lactams (PIP, mezlocillin, ticarcillin (TIC), CTX, ceftriaxone and ceftazidime) were determined in combination with either SUL 4 mg/l or TAZ 8 mg/l. Only PIP or TIC + SUL or TAZ were able to inhibit at least 90% of tested strains. No resistance could be detected with PIP + TAZ combination. As conclusion, the two inhibitors when combined with PIP or TIC offered greater activity against both Gram positive or negative anaerobes and PIP + TAZ remained the more potent combination. PMID:1652729

  13. [Bases of the antibacterial effect of beta lactam antibiotics].

    Science.gov (United States)

    Hof, H

    1991-12-01

    The primary antibacterial effect of betalactam antibiotics is due to the inhibition of cell-wall synthesis. Prerequisites for good antibacterial activity of such an antibiotic are --rapid penetration across the bacterial cell wall, --strong binding to the proper targets in the cytoplasmic membrane, i.e. the penicillin-binding proteins, --resistance to betalactamases which may be produced by the bacterial cell. PMID:1802833

  14. Beta lactam antibiotics residues in cow's milk: comparison of efficacy of three screening tests used in Bosnia and Herzegovina

    Directory of Open Access Journals (Sweden)

    Nihad Fejzic

    2014-08-01

    Full Text Available Beta lactam antibiotics are widely used in therapy of cattle, particularly for the treatment of mastitis.  Over 95% of residue testing in dairies in Bosnia and Herzegovina is for Beta lactams. The aim of this paper is to compare the efficacy of three most common screening tests for Beta lactam residues in cow’s milk in our country. The tests used in the study are SNAP β Lactam test (Idexx, Rosa Charm β Lactam test and Inhibition MRL test. Study samples included: standardized concentrations of penicillin solution (0, 2, 3, 4, 5 and 6 ppb. In addition we tested milk samples from three equal size study groups (not receiving any antibiotic therapy, treated with Beta lactams for mastitis and treated with Beta lactams for diseases other than mastitis. Sensitivity and specificity were determined for each test, using standard penicillin concentrations with threshold value set at concentration of 4 ppb (Maximum residue level – MLR. Additionally we determined proportions of presumably false negative and false positive results for each test using results of filed samples testing. Agreement of test results for each test pair was assessed through Kappa coefficients interpreted by Landis-Koch scale. Detection level of all tests was shown to be well below MRL. This alongside with effects of natural inhibitors in milk contributed to finding of positive results in untreated and treated animals after the withholding period. Screening tests for beta lactam residues are important tools for ensuring that milk for human consumption is free from antibiotics residues.

  15. Activities of oral and parenteral agents against penicillin-susceptible and -resistant pneumococci.

    OpenAIRE

    Pankuch, G A; Visalli, M A; Jacobs, M. R.; Appelbaum, P C

    1995-01-01

    This study examined bacteriostatic and bactericidal activities of oral and parenteral antibiotics for penicillin-susceptible and intermediately and fully penicillin-resistant pneumococci. beta-Lactamase inhibitors did not affect beta-lactam results. The activities of ampicillin, amoxicillin +/- clavulanate, WY-49605, cefuroxime, cefpodoxime, cefdinir, cefixime, and cefaclor against two penicillin-susceptible, two intermediately penicillin-resistant, and two fully penicillin-resistant pneumoco...

  16. Kinetics of enzyme acylation and deacylation in the penicillin acylase-catalyzed synthesis of beta-lactam antibiotics

    NARCIS (Netherlands)

    Alkema, WBL; de Vries, E; Floris, R; Janssen, DB

    2003-01-01

    Penicillin acylase catalyses the hydrolysis and synthesis of semisynthetic beta-lactam antibiotics via formation of a covalent acyl-enzyme intermediate. The kinetic and mechanistic aspects of these reactions were studied. Stopped-flow experiments with the penicillin and ampicillin analogues 2-nitro-

  17. Analysis of 12 beta-lactam antibiotics in human plasma by HPLC with ultraviolet detection.

    Science.gov (United States)

    McWhinney, Brett C; Wallis, Steven C; Hillister, Tara; Roberts, Jason A; Lipman, Jeffrey; Ungerer, Jacobus P J

    2010-07-15

    A simple and economical high performance liquid chromatography method was developed and validated for routine analysis of 12 Penicillin, Cephalosporin and Carbapenem antibiotics in 200 microL of human plasma. Antibiotics determined were Ceftazidime, Meropenem, Ceftriaxone, Ampicillin, Cefazolin, Ertapenem, Cephalothin, Benzylpenicillin, Flucloxacillin, Dicloxacillin, Piperacillin and Ticarcillin. There was a common sample preparation approach involving precipitation of proteins with acetonitrile and removal of lipid-soluble components by a chloroform wash. Separations were performed on a Waters X-bridge C18 column with, depending on analytes, one of three acetonitrile-phosphate buffer mobile phases. Detection was by UV at 210, 260 and 304 nm. Validation has demonstrated the method to be linear, accurate and precise. The method has been used in a pathology laboratory for therapeutic drug monitoring (TDM) of beta-lactams in critically ill patients. PMID:20561826

  18. Mechanism of inhibition of human leucocyte elastase by beta-lactams. 2. Stability, reactivation kinetics, and products of beta-lactam-derived E-I complexes.

    Science.gov (United States)

    Green, B G; Chabin, R; Mills, S; Underwood, D J; Shah, S K; Kuo, D; Gale, P; Maycock, A L; Liesch, J; Burgey, C S

    1995-11-01

    The monocyclic beta-lactams reported by Knight et al. [Knight, W. B., et al. (1992) Biochemistry 31, 8160; Chabin, R., et al. (1993) Biochemistry 32, 8970] as inhibitors of human leucocyte elastase (HLE) produce stable HLE-inhibitor complexes that slowly reactivate with half-lives ranging from less than 1 to 15 h at 37 degrees C. The complexes produced between PPE and two C-3 dimethyl-substituted beta-lactams are less stable than those produced between HLE and analogous C-3 diethyl-substituted lactams. The stability of the HLE-I complexes is governed primarily by the structure of the substituted urea portion of the inhibitors and not by the identity or presence of a leaving group at C-4 of the lactam ring. In some cases substitutions on the urea portion of the inhibitors yielded complexes that displayed biphasic reactivation kinetics. This suggests the presence of at least two different complexes. The stereochemistry of the leaving group at C-4 has a small effect on the stability of the final complex (1.3-2-fold); therefore, the identity of the final complex is dependent upon the initial stereochemistry at that position. The stability of the complexes was relatively insensitive to hydroxylamine, which suggests that the acyl-enzymes are protected from nucleophilic "rescue". The rate of reactivation of the complex derived from L-680,833,[S-R*,S*)]-4-[(1-(((1-(4- methylphenyl)butyl)amino)carbonyl)-3,3-diethyl-2-oxo-4-azetidinyl)ben zeneacetic acid, was pH independent, while the L-684,481, (R)-(1-(((1-(4-methylphenyl)butyl)amino)carbonyl)-3,3-diethyl-2-azeti din one generated complex displayed a pH-dependent reactivation rate. In the latter case, the increase in reactivation rate with pH displayed a pKa of 7.2. This is consistent with the requirement for base catalysis by the active site histidine to regenerate enzymatic activity. Reactivation of the L-680,833-derived complex produced different products as a function of pH, suggesting two different pH-dependent routes

  19. Antibacterial and toxicological evaluation of beta-lactams synthesized by immobilized beta-lactamase-free penicillin amidase produced by Alcaligenes sp.

    Science.gov (United States)

    Gayen, Jiaur R; Majee, Sutapa B; Das, Shuvendu; Samanta, Timir B

    2007-12-01

    Search for anti-beta-lactamase and synthesis of newer penicillin were suggested to overcome resistance to penicillin in chemotherapy. It was found that clavulanic acid, an ant-beta-lactamase was ineffective due to its structural modification by bacteria. Thus, there is a need for the synthesis of newer pencillins. Retro-synthesis was inspired by the success of forward reaction i.e.conversion of penicillin G to 6-aminopenicillanic acid (6-APA) by biological process. In the present study a better enzymatic method of synthesis of newer pencillin by a beta-lactamase-free penicillin amidase produced by Alcaligenes sp. is attempted. Antibacterial and toxicological evaluation of the enzymatically synthesized beta-lactams are reported. Condensation of 6-APA with acyl donor was found to be effective when the reaction is run in dimethyl formamide (DMF 50% v/v) in acetate buffer (25 mM pH 5.0) at 37 degrees C. Periplasm entrapped in calcium alginate exihibited the highest yield (approximately 34%) in synthesis. The minimum inhibitory concentration of the synthetic products against Staphylococcus aureus and Salmonella typhi varied between 20-80 microg/ml. Some of the products exhibited antibacterial activity against enteric pathogens. It was interesting to note that product A was potent like penicillin G. LD50 value of three products (product A, B and C) was more than 12 mg/kg. Furthermore, these synthetic beta-lactams did not exihibit any adverse effect on house keeping enzymes viz., serum glutamate oxalacetate-trans-aminase, serum glutamate pyruvate -trans-aminase, acid phosphatase, alkaline phosphatase of the test animals. The hematological profile (RBC and WBC) of the test animals also remained unaffected. PMID:18254214

  20. Assessment of a self-designed protocol on patients with adverse reactions to beta-lactam antibiotics.

    Science.gov (United States)

    González, J; Guerra, F; Moreno, C; Miguel, R; Daza, J C; Sánchez Guijo, P

    1992-01-01

    Suspected adverse reactions to beta-lactam antibiotics are the most frequent reason for consultation in relation WMH drug allergy. Because of their therapeutical usefulness and wide use, we developed a protocol for confirmation or exclusion of this type of allergy. The proposed protocol is based on clinical, causal and laboratory criteria that are used to assign scores from 0 to 9 points. Patients with scores between 0 and 3 are considered to be highly prone to beta-lactam antibiotic allergy and are given an alternative therapy that is selected by applying skin provocation tests (SPT). Those with a score of 9 points are excluded. Finally, those with scores between 4 and 8 are subjected to skin tests with 5 antigens (penicillin G, ampicillin, cephalothin, Penkit PPL and Penkit MDM); if they give negative results they are subsequently subjected to oral provocation with beta-lactam antibiotics. In this work we report the results obtained from 150 patients analysed for 28 variables altogether. The results allowed us to rule out adverse reactions in 94 patients. Only 9 individuals yielded positive skin tests, and only one gave a positive oral provocation (bronchospasm, 6 hours after subjection to the test). The usefulness of the proposed protocol, the profitability of the test applied and the mechanisms involved are assessed. PMID:1292326

  1. Validation study of the BetaStar plus lateral flow assay for detection of beta-lactam antibiotics in milk.

    Science.gov (United States)

    Abouzied, Mohamed; Driksna, Dana; Walsh, Coilin; Sarzynski, Michael; Walsh, Aaron; Ankrapp, David; Klein, Frank; Rice, Jennifer; Mozola, Mark

    2012-01-01

    A validation study designed to meet the requirements of the AOAC Research Institute and the U.S. Food and Drug Administration, Center for Veterinary Medicine (FDA/CVM) was conducted for a receptor and antibody-based, immunochromatographic method (BetaStar Plus) for detection of beta-lactam antibiotic residues in raw, commingled bovine milk. The assay was found to detect amoxicillin, ampicillin, ceftiofur, cephapirin, cloxacillin, and penicillin G at levels below the FDA tolerance/safe levels, but above the maximum sensitivity thresholds established by the National Conference on Interstate Milk Shipments (NCIMS). Results of the part I (internal) and part II (independent laboratory) dose-response studies employing spiked samples were in close agreement. The test was able to detect all six drugs at the approximate 90/95% sensitivity levels when presented as incurred residues in milk collected from cows that had been treated with the specific drug. Selectivity of the assay was 100%, as no false-positive results were obtained in testing of 1031 control milk samples. Results of ruggedness experiments established the operating parameter tolerances for the BetaStar Plus assay. Results of cross-reactivity testing established that the assay detects certain other beta-lactam drugs (dicloxacillin and ticarcillin), but it does not cross-react with any of 30 drugs belonging to other classes. Abnormally high bacterial or somatic cell counts in raw milk produced no interference with the ability of the test to detect beta-lactams at tolerance/safe levels. PMID:22970593

  2. Validation study of a receptor-based lateral flow assay for detection of beta-lactam antibiotics in milk.

    Science.gov (United States)

    Abouzied, Mohamed; Sarzynski, Michael; Walsh, Aaron; Wood, Heather; Mozola, Mark

    2009-01-01

    A validation study designed to meet the requirements of the AOAC Research Institute and the U.S. Food and Drug Administration (FDA), Center for Veterinary Medicine, was conducted for a receptor-based, immunochromatographic method (BetaStar US) for detection of beta-lactam antibiotic residues in raw, commingled bovine milk. The assay was found to detect amoxicillin, ampicillin, cephapirin, cloxacillin, and penicillin G at levels below the FDA tolerance/safe levels but above the maximum sensitivity thresholds established by the National Conference on Interstate Milk Shipments. Results of the Part I (internal) and Part II (independent laboratory) dose-response studies using spiked samples were in very close agreement for all five drugs tested, with differences between the Part I and Part II 90/95% sensitivity values ranging from 0 to 1 ppb. The test was able to detect all five drugs at the approximate 90/95% sensitivity levels when present as incurred residues in milk collected from cows that had been treated with the specific drug. A sixth drug, ceftiofur, was found to be undetectable at levels of 1000 control milk samples. The assay was found to be applicable to the testing of frozen raw milk samples. Results of ruggedness experiments established the operating parameter tolerances for the BetaStar US assay. Results of cross-reactivity testing established that the assay detects certain other beta-lactam drugs (dicloxacillin and ticarcillin), but it does not cross-react with any of 30 drugs belonging to other classes. Abnormally high bacterial or somatic cell counts in raw milk produced no interference with the ability of the test to detect beta-lactams at tolerance/safe levels. PMID:19610391

  3. {beta}-Lactam antibiotics epitope mapping with STD NMR spectroscopy: a study of drug-human serum albumin interaction

    Energy Technology Data Exchange (ETDEWEB)

    Milagre, Cintia D. F.; Cabeca, Luis F.; Almeida, Wanda P.; Marsaioli, Anita J., E-mail: cmilagre@rc.unesp.br [Institute of Chemistry, University of Campinas (UNICAMP), SP (Brazil)

    2012-03-15

    Molecular recognition events are key issues in many biological processes. STD NMR (saturation transfer difference nuclear magnetic resonance spectroscopy) is one of the techniques used to understand such biological interactions. Herein, we have investigated the interactions of four {beta}-lactam antibiotics belonging to two classes (cephalosporins and penicillins) with human serum albumin (HSA) by {sup 1}H STD NMR revealing that the interaction between the aromatic moiety and HSA is responsible for the binding efficiency. Thus, the structural differences from the five to six-membered thio ring in penicillins and cephalosporins do not seem to influence antibiotic albumin interactions. (author)

  4. Detection limits of four antimicrobial residue screening tests for beta-lactams in goat's milk.

    Science.gov (United States)

    Sierra, D; Sánchez, A; Contreras, A; Luengo, C; Corrales, J C; Morales, C T; de la Fe, C; Guirao, I; Gonzalo, C

    2009-08-01

    This study was conducted to compare the detection limits (DL) of several antibiotic residue screening tests with the maximum residue limits (MRL) authorized by the EU according to the guidance for the standardized evaluation of microbial inhibitor tests of the International Dairy Federation. Composite antibiotic-free milk samples from 30 primiparous Murciano-Granadina goats in good health condition were used to prepare test samples spiked with different concentrations of each antimicrobial. In total, 5,760 analytical determinations of 10 beta-lactam antibiotics (penicillin-G, ampicillin, amoxicillin, cloxacillin, oxacillin, dicloxacillin, cefadroxyl, cefalexin, cefoperazone, and cefuroxime) were performed using 4 antibiotic residue screening tests: the brilliant black reduction test BRT AiM (AiM-Analytik in Milch Produktions-und Vertriebs GmbH, München, Germany), Delvotest MCS (DSM Food Specialties, Delft, the Netherlands), Eclipse 100 (ZEU-Inmunotec SL, Zaragoza, Spain), and the Copan Milk Test (CMT; Copan Italia SpA, Brescia, Italy). For each method, we estimated the detection limits of the antimicrobial agents using a logistic regression model. Using the CMT and Delvotest on samples spiked with the 8 antibiotics for which MRL were available, DL were at or below the MRL. The BRT test provided DL at or below the MRL for all of the agents except cefalexin, whereas the Eclipse 100 method failed to detect 4 antibiotics (ampicillin, amoxicillin, cloxacillin, and cefoperazone) at MRL or below. Logistic regression-determined levels of agreement were highest for the CMT method (98.6 to 100%) and lowest for Eclipse 100 (66.3 to 100%). In general, agreement levels indicated good correlation between observed results and those predicted by logistic regression. The lowest b values (closely related to test sensitivity) were recorded for the cephalosporins (0.074 to 0.430) and highest for penicillin G, ampicillin, and amoxicillin (11.270 to 11.504). Delvotest and CMT best

  5. Comparison of the activity of imipenem and beta-lactams combined with sulbactam and clavulanic acid in beta-lactamase-producing strains of Bacteroides fragilis.

    Science.gov (United States)

    Martín, M A; Castillo, A M; Liébana, J; Marín, A; Alados, J C; Piédrola, G

    1991-01-01

    We compared the "in vitro" activity of imipenem with 14 beta-lactams, both alone and in combination with clavulanic acid, and sulbactam against 110 beta-lactamase-producing strains of Bacteroides fragilis. The following antibiotics were tested: amoxycillin, penicillin, mezlocillin, piperacillin, cephalothin, cephazolin, cefamandole, cefmetazole, cefonicid, cefoxitin, cefotaxime, ceftazidime, ceftizoxime, and ceftriaxone. In all cases, except those of cefoxitin and cefmetazole, these combinations showed a statistically significant increase in beta-lactam activity, which was, however, never higher than that of imipenem, the antibiotic which performed best against Bacteroides fragilis. PMID:1940333

  6. Determination of Beta-Lactam residues in milk by high performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    Roseane Brandão de Brito

    2006-01-01

    Full Text Available A high performance liquid chromatographic method to assay beta-lactam residues in milk was developed and validated. Milk samples were spiked with standard solutions and deproteinated. The extract was cleaned-up on C18 SPE cartridge, the antibiotics eluted with acetonitrile:water (50:50 v/v and derivatized with acetic anhydride and 1-methyl-imidazole solution containing HgCl2. The chromatographic analysis was performed on C18 column using mobile phase consisting of acetonitrile and phosphate buffer (pH 6.5 in the presence of Na2S2O3 gradient and detection at 325 nm. The method was selective for ampicillin, penicillin G and penicillin V, the latter used as internal standard. Average recoveries for ampicillin and penicillin G ranged, respectively, from 60.0% to 104.9% and from 82.7% to 109.2%, with coefficients of variation from 11.1% to 24.6%, and from 2.1% to 25.2%, indicating accuracy and precision. Detection limit of 4.0 µg/L for ampicillin and 3.0 µg/L for penicillin G, and quantification limits of 4.0 µg/L for both were estimated.Um método para determinar resíduos de antibióticos beta-lactâmicos em leite por cromatografia líquida de alta eficiência (CLAE foi desenvolvido e validado. Amostras brancas foram adicionadas de padrão e desproteinizadas. O extrato foi purificado por extração em fase sólida C18, os antibióticos eluídos com acetonitrila:água (50:50 v/v e posteriormente derivatizados com anidrido acético e solução de 1-metil-imidazol contendo HgCl2. A análise cromatográfica foi realizada utilizando coluna C18, fase móvel composta por acetonitrila e tampão fosfato pH 6,5, na presença de Na2S2O3 em gradiente e detecção a 325 nm. O método foi seletivo para ampicilina, penicilina G e penicilina V, sendo este último utilizado como padrão interno. As médias de recuperação para ampicilina e penicilina G situaram-se, respectivamente, na faixa de 60,0% a 104,9% e de 82,7% a 109,2%, com coeficientes de varia

  7. Penicillin G acylase from Achromobacter sp CCM 4824 An efficient biocatalyst for syntheses of beta-lactam antibiotics under conditions employed in large-scale processes

    Czech Academy of Sciences Publication Activity Database

    Bečka, Stanislav; Štěpánek, Václav; Vyasarayani, W. R.; Grulich, Michal; Maršálek, Jaroslav; Plháčková, Kamila; Dobišová, Marie; Marešová, Helena; Plačková, Martina; Valešová, Renata; Palyzová, Andrea; Datla, A.; Ashar, T. K.; Kyslík, Pavel

    2014-01-01

    Roč. 98, č. 3 (2014), s. 1195-1203. ISSN 0175-7598 Institutional support: RVO:61388971 Keywords : Achromobacter sp. * Penicillin G acylase * beta-Lactam antibiotics Subject RIV: EE - Microbiology, Virology Impact factor: 3.337, year: 2014

  8. Type 1 Ig-E mediated allergy to human insulin, insulin analogues and beta-lactam antibiotics*

    Science.gov (United States)

    Andrade, Pedro; Barros, Luísa; Gonçalo, Margarida

    2012-01-01

    Insulin, a crucial therapeutic agent for diabetes mellitus, has been rarely associated with hypersensitivity events. We present a 69-year-old type-2 diabetic patient with urticariform lesions on the sites of subcutaneous injection of insulin. The patient denied any known allergies, except for an unspecific cutaneous reaction after intramuscular penicillin administration in childhood. Prick tests revealed positive reactions to all tested human insulins and insulin analogues. Serum IgE levels were above normal range and RAST tests were positive for human, bovine and porcine insulins, as well as beta-lactams. Type 1 IgE-mediated allergy to insulin analogues demands a prompt diagnosis and represents a significant therapeutic challenge in diabetic patients. PMID:23197216

  9. Augmented renal clearance in critically ill patients: etiology, definition and implications for beta-lactam dose optimization.

    Science.gov (United States)

    Sime, Fekade Bruck; Udy, Andrew A; Roberts, Jason A

    2015-10-01

    The renal clearance of antibiotics may be elevated in some critically ill patients. This paper reviews this recently described phenomenon, referred to as augmented renal clearance (ARC). ARC is considered to be driven by pathophysiological elevation of glomerular filtration, and is defined as a creatinine clearance >130mL/min/173m(2). This in turn promotes very low antibiotic concentrations. This effect may lead to adverse clinical outcomes, particularly with beta-lactam antibiotics, as they require prolonged exposure for optimal antibacterial activity. The use of extended or continuous infusions is an effective strategy to improve exposure. However, because the effect of ARC is potentially quite variable, regular therapeutic drug monitoring (TDM) may be necessary to ensure all patients achieve effective concentrations. PMID:26119486

  10. Beta-Lactam Antibiotics as A Possible Novel Therapy for Managing Epilepsy and Autism, A Case Report and Review of Literature

    Directory of Open Access Journals (Sweden)

    Ahmed GHANIZADEH*

    2015-01-01

    Full Text Available How to Cite This Article: Ghanizadeh A, Berk M. Beta-Lactam Antibiotics as A Possible Novel Therapy for Managing Epilepsy and Autism, A Case Report and Review of Literature. Iran J Child Neurol. 2015 Winter;9(1:99-102.AbstractAutism is a disorder of unknown etiology. There are few FDA approved medications for treating autism. Co-occurring autism and epilepsy is common, and glutamate antagonists improve some symptoms of autism. Ceftriaxone, a beta-lactam antibiotic, increases the expression of the glutamate transporter 1 which decreases extracellular glutamate levels. It is hypothesized that modulating astrocyte glutamate transporter expression by ceftriaxone or cefixime might improve some symptoms of autism. This case report of a child with autism and epilepsy suggests a decrease in seizures after taking cefixime.References Selassie AW, Wilson DA, Martz GU, Smith GG, Wagner JL, Wannamaker BB. Epilepsy beyond seizure: a population-based study of comorbidities. Epilepsy Res 2014;108(2: 305-315.Sansa G, Carlson C, Doyle W, Weiner HL, Bluvstein, Barr W, et al. Medically refractory epilepsy in autism. Epilepsia 2011; 52(6: 1071-1075.Ghanizadeh A. Increased glutamate and homocysteine and decreased glutamine levels in autism: a review and strategies for future studies of amino acids in autism. Dis Markers; 2013;35(5: 281-286.Yamada T, Kawahara K, Kosugi T, Tanaka M.Nitric oxide produced during sublethal ischemia is crucial for the preconditioning-induced down-regulation of glutamate transporter GLT-1 in neuron/astrocyte co-cultures. Neurochem Res 2006:31(1: 49-56.Zeng, LH, Ouyang Y, Gazit V, Cirrito JR, Jansen LA, Ess KC, et al. Abnormal glutamate homeostasis and impaired synaptic plasticity and learning in a mouse model of tuberous sclerosis complex. Neurobiol Dis 2007; 28(2: 184-196.Zeng LH, Bero AW, Zhang B, Holtzman D. M. , Wong M. Modulation of astrocyte glutamate transporters decreases seizures in a mouse model of Tuberous Sclerosis Complex

  11. Effects of beta-lactam antibiotics on peptidoglycan synthesis in growing Neisseria gonorrhoeae, including changes in the degree of O-acetylation.

    OpenAIRE

    Blundell, J K; Perkins, H. R.

    1981-01-01

    Low concentrations of beta-lactam antibiotics caused an increased uptake of radioactive glucosamine into the sodium dodecyl sulfate-insoluble peptidoglycan of growing Neisseria gonorrhoeae. There was no appreciable change in the (small) amount of sodium dodecyl sulfate-soluble polymer present in the cultures. The sodium dodecyl sulfate-insoluble product in control cells was only partially dissolved by egg-white lysozyme (about 40%), but could all be released by the Chalaropsis B muramidase. I...

  12. Use of the chromosomal class A beta-lactamase of Mycobacterium fortuitum D316 to study potentially poor substrates and inhibitory beta-lactam compounds.

    OpenAIRE

    Galleni, M; Franceschini, N; Quinting, B; Fattorini, L.; Orefici, G.; Oratore, A; Frère, J M; Amicosante, G

    1994-01-01

    Sixteen different compounds usually considered beta-lactamase stable or representing potential beta-lactam inhibitors and inactivators were tested against the beta-lactamase produced by Mycobacterium fortuitum. The compounds exhibiting the most interesting properties were BRL42715, which was by far the best inactivator, and CGP31608 and ceftazidime, which were not recognized by the enzyme. These compounds thus exhibited adequate properties for fighting mycobacterial infections. Although cloxa...

  13. Trace determination of 10 beta-lactam antibiotics in environmental and food samples by capillary liquid chromatography.

    Science.gov (United States)

    Bailón-Pérez, M I; García-Campaña, A M; del Olmo-Iruela, M; Gámiz-Gracia, L; Cruces-Blanco, C

    2009-11-20

    A sensitive and reliable method using capillary HPLC with UV-diode array detection (DAD) has been developed and validated for the trace determination of residues of 10 beta-lactam antibiotics of human and veterinary use, in milk, chicken meat and environmental water samples. The analytes included ampicillin, amoxicillin, penicillin V, penicillin G, cloxacillin, oxacillin, dicloxacillin, nafcillin, piperacillin and clavulanic acid. Legal levels are regulated by the EU Council regulation 2377/90 in animal edible tissues for these compounds. For food analysis, a solid-phase extraction (SPE) procedure consisting in a tandem of Oasis HLB and Alumina N cartridges was applied for off-line preconcentration and cleanup. For water analysis, the first step was only necessary. The limits of detection for the studied compounds were between 0.04-0.06 microg l(-1) for water samples and 0.80-1.40 microg l(-1) (or microg kg(-1)) in the case of foods derived from animals. Average recoveries for fortified samples at different concentration levels ranged between 82.9% and 98.2%, with relative standard deviations (RSDs) lower than 9%. The method showed the advantages of capillary HPLC for the detection of these widely applied antibiotics in different samples at very low concentration levels. PMID:19836022

  14. Molecular Characterization of Carbapenemases and Quinolone Resistance Determining Region Enzymes-Producing Isolates in an Outbreak at the University Hospital of Leipzig

    OpenAIRE

    Al Qasem, Hala

    2014-01-01

    Beta lactam resistance producing isolates of Enterobacteriacea and non-Enterobacteriacea have emerged since more than seventy years ago (Abraham and Chain, 1940). They are known to cause both community and hospital-acquired infections. Resistance against carbapenem is primarily mediated by the production of enzymes that destroy the beta lactam antimicrobials, which are produced by these isolates involving the expression of serine and metalobetalactamase genes KPC, IMP, VIM, NDM-1 and OXA-48. ...

  15. Ceftriaxone, a Beta-Lactam Antibiotic, Reduces Ethanol Consumption in Alcohol-Preferring Rats

    OpenAIRE

    Sari, Youssef; Sakai, Makiko; Weedman, Jason M.; Rebec, George V.; Bell, Richard L.

    2011-01-01

    Aims: Changes in glutamatergic transmission affect many aspects of neuroplasticity associated with ethanol and drug addiction. For instance, ethanol- and drug-seeking behavior is promoted by increased glutamate transmission in key regions of the motive circuit. We hypothesized that because glutamate transporter 1 (GLT1) is responsible for the removal of most extracellular glutamate, up-regulation or activation of GLT1 would attenuate ethanol consumption. Methods: Alcohol-preferring (P) rats w...

  16. The KPC type beta-lactamases: new enzymes that confer resistance to carbapenems in Gram-negative bacilli.

    OpenAIRE

    Piotr Wieczorek; Jadwiga Jaworowska; Alina Ostas; Paweł Sacha; Dominika Ojdana; Jerzy Ratajczak; Elzbieta Tryniszewska

    2010-01-01

    Antimicrobial resistance due to the continuous selective pressure from widespread use of antimicrobials in humans, animals and agriculture has been a growing problem for last decades. KPC beta-lactamases hydrolyzed beta-lactams of all classes. Especially, carbapenem antibiotics are hydrolyzed more efficiency than other beta-lactam antibiotics. The KPC enzymes are found most often in Enterobacteriaceae. Recently, these enzymes have been found in isolates of Pseudomonas aeruginosa and Acinetoba...

  17. Beta-lactam induction of ISEcp1B-mediated mobilization of the naturally occurring bla(CTX-M) beta-lactamase gene of Kluyvera ascorbata.

    OpenAIRE

    Nordmann, Patrice; Lartigue, Marie-Frédérique; Poirel, Laurent

    2008-01-01

    ISEcp1B is an insertion element associated with the emerging expanded-spectrum beta-lactamase bla(CTX-M) genes in Enterobacteriaceae. Because ISEcp1B-bla(CTX-M)positive strains may be identified from humans and animals, the ability of this insertion sequence to mobilize the bla(CTX-M-2) gene was tested from its progenitor Kluyvera ascorbata to study the effects of amoxicillin/clavulanic and cefquinome as enhancers of transposition. These beta-lactam molecules are administered parenterally to ...

  18. Beta-Lactam Antibiotics as A Possible Novel Therapy for Managing Epilepsy and Autism, A Case Report and Review of Literature

    Science.gov (United States)

    GHANIZADEH, Ahmad; BERK, Michael

    2015-01-01

    Autism is a disorder of unknown etiology. There are few FDA approved medications for treating autism. Co-occurring autism and epilepsy is common, and glutamate antagonists improve some symptoms of autism. Ceftriaxone, a beta-lactam antibiotic, increases the expression of the glutamate transporter 1 which decreases extracellular glutamate levels. It is hypothesized that modulating astrocyte glutamate transporter expression by ceftriaxone or cefixime might improve some symptoms of autism. This case report of a child with autism and epilepsy suggests a decrease in seizures after taking cefixime PMID:25767546

  19. Beta-lactam antibiotics as a possible novel therapy for managing epilepsy and autism, a case report and review of literature.

    Science.gov (United States)

    Ghanizadeh, Ahmad; Berk, Michael

    2015-01-01

    Autism is a disorder of unknown etiology. There are few FDA approved medications for treating autism. Co-occurring autism and epilepsy is common, and glutamate antagonists improve some symptoms of autism. Ceftriaxone, a beta-lactam antibiotic, increases the expression of the glutamate transporter 1 which decreases extracellular glutamate levels. It is hypothesized that modulating astrocyte glutamate transporter expression by ceftriaxone or cefixime might improve some symptoms of autism. This case report of a child with autism and epilepsy suggests a decrease in seizures after taking cefixime. PMID:25767546

  20. A method for determining the free (unbound) concentration of ten beta-lactam antibiotics in human plasma using high performance liquid chromatography with ultraviolet detection.

    Science.gov (United States)

    Briscoe, Scott E; McWhinney, Brett C; Lipman, Jeffrey; Roberts, Jason A; Ungerer, Jacobus P J

    2012-10-15

    With the clinical imperative to further research in the area of optimising antibiotic dosing in the intensive care setting, a simple high performance liquid chromatography method was developed and validated for routinely determining the free (unbound) concentration of ten beta-lactam antibiotics in 200 μL of human plasma. Antibiotics determined include three cephalosporins (ceftriaxone, cephazolin and cephalotin); two carbapenems (meropenem and ertapenem); and five penicillins (ampicillin, piperacillin, benzylpenicillin, flucloxacillin and dicloxacillin). There was a single common sample preparation method involving ultracentrifugation and stabilisation. Chromatography was performed on a Waters XBridge C18 column with, depending on analytes, one of four acetonitrile-phosphate buffered mobile phases. Peaks of interest were detected via ultraviolet absorbance at 210, 260 and 304 nm. The method has been validated and used in a pathology laboratory for therapeutic drug monitoring in critically ill patients. The significant variability in the level of protein binding that is common with antibiotics traditionally considered to have high protein binding (e.g. ceftriaxone, cephazolin, ertapenem, flucloxacillin and dicloxacillin) suggests that this assay should be preferred for measuring the pharmacologically active concentration of beta-lactam antibiotics in a therapeutic drug monitoring programme. PMID:23026224

  1. Molecular genetic analysis of cephalosporinase production and its role in beta-lactam resistance in clinical isolates of Enterobacter cloacae.

    OpenAIRE

    Nicolas, M H; Honore, N; Jarlier, V; Philippon, A; Cole, S T

    1987-01-01

    Two strains of Enterobacter cloacae were isolated from a patient before (strain MHN1) and during (strain MHN2) treatment with moxalactam and gentamicin. Strain MHN1 exhibited inducible ampC cephalosporinase production. In contrast, strain MHN2 expressed the enzyme constitutively at a 3,000-fold higher level. With the Escherichia coli ampC gene as a hybridization probe it was shown that the genomic arrangement of the ampC region was the same in both strains. To gain more insight into regulator...

  2. Effects of beta-lactam antibiotics imipenem/cilastatin and cefodizime on cellular and humoral immune responses in BALB/c-mice.

    Science.gov (United States)

    Grochla, I; Ko, H L; Beuth, J; Roszkowski, K; Roszkowski, W; Pulverer, G

    1990-11-01

    The effects of a 7-day chemotherapy with two broad-spectrum beta-lactam antibiotics (imipenem/cilastatin and cefodizime) on the humoral and cellular immune responses in BALB/c-mice were investigated. Antibiotic dosages were calculated on a body weight basis from therapeutical dosages in human medicine. Treatment of experimental mice with imipenem/cilastatin and cefodizime did not influence the production of immunoglobulines (IgM and IgG) nor the delayed type hypersensitivity to oxazolone. In vitro, exposure of human granulocytes to imipenem/cilastatin and cefodizime did not interfere with their phagocytic activity as determined by chemiluminescence assay. Subinhibitory concentrations of both antibiotics modified Staphylococcus aureus and made them more susceptible for granulocyte phagocytosis in chemiluminescence assays. PMID:2085374

  3. Streamlining methodology for the multiresidue analysis of beta-lactam antibiotics in bovine kidney using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Mastovska, Katerina; Lightfield, Alan R

    2008-08-22

    A previously reported multiresidue method for the analysis of 11 important beta-lactams (amoxicillin, ampicillin, cefazolin, cephalexin, cloxacillin, desfuroylceftiofur cysteine disulfide (DCCD), deacetylcephapirin, dicloxacillin, nafcillin, oxacillin, and penicillin G) in bovine kidney has been further streamlined. The method is based on a simple extraction using acetonitrile-water (4:1, v/v), followed by dispersive solid-phase extraction clean-up with C(18) sorbent, concentration of an extract aliquot, and filtration of the final extracts using syringeless filter vials, which are used for the sample introduction in the liquid chromatographic-tandem mass spectrometric (LC-MS/MS) analysis. The recoveries have been improved by adding the internal standard [(13)C(6)]sulfamethazine to the homogenized sample before the extraction step, which enabled a proper control of the volume changes during the sample preparation. Average recoveries of fortified samples were 87-103% for all beta-lactams, except for DCCD, which had an average recovery of 60%. Based on the results of the stability study and LC mobile phase tests, methanol has been eliminated from the entire method, including the LC-MS/MS analysis. The best overall LC-MS/MS (electrospray positive ionization) performance was achieved by using 0.1% formic acid as an additive in both parts of the mobile phase, in water and in acetonitrile. To prevent carry-over in the LC-MS/MS analysis, the LC method was divided into two parts: one serving as an analytical method for injection of the sample and elution of the analytes and the other one, starting at a highly organic mobile phase composition, being dedicated for injection of a solvent, washing of the system, and equilibration of the column to the initial conditions of the analytical method. In this way, a blank solvent is injected after each sample, but these in-between injections contribute minimally to the overall sample throughput. PMID:18656204

  4. An international multicenter study of antimicrobial consumption and resistance in Staphylococcus aureus isolates from 15 hospitals in 14 countries

    DEFF Research Database (Denmark)

    Westh, Henrik Torkil; Zinn, Christina Scheel; Rosdahl, Vibeke Thamdrup

    2004-01-01

    usage of therapeutical subgroups of antimicrobials varied significantly between hospitals. A positive correlation was found between S. aureus resistance to methicillin (MRSA) and consumption of beta-lactam combinations, between resistance to quinolones and consumption of beta-lactam combinations and...... carbapenems and resistance to aminoglycosides and consumption of beta-lactam combinations. The consumption of beta-lactamase-sensitive antibiotics was negatively correlated to resistance to methicillin, quinolones, and aminoglycosides. Usage of the different antimicrobial therapeutical subgroups was also...... correlated. Consumption of beta-lactamase-sensitive antibiotics (penicillin) was positively correlated to consumption of beta-lactamase-resistant penicillins and negatively correlated to consumption of carbapenems, quinolones, and glycopeptides, whereas consumption of cephalosporins was positively correlated...

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

    OpenAIRE

    Borović Branka; Spirić Danka; Velebit Branko; Đorđević Vesna; Lakićević Brankica; Baltić Tatjana; Spirić Aurelija

    2013-01-01

    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...

  6. Thioridazine potentiates the effect of a beta-lactam antibiotic against Staphylococcus aureus independently of mecA expression.

    Science.gov (United States)

    Poulsen, Marianne Ø; Jacobsen, Kirstine; Thorsing, Mette; Kristensen, Nadia R D; Clasen, Julie; Lillebæk, Eva M S; Skov, Marianne N; Kallipolitis, Birgitte H; Kolmos, Hans Jørn; Klitgaard, Janne K

    2013-01-01

    The neuroleptic antipsychotic derivate thioridazine has been shown to increase the susceptibility of a methicillin-resistant Staphylococcus aureus (MRSA) isolate towards dicloxacillin. The aim of this study was to investigate the combinatorial effect of the two drugs on a broad selection of staphylococcal strains by analyzing a large collection of MRSA strains carrying different types of SCCmec, as well as MSSA strains. Transcription and translation of the resistance marker PBP2a encoded by mecA within the SCCmec cassette were analyzed by primer extension and western blotting. We observed increased susceptibility to dicloxacillin in the presence of thioridazine in all tested MRSA isolates. In contrast to previously published results, the synergistic effect was also applicable to methicillin-susceptible S. aureus (MSSA). We conclude that the combination of dicloxacillin and thioridazine potentiates the killing effect against S. aureus in a broad selection of clinical isolates. Additionally, the study indicates that the killing effect by the combinatorial treatment is independent of PBP2a-mediated resistance mechanisms. PMID:23089256

  7. Fully automated analysis of beta-lactams in bovine milk by online solid phase extraction-liquid chromatography-electrospray-tandem mass spectrometry.

    Science.gov (United States)

    Kantiani, Lina; Farré, Marinella; Sibum, Martin; Postigo, Cristina; López de Alda, Miren; Barceló, Damiá

    2009-06-01

    A fully automated method for the detection of beta-lactam antibiotics, including six penicillins (amoxicillin, ampicillin, cloxacillin, dicloxacillin, oxacillin, and penicillin G) and four cephalosporins (cefazolin, ceftiofur, cefoperazone, and cefalexin) in bovine milk samples has been developed. The outlined method is based on online solid-phase extraction-liquid chromatography/electrospray-tandem mass spectrometry (SPE-LC/ESI-MS-MS). Target compounds were concentrated from 500 microL of centrifuged milk samples using an online SPE procedure with C18 HD cartridges. Target analytes were eluted with a gradient mobile phase (water + 0.1% formic acid/methanol + 0.1% formic acid) at a flow rate of 0.7 mL/min. Chromatographic separation was achieved within 10 min using a C-12 reversed phase analytical column. For unequivocal identification and confirmation, two multiple reaction monitoring (MRM) transitions were acquired for each analyte in the positive electrospray ionization mode (ESI(+)). Method limits of detection (LODs) in milk were well below the maximum residue limits (MRLs) set by the European Union for all compounds. Limits of quantification in milk were between 0.09 ng/mL and 1.44 ng/mL. The developed method was validated according to EU's requirements, and accuracy results ranged from 80 to 116%. Finally, the method was applied to the analysis of twenty real samples previously screened by the inhibition of microbial growth test Eclipse 100. This new developed method offers high sensitivity and accuracy of results, minimum sample pre-treatment, and uses for the first time an automated online SPE offering a high throughput analysis. Because of all these characteristics, the proposed method is applicable and could be deemed necessary within the field of food control and safety. PMID:19402673

  8. Multiple antibiotic resistance in Stenotrophomonas maltophilia.

    OpenAIRE

    Alonso, A.; Martínez, J L

    1997-01-01

    A cryptic multidrug resistance (MDR) system in Stenotrophomonas maltophilia, the expression of which is selectable by tetracycline, is described. Tetracycline resistance was the consequence of active efflux of the antibiotic, and it was associated with resistance to quinolones and chloramphenicol, but not to aminoglycosides or beta-lactam antibiotics. MDR is linked to the expression of an outer membrane protein (OMP54) both in a model system and in multidrug-resistant clinical isolates.

  9. Antibiotic resistance pattern of bacterial isolates from skin and soft tissue infections

    Directory of Open Access Journals (Sweden)

    Debadutta Mishra

    2016-05-01

    Conclusions: Staphylococcus aureus exhibited high resistance to commonly prescribed antibiotics like beta-lactams, fluroquinolones and fusidic acid. Hence, it is recommended to base the treatment upon culture and sensitivity report. [Int J Res Med Sci 2016; 4(5.000: 1458-1462

  10. Frequent emergence and limited geographic dispersal of methicillin-resistant Staphylococcus aureus

    DEFF Research Database (Denmark)

    Nübel, Ulrich; Roumagnac, Philippe; Feldkamp, Mirjam;

    2008-01-01

    A small number of clonal lineages dominates the global population structure of methicillin-resistant Staphylococcus aureus (MRSA), resulting in the concept that MRSA has emerged on a few occasions after penicillinase-stable beta-lactam antibiotics were introduced to clinical practice, followed...

  11. Commensal Streptococci Serve as a Reservoir for β-Lactam Resistance Genes in Streptococcus pneumoniae

    DEFF Research Database (Denmark)

    Jensen, Anders; Valdórsson, Oskar; Frimodt-Møller, Niels;

    2015-01-01

    Streptococcus pneumoniae is a leading cause of pneumonia, meningitis, septicemia, and middle ear infections. The incidence of S. pneumoniae isolates that are not susceptible to penicillin has risen worldwide and may be above 20% in some countries. Beta-lactam antibiotic resistance in pneumococci is...

  12. In vitro activities of aztreonam, piperacillin, and ticarcillin combined with amikacin against amikacin-resistant Pseudomonas aeruginosa and P. cepacia isolates from children with cystic fibrosis.

    OpenAIRE

    Aronoff, S C; Klinger, J D

    1984-01-01

    Amikacin, combined with aztreonam, piperacillin, or ticarcillin, synergistically inhibited amikacin-resistant sputum isolates of Pseudomonas aeruginosa and P. cepacia from children with cystic fibrosis. Ticarcillin-amikacin was the least active combination. Aminoglycoside resistance should not preclude the use of beta-lactam-aminoglycoside combinations in the treatment of pulmonary infections in cystic fibrosis.

  13. The KPC type beta-lactamases: new enzymes that confer resistance to carbapenems in Gram-negative bacilli.

    Directory of Open Access Journals (Sweden)

    Piotr Wieczorek

    2010-05-01

    Full Text Available Antimicrobial resistance due to the continuous selective pressure from widespread use of antimicrobials in humans, animals and agriculture has been a growing problem for last decades. KPC beta-lactamases hydrolyzed beta-lactams of all classes. Especially, carbapenem antibiotics are hydrolyzed more efficiency than other beta-lactam antibiotics. The KPC enzymes are found most often in Enterobacteriaceae. Recently, these enzymes have been found in isolates of Pseudomonas aeruginosa and Acinetobacter spp. The observations of blaKPC genes isolated from different species in other countries indicate that these genes from common but unknown ancestor may have been mobilized in these areas or that blaKPC-carrying bacteria may have been passively by many vectors. The emergence of carbapenem resistance in Gram-negative bacteria is worrisome because the carbapenem resistance often may be associated with resistance to many beta-lactam and non-beta-lactam antibiotics. Treatment of infections caused by KPC-producing bacteria is extremely difficult because of their multidrug resistance, which results in high mortality rates. Therapeutic options to treat infections caused by multiresistant Gram-negative bacteria producing KPC-carbapenemases could be used polymyxin B or tigecycline.

  14. Role of the Stringent Stress Response in the Antibiotic Resistance Phenotype of Methicillin-Resistant Staphylococcus aureus.

    Science.gov (United States)

    Aedo, Sandra; Tomasz, Alexander

    2016-04-01

    Resistance to beta-lactam antibiotics in methicillin-resistantStaphylococcus aureus(MRSA) requires the presence of an acquired genetic determinant,mecAormecC, which encode penicillin-binding protein PBP2A or PBP2A', respectively. Although all MRSA strains share a mechanism of resistance, the phenotypic expression of beta-lactam resistance shows considerable strain-to-strain variation. The stringent stress response, a stress response that results from nutrient limitation, was shown to play a key role in determining the resistance level of an MRSA strain. In the present study, we validated the impact of the stringent stress response on transcription and translation ofmecAin the MRSA clinical isolate strain N315, which also carries known regulatory genes (mecI/mecR1/mecR2andblaI/blaR1) formecAtranscription. We showed that the impact of the stringent stress response on the resistance level may be restricted to beta-lactam resistance based on a "foreign" determinant such asmecA, as opposed to resistance based on mutations in the nativeS. aureusdeterminantpbpB(encoding PBP2). Our observations demonstrate that high-level resistance mediated by the stringent stress response follows the current model of beta-lactam resistance in which the native PBP2 protein is also essential for expression of the resistance phenotype. We also show that theStaphylococcus sciuri pbpDgene (also calledmecAI), the putative evolutionary precursor ofmecA, confers oxacillin resistance in anS. aureusstrain, generating a heterogeneous phenotype that can be converted to high and homogenous resistance by induction of the stringent stress response in the bacteria. PMID:26833147

  15. Resistance to Third-Generation Cephalosporins and Other Antibiotics by Enterobacteriaceae in Western Nigeria

    OpenAIRE

    Okesola, A.O.; O. Makanjuola

    2009-01-01

    Problem statement: The emergence and spread of resistance to third-generation cephalosporins are threatening to create species resistant to all currently available agents. The most common cause of bacterial resistance to beta-lactam antibiotics is the production of beta-lactamases and many of the 2nd and 3rd-generation penicillins and cephalosporins were specifically designed to resist the hydrolytic action of major ß-lactamases. However new ß-lactamases em...

  16. Antibodies against beta-lactamase can improve ceftazidime treatment of lung infection with beta-lactam-resistant Pseudomonas aeruginosa in a rat model of chronic lung infection

    DEFF Research Database (Denmark)

    Ciofu, Oana; Bagge, Niels; Høiby, Niels

    2002-01-01

    To test the hypothesis that antibodies against the chromosomal beta-lactamase of Pseudomonas aeruginosa (a beta ab) might act as beta-lactamase inhibitors in patients with cystic fibrosis and chronic lung infection with P. aeruginosa, we compared in a rat model of chronic lung infection the...... efficacy of treatment with ceftazidime in beta-lactamase-immunized (group I) and non-immunized (group II) rats. Chronic lung infection was established with alginate-embedded P. aeruginosa producing high amounts of beta-lactamase in 133 Lewis rats. Prior to infection, group I (66 rats) was immunized three...... times at 2-week intervals with purified beta-lactamase in incomplete Freund's adjuvant (IFA) and group II (67 rats) received IFA. Ceftazidime treatment was initiated after challenge and continued for 10 days, after which the rats were sacrificed and the lung bacteriology and pathology were analysed. Rat...

  17. Threat of drug resistant Staphylococcus aureus to health in Nepal

    OpenAIRE

    Ansari, Shamshul; Nepal, Hari Prasad; Gautam, Rajendra; Rayamajhi, Nabin; Shrestha, Sony; Upadhyay, Goma; Acharya, Anju; Chapagain, Moti Lal

    2014-01-01

    Background Staphylococcus aureus is the most commonly isolated organism from the different clinical samples in hospital. The emergence and dissemination of methicillin resistant Staphylococcus aureus (MRSA) and growing resistance to non-beta-lactam antibiotics is making treatment of infections due to this organism increasingly difficult. Methods This study was conducted to determine the frequency of Staphylococcus aureus isolated from different clinical samples, rates of MRSA and full antibio...

  18. Surveillance and Detection of Inhibitor-Resistant Beta-Lactamases in Clinical Isolates of Escherichia coli

    OpenAIRE

    Carl Urban; Patricia Bradford; Joseph Villarin

    2007-01-01

    In recent years, resistance to beta-lactam antibiotics, such as the widely-used cephalosporins and penicillins, has become a major challenge for disease therapy, particularly in common hospital-acquired infections. In the search for the mechanisms behind this increasingly prevalent form of resistance, microbiologists have identified a new type of beta-lactamase enzyme, called inhibitor-resistant TEMs (IRTs), which can withstand the effects of beta-lactamase inhibitor compounds, further reduci...

  19. Susceptibilities of 200 penicillin-susceptible and -resistant pneumococci to piperacillin, piperacillin-tazobactam, ticarcillin, ticarcillin-clavulanate, ampicillin, ampicillin-sulbactam, ceftazidime, and ceftriaxone.

    OpenAIRE

    Pankuch, G A; Jacobs, M. R.; Appelbaum, P C

    1994-01-01

    MICs of eight beta-lactams (piperacillin, piperacillin-tazobactam, ticarcillin, ticarcillin-clavulanate, ampicillin, ampicillin-sulbactam, ceftazidime, and ceftriaxone) were determined by agar dilution against 64 penicillin-susceptible, 70 intermediately penicillin-resistant, and 66 fully penicillin-resistant pneumococci. The MICs of piperacillin with and without tazobactam for 90% of the susceptible, intermediately resistant, and resistant strains tested (MIC90s) were < or = 0.064, 2.0, and ...

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

    OpenAIRE

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

    2014-01-01

    The distribution and quantification of tetracycline, sulfonamide and beta-lactam resistance genes were assessed in slaughterhouse zones throughout meat chain production and the meat products; this study represents the first to report quantitatively monitor antibiotic resistance genes (ARG) in goat and lamb slaughterhouse using a culture independent approach, since most studies focused on individual bacterial species and their specific resistance types. Quantitative PCR (qPCR) revealed a high ...

  1. In vitro activity effects of combinations of cephalothin, dicloxacillin, imipenem, vancomycin and amikacin against methicillin-resistant Staphylococcus spp. strains

    OpenAIRE

    Solórzano-Santos Fortino; Vilchis-Pérez Mariano; Leaños-Miranda Blanca E; Miranda-Novales Guadalupe

    2006-01-01

    Abstract Background combinations of drugs has been proposed as an alternative for oxacillin-resistant staphylococci infections, however, limited information about in vitro combinations are available for multi-resistant strains. The objective of this study was to describe the interaction of beta-lactams in combination with vancomycin or amikacin against 26 oxacillin and amikacin-resistant nosocomial Staphylococcus spp. isolates. Methods activity of dicloxacillin plus amikacin, cephalothin plus...

  2. Catering ESBL resistance challenge through strategic combination of Ceftriaxone, Sulbactam and Ethylenediaminetetraacetic Acid

    OpenAIRE

    Manu Chaudhary; Sudaroli M; Shailesh Kumar; Krishnaraju V

    2012-01-01

    Resistant development in ESBLs producing bacteria to third generation cephalosporin has emerged with alarming rapidity in recent years and become major cause of concern world wide. Therefore, in order to cater growing resistance problem, combination of third generation cephalosporin with beta-lactam inhibitors and Ethylenediaminetetraacetic acid, was studied. The in vitro antibacterial efficacy of various concentration of ceftriaxone +sulbactam and effective dose determination study of EDTA a...

  3. Prevalence of Antibiotic Resistance Genes in Subjects with Successful and Failing Dental Implants. A Pilot Study

    Science.gov (United States)

    Koukos, Georgios; Papadopoulos, Christos; Tsalikis, Lazaros; Sakellari, Dimitra; Arsenakis, Minas; Konstantinidis, Antonios

    2015-01-01

    Objectives : To investigate the prevalence of the bacterial genes encoding resistance to beta-lactams, tetracyclines and metronidazole respectively, in subjects with successful and failing dental implants and to assess the presence of Staphylococcus aureus and the mecA gene encoding for Methicillin Resistant Staphylococcus aureus (MRSA) in the same samples. Materials and Methodology: The subject sample included 20 participants with clinically healthy osseointegrated implants and 20 participants with implants exhibiting peri-implantitis. Clinical parameters were assessed with an automated probe, samples were collected from the peri-implant sulcus or pocket and analyzed with Polymerase Chain Reaction for blaTEM, tetM, tetQ and nim genes, S. aureus and MRSA using primers and conditions previously described in the literature. Results: Findings have shown high frequencies of detection for both groups for the tetracycline resistance genes tetM (>30%), tetQ (>65%) with no statistical differences between them (z-test with Bonferroni corrections, p<0.05). The blaTEM gene, which encodes resistance to beta-lactams, was detected in <15% of the samples. The nim gene, which encodes resistance to metronidazole, S.aureus and the mecA gene encoding for MRSA were not detected in any of the analyzed samples. Conclusions: Healthy peri-implant sulci and peri-implantitis cases often harbor bacterial genes encoding for resistance to the tetracyclines and less often for beta-lactams. Thus, the antimicrobial activity of the tetracyclines and to a lower extent to beta-lactams, might be compromised for treatment of peri-implantitis. Since no metronidazole resistance genes were detected in the present study, its clinical use is supported by the current findings. S.aureus may not participate in peri-implant pathology. PMID:25646133

  4. Expression and inducibility in Staphylococcus aureus of the mecA gene, which encodes a methicillin-resistant S. aureus-specific penicillin-binding protein.

    OpenAIRE

    Ubukata, K; Nonoguchi, R; Matsuhashi, M; Konno, M

    1989-01-01

    A beta-lactam-sensitive strain of Staphylococcus aureus could be converted to methicillin resistance by the introduction of a plasmid carrying the 4.3-kilobase HindIII chromosomal DNA fragment which encoded the mecA gene from a methicillin-resistant S. aureus. Transformant cells produced methicillin-resistant S. aureus-specific penicillin-binding protein constitutively, and additional insertion of an inducible penicillinase plasmid caused production of the pencillin-binding protein to become ...

  5. Identification of porins in outer membrane of Proteus, Morganella, and Providencia spp. and their role in outer membrane permeation of beta-lactams.

    OpenAIRE

    Mitsuyama, J; Hiruma, R; Yamaguchi, A.; Sawai, T

    1987-01-01

    Proteus mirabilis, Proteus vulgaris, Morganella morganii, Providencia rettgeri, and Providencia alcalifaciens, which were once classified into the same genus, Proteus, were studied. Cefoxitin-resistant mutants from these species were isolated, and it was confirmed that the resistance was attributed to the lack of an outer membrane protein, resulting in a significant decrease in the penetration of hydrophilic cephalosporins through the outer membrane. Comparison of the mutant strains with thei...

  6. Impact of Bolus Dosing versus Continuous Infusion of Piperacillin and Tazobactam on the Development of Antimicrobial Resistance in Pseudomonas aeruginosa

    OpenAIRE

    Felton, T. W.; Goodwin, J.; O'Connor, L; Sharp, A.; Gregson, L.; Livermore, J.; Howard, S. J.; Neely, M. N.; Hope, W. W.

    2013-01-01

    Management of nosocomial pneumonia is frequently complicated by bacterial resistance. Extended infusions of beta-lactams are increasingly being used to improve clinical outcomes. However, the impact of this strategy on the emergence of antimicrobial resistance is not known. A hollow-fiber infection model with Pseudomonas aeruginosa (PAO1) was used. Pharmacokinetic (PK) profiles of piperacillin-tazobactam similar to those in humans were simulated over 5 days. Three dosages of piperacillin-tazo...

  7. Relatively high antibiotic resistance among heterotrophic bacteria from arctic fjord sediments than water - Evidence towards better selection pressure in the fjord sediments

    Science.gov (United States)

    Hatha, A. A. Mohamed; Neethu, C. S.; Nikhil, S. M.; Rahiman, K. M. Mujeeb; Krishnan, K. P.; Saramma, A. V.

    2015-12-01

    The objective of this study was to determine the prevalence of antibiotic resistance among aerobic heterotrophic bacteria and coliform bacteria from water and sediment of Kongsfjord. The study was based on the assumption that arctic fjord environments are relatively pristine and offer very little selection pressure for drug resistant mutants. In order to test the hypothesis, 200 isolates belonging to aerobic heterotrophic bacteria and 114 isolates belonging to coliforms were tested against 15 antibiotics belonging to 5 different classes such as beta lactams, aminoglycosides, quinolones, sulpha drugs and tetracyclines. Resistance to beta lactam and extended spectrum beta lactam (ESBL) antibiotics was considerably high and they found to vary significantly (p antibiotic resistance against ESBL's extent and diversity of antibiotic resistance (as revealed by multiple antibiotic resistance index and resistance patterns), was high in the aerobic heterotrophic bacteria. Most striking observation was that isolates from fjord sediments (both heterotrophic bacteria and coliforms) in general showed relatively high prevalence of antibiotic resistance against most of the antibiotics tested, indicating to better selection pressure for drug resistance mutants in the fjord sediments.

  8. Pseudomonas aeruginosa chromosomal beta-lactamase in patients with cystic fibrosis and chronic lung infection. Mechanism of antibiotic resistance and target of the humoral immune response

    DEFF Research Database (Denmark)

    Ciofu, Oana

    2003-01-01

    The intensive antibiotic treatment of cystic fibrosis (CF) patients with chronic lung infection with Pseudomonas aeruginosa has improved the survival rate and the clinical condition of Danish patients. Acquirement of resistance to anti-pseudomonal antibiotics is one of the main drawbacks of this...... therapeutic strategy and our results showed the development of resistance of P. aeruginosa to several antibiotics during 25 years of intensive antibiotic treatment. Our studies have been concentrating on the development of resistance to beta-lactam antibiotics. We have shown an association between the...... induction to even higher levels during treatment with beta-lactam antibiotics, were the most frequent phenotype found among resistant Danish P. aeruginosa CF isolates. We have also shown that the high alginate producing P. aeruginosa isolates, that characterize the chronic lung infection in CF patients, are...

  9. Commensal Streptococci Serve as a Reservoir for β-Lactam Resistance Genes in Streptococcus pneumoniae

    OpenAIRE

    Jensen, Anders; Valdórsson, Oskar; Frimodt-Møller, Niels; Hollingshead, Susan; Kilian, Mogens

    2015-01-01

    Streptococcus pneumoniae is a leading cause of pneumonia, meningitis, septicemia, and middle ear infections. The incidence of S. pneumoniae isolates that are not susceptible to penicillin has risen worldwide and may be above 20% in some countries. Beta-lactam antibiotic resistance in pneumococci is associated with significant sequence polymorphism in penicillin-binding proteins (PBPs). Commensal streptococci, especially S. mitis and S. oralis, have been identified as putative donors of mutate...

  10. Cloning and expression in Escherichia coli of the Azospirillum brasilense Sp7 gene encoding ampicillin resistance.

    OpenAIRE

    Verreth, C; Cammue, B; Swinnen, P; Crombez, D; Michielsen, A; Michiels, K.; Gool, A. van; Vanderleyden, J.

    1989-01-01

    The Azospirillum brasilense ATCC 29145 gene coding for beta-lactamase was cloned in Escherichia coli. The gene was expressed in E. coli from its own promoter as a 30-kilodalton protein, conferring resistance to high levels of beta-lactam antibiotics. The DNA sequence containing the beta-lactamase gene was found to be highly amplified in the Azospirillum genome, scattered in the chromosomal as well as in the plasmidic DNA.

  11. Alergia a beta-lactâmicos na clínica pediátrica: uma abordagem prática Allergy to beta-lactams in pediatrics: a practical approach

    Directory of Open Access Journals (Sweden)

    Nelson A. Rosário

    2006-11-01

    Full Text Available OBJETIVO: Apresentar uma abordagem prática ao diagnóstico e conduta na alergia a antibióticos beta-lactâmicos. FONTES DOS DADOS: Periódicos da área de alergia indexados nas bases MEDLINE e LILACS, além de estudos e textos clássicos que tratam do tema. SÍNTESE DOS DADOS: A alergia à penicilina é relatada com freqüência, em muitos casos resultando na exclusão desse medicamento do arsenal terapêutico. Cerca de 10% dos relatos de alergia a drogas são confirmados. As manifestações clínicas decorrentes da reação alérgica à penicilina são bastante amplas, destacando-se os quadros cutâneos. Os quatro mecanismos de hipersensibilidade de Gell & Coombs estão envolvidos nas reações alérgicas. A penicilina é degradada em determinante maior (95% dos produtos e em determinantes menores (5% dos produtos. As reações imediatas, mediadas por IgE, e que determinam quadros de anafilaxia, estão relacionadas aos determinantes menores em 95% dos casos. A hipersensibilidade a esses produtos pode ser avaliada através de testes cutâneos realizados com os determinantes maior e menores, permitindo, assim, evitar o choque anafilático em indivíduos alérgicos. O texto ressalta conhecimentos básicos sobre a alergia à penicilina, propiciando um diagnóstico mais adequado desse evento e a conduta em casos de suspeita de alergia a beta-lactâmicos. CONCLUSÃO: O diagnóstico de alergia à penicilina tem sido feito de forma inadequada, resultando em sua exclusão do arsenal terapêutico. O melhor reconhecimento dessas condições permitirá o uso da penicilina com diminuição dos riscos decorrentes da hipersensibilidade.OBJECTIVE: To present a practical approach to the diagnosis and management of allergy to beta-lactam antibiotics. SOURCES: Allergy journals indexed in MEDLINE and LILACS, as well as seminal studies and texts. SUMMARY OF THE FINDINGS: Allergy to penicillin is commonly reported. In many cases, this results in the decision not

  12. Type 1 Ig-E mediated allergy to human insulin, insulin analogues and beta-lactam antibiotics Hipersensibilidade imediata a insulina humana, análogos de insulina e a antibióticos beta-lactâmicos

    Directory of Open Access Journals (Sweden)

    Pedro Andrade

    2012-12-01

    Full Text Available Insulin, a crucial therapeutic agent for diabetes mellitus, has been rarely associated with hypersensitivity events. We present a 69-year-old type-2 diabetic patient with urticariform lesions on the sites of subcutaneous injection of insulin. The patient denied any known allergies, except for an unspecific cutaneous reaction after intramuscular penicillin administration in childhood. Prick tests revealed positive reactions to all tested human insulins and insulin analogues. Serum IgE levels were above normal range and RAST tests were positive for human, bovine and porcine insulins, as well as beta-lactams. Type 1 IgEmediated allergy to insulin analogues demands a prompt diagnosis and represents a significant therapeutic challenge in diabetic patients.A insulina é um agente indispensável para o controlo da diabetes mellitus. Os efeitos adversos da sua administração, em particular fenómenos de hipersensibilidade, são raros. Apresentamos um doente de 69 anos, diabético do tipo 2, com episódios recorrentes de lesões urticariformes nos locais de administração subcutânea de insulina. Negava alergias medicamentosas, à excepção de reacção não especificada na infância após penicilina intramuscular. Foram realizados testes cutâneos por puntura (prick tests com diversos tipos de insulina humana e análogos, todos com reacções positivas, associando elevação dos níveis de IgE sérica e provas RAST positivas para as insulinas humana, bovina e porcina e para os antibióticos beta-lactâmicos. A alergia a análogos de insulina exige um diagnóstico precoce, originando um desafio terapêutico importante no doente diabético.

  13. Hospital outbreak of carbapenem-resistant Pseudomonas aeruginosa producing VIM-1, a novel transferable metallo-beta-lactamase.

    Science.gov (United States)

    Cornaglia, G; Mazzariol, A; Lauretti, L; Rossolini, G M; Fontana, R

    2000-11-01

    A total of 8 Pseudomonas aeruginosa isolates was collected from 7 different patients in different wards of the University Hospital of Verona, Italy, from February 1997 to February 1998. The high level of resistance to carbapenems (imipenem minimum inhibitory concentration was always >128 microg/mL) and other broad-spectrum beta-lactams and the rate of imipenem hydrolysis and its inhibition by ethylenediamine-tetra-acetic acid were all suggestive of production of a carbapenem-hydrolyzing metallo-beta-lactamase. A specific DNA probe derived from the recently cloned bla(VIM-1) gene hybridized to all the isolates. A genomic DNA fingerprinting profile revealed clonal relatedness for 7 of 8 isolates. A description of this hospital outbreak is reported, the occurrence of which confirms that proliferation of metallo-beta-lactamase-producing strains multiply resistant to beta-lactams is already a reality outside Japan. These findings emphasize the need for early recognition of similar isolates. PMID:11073738

  14. [In vitro activity of meropenem and seven other beta-lactam antibiotics against K.pneumoniae and enterobacteriaceae producing beta-lactamases with extended spectrum].

    Science.gov (United States)

    Cavallo, J D; Fabre, R; Crenn, Y; Meyran, M

    1994-05-01

    Meropenem is a broad antibacterial spectrum carbapenem with a good activity on betalactam resistant Gram-negative bacilli. 120 non repetitive strains isolated from clinical samples from 1989 to 1992 were selected: 60 K. pneumoniae, 7 E. coli, 2 E. aerogenes and 1 S. marcescens with extended spectrum betalactamases (23 CTX-1, 18 SHV-2, 5 SHV-3, 16 SHV-4, 4 SHV-5, 3 CTX-1 + SHV-4, 1 CAZ-1), 10 K. pneumoniae with broad spectrum TEM-1 enzyme, and 40 K. pneumoniae with only SHV-1 chromosomal betalactamase. Determination of Minimal inhibitory concentrations (MIC) was done by agar dilution method for meropenem and 7 other betalactams (amoxicillin + clavulanic acid 2 mg/l, piperacillin + tazobactam 4 mg/l, cefoxitin, cefotetan, cefotaxime, ceftazidime, imipenem). All antibiotics except amoxicillin + clavulanic acid are active against strains with constitutive penicillinase. For strains with TEM-1 penicillinase, cephamycins, third generation cephalosporins and carbapenems are active. For strains with different extended spectrum betalactamases only cephamycins and carbapenems are efficious. There is no difference according to the period of isolation: 1989-90 or 1991-92. Meropenem has the best in vitro activity (MIC50 = 0.03 mg/l) for all strains independently of the nature of betalactamase. PMID:7824297

  15. Homology of mecA gene in methicillin-resistant Staphylococcus haemolyticus and Staphylococcus simulans to that of Staphylococcus aureus.

    OpenAIRE

    Ubukata, K; Nonoguchi, R; Song, M D; Matsuhashi, M; Konno, M

    1990-01-01

    A penicillin-binding protein of molecular weight 76,000 inducible by beta-lactams was detected in methicillin-resistant Staphylococcus haemolyticus and Staphylococcus simulans. DNA from these strains hybridized to the mecA gene from Staphylococcus aureus; however, the chromosomal HindIII fragments containing the mecA genes were 3.4 kilobases in S. haemolyticus and 4.3 kilobases in S. simulans.

  16. Mutation of Salmonella paratyphi A conferring cross-resistance to several groups of antibiotics by decreased permeability and loss of invasiveness.

    OpenAIRE

    Gutmann, L; Billot-Klein, D; Williamson, R.; Goldstein, F W; Mounier, J; Acar, J F; Collatz, E

    1988-01-01

    A spontaneous one-step mutant of Salmonella paratyphi A selected on ampicillin showed cross-resistance to all beta-lactam antibiotics except imipenem and to aminoglycosides, chloramphenicol, tetracycline, trimethoprim, and quinolones. It also grew as small colonies. Examination of the cell envelope of the mutant showed a quantitative decrease in three major outer membrane proteins of 40.6, 39.6 (presumably porins), and 24 kilodaltons and quantitative as well as qualitative modifications in th...

  17. Multiple Breed Validation of Five QTL Affecting Mastitis Resistance

    OpenAIRE

    Vilkki, Johanna; Dolezal, Marlies A; Sahana, Goutam; Iso-Touru, Terhi; Panitz, Frank; Fasold, Mario; Bagnato, Alessandro; Soller, Morris

    2014-01-01

    Mastitis is a major animal welfare problem and the most costly disease in dairy cattle worldwide. Within the EU FP7 Quantomics project, we aimed at validating quantitative trait loci affecting mastitis resistance at the molecular level. Eight chromosome regions with major effects on resistance to mastitis were identified by GWAS using high-density SNP array in the Finnish Ayrshire and Brown Swiss breeds. These targeted regions were analyzed for polymorphisms from 20X whole-genome sequences of...

  18. Expression, purification, crystallization, and preliminary X-ray crystallographic analysis of OXA-17, an extended-spectrum {beta}-lactamase conferring severe antibiotic resistance

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. H., E-mail: msgjhlee@mju.ac.kr; Sohn, S. G., E-mail: sgsohn@mju.ac.kr; Jung, H. I., E-mail: jhinumber1@hanmail.net; An, Y. J., E-mail: anyj0120@hanmail.net; Lee, S. H., E-mail: sangheelee@mju.ac.kr [Myongji University, Drug Resistance Proteomics Laboratory, Department of Biological Sciences (Korea, Republic of)

    2013-07-15

    OXA-17, an extended-spectrum {beta}-lactamase (ESBL) conferring severe antibiotic resistance, hydrolytically inactivates {beta}-lactam antibiotics, inducing a lack of eradication of pathogenic bacteria by oxyimino {beta}-lactams and not helping hospital infection control. Thus, the enzyme is a potential target for developing antimicrobial agents against pathogens producing ESBLs. OXA-17 was purified and crystallized at 298 K. X-ray diffraction data from OXA-17 crystal have been collected to 1.85 A resolution using synchrotron radiation. The crystal of OXA-17 belongs to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 48.37, b = 101.12, and c = 126.07 A. Analysis of the packing density shows that the asymmetric unit probably contains two molecules with a solvent content of 54.6%.

  19. Pharmacodynamics of a New Cephalosporin, PPI-0903 (TAK-599), Active against Methicillin-Resistant Staphylococcus aureus in Murine Thigh and Lung Infection Models: Identification of an In Vivo Pharmacokinetic-Pharmacodynamic Target

    OpenAIRE

    Andes, D.; Craig, W A

    2014-01-01

    PPI-0903 is a new cephalosporin with broad-spectrum activity, including beta-lactam-resistant Streptococcus pneumoniae and Staphylococcus aureus. We used the neutropenic murine thigh and lung infection models to examine the pharmacodynamic characteristics of PPI-0903. Serum drug levels following four fourfold-escalating single doses of PPI-0903 were measured by microbiologic assay. In vivo postantibiotic effects (PAEs) were determined after doses of 1.56, 6.25, 25, and 100 mg/kg of body weigh...

  20. KPC-mediated resistance in Klebsiella pneumoniae in two hospitals in Padua, Italy, June 2009-December 2011: massive spreading of a KPC-3-encoding plasmid and involvement of non-intensive care units

    OpenAIRE

    Richter Sara N; Frasson Ilaria; Franchin Elisa; Bergo Cristina; Lavezzo Enrico; Barzon Luisa; Cavallaro Antonietta; Palù Giorgio

    2012-01-01

    Abstract Background Klebsiella pneumoniae carbapenemases (KPCs) producing bacteria have emerged as a cause of multidrug-resistant nosocomial infections worldwide. KPCs are plasmid-encoded enzymes capable of hydrolysing a broad spectrum of beta-lactams, including carbapenems and monobactams, therefore worryingly limiting antimicrobial treatment options. Analysis of circulating bacterial strains and KPC alleles may help understanding the route of KPC dissemination and therefore help containing ...

  1. Proti meticilinu odporna bakterija Staphylococcus aureus domačega okolja (CA-MRSA): Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA):

    OpenAIRE

    Dermota, Urška; Grmek-Košnik, Irena; Juteršek, Borut

    2005-01-01

    Background. Community acquired MRSA (CA-MRSA) infections affect patients without risk factors. CA-MRSA infections can be serious and also fatal even inpreviously healthy subjects. CA-MRSA differs from hospital acquired MRSA (HA-MRSA). CA-MRSA is more susceptible for non-beta-lactam antibiotics than HA-MRSA, has different PFGE subtypes, and can produce Panton-Valentine leukocidine. Methods. In Institute of Public Health Kranj we routinely performepidemiologic survey of MRSA positive patients. ...

  2. Fire Reterdant Chemicals Affecting Combustion Resistance of Wood

    OpenAIRE

    Yalçın ÖRS; Sönmez, Abdullah

    1998-01-01

    Wood is an important material used in construction elements. However since it can be affected by biotic and abiotic deteriorating agents, it should be treated with chemical impregnating materials prior to use. In this study, the effects of water-soluble impregnating chemicals on the combustion resistance of wood was investigated. For this purpose, panels were prepared with oriental beech wood (Fagus orientalis L.) and pine wood (Pinus silvestris L.), which are widely used in industry. These ...

  3. Partial aphid resistance in lettuce negatively affects parasitoids.

    Science.gov (United States)

    Lanteigne, Marie-Eve; Brodeur, Jacques; Jenni, Sylvie; Boivin, Guy

    2014-10-01

    This study investigated the effects of partial plant resistance on the lettuce aphid Nasonovia ribisnigri (Mosley) (Hemiptera: Aphididae), a major pest of cultivated lettuce (Lactuca sativa L.), and one of its parasitoids, Aphidius ervi Haliday (Hymenoptera: Braconidae). Aphids were reared on susceptible (L. sativa variety Estival; S) or partially resistant (Lactuca serriola L. PI 491093; PR) lettuce, and next parasitized by A. ervi females. Fitness proxies were measured for both aphids and parasitoids. Developmental time to adult stage took longer for alate and apterous aphids (an average of 3.5 and 1.5 additional days, respectively) on PR than on S lettuce, and fecundity of alate aphids reared on PR lettuce was reduced by 37.8% relative to those reared on S lettuce. Size (tibia length) and weight of aphids reared on PR lettuce were lower than for aphids reared on S lettuce from the third and second instar onward, respectively. Parasitism of aphids reared on PR plants resulted in lower parasitoid offspring emergence (-49.9%), lower adult female (-30.3%) and male (-27.5%) weight, smaller adult female (-17.5%) and male (-11.9%) size, and lower female fecundity (37.8% fewer eggs) than when parasitoids developed from aphids reared on S plants. Our results demonstrate that partial aphid resistance in lettuce negatively affects both the second and third trophic levels. Host plant resistance in cultivated lettuce may therefore create an ecological sink for aphid parasitoids. PMID:25197882

  4. Multiple Breed Validation of Five QTL Affecting Mastitis Resistance

    DEFF Research Database (Denmark)

    Vilkki, Johanna; Dolezal, Marlies A; Sahana, Goutam;

    Mastitis is a major animal welfare problem and the most costly disease in dairy cattle worldwide. Within the EU FP7 Quantomics project, we aimed at validating quantitative trait loci affecting mastitis resistance at the molecular level. Eight chromosome regions with major effects on resistance to...... mastitis were identified by GWAS using high-density SNP array in the Finnish Ayrshire and Brown Swiss breeds. These targeted regions were analyzed for polymorphisms from 20X whole-genome sequences of 38 ancestral bulls of the two populations. A set of 384 SNPs were selected based on their ranking from the...... functional studies of promising candidates. The information can also be used for prior weighting of genomic segments in genomic selection...

  5. Development of a miniaturised microarray-based assay for the rapid identification of antimicrobial resistance genes in Gram-negative bacteria

    DEFF Research Database (Denmark)

    Batchelor, Miranda; Hopkins, Katie L; Liebana, Ernesto;

    2008-01-01

    We describe the development of a miniaturised microarray for the detection of antimicrobial resistance genes in Gram-negative bacteria. Included on the array are genes encoding resistance to aminoglycosides, trimethoprim, sulphonamides, tetracyclines and beta-lactams, including extended...... also seen in the number and type of resistance genes harboured by E. coli and Salmonella strains. The array provides an effective, fast and simple method for detection of resistance genes in clinical isolates suitable for use in diagnostic laboratories, which in future will help to understand the...... epidemiology of isolates and to detect gene linkage in bacterial populations. (C) 2008 Published by Elsevier B.V. and the International Society of Chemotherapy....

  6. Outcome of infections due to pandrug-resistant (PDR Gram-negative bacteria

    Directory of Open Access Journals (Sweden)

    Bliziotis Ioannis A

    2005-04-01

    Full Text Available Abstract Background The increasing problem of infections due to multidrug-resistant Gram-negative bacteria has led to re-use of polymyxins in several countries. However, there are already clinical isolates of Gram-negative bacteria that are resistant to all available antibiotics, including polymyxins. Methods We present a case series of patients with infections due to pathogens resistant to all antimicrobial agents tested, including polymyxins. An isolate was defined as pandrug-resistant (PDR if it exhibited resistance to all 7 anti-pseudomonal antimicrobial agents, i.e. antipseudomonal penicillins, cephalosporins, carbapenems, monobactams, quinolones, aminoglycosides, and polymyxins. Results Clinical cure of the infection due to pandrug-resistant (PDR Gram-negative bacteria, namely Pseudomonas aeruginosa or Klebsiella pneumoniae was observed in 4 out of 6 patients with combination of colistin and beta lactam antibiotics. Conclusion Colistin, in combination with beta lactam antibiotics, may be a useful agent for the management of pandrug-resistant Gram-negative bacterial infections. The re-use of polymyxins, an old class of antibiotics, should be done with caution in an attempt to delay the rate of development of pandrug-resistant Gram-negative bacterial infections.

  7. Removal of antibiotic resistance gene-carrying plasmids from Lactobacillus reuteri ATCC 55730 and characterization of the resulting daughter strain, L. reuteri DSM 17938.

    Science.gov (United States)

    Rosander, Anna; Connolly, Eamonn; Roos, Stefan

    2008-10-01

    The spread of antibiotic resistance in pathogens is primarily a consequence of the indiscriminate use of antibiotics, but there is concern that food-borne lactic acid bacteria may act as reservoirs of antibiotic resistance genes when distributed in large doses to the gastrointestinal tract. Lactobacillus reuteri ATCC 55730 is a commercially available probiotic strain which has been found to harbor potentially transferable resistance genes. The aims of this study were to define the location and nature of beta-lactam, tetracycline, and lincosamide resistance determinants and, if they were found to be acquired, attempt to remove them from the strain by methods that do not genetically modify the organism before subsequently testing whether the probiotic characteristics were retained. No known beta-lactam resistance genes was found, but penicillin-binding proteins from ATCC 55730, two additional resistant strains, and three sensitive strains of L. reuteri were sequenced and comparatively analyzed. The beta-lactam resistance in ATCC 55730 is probably caused by a number of alterations in the corresponding genes and can be regarded as not transferable. The strain was found to harbor two plasmids carrying tet(W) tetracycline and lnu(A) lincosamide resistance genes, respectively. A new daughter strain, L. reuteri DSM 17938, was derived from ATCC 55730 by removal of the two plasmids, and it was shown to have lost the resistances associated with them. Direct comparison of the parent and daughter strains for a series of in vitro properties and in a human clinical trial confirmed the retained probiotic properties of the daughter strain. PMID:18689509

  8. Heavy metals in liquid pig manure in light of bacterial antimicrobial resistance

    Energy Technology Data Exchange (ETDEWEB)

    Hoelzel, Christina S., E-mail: Christina.Hoelzel@wzw.tum.de [Chair of Animal Hygiene, Technische Universitaet Muenchen, Weihenstephaner Berg 3, 85354 Freising (Germany); Mueller, Christa [Institute for Agroecology, Organic Farming and Soil Protection, Bavarian State Research Center for Agriculture (LfL), Lange Point 12, 85354 Freising (Germany); Harms, Katrin S. [Chair of Animal Hygiene, Technische Universitaet Muenchen, Weihenstephaner Berg 3, 85354 Freising (Germany); Mikolajewski, Sabine [Department for Quality Assurance and Analytics, Bavarian State Research Center for Agriculture (LfL), Lange Point 4, 85354 Freising (Germany); Schaefer, Stefanie; Schwaiger, Karin; Bauer, Johann [Chair of Animal Hygiene, Technische Universitaet Muenchen, Weihenstephaner Berg 3, 85354 Freising (Germany)

    2012-02-15

    Heavy metals are regularly found in liquid pig manure, and might interact with bacterial antimicrobial resistance. Concentrations of heavy metals were determined by atomic spectroscopic methods in 305 pig manure samples and were connected to the phenotypic resistance of Escherichia coli (n=613) against 29 antimicrobial drugs. Concentrations of heavy metals (/kg dry matter) were 0.08-5.30 mg cadmium, 1.1-32.0 mg chrome, 22.4-3387.6 mg copper, <2.0-26.7 mg lead, <0.01-0.11 mg mercury, 3.1-97.3 mg nickel and 93.0-8239.0 mg zinc. Associated with the detection of copper and zinc, resistance rates against {beta}-lactams were significantly elevated. By contrast, the presence of mercury was significantly associated with low antimicrobial resistance rates of Escherichia coli against {beta}-lactams, aminoglycosides and other antibiotics. Effects of subinhibitory concentrations of mercury on bacterial resistance against penicillins, cephalosporins, aminoglycosides and doxycycline were also demonstrated in a laboratory trial. Antimicrobial resistance in the porcine microflora might be increased by copper and zinc. By contrast, the occurrence of mercury in the environment might, due to co-toxicity, act counter-selective against antimicrobial resistant strains.

  9. Breast abscess caused by penicillin resistant Pneumococci

    Directory of Open Access Journals (Sweden)

    Boppe Appalaraju

    2011-01-01

    Full Text Available Breast abscess is mostly caused by Staphylococcus aureus. A 26-year-old immunocompetent lady was admitted with breast abscess. Incision and drainage (I/D was done and Pneumococci were isolated from the drained pus. The patient was earlier treated with Augmentin which was later changed to linezolid after testing for antibiotic susceptibility. This strain showed a high level of resistance to penicillin. It had been noticed that there was a slow increase in the number of penicillin resistant Pneumococci isolated in our hospitals. The increase in penicillin-resistant Pneumococci correlates with the intensive use of beta-lactam antibiotics. Hence, antibiotics should be used judiciously, avoiding their use particularly in mild self-limiting upper respiratory infections. Attention therefore, should focus on monitoring resistance in Pneumococci to prevent mortality and morbidity associated with this organism, which continues to take a heavy toll on children and the elderly.

  10. In vitro activity effects of combinations of cephalothin, dicloxacillin, imipenem, vancomycin and amikacin against methicillin-resistant Staphylococcus spp. strains

    Directory of Open Access Journals (Sweden)

    Solórzano-Santos Fortino

    2006-10-01

    Full Text Available Abstract Background combinations of drugs has been proposed as an alternative for oxacillin-resistant staphylococci infections, however, limited information about in vitro combinations are available for multi-resistant strains. The objective of this study was to describe the interaction of beta-lactams in combination with vancomycin or amikacin against 26 oxacillin and amikacin-resistant nosocomial Staphylococcus spp. isolates. Methods activity of dicloxacillin plus amikacin, cephalothin plus amikacin, cephalothin plus vancomycin, imipenem plus vancomycin and vancomycin plus amikacin was evaluated by checkerboard synergy tests and the fractional inhibitory concentration index (FIC was calculated. Results: dicloxacillin plus amikacin, and cephalothin plus amikacin were synergistic or partially synergistic in 84.6% and 100% respectively. For nearly half of the isolates the mean concentrations of dicloxacillin, cephalothin and amikacin at which FIC indexes were calculated were achievable therapeutically. Vancomycin plus amikacin had synergistic effect only against two isolates, and partially synergistic in 38.6%. For the combinations vancomycin plus cephalothin and vancomycin plus imipenem the effect was additive in 76.9% and 80.7% respectively. Conclusion in this study the checkerboard analysis showed that amikacin in combination with cephalothin or dicloxacillin was synergistic against most of the resistant strains of S. aureus and coagulase-negative Staphylococcus. Vancomycin in combination with a beta-lactam (cephalothin or imipenem showed additivity. An indifferent effect predominated for the combination vancomycin plus amikacin. Even though a synergistic effect is expected when using a beta-lactam plus amikacin combination, it is possible that the effect cannot be clinically achievable. Careful selection of antimicrobial combinations and initial MICs are mandatory for future evaluations.

  11. The mecA homolog mecC confers resistance against β-lactams in Staphylococcus aureus irrespective of the genetic strain background.

    Science.gov (United States)

    Ballhausen, Britta; Kriegeskorte, André; Schleimer, Nina; Peters, Georg; Becker, Karsten

    2014-07-01

    In staphylococci, methicillin resistance is mediated by mecA-encoded penicillin-binding protein 2a (PBP2a), which has a low affinity for beta-lactams. Recently, a novel PBP2a homolog was described as being encoded by mecC, which shares only 70% similarity to mecA. To prove that mecC is the genetic determinant that confers methicillin resistance in Staphylococcus aureus, a mecC knockout strain was generated. The S. aureus ΔmecC strain showed considerably reduced oxacillin and cefoxitin MICs (0.25 and 4 μg/ml, respectively) compared to those of the corresponding wild-type methicillin-resistant S. aureus (MRSA) strain (8 and 16 μg/ml, respectively). Complementing the mutant in trans with wild-type mecC restored the resistance to oxacillin and cefoxitin. By expressing mecC and mecA in different S. aureus clonal lineages, we found that mecC mediates resistance irrespective of the genetic strain background, yielding oxacillin and cefoxitin MIC values comparable to those with mecA. In addition, we showed that mecC expression is inducible by oxacillin, which supports the assumption that a functional beta-lactam-dependent regulatory system is active in MRSA strains possessing staphylococcal cassette chromosome mec (SCCmec) type XI. In summary, we showed that mecC is inducible by oxacillin and mediates beta-lactam resistance in SCCmec type XI-carrying strains as well as in different S. aureus genetic backgrounds. Furthermore, our results could explain the comparatively low MICs for clinical mecC-harboring S. aureus isolates. PMID:24752255

  12. Optimising dosing strategies of antibacterials utilising pharmacodynamic principles: impact on the development of resistance.

    Science.gov (United States)

    DeRyke, C Andrew; Lee, Su Young; Kuti, Joseph L; Nicolau, David P

    2006-01-01

    Evolving antimicrobial resistance is of global concern. The impact of decreased susceptibility to current antibacterials coupled with the decline in the marketing of new agents with novel mechanisms of action places a tremendous burden on clinicians to appropriately use available agents. Optimising antibacterial dose administration through the use of pharmacodynamic principles can aid clinicians in accomplishing this task more effectively. Methods to achieve this include: continuous or prolonged infusion, or the use of smaller doses administered more frequently for the time-dependent beta-lactam agents; or higher, less frequent dose administration of the concentration-dependent aminoglycosides and fluoroquinolones. Pharmacodynamic breakpoints, which are predictive of clinical and/or microbiological success in the treatment of infection, have been determined for many classes of antibacterials, including the fluoroquinolones, aminoglycosides and beta-lactams. Although surpassing these values may predict efficacy, it may not prevent the development of resistance. Recent studies seek to determine the pharmacodynamic breakpoints that prevent the development of resistance. Numerous studies to this point have determined these values in fluoroquinolones in both Gram-positive and Gram-negative bacteria. However, among the other antibacterial classes, there is a lack of sufficient data. Additionally, a new term, the mutant prevention concentration, has been based on the concentrations above which resistance is unlikely to occur. Future work is needed to fully characterise these target concentrations that prevent resistance. PMID:16398565

  13. The Role and Impact of Affect in the Process of Resistance to Persuasion.

    Science.gov (United States)

    Pfau, Michael; Szabo, Erin Alison; Anderson, Jason; Morrill, Joshua; Zubric, Jessica; Wan, Hua-Hsin

    2001-01-01

    Deals with the role and impact of affect in the process of resistance among undergraduate students. Notes that initial results indicated that the cognitive, affective-anger, and affective-happiness inoculation treatments all conferred resistance to persuasive attacks. Indicates that greater receiver involvement was positively associated with…

  14. Antibiotic Resistance Patterns in Invasive Group B Streptococcal Isolates

    Directory of Open Access Journals (Sweden)

    Mei L. Castor

    2008-01-01

    Full Text Available Antibiotics are used for both group B streptococcal (GBS prevention and treatment. Active population-based surveillance for invasive GBS disease was conducted in four states during 1996—2003. Of 3813 case-isolates, 91.0% (3471 were serotyped, 77.1% (2937 had susceptibility testing, and 46.6% (3471 had both. All were sensitive to penicillin, ampicillin, cefazolin, cefotaxime, and vancomycin. Clindamycin and erythromycin resistance was 12.7% and 25.6%, respectively, and associated with serotype V (P<.001. Clindamycin resistance increased from 10.5% to 15.0% (X2 for trend 12.70; P<.001; inducible clindamycin resistance was associated with the erm genotype. Erythromycin resistance increased from 15.8% to 32.8% (X2 for trend 55.46; P<.001. While GBS remains susceptible to beta-lactams, resistance to alternative agents such as erythromycin and clindamycin is an increasing concern.

  15. Seneca’s Error: An Affective Model of Cognitive Resistance

    NARCIS (Netherlands)

    De Boer, R.J.

    2012-01-01

    The aim of this research is to contribute to the body of knowledge on mental models in the fields of design methodology, engineering psychology and human factors by studying the resistance of mental models to change. In this work the term cognitive resistance is introduced as the capacity to endure

  16. The Structural Bases of Antibiotic Resistance in the Clinically Derived Mutant beta-Lactamases TEM-30, TEM-32, and TEM-34

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaojun; Minasov, George; Shoichet, Brian K. (NWU)

    2010-03-08

    Widespread use of {beta}-lactam antibiotics has promoted the evolution of {beta}-lactamase mutant enzymes that can hydrolyze ever newer classes of these drugs. Among the most pernicious mutants are the inhibitor-resistant TEM {beta}-lactamases (IRTs), which elude mechanism-based inhibitors, such as clavulanate. Despite much research on these IRTs, little is known about the structural bases of their action. This has made it difficult to understand how many of the resistance substitutions act as they often occur far from Ser-130. Here, three IRT structures, TEM-30 (R244S), TEM-32 (M69I/M182T), and TEM-34 (M69V), are determined by x-ray crystallography at 2.00, 1.61, and 1.52 {angstrom}, respectively. In TEM-30, the Arg-244 {yields} Ser substitution (7.8 {angstrom} from Ser-130) displaces a conserved water molecule that usually interacts with the {beta}-lactam C3 carboxylate. In TEM-32, the substitution Met-69 {yields} Ile (10 {angstrom} from Ser-130) appears to distort Ser-70, which in turn causes Ser-130 to adopt a new conformation, moving its O{gamma} further away, 2.3 {angstrom} from where the inhibitor would bind. This substitution also destabilizes the enzyme by 1.3 kcal/mol. The Met-182 {yields} Thr substitution (20 {angstrom} from Ser-130) has no effect on enzyme activity but rather restabilizes the enzyme by 2.9 kcal/mol. In TEM-34, the Met-69 {yields} Val substitution similarly leads to a conformational change in Ser-130, this time causing it to hydrogen bond with Lys-73 and Lys-234. This masks the lone pair electrons of Ser-130 O{gamma}, reducing its nucleophilicity for cross-linking. In these three structures, distant substitutions result in accommodations that converge on the same point of action, the local environment of Ser-130. TEM-1 {beta}-lactamase is the predominant source of resistance to {beta}-lactams, such as the penicillins. TEM-1 and related class A {beta}-lactamases confer resistance by hydrolyzing the {beta}-lactam ring of these antibiotics

  17. Seneca’s Error: An Affective Model of Cognitive Resistance

    OpenAIRE

    Boer, R.J. de

    2012-01-01

    The aim of this research is to contribute to the body of knowledge on mental models in the fields of design methodology, engineering psychology and human factors by studying the resistance of mental models to change. In this work the term cognitive resistance is introduced as the capacity to endure stimuli from the environment that contradict the mental model, and its episodic nature is investigated. Three main points have been addressed in the current research: the identification of the comp...

  18. Prevalence of Antibiotic-Resistant Bacteria on Rectal Swabs and Factors Affecting Resistance to Antibiotics in Patients Undergoing Prostate Biopsy

    OpenAIRE

    Kim, Jong Beom; Jung, Seung Il; Hwang, Eu Chang; Kwon, Dong Deuk

    2014-01-01

    Purpose The prevalence of antibiotic-resistant bacteria on rectal swabs in patients undergoing transrectal ultrasound (TRUS)-guided prostate biopsy and the factors affecting resistance to antibiotics were evaluated. Materials and Methods Two hundred twenty-three men who underwent TRUS-guided prostate biopsy from November 2011 to December 2012 were retrospectively evaluated. Rectal swabs were cultured on MacConkey agar to identify antibiotic-resistant bacteria in rectal flora before TRUS-guide...

  19. In vivo selection of a chromosomally encoded beta-lactamase variant conferring ceftazidime resistance in Klebsiella oxytoca.

    Science.gov (United States)

    Mammeri, Hedi; Poirel, Laurent; Nordmann, Patrice

    2003-12-01

    Klebsiella oxytoca clinical isolate A was recovered from the urine of a 55-year-old man with prostatic and urinary tract infections. This isolate displayed a beta-lactam resistance phenotype consistent with overproduction of a chromosomally encoded class A beta-lactamase and had decreased susceptibilities to all beta-lactams except ceftazidime, cephamycins, and carbapenems. Four weeks after treatment with an antibiotic regimen that included ceftazidime, K. oxytoca isolate B, which had a high level of resistance to ceftazidime, was isolated from the urine of the same patient. Isoelectric focusing analysis of the culture extracts of these isolates gave a pI of 5.4 for both isolates. Cloning experiments with the PCR products of the bla(OXY) gene resulted in two Escherichia coli DH10B recombinant clones with resistance phenotypes mirroring those of the parental isolates. Sequencing analysis revealed that the bla(OXY-2-5) gene from K. oxytoca B had a single nucleotide substitution compared to the sequence of the bla(OXY-2) gene from K. oxytoca A, leading to a proline-to-serine substitution at position 167, according to the numbering of Ambler. Biochemical analysis of purified OXY-2-5 showed that it had the ability to hydrolyze ceftazidime. This is the first report of in vivo selection of a K. oxytoca isolate that produced a chromosomally encoded beta-lactamase conferring resistance to ceftazidime. PMID:14638475

  20. Biocide Susceptibility of Staphylococcus aureus CC398 and CC30 Isolates from Pigs and Identification of the Biocide Resistance Genes, qacG and qacC

    DEFF Research Database (Denmark)

    Seier-Petersen, Maria Amalie; Nielsen, Lene Nørby; Ingmer, Hanne;

    2015-01-01

    screened for lukPV and tst genes with PCR, and hemolytic activities were determined using an agar plate assay. Results: S. aureus isolates did not show reduced susceptibility to the biocides tested. However, the QAC resistance gene, qacG, was detected in three MRSA CC30 isolates and the qacC in one MRSA CC......30 isolate. CC30 isolates were generally more susceptible to non-beta-lactam antibiotics than CC398. Isolates generally had low hemolytic activity and none encoded PVL or TSST-1. Conclusion: The presence of qac genes in European porcine S. aureus isolates and in livestock-associated MRSA CC30 is for...

  1. Reduced virulence of Candida albicans mutants affected in multidrug resistance.

    OpenAIRE

    Becker, J. M.; Henry, L K; Jiang, W; Koltin, Y.

    1995-01-01

    Disruption of a multidrug resistance gene (CaMDR1) in Candida albicans resulted in mutant strains that colonized mouse kidneys to very high levels but were markedly reduced in their virulence. No obvious differences in several properties related to colonization and dissemination were noted among MDR+ or mdr- strains. These results suggest that specific fungal efflux pumps play a role in fungal pathogenicity.

  2. Concentric resistance training increases muscle strength without affecting microcirculation

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Marc-Andre [Department of Diagnostic and Interventional Radiology, University of Heidelberg, Heidelberg (Germany)], E-mail: MarcAndre.Weber@med.uni-heidelberg.de; Hildebrandt, Wulf [Immunochemistry, German Cancer Research Center (dkfz), Heidelberg (Germany); Schroeder, Leif [Medical Physics in Radiology, German Cancer Research Center (dkfz), Heidelberg (Germany); Kinscherf, Ralf [Department of Anatomy and Developmental Biology, University of Heidelberg, Heidelberg (Germany); Krix, Martin [Radiology, German Cancer Research Center (dkfz), Heidelberg (Germany); Bachert, Peter [Medical Physics in Radiology, German Cancer Research Center (dkfz), Heidelberg (Germany); Delorme, Stefan; Essig, Marco [Radiology, German Cancer Research Center (dkfz), Heidelberg (Germany); Kauczor, Hans-Ulrich [Department of Diagnostic and Interventional Radiology, University of Heidelberg, Heidelberg (Germany); Krakowski-Roosen, Holger [National Center for Tumor Diseases (NCT), Heidelberg (Germany)

    2010-03-15

    Purpose: While the evidence is conclusive regarding the positive effects of endurance training, there is still some controversy regarding the effects of resistance training on muscular capillarity. Thus, the purpose was to assess whether resistance strength training influences resting skeletal muscle microcirculation in vivo. Materials and methods: Thirty-nine middle-aged subjects (15 female, 24 male; mean age, 54 {+-} 9 years) were trained twice a week on an isokinetic system (altogether 16 sessions lasting 50 min, intensity 75% of maximum isokinetic and isometric force of knee flexors and extensors). To evaluate success of training, cross-sectional area (CSA) of the quadriceps femoris muscle and its isokinetic and isometric force were quantified. Muscular capillarization was measured in biopsies of the vastus lateralis muscle. In vivo, muscular energy and lipid metabolites were quantified by magnetic resonance spectroscopy and parameters of muscular microcirculation, such as local blood volume, blood flow and velocity, by contrast-enhanced ultrasound analyzing replenishment kinetics. Results: The significant (P < 0.001) increase in CSA (60 {+-} 16 before vs. 64 {+-} 15 cm{sup 2} after training) and in absolute muscle strength (isometric, 146 {+-} 44 vs. 174 {+-} 50 Nm; isokinetic, 151 {+-} 53 vs. 174 {+-} 62 Nm) demonstrated successful training. Neither capillary density ex vivo (351 {+-} 75 vs. 326 {+-} 62) nor ultrasonographic parameters of resting muscle perfusion were significantly different (blood flow, 1.2 {+-} 1.2 vs. 1.1 {+-} 1.1 ml/min/100 g; blood flow velocity, 0.49 {+-} 0.44 vs. 0.52 {+-} 0.74 mm s{sup -1}). Also, the intensities of high-energy phosphates phosphocreatine and {beta}-adenosintriphosphate were not different after training within the skeletal muscle at rest ({beta}-ATP/phosphocreatine, 0.29 {+-} 0.06 vs. 0.28 {+-} 0.04). Conclusion: The significant increase in muscle size and strength in response to concentric isokinetic and isometric

  3. Concentric resistance training increases muscle strength without affecting microcirculation

    International Nuclear Information System (INIS)

    Purpose: While the evidence is conclusive regarding the positive effects of endurance training, there is still some controversy regarding the effects of resistance training on muscular capillarity. Thus, the purpose was to assess whether resistance strength training influences resting skeletal muscle microcirculation in vivo. Materials and methods: Thirty-nine middle-aged subjects (15 female, 24 male; mean age, 54 ± 9 years) were trained twice a week on an isokinetic system (altogether 16 sessions lasting 50 min, intensity 75% of maximum isokinetic and isometric force of knee flexors and extensors). To evaluate success of training, cross-sectional area (CSA) of the quadriceps femoris muscle and its isokinetic and isometric force were quantified. Muscular capillarization was measured in biopsies of the vastus lateralis muscle. In vivo, muscular energy and lipid metabolites were quantified by magnetic resonance spectroscopy and parameters of muscular microcirculation, such as local blood volume, blood flow and velocity, by contrast-enhanced ultrasound analyzing replenishment kinetics. Results: The significant (P 2 after training) and in absolute muscle strength (isometric, 146 ± 44 vs. 174 ± 50 Nm; isokinetic, 151 ± 53 vs. 174 ± 62 Nm) demonstrated successful training. Neither capillary density ex vivo (351 ± 75 vs. 326 ± 62) nor ultrasonographic parameters of resting muscle perfusion were significantly different (blood flow, 1.2 ± 1.2 vs. 1.1 ± 1.1 ml/min/100 g; blood flow velocity, 0.49 ± 0.44 vs. 0.52 ± 0.74 mm s-1). Also, the intensities of high-energy phosphates phosphocreatine and β-adenosintriphosphate were not different after training within the skeletal muscle at rest (β-ATP/phosphocreatine, 0.29 ± 0.06 vs. 0.28 ± 0.04). Conclusion: The significant increase in muscle size and strength in response to concentric isokinetic and isometric resistance training occurs without an increase in the in vivo microcirculation of the skeletal muscles at rest.

  4. Combination of essential oils and antibiotics reduce antibiotic resistance in plasmid-conferred multidrug resistant bacteria.

    Science.gov (United States)

    Yap, Polly Soo Xi; Lim, Swee Hua Erin; Hu, Cai Ping; Yiap, Beow Chin

    2013-06-15

    In this study we investigated the relationship between several selected commercially available essential oils and beta-lactam antibiotics on their antibacterial effect against multidrug resistant bacteria. The antibacterial activity of essential oils and antibiotics was assessed using broth microdilution. The combined effects between essential oils of cinnamon bark, lavender, marjoram, tea tree, peppermint and ampicillin, piperacillin, cefazolin, cefuroxime, carbenicillin, ceftazidime, meropenem, were evaluated by means of the checkerboard method against beta-lactamase-producing Escherichia coli. In the latter assays, fractional inhibitory concentration (FIC) values were calculated to characterize interaction between the combinations. Substantial susceptibility of the bacteria toward natural antibiotics and a considerable reduction in the minimum inhibitory concentrations (MIC) of the antibiotics were noted in some paired combinations of antibiotics and essential oils. Out of 35 antibiotic-essential oil pairs tested, four of them showed synergistic effect (FIC≤0.5) and 31 pairs showed no interaction (FIC>0.5-4.0). The preliminary results obtained highlighted the occurrence of a pronounced synergistic relationship between piperacillin/cinnamon bark oil, piperacillin/lavender oil, piperacillin/peppermint oil as well as meropenem/peppermint oil against two of the three bacteria under study with a FIC index in the range 0.26-0.5. The finding highlighted the potential of peppermint, cinnamon bark and lavender essential oils being as antibiotic resistance modifying agent. Reduced usage of antibiotics could be employed as a treatment strategy to decrease the adverse effects and possibly to reverse the beta-lactam antibiotic resistance. PMID:23537749

  5. Endemic carbapenem-resistant Pseudomonas aeruginosa with acquired metallo-beta-lactamase determinants in European hospital.

    Science.gov (United States)

    Lagatolla, Cristina; Tonin, Enrico A; Monti-Bragadin, Carlo; Dolzani, Lucilla; Gombac, Francesca; Bearzi, Claudia; Edalucci, Elisabetta; Gionechetti, Fabrizia; Rossolini, Gian Maria

    2004-03-01

    Acquired metallo-beta-lactamases (MBLs) can confer broad-spectrum beta-lactam resistance (including carbapenems) not reversible by conventional beta-lactamase inhibitors and are emerging resistance determinants of remarkable clinical importance. In 2001, multidrug-resistant Pseudomonas aeruginosa carrying bla(VIM) MBL genes were found to be widespread (approximately 20% of all P. aeruginosa isolates and 70% of the carbapenem-resistant isolates) at Trieste University Hospital. Clonal diversity and heterogeneity of resistance determinants (either bla(VIM-1)-like or bla(VIM-2)-like) were detected among MBL producers. This evidence is the first that acquired MBLs can rapidly emerge and establish a condition of endemicity in certain epidemiologic settings. PMID:15109432

  6. How could preventive therapy affect the prevalence of drug resistance? Causes and consequences.

    Science.gov (United States)

    Kunkel, Amber; Colijn, Caroline; Lipsitch, Marc; Cohen, Ted

    2015-06-01

    Various forms of preventive and prophylactic antimicrobial therapies have been proposed to combat HIV (e.g. pre-exposure prophylaxis), tuberculosis (e.g. isoniazid preventive therapy) and malaria (e.g. intermittent preventive treatment). However, the potential population-level effects of preventative therapy (PT) on the prevalence of drug resistance are not well understood. PT can directly affect the rate at which resistance is acquired among those receiving PT. It can also indirectly affect resistance by altering the rate at which resistance is acquired through treatment for active disease and by modifying the level of competition between transmission of drug-resistant and drug-sensitive pathogens. We propose a general mathematical model to explore the ways in which PT can affect the long-term prevalence of drug resistance. Depending on the relative contributions of these three mechanisms, we find that increasing the level of coverage of PT may result in increases, decreases or non-monotonic changes in the overall prevalence of drug resistance. These results demonstrate the complexity of the relationship between PT and drug resistance in the population. Care should be taken when predicting population-level changes in drug resistance from small pilot studies of PT or estimates based solely on its direct effects. PMID:25918446

  7. Surveillance and Detection of Inhibitor-Resistant Beta-Lactamases in Clinical Isolates of Escherichia coli

    Directory of Open Access Journals (Sweden)

    Carl Urban

    2007-06-01

    Full Text Available In recent years, resistance to beta-lactam antibiotics, such as the widely-used cephalosporins and penicillins, has become a major challenge for disease therapy, particularly in common hospital-acquired infections. In the search for the mechanisms behind this increasingly prevalent form of resistance, microbiologists have identified a new type of beta-lactamase enzyme, called inhibitor-resistant TEMs (IRTs, which can withstand the effects of beta-lactamase inhibitor compounds, further reducing the arsenal of drugs available to physicians facing resistant bacteria. In this study, we examined the enzymatic and genetic basis of Escherichia coli isolates demonstrating such resistance to beta-lactam/beta-lactamase inhibitor combinations. Susceptibility trials played a major role in composing the experimental cohort for this project (n=50; each isolate was thoroughly tested to ensure that it was resistant to ampicillin-sulbactam, an inhibitor combination, but susceptible to the third-generation cephalosporin ceftazidime. Subsequently, a number of samples were subjected to assay by pulsed-field gel electrophoresis (n=18 and polymerase chain reaction (n=3 so that their genetic composition and relatedness might be known. In particular, the presence of genes coding for TEM-type beta-lactamases was investigated for each of the 3 isolates sequenced. Even though it was anticipated that the isolates would possess resistance to inhibitor combinations due to an IRT gene, this was not found to be the case. Instead, the mechanism of resistance turned out to be over-expression of a gene coding for a normal TEM enzyme. The results of these experiments have implications for ensuring successful therapy of bacterial infections and for preventing the spread of antimicrobial resistance.

  8. CHARACTERIZATION OF HOSPITAL ACQUIRED METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS

    Directory of Open Access Journals (Sweden)

    Preethi. B.M

    2012-12-01

    Full Text Available Methicillin Resistant Staphylococcus aureus (MRSA strains have emerged as one of the most important nosocomial pathogens. The MRSA can cause a wide range of diseases, which is associated with its production to large number of extracellular toxins and other virulence factors. The diseases are toxic shock syndrome, scalded skin syndrome and food poisoning. Hospital-acquired MRSA (HA-MRSA in persons who have had frequent or recent contact with hospitals or healthcare facilities within the previous year, has recently undergone an invasive medical procedure, or is immunocompromised. Mostly HA-MRSA are transmitted most frequently through direct skin-to-skin contact or contact with shared items or surfaces that have come into contact with someone else’s colonized or infected skin. Panton Valentine Leukocidin (PVL is a biocomponent toxin has been shown to induce lysis of host defence cells. The absence of the PVL gene confirms the MRSA as HA-MRSA. Slime layer plays a remarkable role in bacterial colonization of exterior surfaces by adhesion and production of slime factor plays an important role in antibiotic resistance. Beta lactamases render bacteria resistant to beta-lactam antibiotics by hydrolyzing the beta lactam ring of penicillin’s and cephalosporins.There is a linear correlation between beta-lactamase activity and the level of resistance of bacteria to penicillins. The phage groups II and III were present in hospital acquired MRSA which colonizes on the normal skin and enter the body through cut/wound or by fracture and cause osteomyelitis and bacterial arthritis. Bacteriophage typing of MRSA strains is an epidemiological marker and is a successful method in strain characterization.

  9. Abiotic stresses affect Trichoderma harzianum T39-induced resistance to downy mildew in grapevine.

    Science.gov (United States)

    Roatti, Benedetta; Perazzolli, Michele; Gessler, Cesare; Pertot, Ilaria

    2013-12-01

    Enhancement of plant defense through the application of resistance inducers seems a promising alternative to chemical fungicides for controlling crop diseases but the efficacy can be affected by abiotic factors in the field. Plants respond to abiotic stresses with hormonal signals that may interfere with the mechanisms of induced systemic resistance (ISR) to pathogens. In this study, we exposed grapevines to heat, drought, or both to investigate the effects of abiotic stresses on grapevine resistance induced by Trichoderma harzianum T39 (T39) to downy mildew. Whereas the efficacy of T39-induced resistance was not affected by exposure to heat or drought, it was significantly reduced by combined abiotic stresses. Decrease of leaf water potential and upregulation of heat-stress markers confirmed that plants reacted to abiotic stresses. Basal expression of defense-related genes and their upregulation during T39-induced resistance were attenuated by abiotic stresses, in agreement with the reduced efficacy of T39. The evidence reported here suggests that exposure of crops to abiotic stress should be carefully considered to optimize the use of resistance inducers, especially in view of future global climate changes. Expression analysis of ISR marker genes could be helpful to identify when plants are responding to abiotic stresses, in order to optimize treatments with resistance inducers in field. PMID:23841621

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

    Science.gov (United States)

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

    2014-01-01

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

  11. Antibiotic resistance in lactic acid bacteria and Micrococcaceae/Staphylococcaceae isolates from artisanal raw milk cheeses, and potential implications on cheese making.

    Science.gov (United States)

    Rodríguez-Alonso, P; Fernández-Otero, C; Centeno, J A; Garabal, J I

    2009-08-01

    Antibiotic susceptibility against 19 antimicrobial agents was evaluated in isolates of the genera Lactococcus (46 isolates), Leuconostoc (22), Lactobacillus (19), Staphylococcus (8), Enterococcus (7), and Microccoccus/Kocuria (5) obtained from the predominant microflora of nonrecent and recent types of artisanal raw cow's milk cheeses. Beta-lactams showed broad activity against all genera, although leuconostocs and lactobacilli were highly resistant to oxacillin (80% to 95.5%). Resistance to aminoglycosides was frequent for lactococci and enterococci (particularly for streptomycin), whereas lower rates of resistance were detected for lactobacilli and leuconostocs. Technologically interesting traits for the food industry were distributed among isolates that showed different degrees of resistance to common antibiotics. However, isolates showing resistance to less than 2 antibiotics were mainly those with properties of greatest technological interest (acidifying activity, proteolytic/lipolytic activities, or diacetyl production). PMID:19723213

  12. Longitudinal nasopharyngeal carriage and antibiotic resistance of respiratory bacteria in indigenous Australian and Alaska native children with bronchiectasis.

    Directory of Open Access Journals (Sweden)

    Kim M Hare

    Full Text Available BACKGROUND: Indigenous children in Australia and Alaska have very high rates of chronic suppurative lung disease (CSLD/bronchiectasis. Antibiotics, including frequent or long-term azithromycin in Australia and short-term beta-lactam therapy in both countries, are often prescribed to treat these patients. In the Bronchiectasis Observational Study we examined over several years the nasopharyngeal carriage and antibiotic resistance of respiratory bacteria in these two PCV7-vaccinated populations. METHODS: Indigenous children aged 0.5-8.9 years with CSLD/bronchiectasis from remote Australia (n = 79 and Alaska (n = 41 were enrolled in a prospective cohort study during 2004-8. At scheduled study visits until 2010 antibiotic use in the preceding 2-weeks was recorded and nasopharyngeal swabs collected for culture and antimicrobial susceptibility testing. Analysis of respiratory bacterial carriage and antibiotic resistance was by baseline and final swabs, and total swabs by year. RESULTS: Streptococcus pneumoniae carriage changed little over time. In contrast, carriage of Haemophilus influenzae declined and Staphylococcus aureus increased (from 0% in 2005-6 to 23% in 2010 in Alaskan children; these changes were associated with increasing age. Moraxella catarrhalis carriage declined significantly in Australian, but not Alaskan, children (from 64% in 2004-6 to 11% in 2010. While beta-lactam antibiotic use was similar in the two cohorts, Australian children received more azithromycin. Macrolide resistance was significantly higher in Australian compared to Alaskan children, while H. influenzae beta-lactam resistance was higher in Alaskan children. Azithromycin use coincided significantly with reduced carriage of S. pneumoniae, H. influenzae and M. catarrhalis, but increased carriage of S. aureus and macrolide-resistant strains of S. pneumoniae and S. aureus (proportion of carriers and all swabs, in a 'cumulative dose-response' relationship

  13. A signaling protease required for melanization in Drosophila affects resistance and tolerance of infections.

    Directory of Open Access Journals (Sweden)

    Janelle S Ayres

    2008-12-01

    Full Text Available Organisms evolve two routes to surviving infections-they can resist pathogen growth (resistance and they can endure the pathogenesis of infection (tolerance. The sum of these two properties together defines the defensive capabilities of the host. Typically, studies of animal defenses focus on either understanding resistance or, to a lesser extent, tolerance mechanisms, thus providing little understanding of the relationship between these two mechanisms. We suggest there are nine possible pairwise permutations of these traits, assuming they can increase, decrease, or remain unchanged in an independent manner. Here we show that by making a single mutation in the gene encoding a protease, CG3066, active in the melanization cascade in Drosophila melanogaster, we observe the full spectrum of changes; these mutant flies show increases and decreases in their resistance and tolerance properties when challenged with a variety of pathogens. This result implicates melanization in fighting microbial infections and shows that an immune response can affect both resistance and tolerance to infections in microbe-dependent ways. The fly is often described as having an unsophisticated and stereotypical immune response where single mutations cause simple binary changes in immunity. We report a level of complexity in the fly's immune response that has strong ecological implications. We suggest that immune responses are highly tuned by evolution, since selection for defenses that alter resistance against one pathogen may change both resistance and tolerance to other pathogens.

  14. Resistance of Xanthomonas maltophilia to antibiotics and the effect of beta-lactamase inhibitors.

    Science.gov (United States)

    Neu, H C; Saha, G; Chin, N X

    1989-01-01

    We examined the susceptibility of 50 isolates of Xanthomonas maltophilia and the effect of beta-lactamase inhibitors upon the susceptibility. The majority of isolates were resistant to azlocillin, piperacillin, mezlocillin, ticarcillin, cefotaxime, ceftizoxime, ceftriaxone, cefoperazone, and ceftazidime. All isolates were resistant to imipenem, CGP 31608, aztreonam, and carumonam. Although disk susceptibility tests showed that the combination of clavulanate with ticarcillin inhibited many isolates, at a ratio of 1:20 few isolates were susceptible to the combination. Addition of clavulanate to aztreonam and to imipenem failed to make organisms susceptible. Sulbactam combined with cefoperazone made some organisms susceptible, but ampicillin-sulbactam was ineffective, whereas tazobactam combined with piperacillin at a ratio of 1:4 made half the isolates have MICs of 32 micrograms/ml or less. The beta-lactamases from the isolates hydrolyzed all of the beta-lactams. PMID:2791491

  15. Crystal Structures of Penicillin-Binding Protein 2 From Penicillin-Susceptible And -Resistant Strains of Neisseria Gonorrhoeae Reveal An Unexpectedly Subtle Mechanism for Antibiotic Resistance

    Energy Technology Data Exchange (ETDEWEB)

    Powell, A.J.; Tomberg, J.; Deacon, A.M.; Nicholas, R.A.; Davies, C.

    2009-05-21

    Penicillin-binding protein 2 (PBP2) from N. gonorrhoeae is the major molecular target for {beta}-lactam antibiotics used to treat gonococcal infections. PBP2 from penicillin-resistant strains of N. gonorrhoeae harbors an aspartate insertion after position 345 (Asp-345a) and 4-8 additional mutations, but how these alter the architecture of the protein is unknown. We have determined the crystal structure of PBP2 derived from the penicillin-susceptible strain FA19, which shows that the likely effect of Asp-345a is to alter a hydrogen-bonding network involving Asp-346 and the SXN triad at the active site. We have also solved the crystal structure of PBP2 derived from the penicillin-resistant strain FA6140 that contains four mutations near the C terminus of the protein. Although these mutations lower the second order rate of acylation for penicillin by 5-fold relative to wild type, comparison of the two structures shows only minor structural differences, with the positions of the conserved residues in the active site essentially the same in both. Kinetic analyses indicate that two mutations, P551S and F504L, are mainly responsible for the decrease in acylation rate. Melting curves show that the four mutations lower the thermal stability of the enzyme. Overall, these data suggest that the molecular mechanism underlying antibiotic resistance contributed by the four mutations is subtle and involves a small but measurable disordering of residues in the active site region that either restricts the binding of antibiotic or impedes conformational changes that are required for acylation by {beta}-lactam antibiotics.

  16. Antimicrobial Resistance Prediction in PATRIC and RAST.

    Science.gov (United States)

    Davis, James J; Boisvert, Sébastien; Brettin, Thomas; Kenyon, Ronald W; Mao, Chunhong; Olson, Robert; Overbeek, Ross; Santerre, John; Shukla, Maulik; Wattam, Alice R; Will, Rebecca; Xia, Fangfang; Stevens, Rick

    2016-01-01

    The emergence and spread of antimicrobial resistance (AMR) mechanisms in bacterial pathogens, coupled with the dwindling number of effective antibiotics, has created a global health crisis. Being able to identify the genetic mechanisms of AMR and predict the resistance phenotypes of bacterial pathogens prior to culturing could inform clinical decision-making and improve reaction time. At PATRIC (http://patricbrc.org/), we have been collecting bacterial genomes with AMR metadata for several years. In order to advance phenotype prediction and the identification of genomic regions relating to AMR, we have updated the PATRIC FTP server to enable access to genomes that are binned by their AMR phenotypes, as well as metadata including minimum inhibitory concentrations. Using this infrastructure, we custom built AdaBoost (adaptive boosting) machine learning classifiers for identifying carbapenem resistance in Acinetobacter baumannii, methicillin resistance in Staphylococcus aureus, and beta-lactam and co-trimoxazole resistance in Streptococcus pneumoniae with accuracies ranging from 88-99%. We also did this for isoniazid, kanamycin, ofloxacin, rifampicin, and streptomycin resistance in Mycobacterium tuberculosis, achieving accuracies ranging from 71-88%. This set of classifiers has been used to provide an initial framework for species-specific AMR phenotype and genomic feature prediction in the RAST and PATRIC annotation services. PMID:27297683

  17. Ketamine-induced affective switch in a patient with treatment-resistant depression

    Directory of Open Access Journals (Sweden)

    Girish Banwari

    2015-01-01

    Full Text Available There is growing evidence to support the rapid, albeit short-lived antidepressant effect of subanesthetic dose of ketamine, a noncompetitive glutamate N-methyl-D-aspartate receptor antagonist in treatment-resistant unipolar and bipolar depression. Ketamine is known to cause transient mood elevation or euphoria, psychotomimetic effects, and dissociative symptoms, but its use in unipolar or bipolar depression has not been reported to induce an affective switch amounting to persistent or prolonged hypomania/mania or manic-like syndrome. We report the case of a 52-year-old male with first episode, continuous, nonpsychotic, treatment-resistant, unipolar major depression of 10 years duration, who manifested a switch from depression to mania while being treated with subanesthetic dose of ketamine, given intramuscularly. This case suggests that polarity switch should be considered as a potential side effect while using ketamine for treatment-resistant depression.

  18. Ketamine-induced affective switch in a patient with treatment-resistant depression

    OpenAIRE

    Girish Banwari; Prutha Desai; Prahlad Patidar

    2015-01-01

    There is growing evidence to support the rapid, albeit short-lived antidepressant effect of subanesthetic dose of ketamine, a noncompetitive glutamate N-methyl-D-aspartate receptor antagonist in treatment-resistant unipolar and bipolar depression. Ketamine is known to cause transient mood elevation or euphoria, psychotomimetic effects, and dissociative symptoms, but its use in unipolar or bipolar depression has not been reported to induce an affective switch amounting to persistent or prolong...

  19. Methicillin-resistant Staphylococcus aureus containing mecC in Swedish dairy cows

    Directory of Open Access Journals (Sweden)

    Unnerstad Helle Ericsson

    2013-01-01

    Full Text Available Abstract Background Hitherto, methicillin-resistant Staphylococcus aureus (MRSA has not been detected in Swedish cattle. However, due to the report of mecC, a novel homologue to the mecA gene, there was reason to re-evaluate susceptibility results from strain collections of Staphylococcus aureus and test suspected isolates for the presence of mecC. Findings Bovine isolates of S. aureus with elevated minimum inhibitory concentrations of beta-lactams were retrospectively tested for presence of mecC. In four of the isolates mecC was detected. Conclusion In Sweden, this is the first finding of MRSA in cattle and the first detection of MRSA harbouring mecC of domestic animal origin. MRSA in animal populations has implications as a potential reservoir with risk for spread to humans. Occurrence of MRSA among Swedish cattle appears still very limited.

  20. Sitamaquine-resistance in Leishmania donovani affects drug accumulation and lipid metabolism.

    Science.gov (United States)

    Imbert, L; Cojean, S; Libong, D; Chaminade, P; Loiseau, P M

    2014-09-01

    This study focuses on the mechanism of sitamaquine-resistance in Leishmania donovani. Sitamaquine accumulated 10 and 1.4 fold more in cytosol than in membranes of wild-type (WT) and of sitamaquine-resistant (Sita-R160) L. donovani promastigotes, respectively. The sitamaquine accumulation was a concentration-dependent process in WT whereas a saturation occurred in Sita-R160 suggesting a reduced uptake or an increase of the sitamaquine efflux. Membrane negative phospholipids being the main target for sitamaquine uptake, a lipidomic analysis showed that sitamaquine-resistance did not rely on a decrease of membrane negative phospholipid rate in Sita-R160, discarding the hypothesis of reduced uptake. However, sterol and phospholipid metabolisms were strongly affected in Sita-R160 suggesting that sitamaquine-resistance could be related to an alteration of phosphatidylethanolamine-N-methyl-transferase and choline kinase activities and to a decrease in cholesterol uptake and of ergosterol biosynthesis. Preliminary data of proteomics analysis exhibited different protein profiles between WT and Sita-160R remaining to be characterized. PMID:25201056

  1. Prevalence of plasmid-mediated multidrug resistance determinants in fluoroquinolone-resistant bacteria isolated from sewage and surface water.

    Science.gov (United States)

    Osińska, Adriana; Harnisz, Monika; Korzeniewska, Ewa

    2016-06-01

    Fluoroquinolones (FQs) are fully synthetic broad-spectrum antibacterial agents that are becoming increasingly popular in the treatment of clinical and veterinary infections. Being excreted during treatment, mostly as active compounds, their biological action is not limited to the therapeutic site, but it is moved further as resistance selection pressure into the environment. Water environment is an ideal medium for the aggregation and dissemination of antibiotics, antibiotic-resistant bacteria (ARB), and antibiotic resistance genes (ARGs), which can pose a serious threat to human health. Because of this, the aim of this study was to determine the number of fluoroquinolone-resistant bacteria (FQRB) and their share in total heterotrophic plate counts (HPC) in treated wastewater (TWW), and upstream and downstream river water (URW, DRW) samples where TWW is discharged. The spread of plasmid-mediated quinolone resistance (PMQR) determinants and the presence/absence of resistance genes to other most popular antibiotic groups (against tetracyclines and beta-lactams) in selected 116 multiresistant isolates were investigated. The share of FQRB in total HPC in all samples was rather small and ranged from 0.7 % in URW samples to 7.5 % in TWW. Bacteria from Escherichia (25.0 %), Acinetobacter (25.0 %), and Aeromonas (6.9 %) genera were predominant in the FQRB group. Fluoroquinolone resistance was mostly caused by the presence of the gene aac(6')-1b-cr (91.4 %). More rarely reported was the occurrence of qnrS, qnrD, as well as oqxA, but qnrA, qnrB, qepA, and oqxB were extremely rarely or never noted in FQRB. The most prevalent bacterial genes connected with beta-lactams' resistance in FQRB were bla TEM, bla OXA, and bla CTX-M. The bla SHV was less common in the community of FQRB. The occurrence of bla genes was reported in almost 29.3 % of FQRB. The most abundant tet genes in FQRB were tet(A), tet(L), tet(K), and tet(S). The prevalence of tet genes was observed in 41.4

  2. Characterization of multi-drug resistant ESBL producing nonfermenter bacteria isolated from patients blood samples using phenotypic methods in Shiraz (Iran

    Directory of Open Access Journals (Sweden)

    Maneli Amin Shahidi

    2015-10-01

    Full Text Available Background and Aim: The emergence of  nonfermenter bacteria that are resistant to multidrug resistant ESBL  are  nowadays a principal problem  for hospitalized patients. The present study aimed at surveying the emergence of nonfermenter bacteria resistant to multi-drug ESBL producing isolated from patients blood samples using BACTEC 9240 automatic system in Shiraz. Materials and Methods: In this cross-sectional study, 4825 blood specimens were collected from hospitalized patients in Shiraz (Iran, and positive samples were detected by means of  BACTEC 9240 automatic system. The isolates  containing nonfermenter bacteria were identified based on biochemical tests embedded in the API-20E system. Antibiotic sensitivity  test was performed  and identification of  ESBL producing strains were done  using phenotypic detection of extended spectrum beta-lactamase producing isolates(DDST according to CLSI(2013 guidelines.   Results: Out of 4825 blood samples, 1145 (24% specimen were gram-positive using BACTEC system. Among all isolated microorganisms, 206 isolates were non-fermenting gram- negative bacteria. The most common non-fermenter isolates were Pseudomonas spp. (48%, Acinetobacter spp. (41.7% ,and Stenotrophomonas spp. (8.2%. Seventy of them (81.4% were  Acinetobacter spp. which were ESBL positive. Among &beta-lactam antibiotics, Pseudomonas spp. showed  the best sensitivity to piperacillin-tazobactam (46.5%.  Conclusion: It was found that  &beta-lactam antibiotics are not effective against more than 40% of Pseudomonas spp. infections and 78% Acinetobacter infections. Emergence of multi-drug resistant strains that are resistant to most antibiotic classes is a major public health problem in Iran. To resolve this problem using of practical guidelines is critical.

  3. Effect of certain bioactive plant extracts on clinical isolates of beta-lactamase producing methicillin resistant Staphylococcus aureus.

    Science.gov (United States)

    Aqil, Farrukh; Khan, M Sajjad A; Owais, Mohd; Ahmad, Iqbal

    2005-01-01

    Ethanolic extracts and some fractions from 10 Indian medicinal plants, known for antibacterial activity, were investigated for their ability to inhibit clinical isolates of beta-lactamase producing methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive S. aureus (MSSA). Synergistic interaction of plant extracts with certain antibiotics was also evaluated. The MRSA test strains were found to be multi-drug resistant and also exhibited high level of resistance to common beta-lactam antibiotics. These strains produced beta-lactamases, which hydrolyze one or other beta-lactam antibiotics, tested. The extract of the plants from Camellia sinensis (leaves), Delonix regia (flowers), Holarrhena antidysenterica (bark), Lawsonia inermis (leaves), Punica granatum (rind), Terminalia chebula (fruits) and Terminalia belerica (fruits) showed a broad-spectrum of antibacterial activity with an inhibition zone size of 11 mm to 27 mm, against all the test bacteria. The extracts from the leaves of Ocimum sanctum showed better activity against the three MRSA strains. On the other hand, extracts from Allium sativum (bulb) and Citrus sinensis (rind) exhibited little or no activity, against MRSA strains. The antibacterial potency of crude extracts was determined in terms of minimum inhibitory concentration (MIC) by the tube dilution method. MIC values, of the plant extracts, ranged from 1.3 to 8.2 mg/ml, against the test bacteria. Further, the extracts from Punica granatum and Delonix regia were fractionated in benzene, acetone and methanol. Antibacterial activity was observed in acetone as well as in the methanol fractions. In vitro synergistic interaction of crude extracts from Camellia sinensis, Lawsonia inermis, Punica granatum, Terminalia chebula and Terminalia belerica was detected with tetracycline. Moreover, the extract from Camellia sinensis also showed synergism with ampicillin.TLC of the above extracts revealed the presence of major phytocompounds, like

  4. Defective active silicon uptake affects some components of rice resistance to brown spot.

    Science.gov (United States)

    Dallagnol, Leandro J; Rodrigues, Fabrício A; Mielli, Mateus V B; Ma, Jian F; Datnoff, Lawrence E

    2009-01-01

    Rice is known to accumulate high amounts of silicon (Si) in plant tissue, which helps to decrease the intensity of many economically important rice diseases. Among these diseases, brown spot, caused by the fungus Bipolaris oryzae, is one of the most devastating because it negatively affects yield and grain quality. This study aimed to evaluate the importance of active root Si uptake in rice for controlling brown spot development. Some components of host resistance were evaluated in a rice mutant, low silicon 1 (lsi1), defective in active Si uptake, and its wild-type counterpart (cv. Oochikara). Plants were inoculated with B. oryzae after growing for 35 days in a hydroponic culture amended with 0 or 2 mMol Si. The components of host resistance evaluated were incubation period (IP), relative infection efficiency (RIE), area under brown spot progress curve (AUBSPC), final lesion size (FLS), rate of lesion expansion (r), and area under lesion expansion progress curve (AULEPC). Si content from both Oochikara and lsi1 in the +Si treatment increased in leaf tissue by 219 and 178%, respectively, over the nonamended controls. Plants from Oochikara had 112% more Si in leaf tissue than plants from lsi1. The IP of brown spot from Oochikara increased approximately 6 h in the presence of Si and the RIE, AUBSPC, FLS, r, and AULEPC were significantly reduced by 65, 75, 33, 36, and 35%, respectively. In the presence of Si, the IP increased 3 h for lsi1 but the RIE, AUBSPC, FLS, r, and AULEPC were reduced by only 40, 50, 12, 21, and 12%, respectively. The correlation between Si leaf content and IP was significantly positive but Si content was negatively correlated with RIE, AUBSPC, FLS, r, and AULEPC. Single degree-of-freedom contrasts showed that Oochikara and lsi1 supplied with Si were significantly different from those not supplied with Si for all components of resistance evaluated. This result showed that a reduced Si content in tissues of plants from lsi1 dramatically affected

  5. Time-lapse electrical resistivity monitoring of salt-affected soil and groundwater

    Science.gov (United States)

    Hayley, Kevin; Bentley, L. R.; Gharibi, M.

    2009-07-01

    In order to develop and test a methodology for incorporating time-lapse electrical resistivity imaging (ERI) into the monitoring of salt-affected soil and groundwater, a multifaceted study including time-lapse electrical resistivity imaging, push tool conductivity (PTC), and core analysis was conducted to monitor the movement of a saline contaminant plume over the span of 3 years. The survey was done on a field site containing salt-affected soils and groundwater to depths of over 7 m. The site contained a tile drain system at approximately 2 m below ground level. Temperature and saturation changes were accounted for in electrical conductivity (EC) measurements to isolate changes in electrical conductivity due to changes in salt distribution. ERI inversion parameters were selected so that the inverse models gave the best match to PTC depth profiles and the best correlation with core EC data. A strong correlation between the core data and the ERI results was observed. Time-lapse ERI difference images showed that the subsurface EC distribution was consistent with preferential solute removal above the tile drains in some locations. The ERI-delineated reduction in solute concentration is consistent with nonuniform flushing due to depression-focused recharge. The addition of time-lapse ERI to the study allowed delineation of details of solute redistribution that would not have been possible with point measurements alone.

  6. Captures of MFO-resistant Cydia pomonella adults as affected by lure, crop management system and flight

    OpenAIRE

    Bosch, D; Rodríguez, M.A.; Avilla, J.

    2015-01-01

    The main resistance mechanism of codling moth (Cydia pomonella) in the tree fruit area of Lleida (NE Spain) is multifunction oxidases (MFO). We studied the frequency of MFO-resistant adults captured by different lures, with and without pear ester, and flights in orchards under different crop management systems. The factor year affected codling moth MFO-resistance level, particularly in the untreated orchards, highlighting the great influence of codling moth migration on the spread of resistan...

  7. Development of antibiotic resistance in Pseudomonas aeruginosa during two decades of antipseudomonal treatment at the Danish CF Center

    DEFF Research Database (Denmark)

    Ciofu, O; Giwercman, B; Pedersen, S S;

    1994-01-01

    At the Danish CF Center patients with chronic Pseudomonas aeruginosa lung infection were treated 3-4 times a year (from 1976) with a 2-week intravenous antipseudomonal course which included preferentially an aminoglycoside and a beta-lactam antibiotic. We investigated the development of antibiotic...... 1991 (100 strains). All the strains were screened and assayed semiquantitatively for beta-lactamase activity by use of nitrocefin. We found a significant (p < 0.005) increase in the MIC values of the P. aeruginosa strains against piperacillin and ceftazidime. However, no significant correlation was...... found between the MIC and the number of antipseudomonal courses of antibiotics. The proportion of resistant in vivo selected P. aeruginosa strains, presumed to be stably derepressed producers of chromosomal beta-lactamase, also increased significantly during the period studied. Our results confirm that...

  8. Prevalence and characteristics of methicillin-resistant coagulase-negative staphylococci from livestock, chicken carcasses, bulk tank milk, minced meat, and contact persons

    Directory of Open Access Journals (Sweden)

    Zweifel Claudio

    2011-01-01

    Full Text Available Abstract Background Methicillin-resistant coagulase-negative staphylococci (MR-CNS are of increasing importance to animal and public health. In veterinary medicine and along the meat and milk production line, only limited data were so far available on MR-CNS characteristics. The aim of the present study was to evaluate the prevalence of MR-CNS, to identify the detected staphylococci to species level, and to assess the antibiotic resistance profiles of isolated MR-CNS strains. Results After two-step enrichment and growth on chromogenic agar, MR-CNS were detected in 48.2% of samples from livestock and chicken carcasses, 46.4% of samples from bulk tank milk and minced meat, and 49.3% of human samples. Using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS, 414 selected MR-CNS strains belonged to seven different species (S. sciuri, 32.6%; S. fleurettii, 25.1%; S. haemolyticus, 17.4%; S. epidermidis, 14.5%, S. lentus, 9.2%; S. warneri, 0.7%; S. cohnii, 0.5%. S. sciuri and S. fleurettii thereby predominated in livestock, BTM and minced meat samples, whereas S. epidermidis and S. haemolyticus predominated in human samples. In addition to beta-lactam resistance, 33-49% of all 414 strains were resistant to certain non-beta-lactam antibiotics (ciproflaxacin, clindamycin, erythromycin, tetracycline. Conclusions A high prevalence of MR-CNS was found in livestock production. This is of concern in view of potential spread of mecA to S. aureus (MRSA. Multiresistant CNS strains might become an emerging problem for veterinary medicine. For species identification of MR-CNS isolated from different origins, MALDI-TOF MS proved to be a fast and reliable tool and is suitable for screening of large sample amounts.

  9. Hybridization of an invasive shrub affects tolerance and resistance to defoliation by a biological control agent

    Science.gov (United States)

    Williams, Wyatt I.; Friedman, Jonathan M.; Gaskin, John F.; Norton, Andrew P.

    2014-01-01

    Evolution has contributed to the successful invasion of exotic plant species in their introduced ranges, but how evolution affects particular control strategies is still under evaluation. For instance, classical biological control, a common strategy involving the utilization of highly specific natural enemies to control exotic pests, may be negatively affected by host hybridization because of shifts in plant traits, such as root allocation or chemical constituents. We investigated introgression between two parent species of the invasive shrub tamarisk (Tamarix spp.) in the western United States, and how differences in plant traits affect interactions with a biological control agent. Introgression varied strongly with latitude of origin and was highly correlated with plant performance. Increased levels of T. ramosissima introgression resulted in both higher investment in roots and tolerance to defoliation and less resistance to insect attack. Because tamarisk hybridization occurs predictably on the western U.S. landscape, managers may be able to exploit this information to maximize control efforts. Genetic differentiation in plant traits in this system underpins the importance of plant hybridization and may explain why some biological control releases are more successful than others.

  10. Health risks associated with the presence of antibiotic resistant bacteria in greywater

    Directory of Open Access Journals (Sweden)

    Juan Moretton

    2012-04-01

    Full Text Available The removal and disposal of waste from domestic activities is a major health problem in densely populated urban areas. In many areas of Greater Buenos Aires, greywater is disposed in open ditches and risk potential of this has not been adequately quantified. The aim of this study was to evaluate the prevalence of antibiotic-resistant bacteria and its resistance profile present in raw greywater obtained from a channel located in the area of Ingeniero Budge Buenos Aires Province. Thus, the prevalence of heterotrophic bacteria, Gram-negative bacteria resistant to beta-lactam antibiotics and vancomycin-resistant enterococci in greywater, their typing, and resistance to other antibiotics were determined. The prevalence of resistant bacteria was determined by the agar dilution method. Of all the antibiotics tested, the highest prevalence of resistant heterotrophic bacteria was detected with cephalothin (19% and ampicillin (8%. With regard to Gram-negative bacteria, the highest prevalence of resistance was given by coliforms ampicillin (34% and cephalothin (17%. A total of 38% of enterococci with low level resistance to vancomycin was detected. The multiresistant isolates were identified as Escherichia coli, Alcaligenes faecalis y Stenotrophomonas maltophilia. These results indicate that greywater can be considered as a reservoir of bacteria resistant to antibiotics, thus increasing their health risk.

  11. Antimicrobial resistance of Staphylococcus spp. from small ruminant mastitis in Brazil

    Directory of Open Access Journals (Sweden)

    Chirles A. França

    2012-08-01

    Full Text Available The study aimed to determine the antimicrobial resistance patterns and to identify molecular resistance markers in Staphylococcus spp. (n=210 isolated from small ruminant mastitis in Brazil. The antimicrobial resistance patterns were evaluated by the disk diffusion test and by detection of the presence of mecA, blaZ, ermA, ermB, ermC and msrA genes by PCR. The efflux pump test was performed using ethidium bromide and biofilm production was determined by Congo red agar test along with PCR for detection of the icaD gene. The isolates were most resistant to amoxicillin (50.0%, streptomycin (42.8%, tetracycline (40.4%, lincomycin (39.0% and erythromycin (33.8%. Pan-susceptibility to all tested drugs was observed in 71 (33.8% isolates and 41 Staphylococcus isolates were positive for the efflux pump. Although phenotypic resistance to oxacillin was observed in 12.8% of the isolates, none harbored the mecA gene. However, 45.7% of the isolates harbored blaZ indicating that beta-lactamase production was the main mechanism associated with staphylococci resistance to beta-lactams in the present study. The other determinants of resistance to antimicrobial agents ermA, ermB, ermC, and msrA were observed in 1.4%, 10.4%, 16.2%, and 0.9% of the isolates, respectively. In addition, the icaD gen was detected in 32.9% of the isolates. Seventy three isolates (54 from goats and 19 from sheep were negative for all resistance genes tested and 69 isolates presented two or more resistance genes. Association among blaZ, ermA, ermB, ermC and efflux pump were observed in 17 isolates, 14 of which originated from goats and three from sheep. The data obtained in this study show the resistance of the isolates to beta-lactamics, which may be associated with the use of antimicrobial drugs without veterinary control.

  12. Low Prevalence of Carbapenem-Resistant Bacteria in River Water: Resistance Is Mostly Related to Intrinsic Mechanisms.

    Science.gov (United States)

    Tacão, Marta; Correia, António; Henriques, Isabel S

    2015-10-01

    Carbapenems are last-resort antibiotics to handle serious infections caused by multiresistant bacteria. The incidence of resistance to these antibiotics has been increasing and new resistance mechanisms have emerged. The dissemination of carbapenem resistance in the environment has been overlooked. The main goal of this research was to assess the prevalence and diversity of carbapenem-resistant bacteria in riverine ecosystems. The presence of frequently reported carbapenemase-encoding genes was inspected. The proportion of imipenem-resistant bacteria was on average 2.24 CFU/ml. Imipenem-resistant strains (n=110) were identified as Pseudomonas spp., Stenotrophomonas maltophilia, Aeromonas spp., Chromobacterium haemolyticum, Shewanella xiamenensis, and members of Enterobacteriaceae. Carbapenem-resistant bacteria were highly resistant to other beta-lactams such as quinolones, aminoglycosides, chloramphenicol, tetracyclines, and sulfamethoxazole/trimethoprim. Carbapenem resistance was mostly associated with intrinsically resistant bacteria. As intrinsic resistance mechanisms, we have identified the blaCphA gene in 77.3% of Aeromonas spp., blaL1 in all S. maltophilia, and blaOXA-48-like in all S. xiamenensis. As acquired resistance mechanisms, we have detected the blaVIM-2 gene in six Pseudomonas spp. (5.45%). Integrons with gene cassettes encoding resistance to aminoglycosides (aacA and aacC genes), trimethoprim (dfrB1b), and carbapenems (blaVIM-2) were found in Pseudomonas spp. Results suggest that carbapenem resistance dissemination in riverine ecosystems is still at an early stage. Nevertheless, monitoring these aquatic compartments for the presence of resistance genes and its host organisms is essential to outline strategies to minimize resistance dissemination. PMID:26430939

  13. Emergence of clonally related multidrug resistant Haemophilus influenzae with penicillin-binding protein 3-mediated resistance to extended-spectrum cephalosporins, Norway, 2006 to 2013.

    Science.gov (United States)

    Skaare, D; Anthonisen, I L; Kahlmeter, G; Matuschek, E; Natås, O B; Steinbakk, M; Sundsfjord, A; Kristiansen, B E

    2014-01-01

    Resistance to cephalosporins in Haemophilus influenzae is usually caused by characteristic alterations in penicillin-binding protein 3 (PBP3), encoded by the ftsI gene. Resistance to extended-spectrum cephalosporins is associated with high-level PBP3-mediated resistance (high-rPBP3), defined by the second stage S385T substitution in addition to a first stage substitution (R517H or N526K). The third stage L389F substitution is present in some high-rPBP3 strains. High-rPBP3 H. influenzae are considered rare outside Japan and Korea. In this study, 30 high-rPBP3 isolates from Norway, collected between 2006 and 2013, were examined by serotyping, multilocus sequence typing (MLST), ftsI sequencing, detection of beta-lactamase genes and minimum inhibitory concentration (MIC) determination. MICs were interpreted according to clinical breakpoints from the European Committee on Antimicrobial Susceptibility Testing (EUCAST). Respiratory isolates predominated (proportion: 24/30). The 30 isolates included one serotype f isolate, while the remaining 29 lacked polysaccharide capsule genes. Resistance to extended-spectrum cephalosporins (cefixime, 29 isolates/30 isolates; cefepime, 28/30; cefotaxime, 26 /30; ceftaroline, 26/30; ceftriaxone, 14/30), beta-lactamase production (11/30) and co-resistance to non-beta-lactams (trimethoprim-sulfamethoxazole, 13/30; tetracycline, 4/30; chloramphenicol, 4/30; ciprofloxacin, 3/30) was frequent. The N526K substitution in PBP3 was present in 23 of 30 isolates; these included a blood isolate which represents the first invasive S385T + N526K isolate reported from Europe. The L389F substitution, present in 16 of 30 isolates, coincided with higher beta-lactam MICs. Non-susceptibility to meropenem was frequent in S385T + L389F + N526K isolates (8/12). All 11 beta-lactamase positive isolates were TEM-1. Five clonal groups of two to 10 isolates with identical MLST-ftsI allelic profiles were observed, including the first reported high-rPBP3

  14. Study of the Raveling Resistance of Porous Asphalt Pavements Used in Sustainable Drainage Systems Affected by Hydrocarbon Spills

    OpenAIRE

    Jorge Rodriguez-Hernandez; Valerio C. Andrés-Valeri; Miguel A. Calzada-Pérez; Ángel Vega-Zamanillo; Daniel Castro-Fresno

    2015-01-01

    Permeable pavements are one of the most commonly-used sustainable drainage systems (SuDS) in urban areas for managing stormwater runoff problems. Porous asphalt is widely used in surface layers of permeable pavement systems, where it can suffer from accidental oil spills from vehicles. Oil spills affect bituminous mixes through the solvent action of the hydrocarbons on the bitumen, reducing the raveling resistance of asphalt pavements. In order to assess the raveling resistance in porous asph...

  15. Arabidopsis flower specific defense gene expression patterns affect resistance to pathogens.

    Science.gov (United States)

    Ederli, Luisa; Dawe, Adam; Pasqualini, Stefania; Quaglia, Mara; Xiong, Liming; Gehring, Chris

    2015-01-01

    We investigated whether the Arabidopsis flower evolved protective measures to increase reproductive success. Firstly, analyses of available transcriptome data show that the most highly expressed transcripts in the closed sepal (stage 12) are enriched in genes with roles in responses to chemical stimuli and cellular metabolic processes. At stage 15, there is enrichment in transcripts with a role in responses to biotic stimuli. Comparative analyses between the sepal and petal in the open flower mark an over-representation of transcripts with a role in responses to stress and catalytic activity. Secondly, the content of the biotic defense-associated phytohormone salicylic acid (SA) in sepals and petals is significantly higher than in leaves. To understand whether the high levels of stress responsive transcripts and the higher SA content affect defense, wild-type plants (Col-0) and transgenic plants defective in SA accumulation (nahG) were challenged with the biotrophic fungus Golovinomyces cichoracearum, the causal agent of powdery mildew, and the necrotrophic fungus Botrytis cinerea. NahG leaves were more sensitive than those of Col-0, suggesting that in leaves SA has a role in the defense against biotrophs. In contrast, sepals and petals of both genotypes were resistant to G. cichoracearum, indicating that in the flower, resistance to the biotrophic pathogen is not critically dependent on SA, but likely dependent on the up-regulation of stress-responsive genes. Since sepals and petals of both genotypes are equally susceptible to B. cinerea, we conclude that neither stress-response genes nor increased SA accumulation offers protection against the necrotrophic pathogen. These results are interpreted in the light of the distinctive role of the flower and we propose that in the early stages, the sepal may act as a chemical defense barrier of the developing reproductive structures against biotrophic pathogens. PMID:25750645

  16. Arabidopsis flower specific defense gene expression patterns affect resistance to pathogens

    KAUST Repository

    Ederli, Luisa

    2015-02-20

    We investigated whether the Arabidopsis flower evolved protective measures to increase reproductive success. Firstly, analyses of available transcriptome data show that the most highly expressed transcripts in the closed sepal (stage 12) are enriched in genes with roles in responses to chemical stimuli and cellular metabolic processes. At stage 15, there is enrichment in transcripts with a role in responses to biotic stimuli. Comparative analyses between the sepal and petal in the open flower mark an over-representation of transcripts with a role in responses to stress and catalytic activity. Secondly, the content of the biotic defense-associated phytohormone salicylic acid (SA) in sepals and petals is significantly higher than in leaves. To understand whether the high levels of stress responsive transcripts and the higher SA content affect defense, wild-type plants (Col-0) and transgenic plants defective in SA accumulation (nahG) were challenged with the biotrophic fungus Golovinomyces cichoracearum, the causal agent of powdery mildew, and the necrotrophic fungus Botrytis cinerea. NahG leaves were more sensitive than those of Col-0, suggesting that in leaves SA has a role in the defense against biotrophs. In contrast, sepals and petals of both genotypes were resistant to G. cichoracearum, indicating that in the flower, resistance to the biotrophic pathogen is not critically dependent on SA, but likely dependent on the up-regulation of stress-responsive genes. Since sepals and petals of both genotypes are equally susceptible to B. cinerea, we conclude that neither stress-response genes nor increased SA accumulation offers protection against the necrotrophic pathogen. These results are interpreted in the light of the distinctive role of the flower and we propose that in the early stages, the sepal may act as a chemical defense barrier of the developing reproductive structures against biotrophic pathogens.

  17. Does Culture Affect how People Receive and Resist Persuasive Messages? Research Proposals about Resistance to Persuasion in Cultural Groups

    Directory of Open Access Journals (Sweden)

    Renata Kolodziej-Smith

    2013-10-01

    Full Text Available Abstract Even though persuasion has been a widely researched topic in consumer behavior, the great majority of these studies have involved American consumers and focused on persuasion itself, with very few addressing resistance to persuasive attempts. None has addressed resistance to persuasion in a cross-cultural context. We aim to contribute to closing this gap in the literature with this paper. Specifically, we aim to expand knowledge of the persuasive process by applying the cultural dimensions of self-construal and face negotiation theories to Gopinath and Nyer’s (2009 work conducted on American consumers about the effect of public commitment on resistance to persuasion. Our research focus is on why people from different ethnic/cultural backgrounds will receive or resist persuasive messages differently. We anchor this notion in face negotiation theory (Ting-Toomey, 2005. This perspective addresses different types of facework behaviors that people choose in a multicultural environment, thus shedding light on processes underlying persuasion and resistance to persuasion mechanisms as influenced by culture. Understanding the effects of cultural differences on a person’s reception of, or resistance to, counter-attitudinal persuasion should be valuable to managers who make decisions about cultural adaptations and target audience changes.

  18. Antimicrobial resistance and genetic characterization of fluoroquinolone resistance of Pseudomonas aeruginosa isolated from canine infections.

    Science.gov (United States)

    Rubin, J; Walker, R D; Blickenstaff, K; Bodeis-Jones, S; Zhao, S

    2008-09-18

    Infections with antimicrobial-resistant bacteria are a great challenge in both human and veterinary medicine. The purpose of this study was to determine antimicrobial susceptibility of 106 strains of Pseudomonas aeruginosa isolated from dogs with otitis and pyoderma from 2003 to 2006 in the United States. Three antimicrobial panels, including 6 classes and 32 antimicrobial agents, were used. A wide range of susceptibility patterns were noted with some isolates being resistant to between 8 and 28 (mean 16) of the antimicrobials tested. Among the beta-lactams, all isolates were resistant to ampicillin, cefoxitin, cefpodoxime, cephalothin and cefazolin followed by amoxicillin/clavulanic acid (99%), ceftiofur (97%), ceftriaxone (39%), cefotaxime (26%), and cefotaxime/clavulanic acid (20%), whereas less than 7% of isolates were resistant to ceftazidime/clavulanic acid, ceftazidime, piperacillin/tazobactam or cefepime. Two isolates were resistant to the carbapenems. Among the quinolones and fluoroquinolones, the most isolates were resistant to naladixic acid (96%), followed by orbifloxacin (52%), difloxacin (43%), enrofloxacin (31%), marbofloxacin (27%), gatifloxacin (23%), levofloxacin (21%), and ciprofloxacin (16%). Among the aminoglycosides, the most resistance was seen to kanamycin (90%), followed by streptomycin (69%), gentamicin (7%), and amikacin (3%). Of the remaining antimicrobials 100% of the isolates were resistant to chloramphenicol followed by tetracycline (98%), trimethoprim/sulfamethoxazole (57%), and sulfisoxazole (51%). Point mutations were present in gyrA, gyrB, parC, and/or parE genes among 34 of the 102 naladixic acid-resistant isolates. Two isolates contained class 1 integrons carrying aadA gene conferring streptomycin and spectinomycin resistance. The findings suggest that many antimicrobial agents commonly used in companion animals may not constitute appropriate therapy for canine pseudomonas infections. PMID:18395369

  19. Acute arginine supplementation fails to improve muscle endurance or affect blood pressure responses to resistance training.

    Science.gov (United States)

    Greer, Beau K; Jones, Brett T

    2011-07-01

    Dietary supplement companies claim that arginine supplements acutely enhance skeletal muscular endurance. The purpose of this study was to determine whether acute arginine α-ketoglutarate supplementation (AAKG) will affect local muscle endurance of the arm and shoulder girdle or the blood pressure (BP) response to anaerobic exercise. Twelve trained college-aged men (22.6 ± 3.8 years) performed 2 trials of exercise separated by at least 1 week. At 4 hours before, and 30 minutes before exercise, a serving of an AAKG supplement (3,700 mg arginine alpha-ketoglutarate per serving) or placebo was administered. Resting BP was assessed pre-exercise after 16 minutes of seated rest, and 5 and 10 minutes postexercise. Three sets each of chin-ups, reverse chin-ups, and push-ups were performed to exhaustion with 3 minutes of rest between each set. Data were analyzed using repeated-measures analysis of variance and paired t-tests. The AAKG supplementation did not improve muscle endurance or significantly affect the BP response to anaerobic work. Subjects performed fewer total chin-ups (23.75 ± 6.38 vs. 25.58 ± 7.18) and total trial repetitions (137.92 ± 28.18 vs. 141.08 ± 28.57) in the supplement trial (p ≤ 0.05). Subjects executed fewer reverse chin-ups (5.83 ± 1.85 vs. 6.75 ± 2.09) during set 2 after receiving the supplement as compared to the placebo (p AAKG supplementation may hinder muscular endurance, the use of these supplements before resistance training should be questioned. PMID:21399536

  20. Evaluation of prevalence of low and high level mupirocin resistance in methicillin resistant staphylococcus aureus isolates at a tertiary care hospital

    International Nuclear Information System (INIS)

    To evaluate the trend of mupirocin resistance in MRSA, isolated at the Clinical Microbiology Laboratory of a tertiary care hospital. Methods: A total of 200 MRSA strains recovered over a 2 year period from various body sites were tested using the 5 and 200 mu g discs of mupirocin to detect its resistance. Results: High level and low level mupirocin resistance were detected in zero and 1 % of MRSA strains, respectively. Resistance to other non beta lactam antibiotics was also high. No MRSA strains were found to be resistant to vancomycin and tegicycline. Conclusion: Mupirocin resistance was found to be very low among local clinical isolates of MRSA. Its judicious use to decolonize nasal carriers should be promoted among hospitalized patients to avoid further transmission and infections due to prevalent endemic MRSA strains in any health care setting. Concomitantly, regular surveillance and effective infection control initiatives are desirable to reduce the incidence of health care associated infections due to MRSA and also of mupirocin resistance. (author)

  1. Incidence of cephalosporin resistance among clinical isolates of Pseudomonas aeruginosa in Ibadan, South- Western Nigeria

    Directory of Open Access Journals (Sweden)

    Oladipo E.K

    2015-12-01

    Full Text Available Background: The emergence of beta-lactam resistance in Pseudomonas aeruginosa is a major global challenge, particularly, the rise in the resistance to 3rd and 4th generation cephalosporins. Aim: This study was carried out to determine the resistance pattern of Pseudomonas aeruginosa to different generations of cephalosporins. Methods: A total number of one hundred clinical isolates of Pseudomonas aeruginosa were collected from June to November 2014 at University Teaching Hospital Ibadan, Oyo State. These were tested for their sensitivity to antibiotics by means of disc diffusion method using prepared antibiotics disc containing different μ of antibiotics; Cefotaxine (30μ, Cefaclor (30μ, Cefamandole (30μ, Cefixime (5μ, Cefepime (30μ, Cefpodoxime (30μ and Ceftazidime (30μ. Results: Pseudomonas aeruginosa showed absolute resistance to all antibiotics used except Ceftazidime, and Cefepime which are third and fourth generation of cephalosporin respectively. Ceftazidime had minimal resistant of 21% and higher susceptibility rate of 76%, Cefepime had the highest susceptibility rate of 90% and minimal resistance of 6%. Cefotaxime and Cefpodoxime had minimal intermediate of 1%, Ceftazidime of 3% and Cefepime of 4%. Conclusion: The result from this study provided more evidence that among third generation of cephalosporins used, some are more active than the other while fourth generation is still the most effective of all other generations. Knowledge on the distribution of cephalosporin-resistant organisms is of ultimate importance as a guide in empirical therapy, taking note of preventive strategies as well as control measures against the spread of resistant microorganisms.

  2. Identification of quantitative trait loci affecting gastrointestinal parasite resistance in an experimental Angus population.

    Science.gov (United States)

    Kim, Eui-Soo; Sonstegard, Tad S; Silva, Marcos Vinicius G B; Gasbarre, Louis C; Van Tassell, Curtis P

    2014-02-01

    DNA markers associated with quantitative trait loci (QTL) affecting host tolerance to gastrointestinal (GI) parasite infection are ideal targets for marker-assisted selection. However, few studies in cattle have attempted to identify this type of QTL due to the difficulty of generating accurate phenotypic data from a resource population with adequate statistical power for detection. For this effort, we amassed fecal egg count (FEC) measures from annual natural field challenges with GI nematodes that spanned 12 different contemporary groups of Angus calves (1992-2000) derived from a closed breeding population. FEC and blood pepsinogen measures were taken weekly over a 26-week period post-weaning, and the FEC data were Box-Cox transformed to normalize the distribution of phenotypes. These 305 test animals and more than 100 founding animals from the extended pedigree were genotyped across 190 microsatellites markers. The genome-wide analyses identified a suggestive genome-wide QTL on bovine chromosome (Chr) 8 (P cattle, and some corresponded to previously identified QTL locations for parasite-related traits in sheep to provide genome locations for further fine mapping of parasite resistance/susceptibility in Angus cattle. PMID:24303892

  3. Antimicrobial resistances do not affect colonization parameters of intestinal E. coli in a small piglet group

    Directory of Open Access Journals (Sweden)

    Schierack Peter

    2009-10-01

    Full Text Available Abstract Background Although antimicrobial resistance and persistence of resistant bacteria in humans and animals are major health concerns worldwide, the impact of antimicrobial resistance on bacterial intestinal colonization in healthy domestic animals has only been rarely studied. We carried out a retrospective analysis of the antimicrobial susceptibility status and the presence of resistance genes in intestinal commensal E. coli clones from clinically healthy pigs from one production unit with particular focus on effects of pheno- and/or genotypic resistance on different nominal and numerical intestinal colonization parameters. In addition, we compared the occurrence of antimicrobial resistance phenotypes and genotypes with the occurrence of virulence associated genes typical for extraintestinal pathogenic E. coli. Results In general, up to 72.1% of all E. coli clones were resistant to ampicillin, chloramphenicol, kanamycin, streptomycin, sulfamethoxazole or tetracycline with a variety of different resistance genes involved. There was no significant correlation between one of the nominal or numerical colonization parameters and the absence or presence of antimicrobial resistance properties or resistance genes. However, there were several statistically significant associations between the occurrence of single resistance genes and single virulence associated genes. Conclusion The demonstrated resistance to the tested antibiotics might not play a dominant role for an intestinal colonization success in pigs in the absence of antimicrobial drugs, or cross-selection of other colonization factors e.g. virulence associated genes might compensate "the cost of antibiotic resistance". Nevertheless, resistant strains are not outcompeted by susceptible bacteria in the porcine intestine. Trial Registration The study was approved by the local animal welfare committee of the "Landesamt für Arbeitsschutz, Gesundheitsschutz und technische Sicherheit" Berlin

  4. The softened heat-affected zone in resistance spot welded tailor hardened boron steel: a material model for crash simulation

    NARCIS (Netherlands)

    Eller, T.K.; Greve, L.; Andres, M.T.; Medricky, M.; Geijselaers, H.J.M.; Meinders, V.T.; Boogaard, van den A.H.

    2016-01-01

    A hardness-based model for tailor hardened boron steel is presented that takes into account the softened heat-affected zone of resistance spot welds. The computational model is designed for crashworthiness simulation of fully and partially hardened components obtained by tailored tooling. Five diff

  5. Plasticity and fracture modeling of the heat-affected zone in resistance spot welded tailor hardened boron steel

    NARCIS (Netherlands)

    Eller, T.K.; Greve, L.; Andres, M.T.; Medricky, M.; Geijselaers, H.J.M.; Meinders, V.T.; Boogaard, van den A.H.

    2016-01-01

    tFive hardness grades of 22MnB5 are considered, covering the full strength-range from 600 MPa in theferritic/pearlitic range to 1500 MPa in the fully hardened, martensitic state. These five grades form thebasis for a hardness-based material model for the heat-affected zone found around resistance sp

  6. Antibiotic and metal resistance in a ST395 Pseudomonas aeruginosa environmental isolate: A genomics approach.

    Science.gov (United States)

    Teixeira, Pedro; Tacão, Marta; Alves, Artur; Henriques, Isabel

    2016-09-15

    We analyzed the resistome of Pseudomonas aeruginosa E67, an epiphytic isolate from a metal-contaminated estuary. The aim was to identify genetic determinants of resistance to antibiotics and metals, assessing possible co-selection mechanisms. Identification was based on phylogenetic analysis and average nucleotide identity value calculation. MLST affiliated E67 to ST395, previously described as a high-risk clone. Genome analysis allowed identifying genes probably involved in resistance to antibiotics (e.g. beta-lactams, aminoglycosides and chloramphenicol) and metals (e.g. mercury and copper), consistent with resistance phenotypes. Several genes associated with efflux systems, as well as genetic determinants contributing to gene motility, were identified. Pseudomonas aeruginosa E67 possesses an arsenal of resistance determinants, probably contributing to adaptation to a polluted ecosystem. Association to mobile structures highlights the role of these platforms in multi-drug resistance. Physical links between metal and antibiotic resistance genes were not identified, suggesting a predominance of cross-resistance associated with multidrug efflux pumps. PMID:27371958

  7. Food Conditioning Affects Expression of Insect Resistance in Diploid Willows (Salix spp.)

    OpenAIRE

    Christer Björkman; Karin Eklund; Anna Lehrman; Stenberg, Johan A

    2013-01-01

    The high energy quota and versatility of use make willows (Salix spp.) attractive as bioenergy crops. Insect defoliation constitutes a threat to the profitability of willow growers. Hitherto, the breeding for resistance against the main insect pests has been hampered by the fact that all known resistant willow clones are polyploids, and existing molecular breeding tools work most effectively for diploids. Here, we firstly report diploid willows highly resistant to the main insect defoliator, ...

  8. [Bacteria isolated from pleural fluid and their resistance to antimicrobials].

    Science.gov (United States)

    Dorobăţ, Olga-Mihaela; Moisoiu, Adriana; Tălăpan, Daniela

    2006-01-01

    The aim of this study is to evaluate the frequency of microorganisms isolated from pleural fluids and their resistance to antimicrobial agents. A total of 272 pleural fluids were studied between July 2004 - July 2005 from the patients hospitalized in ICU/surgery (127) and respiratory diseases wards (145) at Marius Nasta Institute. The laboratory investigations included: direct microscopy, cultures for aerobic and anaerobic bacteria, identification, disk diffusion method according with CLSI recommendations for resistance and Etest for detection of metallo-beta-lactamase producing isolates of Pseudomonas aeruginosa. Microorganisms were isolated from 159 samples (58.4%), 48 pleural fluids were positive only in microscopy (17.6%). The most frequent isolated strain was P. aeruginosa (49.6%), followed by Staphylococcus aureus (12.8%) and Enterobacteriaceae (11.2%) polymicrobial infections were mostly due to combinations of Pseudomonas with Enterobacteriaceae. For P. aeruginosa the resistance rate was higher than 71% for all beta-lactams. For aminoglycosides the lower resistance rate was to amikacin (18.0%). For quinolones, resistance of P. aeruginosa was 67.8% to ciprofloxacin. P. aeruginosa isolated from patients hospitalized in ICU/surgery were more resistant to some antimicrobials than the strains isolated in the respiratory diseases wards: resistance to amikacin was 24.5% versus 10% respectively. From 21 P. aeruginosa imipenem and multidrug resistant strains tested, 3 were probably producing of metallo-beta-lactamase. S. aureus showed 47.1% oxacillin resistance, 38.9% resistance to gentamicin and ciprofloxacin and 27.7% to erythromycin. All S.aureus strains were susceptible to linezolid, teicoplanin and vancomycin. The resistance of Enterobacteriaceae strains was high to ampicillin (80.0%), amoxicillin/clavulanic acid and trimethoprim/sulfamethoxazole e(57.6%); the lowest resistance rate was to cefoperazone/sulbactam (7.7%) and to imipenem and ciprofloxacin (10

  9. A fluoroquinolone resistance associated mutation in gyrA affects DNA supercoiling in Campylobacter jejuni

    Directory of Open Access Journals (Sweden)

    Jing eHan

    2012-03-01

    Full Text Available The prevalence of fluoroquinolone (FQ-resistant Campylobacter has become a concern for public health. To facilitate the control of FQ-resistant Campylobacter, it is necessary to understand the impact of FQ resistance on the fitness of Campylobacter in its natural hosts as understanding fitness will help to determine and predict the persistence of FQ-resistant Campylobacter. Previously it was shown that acquisition of resistance to FQ antimicrobials enhanced the in vivo fitness of FQ-resistant Campylobacter. In this study, we confirmed the role of the Thr-86-Ile mutation in GyrA in modulating Campylobacter fitness by reverting the mutation to the wild-type allele, which resulted in the loss of the fitness advantage. Additionally, we determined if the resistance-conferring GyrA mutations alter the enzymatic function of the DNA gyrase. Recombinant wild-type gyrase and mutant gyrases with three different types of mutations (Thr-86-Ile, Thr-86-Lys, and Asp-90-Asn, which are associated with FQ resistance in Campylobacter, were generated in E. coli and compared for their supercoiling activities using an in vitro assay. The mutant gyrase with the Thr-86-Ile change showed a greatly reduced supercoiling activity compared with the wild-type gyrase, while other mutant gyrases did not show an altered supercoiling. Furthermore, we measured DNA supercoiling within Campylobacter cells using a reporter plasmid. Consistent with the results from the in vitro supercoiling assay, the FQ-resistant mutant carrying the Thr-86-Ile change in GyrA showed much less DNA supercoiling than the wild-type strain and the mutant strains carrying other mutations. Together, these results indicate that the Thr-86-Ile mutation, which is predominant in clinical FQ-resistant Campylobacter, modulates DNA supercoiling homeostasis in FQ-resistant Campylobacter.

  10. Multidrug resistance and ESBL-producing Salmonella spp. isolated from broiler processing plants

    Science.gov (United States)

    Ziech, Rosangela Estel; Lampugnani, Camila; Perin, Ana Paula; Sereno, Mallu Jagnow; Sfaciotte, Ricardo Antônio Pilegi; Viana, Cibeli; Soares, Vanessa Mendonça; de Almeida Nogueira Pinto, José Paes; dos Santos Bersot, Luciano

    2016-01-01

    The aim of this study was to investigate the occurrence of multidrug-resistant, extended spectrum beta-lactamase (ESBL) producing Salmonella spp. isolated from conveyor belts of broiler cutting rooms in Brazilian broiler processing plants. Ninety-eight strains of Salmonella spp. were analyzed. Multidrug resistance was determined by the disk diffusion test and the susceptibility of the isolated bacteria was evaluated against 18 antimicrobials from seven different classes. The double disk diffusion test was used to evaluate ESBL production. Of the 98 strains tested, 84 were multidrug resistant. The highest rates of resistance were against nalidixic acid (95%), tetracycline (91%), and the beta-lactams: ampicillin and cefachlor (45%), followed by streptomycin and gentamicin with 19% and 15% of strain resistance, respectively. By contrast, 97% of the strains were sensitive to chloramphenicol. 45% of the strains were positive for the presence of ESBL activity. In this study, high rates of multidrug resistance and ESBL production were observed in Salmonella spp. PMID:26887244

  11. Epidemiology and resistance patterns in urinary pathogens from long-term care facilities and GP populations.

    LENUS (Irish Health Repository)

    Brabazon, E D

    2012-06-01

    Urinary tract infections (UTIs) are a major source of antimicrobial prescribing in the clinical setting and a potential reservoir for the emergence of resistant organisms. Although studies have been published on resistance rates for urinary pathogens from both hospital and general practitioner (GP) settings, there is little information from Long-Term Care Facilities (LTCFs) in Ireland. This study aimed to document the epidemiology and resistance rates in urinary isolates, in the LTCF and GP setting, from samples submitted to a typical microbiology laboratory. In 2010, there were 963 urinary isolates from LTCFs and 1,169 urinary isolates from GPs, identified from patients 65 years and over, with cytology suggestive of infection. E. coil was the most common causative organism identified. There were significantly higher levels of resistance to ampicillin, co-amoxiclav, ciprofloxacin, nitrofurantoin, trimethoprim, and piperacillin\\/tazobactam in the LTCF population compared to the GP population (e.g. for E. coli, 86%-v-69%; 30%-v- 21%; 58%-v-26%, 10%-v-3%, 68%-v-48%, 10%-v- 4% respectively). Isolates with resistance mechanisms to beta-lactams, were identified in both populations. Results presented in this paper demonstrate significant differences between resistance rates in LTCF and GP populations which suggest that there are implications for empiric antimicrobial prescribing for UTIs in the LTCF setting.

  12. ramR Mutations Affecting Fluoroquinolone Susceptibility in Epidemic Multidrug-Resistant Salmonella enterica Serovar Kentucky ST198

    Directory of Open Access Journals (Sweden)

    AxelCloeckaert

    2013-07-01

    Full Text Available A screening for non-target mutations affecting fluoroquinolone susceptibility was conducted in epidemic multidrug-resistant Salmonella enterica serovar Kentucky ST198. Among a panel of representative isolates (n=30, covering the epidemic, only three showed distinct mutations in ramR resulting in enhanced expression of genes encoding the AcrAB-TolC efflux system and low increase in ciprofloxacin MIC. No mutations were detected in other regulatory regions of this efflux system. Ciprofloxacin resistance in serovar Kentucky ST198 is thus currently mainly due to multiple target gene mutations.

  13. Insulin resistance in different forms of hyperketonemia and in cows affected by puerperal metritis

    International Nuclear Information System (INIS)

    oestrus on day about ≥50 were inseminated and those not returning to oestrus were checked for pregnancy by rectal palpation on day 45-60 after AI. Resumption of ovarian activity was monitored by the means of individual milk progesterone profiles Based on BHB level and clinical examination cows were categorized in four groups: 1. Normoketonemic (NK) throughout the study (n = 9); 2. Transiently hyperketonemic (HK; n = 7); 3. Continuously HK (n = 7); 4. Continuously HK with severe puerperal metritis (HK+PM; n = 6). Cows with continuous HK showed lower insulin and leptin levels than their normoketonemic mates from day 4-10 before calving, and these tendencies existed throughout the study. The plasma leptin and insulin patterns of cows with transient ketone increase around parturition represented an intermediate situation. Insulin area under the curve (AUC) and maximal insulin response to glucose were significantly lower in the early postpartum period than in late pregnant or mid lactating animals (P 0.05). Normoketonemic cows ovulated earlier than cows from group 2, 3 or 4 (day 26.2 ± 3.34; 7 ± 4; 44 ± 4; 50.1 ± 5; P = 0.002). Insulin AUC and maximal insulin response in cows affected by HK and PM were still lower on d 70 pp (P = 0.051 and P = 0.23) than in normo- or hyperketonemic animals. In conclusion we showed that pancreatic β-cell function and the biological potency of insulin is impaired in cows with long-term hyperketonemia. Short term elevation in plasma BHB and free fatty acid may not potentially induce further increase in peripheral tissue IR in the early lactation. Severe puerperal genital diseases like puerperal metritis and mastitis can further accentuate insulin resistance in dairy cows, with long term effects on metabolism and reproduction. (author)

  14. Captures of MFO-resistant Cydia pomonella adults as affected by lure, crop management system and flight.

    Science.gov (United States)

    Bosch, D; Rodríguez, M A; Avilla, J

    2016-02-01

    The main resistance mechanism of codling moth (Cydia pomonella) in the tree fruit area of Lleida (NE Spain) is multifunction oxidases (MFO). We studied the frequency of MFO-resistant adults captured by different lures, with and without pear ester, and flights in orchards under different crop management systems. The factor year affected codling moth MFO-resistance level, particularly in the untreated orchards, highlighting the great influence of codling moth migration on the spread of resistance in field populations. Chemical treatments and adult flight were also very important but mating disruption technique showed no influence. The second adult flight showed the highest frequency, followed by the first flight and the third flight. In untreated orchards, there were no significant differences in the frequency of MFO-resistant individuals attracted by Combo and BioLure. Red septa lures baited with pear ester (DA) captured sufficient insects only in the first generation of 2010, obtaining a significantly lower proportion of MFO-resistant adults than Combo and BioLure. In the chemically treated orchards, in 2009 BioLure caught a significantly lower proportion of MFO-resistant adults than Combo during the first and third flight, and also than DA during the first flight. No significant differences were found between the lures or flights in 2010. These results cannot support the idea of a higher attractiveness of the pear ester for MFO-resistant adults in the field but do suggest a high influence of the response to the attractant depending on the management of the orchard, particularly with regard to the use of chemical insecticides. PMID:26497943

  15. Genetic modification of alternative respiration in Nicotiana benthamiana affects basal and salicylic acid-induced resistance to potato virus X

    Directory of Open Access Journals (Sweden)

    Verchot-Lubicz Jeanmarie

    2011-02-01

    Full Text Available Abstract Background Salicylic acid (SA regulates multiple anti-viral mechanisms, including mechanism(s that may be negatively regulated by the mitochondrial enzyme, alternative oxidase (AOX, the sole component of the alternative respiratory pathway. However, studies of this mechanism can be confounded by SA-mediated induction of RNA-dependent RNA polymerase 1, a component of the antiviral RNA silencing pathway. We made transgenic Nicotiana benthamiana plants in which alternative respiratory pathway capacity was either increased by constitutive expression of AOX, or decreased by expression of a dominant-negative mutant protein (AOX-E. N. benthamiana was used because it is a natural mutant that does not express a functional RNA-dependent RNA polymerase 1. Results Antimycin A (an alternative respiratory pathway inducer and also an inducer of resistance to viruses and SA triggered resistance to tobacco mosaic virus (TMV. Resistance to TMV induced by antimycin A, but not by SA, was inhibited in Aox transgenic plants while SA-induced resistance to this virus appeared to be stronger in Aox-E transgenic plants. These effects, which were limited to directly inoculated leaves, were not affected by the presence or absence of a transgene constitutively expressing a functional RNA-dependent RNA polymerase (MtRDR1. Unexpectedly, Aox-transgenic plants infected with potato virus X (PVX showed markedly increased susceptibility to systemic disease induction and virus accumulation in inoculated and systemically infected leaves. SA-induced resistance to PVX was compromised in Aox-transgenic plants but plants expressing AOX-E exhibited enhanced SA-induced resistance to this virus. Conclusions We conclude that AOX-regulated mechanisms not only play a role in SA-induced resistance but also make an important contribution to basal resistance against certain viruses such as PVX.

  16. Study of the Raveling Resistance of Porous Asphalt Pavements Used in Sustainable Drainage Systems Affected by Hydrocarbon Spills

    Directory of Open Access Journals (Sweden)

    Jorge Rodriguez-Hernandez

    2015-12-01

    Full Text Available Permeable pavements are one of the most commonly-used sustainable drainage systems (SuDS in urban areas for managing stormwater runoff problems. Porous asphalt is widely used in surface layers of permeable pavement systems, where it can suffer from accidental oil spills from vehicles. Oil spills affect bituminous mixes through the solvent action of the hydrocarbons on the bitumen, reducing the raveling resistance of asphalt pavements. In order to assess the raveling resistance in porous asphalt pavements, the Cantabro abrasion test was performed on 200 test samples after applying controlled oil spills. Three different types of binders were used: conventional bitumen, polymer-modified bitumen and special fuel-resistant bitumen. After analyzing the results, it was concluded that the most suitable bitumen to protect against oil leakages is the polymer-modified one, which is far better than the other two types of bitumen tested.

  17. ramR Mutations Affecting Fluoroquinolone Susceptibility in Epidemic Multidrug-Resistant Salmonella enterica Serovar Kentucky ST198

    OpenAIRE

    Axel eCloeckaert

    2013-01-01

    A screening for non-target mutations affecting fluoroquinolone susceptibility was conducted in epidemic multidrug-resistant Salmonella enterica serovar Kentucky ST198. Among a panel of representative isolates (n=30), covering the epidemic, only three showed distinct mutations in ramR resulting in enhanced expression of genes encoding the AcrAB-TolC efflux system and low increase in ciprofloxacin MIC. No mutations were detected in other regulatory regions of this efflux system. Ciprofloxacin r...

  18. ramR mutations affecting fluoroquinolone susceptibility in epidemic multidrug-resistant Salmonella enterica serovar Kentucky ST198

    OpenAIRE

    Baucheron, Sylvie; Le Hello, Simon; Doublet, Benoît; Giraud, Etienne; Weill, François-Xavier; Cloeckaert, Axel

    2013-01-01

    International audience A screening for non-target mutations affecting fluoroquinolone susceptibility was conducted in epidemic multidrug-resistant Salmonella enterica serovar Kentucky ST198. Among a panel of representative isolates (n = 27), covering the epidemic, only three showed distinct mutations in ramR resulting in enhanced expression of genes encoding the AcrAB-TolC efflux system and low increase in ciprofloxacin MIC. No mutations were detected in other regulatory regions of this ef...

  19. ramR mutations affecting fluoroquinolone susceptibility in epidemic multidrug-resistant Salmonella enterica serovar Kentucky ST198

    OpenAIRE

    2013-01-01

    A screening for non-target mutations affecting fluoroquinolone susceptibility was conducted in epidemic multidrug-resistant Salmonella enterica serovar Kentucky ST198. Among a panel of representative isolates (n = 27), covering the epidemic, only three showed distinct mutations in ramR resulting in enhanced expression of genes encoding the AcrAB-TolC efflux system and low increase in ciprofloxacin MIC. No mutations were detected in other regulatory regions of this efflux system. Ciprofloxacin...

  20. Microsatellite mapping of QTLs affecting resistance to coccidiosis (Eimeria tenella) in a Fayoumi × White Leghorn cross

    OpenAIRE

    Gourichon David; Legros Hélène; Thomas Aurélie; Leroux Sophie; Feve Katia; Pitel Frédérique; Coville Jean-Luc; Bed'hom Bertrand; Pinard-van der Laan Marie-Hélène; Repérant Jean-Michel; Rault Paul

    2009-01-01

    Abstract Background Avian coccidiosis is a major parasitic disease of poultry, causing severe economical loss to poultry production by affecting growth and feed efficiency of infected birds. Current control strategies using mainly drugs and more recently vaccination are showing drawbacks and alternative strategies are needed. Using genetic resistance that would limit the negative and very costly effects of the disease would be highly relevant. The purpose of this work was to detect for the fi...

  1. Analysis of the Factors Affecting Resistance to Changes in Management Accounting Systems

    Directory of Open Access Journals (Sweden)

    Rodrigo Angonese

    2014-12-01

    Full Text Available Despite changes in the environment and management accounting practices, studies indicate that management accounting systems do not change or change at a much slower rate than expected. The stability of the management accounting systems used by companies may relate to resistance to changing these systems. This study analyzes the factors that contribute to resistance to implementing an integrated management system from the perspective of institutional theory, grounded in the old institutional economics. Methodologically, this study provides a qualitative assessment of the problem and a descriptive analysis of the resistance factors through a case-study approach. The data were collected using semi-structured interviews and analyzed through content analysis. Two companies were selected for this study due to their differing characteristics. The following seven factors were analyzed for resistance to implementing integrated management systems: institutional power, ontological insecurity, trust, inertia, lack of knowledge, acceptance of routines and decoupling. However, there was no evidence to characterize hierarchical power. The research findings indicate that changing management accounting systems, through the implementation of an integrated management system, faces internal resistance in these organizations. Each factor varies in intensity but is permanently present in these companies, such as ontological insecurity, trust, inertia, lack of knowledge, acceptance of routines and decoupling. These factors are awakened when the change process begins and, if they gather enough force, can stop the change.

  2. Mycoplasma pneumoniae: Current Knowledge on Macrolide Resistance and Treatment.

    Science.gov (United States)

    Pereyre, Sabine; Goret, Julien; Bébéar, Cécile

    2016-01-01

    Mycoplasma pneumoniae causes community-acquired respiratory tract infections, particularly in school-aged children and young adults. These infections occur both endemically and epidemically worldwide. M. pneumoniae lacks cell wall and is subsequently resistant to beta-lactams and to all antimicrobials targeting the cell wall. This mycoplasma is intrinsically susceptible to macrolides and related antibiotics, to tetracyclines and to fluoroquinolones. Macrolides and related antibiotics are the first-line treatment of M. pneumoniae respiratory tract infections mainly because of their low MIC against the bacteria, their low toxicity and the absence of contraindication in young children. The newer macrolides are now the preferred agents with a 7-to-14 day course of oral clarithromycin or a 5-day course of oral azithromycin for treatment of community-acquired pneumonia due to M. pneumoniae, according to the different guidelines worldwide. However, macrolide resistance has been spreading for 15 years worldwide, with prevalence now ranging between 0 and 15% in Europe and the USA, approximately 30% in Israel and up to 90-100% in Asia. This resistance is associated with point mutations in the peptidyl-transferase loop of the 23S rRNA and leads to high-level resistance to macrolides. Macrolide resistance-associated mutations can be detected using several molecular methods applicable directly from respiratory specimens. Because this resistance has clinical outcomes such as longer duration of fever, cough and hospital stay, alternative antibiotic treatment can be required, including tetracyclines such as doxycycline and minocycline or fluoroquinolones, primarily levofloxacin, during 7-14 days, even though fluoroquinolones and tetracyclines are contraindicated in all children and in children fluoroquinolones has never been reported in M. pneumoniae clinical isolates but reduced susceptibility was reported in in vitro selected mutants. This article focuses on M. pneumoniae

  3. Novel TetR family transcriptional factor regulates expression of multiple transport-related genes and affects rifampicin resistance in Mycobacterium smegmatis

    OpenAIRE

    Huicong Liu; Min Yang; Zheng-Guo He

    2016-01-01

    Transport-related genes significantly affect bacterial antibiotic resistance. However, the effects of these genes and their regulation of bacterial drug resistance in several mycobacterial species, including the fast-growing Mycobacterium smegmatis, the pathogen M. tuberculosis and M. avium have not been clearly characterized. We identified Ms4022 (MSMEG_4022) as a novel TetR family regulator that activates the expression of seven transport-related genes and affects drug resistance in M. smeg...

  4. Selective pressure affects transfer and establishment of a Lactobacillus plantarum resistance plasmid in the gastrointestinal environment

    DEFF Research Database (Denmark)

    Feld, Louise; Schjorring, S.; Hammer, Karin;

    2008-01-01

    Objectives and methods: A Lactobacillus plantarum strain recently isolated from French raw-milk cheese was tested for its ability to transfer a small plasmid pLFE1 harbouring the erythromycin resistance gene erm(B) to Enterococcus faecalis. Mating was studied in vitro and in different gastrointes......Objectives and methods: A Lactobacillus plantarum strain recently isolated from French raw-milk cheese was tested for its ability to transfer a small plasmid pLFE1 harbouring the erythromycin resistance gene erm(B) to Enterococcus faecalis. Mating was studied in vitro and in different...

  5. Microsatellite mapping of QTLs affecting resistance to coccidiosis (Eimeria tenella in a Fayoumi × White Leghorn cross

    Directory of Open Access Journals (Sweden)

    Gourichon David

    2009-01-01

    Full Text Available Abstract Background Avian coccidiosis is a major parasitic disease of poultry, causing severe economical loss to poultry production by affecting growth and feed efficiency of infected birds. Current control strategies using mainly drugs and more recently vaccination are showing drawbacks and alternative strategies are needed. Using genetic resistance that would limit the negative and very costly effects of the disease would be highly relevant. The purpose of this work was to detect for the first time QTL for disease resistance traits to Eimeria tenella in chicken by performing a genome scan in an F2 cross issued from a resistant Fayoumi line and a susceptible Leghorn line. Results The QTL analysis detected 21 chromosome-wide significant QTL for the different traits related to disease resistance (body weight growth, plasma coloration, hematocrit, rectal temperature and lesion on 6 chromosomes. Out of these, a genome-wide very significant QTL for body weight growth was found on GGA1, five genome-wide significant QTL for body weight growth, plasma coloration and hematocrit and one for plasma coloration were found on GGA1 and GGA6, respectively. Two genome-wide suggestive QTL for plasma coloration and rectal temperature were found on GGA1 and GGA2, respectively. Other chromosme-wide significant QTL were identified on GGA2, GGA3, GGA6, GGA15 and GGA23. Parent-of-origin effects were found for QTL for body weight growth and plasma coloration on GGA1 and GGA3. Several QTL for different resistance phenotypes were identified as co-localized on the same location. Conclusion Using an F2 cross from resistant and susceptible chicken lines proved to be a successful strategy to identify QTL for different resistance traits to Eimeria tenella, opening the way for further gene identification and underlying mechanisms and hopefully possibilities for new breeding strategies for resistance to coccidiosis in the chicken. From the QTL regions identified, several

  6. Affective Responses to Acute Resistance Exercise Performed at Self-Selected and Imposed Loads in Trained Women.

    Science.gov (United States)

    Focht, Brian C; Garver, Matthew J; Cotter, Joshua A; Devor, Steven T; Lucas, Alexander R; Fairman, Ciaran M

    2015-11-01

    The purpose of this study was to examine the affective responses to acute resistance exercise (RE) performed at self-selected (SS) and imposed loads in recreationally trained women. Secondary purposes were to (a) examine differences in correlates of motivation for future participation in RE and (b) determine whether affective responses to RE were related to these select motivational correlates of RE participation. Twenty recreationally trained young women (mean age = 23 years) completed 3 RE sessions involving 3 sets of 10 repetitions using loads of 40% of 1 repetition maximum (1RM), 70% 1RM, and an SS load. Affective responses were assessed before, during, and after each RE session using the Feeling Scale. Self-efficacy and intention for using the imposed and SS loads for their regular RE participation during the next month were also assessed postexercise. Results revealed that although the SS and imposed load RE sessions yielded different trajectories of change in affect during exercise (p motivational correlates of resistance training. PMID:26506060

  7. Rate of Conditioned Reinforcement Affects Observing Rate but Not Resistance to Change

    Science.gov (United States)

    Shahan, Timothy A.; Podlesnik, Christopher A.

    2005-01-01

    The effects of rate of conditioned reinforcement on the resistance to change of operant behavior have not been examined. In addition, the effects of rate of conditioned reinforcement on the rate of observing have not been adequately examined. In two experiments, a multiple schedule of observing-response procedures was used to examine the effects…

  8. Sputtering parameters affecting the corrosion resistance of CoCrPtTa thin film media

    International Nuclear Information System (INIS)

    Corrosion resistance of CoCrPtTa thin film media under high temperature and humidity environment (60 deg. C, 80 RH) was investigated. Effects of sputtering parameters, such as film thickness, Ar pressure, substrate bias, protective layer thickness and composition were studied. It is shown that Cr underlayer thickness and Ar pressure play important roles in the suppression of Co corrosion

  9. Volatiles produced by soil-borne endophytic bacteria increase plant pathogen resistance and affect tritrophic interactions.

    Science.gov (United States)

    D'Alessandro, Marco; Erb, Matthias; Ton, Jurriaan; Brandenburg, Anna; Karlen, Danielle; Zopfi, Jakob; Turlings, Ted C J

    2014-04-01

    Volatile organic compounds (VOCs) released by soil microorganisms influence plant growth and pathogen resistance. Yet, very little is known about their influence on herbivores and higher trophic levels. We studied the origin and role of a major bacterial VOC, 2,3-butanediol (2,3-BD), on plant growth, pathogen and herbivore resistance, and the attraction of natural enemies in maize. One of the major contributors to 2,3-BD in the headspace of soil-grown maize seedlings was identified as Enterobacter aerogenes, an endophytic bacterium that colonizes the plants. The production of 2,3-BD by E. aerogenes rendered maize plants more resistant against the Northern corn leaf blight fungus Setosphaeria turcica. On the contrary, E. aerogenes-inoculated plants were less resistant against the caterpillar Spodoptera littoralis. The effect of 2,3-BD on the attraction of the parasitoid Cotesia marginiventris was more variable: 2,3-BD application to the headspace of the plants had no effect on the parasitoids, but application to the soil increased parasitoid attraction. Furthermore, inoculation of seeds with E. aerogenes decreased plant attractiveness, whereas inoculation of soil with a total extract of soil microbes increased parasitoid attraction, suggesting that the effect of 2,3-BD on the parasitoid is indirect and depends on the composition of the microbial community. PMID:24127750

  10. Mechanisms of antimicrobial resistance in Gram-negative bacilli.

    Science.gov (United States)

    Ruppé, Étienne; Woerther, Paul-Louis; Barbier, François

    2015-12-01

    The burden of multidrug resistance in Gram-negative bacilli (GNB) now represents a daily issue for the management of antimicrobial therapy in intensive care unit (ICU) patients. In Enterobacteriaceae, the dramatic increase in the rates of resistance to third-generation cephalosporins mainly results from the spread of plasmid-borne extended-spectrum beta-lactamase (ESBL), especially those belonging to the CTX-M family. The efficacy of beta-lactam/beta-lactamase inhibitor associations for severe infections due to ESBL-producing Enterobacteriaceae has not been adequately evaluated in critically ill patients, and carbapenems still stands as the first-line choice in this situation. However, carbapenemase-producing strains have emerged worldwide over the past decade. VIM- and NDM-type metallo-beta-lactamases, OXA-48 and KPC appear as the most successful enzymes and may threaten the efficacy of carbapenems in the near future. ESBL- and carbapenemase-encoding plasmids frequently bear resistance determinants for other antimicrobial classes, including aminoglycosides (aminoglycoside-modifying enzymes or 16S rRNA methylases) and fluoroquinolones (Qnr, AAC(6')-Ib-cr or efflux pumps), a key feature that fosters the spread of multidrug resistance in Enterobacteriaceae. In non-fermenting GNB such as Pseudomonas aeruginosa, Acinetobacter baumannii and Stenotrophomonas maltophilia, multidrug resistance may emerge following the sole occurrence of sequential chromosomal mutations, which may lead to the overproduction of intrinsic beta-lactamases, hyper-expression of efflux pumps, target modifications and permeability alterations. P. aeruginosa and A. baumannii also have the ability to acquire mobile genetic elements encoding resistance determinants, including carbapenemases. Available options for the treatment of ICU-acquired infections due to carbapenem-resistant GNB are currently scarce, and recent reports emphasizing the spread of colistin resistance in environments with high

  11. Obesity and Prader-Willi Syndrome Affect Heart Rate Recovery from Dynamic Resistance Exercise in Youth

    OpenAIRE

    Castner, Diobel M.; Clark, Susan J.; Judelson, Daniel A.; Rubin, Daniela A

    2016-01-01

    Following exercise, heart rate decline is initially driven by parasympathetic reactivation and later by sympathetic withdrawal. Obesity delays endurance exercise heart rate recovery (HRR) in both children and adults. Young people with Prader-Willi Syndrome (PWS), a congenital cause for obesity, have shown a slower 60-s endurance exercise HRR compared to lean and obese children, suggesting compromised regulation. This study further evaluated effects of obesity and PWS on resistance exercise HR...

  12. Modulating affect, cognition and behavior – prospects of deep brain stimulation for treatment resistant psychiatric disorders

    OpenAIRE

    Schlaepfer, Thomas E

    2011-01-01

    Most patients suffering from psychiatric disorders respond to combina-tions of psycho- and psychopharmacotherapy, however there are patients who profit little if anything even after many years of treatment. Since about a decade different modalities of targeted neuromodulation – among them most prominently – Deep Brain Stimulation (DBS) - are being actively researched as putative approaches to very treatment resistant forms of those disorders. Recently, promising pilot data have been re-ported...

  13. Resistance exercise performed with repetitions until failure affects nocturnal blood pressure decreases in hypertensive women

    Directory of Open Access Journals (Sweden)

    Marilia de Almeida Correia

    2015-12-01

    Full Text Available Studies have shown that resistance exercise reduces 24-hour blood pressure to levels below resting values, although this is not a universal finding. The number of repetitions has been shown to influence this response. Thus, the aim of the study was to analyze the effects of resistance exercise performed until failure (UF on 24-hour blood pressure in hypertensive women. Thirteen hypertensive women underwent three experimental sessions in random order: UF, resistance exercise with repetitions before concentric failure (BF and control (C. Prior to and up to 24 hours after the sessions, cardiovascular variables, as well as the nocturnal fall in blood pressure, the morning surge, and the presence or absence of a blood pressure dip pattern were established using an ambulatory blood pressure monitor. In both wakefulness and sleep there was no significant difference among the three groups. However, after UF and C fewer patients presented a dip in blood pressure (46% and 38%, respectively compared BF (77%, p=0.047. In conclusion, the UF attenuated blood pressure dips at night in hypertensive patients.

  14. VARNISH LAYER HARDNESS, SCRATCH RESISTANCE, AND GLOSSINESS OF VARIOUS WOOD SPECIES AS AFFECTED BY HEAT TREATMENT

    Directory of Open Access Journals (Sweden)

    Nevzat Çakıcıer

    2011-03-01

    Full Text Available The aim of the study was to determine the effects of different heat treatment and varnish application combinations on hardness, scratch resistance, and glossiness of wood materials sampled from limba (Terminalia superba, iroko (Chlorophora excelsa, ash (Fraxinus excelsior L., and Anatolian chestnut (Castenea sativa Mill. species. The heat treatment was applied at two levels (150 and 180 oC for both 3 and 6 hour periods. After the heat treatment, four types of varnish (cellulose lacquer, synthetic varnish, polyurethane varnish, and water based varnish were applied, and hardness, scratch resistance, and glossiness of varnish film layers of the treated woods were measured. The effects of heat treatment and varnish combination applications on above mentioned variables were analyzed according to the study design (factorial design with 4 (species x 2 (heat x 2(duration x 4 (varnish = 64 experimental units with 10 samples for each combination of parameters. Glossiness increased on wood samples for all of the four wood species treated with cellulose lacquer and synthetic varnish and across all heating treatments. However, glossiness values were decreased for all the wood species depending on heating temperature and time. Values of hardness and scratch resistance were also decreased for all the four wood species across all the treatment combinations. The results were obtained from the upper surface of the application process and are thought to contribute to the national economy.

  15. Modulating affect, cognition and behavior – prospects of deep brain stimulation for treatment resistant psychiatric disorders

    Directory of Open Access Journals (Sweden)

    Thomas E. Schlaepfer

    2011-06-01

    Full Text Available Most patients suffering from psychiatric disorders respond to combina-tions of psycho- and psychopharmacotherapy, however there are patients who profit little if anything even after many years of treatment. Since about a decade different modalities of targeted neuromodulation – among them most prominently – Deep Brain Stimulation (DBS - are being actively researched as putative approaches to very treatment resistant forms of those disorders. Recently, promising pilot data have been re-ported both for Major Depression (MD and Obsessive-Compulsive Disor-der (OCD. Given the fact that patients studied had been treated unsuc-cessfully for many years renders these findings remarkable. Remarkable is the fact, that in case of the long-term studies underway for MD, patients show a stable response. This gives hope to a substantial percentage of therapy-resistant psychiatric patients requiring new therapy approaches. There are no fundamental ethic objections to its use in psychiatric disor-ders, but until substantial clinical data is available, mandatory standards are needed. DBS is a unique and very promising method for the treat-ment of therapy-resistant psychiatric patients. The method allows ma-nipulating pathological neuronal networks in a very precise way.

  16. Identifying quantitative trait loci affecting resistance to congenital hypothyroidism in 129/SvJcl strain mice.

    Directory of Open Access Journals (Sweden)

    Yayoi Hosoda

    Full Text Available Tyrosylprotein sulfotransferase 2 (TPST2 is one of the enzymes responsible for tyrosine O-sulfation and catalyzes the sulfation of the specific tyrosine residue of thyroid stimulating hormone receptor (TSHR. Since this modification is indispensable for the activation of TSH signaling, a non-functional TPST2 mutation (Tpst2(grt in DW/J-grt mice leads to congenital hypothyroidism (CH characterized by severe thyroid hypoplasia and dwarfism related to TSH hyporesponsiveness. Previous studies indicated that the genetic background of the 129(+Ter/SvJcl (129 mouse strain ameliorates Tpst2(grt-induced CH. To identify loci responsible for CH resistance in 129 mice, we performed quantitative trait locus (QTL analysis using backcross progenies from susceptible DW/J and resistant 129 mice. We used the first principal component calculated from body weights at 5, 8 and 10 weeks as an indicator of CH, and QTL analysis mapped a major QTL showing a highly significant linkage to the distal portion of chromosome (Chr 2; between D2Mit62 and D2Mit304, particularly close to D2Mit255. In addition, two male-specific QTLs showing statistically suggestive linkage were also detected on Chrs 4 and 18, respectively. All QTL alleles derived from the 129 strain increased resistance to growth retardation. There was also a positive correlation between recovery from thyroid hypoplasia and the presence of the 129 allele at D2Mit255 in male progenies. These results suggested that the major QTL on Chr 2 is involved in thyroid development. Moreover, since DW/J congenic strain mice carrying both a Tpst2(grt mutation and 129 alleles in the major QTL show resistance to dwarfism and thyroid hypoplasia, we confirmed the presence of the resistant gene in this region, and that it is involved in thyroid development. Further genetical analysis should lead to identification of genes for CH tolerance and, from a better understanding of thyroid organogenesis and function, the subsequent

  17. Extended spectrum beta-lactamase-producing Escherichia coli forms filaments as an initial response to cefotaxime treatment

    DEFF Research Database (Denmark)

    Kjeldsen, Thea S. B.; Sommer, Morten Otto Alexander; Olsen, John E.

    2015-01-01

    Background: beta-lactams target the peptidoglycan layer in the bacterial cell wall and most beta-lactam antibiotics cause filamentation in susceptible Gram-negative bacteria at low concentrations. The objective was to determine the initial morphological response of cephalosporin resistant CTX-M-1...

  18. Resistance of canola cultivars affect life table parameters of Nysius cymoides (Spinola (Hemiptera: Lygaeidae

    Directory of Open Access Journals (Sweden)

    Mollashahi Mehdi

    2016-01-01

    Full Text Available A life table can be used as an important and appropriate tool to evaluate the susceptibility or resistance level of different host plant cultivars to insect pests. In the current study, we determined the suitability or inferiority of five different canola cultivars (Hayula420, Hayula401, Hayula50, Hayula60, RGS to Nysius cymoides, under laboratory conditions. Data were analysed based on the age-stage, two-sex life table theory. Nysius cymoides which fed on Hayula420 had the longest nymphal period, while those which fed on Hayula50 had the shortest nymphal period. Developmental times (sum of incubation and nymphal periods was longest for those which fe d on Hayula420 and the shortest for those which fed on Hayula50. The adult pre-oviposition period (APOP, total pre-oviposition period (TPOP, mean fecundity, and adult longevity of adults reared on different canola cultivars showed significant differences. The highest and lowest net reproductive rates (R0 were obtained for those which fed on Hayula420 (11.40 offspring per individual and Hayula401 (5.47 offspring per individual, respectively. The highest value (0.0395 d-1 for the intrinsic rate of increase (r was obtained for those which fed on Hayula 60 cultivar and the lowest value (0.0261 d-1 for those which fed on Hayula401 cultivar. The shortest and longest mean generation times (T were obtained for those which fed on RGS and H401 cultivars, respectively. The lowest and highest values of life expectancy (exj were obtained for those which fed on RGS and Hayula420 cultivars, respectively. The results showed that Hayula401 and RGS were not susceptible cultivars to N. cymoides. These cultivars showed higher resistance to N. cymoides, while Hayula60, Hayula420, and Hayula50 were found to be suitable cultivars but with lower resistance to N. cymoides, respectively.

  19. Mechanisms affecting performance of the BaBar resistive plate chambers and searches for remediation

    International Nuclear Information System (INIS)

    The BaBar experiment at PEPII relies on the instrumentation of the flux return (IFR) for both muon identification and KL detection. The active detector is composed of resistive plate chambers (RPCs) operated in streamer mode. Since the start of operation the RPCs have suffered persistent efficiency deterioration and dark current increase problems. The 'autopsy' of bad BaBar RPCs revealed that in many cases uncured linseed oil droplets had formed on the inner surface of the Bakelite plates, leading to current paths from oil 'stalagmites' bridging the 2 mm gap. In this paper, a possible model of this 'stalagmite' formation and its effect on the dark current and efficiency of RPC chambers is presented. Laboratory test results strongly support this model. Based upon this model we are searching for solutions to eliminate the unfavorable effect of the oil stalagmites. The lab tests show that the stalagmite resistivity increases dramatically if exposed to the air, an observation that points to a possible way to remedy the damage and increase the efficiency. We have seen that flowing an oxygen gas mixture into the chamber helps to polymerize the uncured linseed oil. Consequently, the resistivity of the bridged oil stalagmites increases, as does that of the oil coating on the frame edges and spacers, significantly reducing the RPC dark currents and low-efficiency regions. We have tested this idea on two chambers removed from BaBar because of their low efficiency and high dark current. These test results are reported in the paper, and two other remediation methods also mentioned. We continue to study this problem, and try to find new treatments with permanent improvement

  20. Strengths amidst vulnerabilities: the paradox of resistance in a mining-affected community in Guatemala.

    Science.gov (United States)

    Caxaj, C Susana; Berman, Helene; Ray, Susan L; Restoule, Jean-Paul; Varcoe, Coleen

    2014-11-01

    The influence of large-scale mining on the psychosocial wellbeing and mental health of diverse Indigenous communities has attracted increased attention. In previous reports, we have discussed the influence of a gold mining operation on the health of a community in the Western highlands of Guatemala. Here, we discuss the community strengths, and acts of resistance of this community, that is, community processes that promoted mental health amidst this context. Using an anti-colonial narrative methodology that incorporated participatory action research principles, we developed a research design in collaboration with community leaders and participants. Data collection involved focus groups, individual interviews and photo-sharing with 54 men and women between the ages of 18 and 67. Data analysis was guided by iterative and ongoing conversations with participants and McCormack's narrative lenses. Study findings revealed key mechanisms and sources of resistance, including a shared cultural identity, a spiritual knowing and being, 'defending our rights, defending our territory,' and, speaking truth to power. These overlapping strengths were identified by participants as key protective factors in facing challenges and adversity. Yet ultimately, these same strengths were often the most eroded or endangered due the influence of large-scale mining operations in the region. These community strengths and acts of resistance reveal important priorities for promoting mental health and wellbeing for populations impacted by large-scale mining operations. Mental health practitioners must attend to both the strengths and parallel vulnerabilities that may be occasioned by large-scale projects of this nature. PMID:25353295

  1. The lion at the gate: an HIV-affected caregiver resists stigma.

    Science.gov (United States)

    Poindexter, Cynthia Cannon

    2005-02-01

    This article examines two bounded stories of HIV stigma told by an older woman who took care of her adult son as he died of AIDS. Her self-definition as a protector of her dying son was challenged when she encountered ostracism and prejudice. Her words and expressions illuminate her confrontation and resistance to associative stigma. An expansion of Goffman's view of stigma management is necessary to understand this caregiver's experiences in the face of the larger cultural narrative of HIV stigma:This caregiver did not manage stigma, she actively fought it. PMID:15847239

  2. Surveillance of multidrug resistant suppurative infection causing bacteria in hospitalized patients in an Indian tertiary care hospital

    Institute of Scientific and Technical Information of China (English)

    Nabakishore Nayak; Rajesh K Lenka; Rabindra N Padhy

    2014-01-01

    Objective:To examine antibiograms of a cohort of suppurative bacteria isolated from wound-swabs from hospitalized patients of all economic groups of a typicalIndian teaching hospital. Methods:In surveillance, antibiotic resistance patterns of10 species of suppurative bacteria isolated from wound-swabs over a period of24 months were recorded.Those were subjected to antibiotic sensitivity test, using16 prescribed antibiotics of5 different groups(3 aminoglycosides, 4 beta-lactams,3 cephalosporins,4 fluoroquinolones, and2 stand-alone) in each6-month interval of the study period.Results:Of1156 samples collected,819 samples yielded pathogenic bacteria, of which,Staphylococcus aureus(S. aureus),Streptococcus pyogenes(S. pyogenes), Escherichia coli(E. coli),Pseudomonas aeruginosa(P. aeruginosa),Enterococcus faecalis(E. faecalis), Klebsiella pneumoniae(K. pneumoniae),Acinetobacter baumannii(A. baumannii),Enterobacter aerogenes(E. aerogenes),Proteus mirabilis(P. mirabilis) andProteus vulgaris(P. vulgaris) were isolated in the order of predominance.Isolated bacterial strains were floridly multidrug resistant.Strains ofE. faecalis andS. aureus were found resistant to vancomycin, one of the newly introduced antibiotics.Conclusions:Of theseS. aureus, particularly the methicillin resistant strain predominates, followed by strains ofS. pyogenes andP. aeruginosa that were in the higher proportions of multidrug resistance.

  3. Jammed granular cones affect frictional resistive forces at the onset of intrusion

    Science.gov (United States)

    Aguilar, Jeffrey; Goldman, Daniel

    Characterizing the functional form of granular resistive forces has allowed for analysis of the locomotion of animals and robots on and within dry granular media. Resistive force theory (RFT) has been an effective tool in predicting these forces for various locomotive gaits within the ``frictional fluid'' regime, where intrusions are sufficiently slow such that granular inertial effects are negligible. These forces have been typically described by a linear dependence to submersion depth. However, recent experiments on robotic jumping [Aguilar & Goldman, Nature Physics, 2015] have revealed the importance of considering the nonlinear effects at the onset of intrusion to accurately predict robot kinematics. Particle image velocimetry (PIV) analysis of sidewall grain flow during foot intrusion reveals a jammed granular cone that develops beneath the foot at the onset of intrusion. A geometric model of cone development combined with empirical RFT forces on angled conical surfaces was able to predict the non-linear force trajectory vs. depth for experimental intrusions of various foot sizes, suggesting that intruders experience non-linear frictional forces according to the shape of the granular jamming fronts that form at the onset of movement. This work was supported by NSF Physics of Living Systems, Burroughs Wellcome Fund, and the Army Research Office.

  4. Insulin Resistance and Obesity Affect Lipid Profile in the Salivary Glands

    Science.gov (United States)

    Matczuk, Jan; Zalewska, Anna; Łukaszuk, Bartłomiej; Knaś, Małgorzata; Maciejczyk, Mateusz; Garbowska, Marta; Ziembicka, Dominika M.; Waszkiel, Danuta; Chabowski, Adrian; Żendzian-Piotrowska, Małgorzata

    2016-01-01

    In today's world wrong nutritional habits together with a low level of physical activity have given rise to the development of obesity and its comorbidity, insulin resistance. More specifically, many researches indicate that lipids are vitally involved in the onset of a peripheral tissue (e.g., skeletal muscle, heart, and liver) insulin resistance. Moreover, it seems that diabetes can also induce changes in respect of lipid composition of both the salivary glands and saliva. However, judging by the number of research articles, the salivary glands lipid profile still has not been sufficiently explored. In the current study we aim to assess the changes in the main lipid fractions, namely, triacylglycerols, phospholipids, free fatty acids, and diacylglycerols, in the parotid and the submandibular salivary glands of rats exposed to a 5-week high fat diet regimen. We observed that the high caloric fat diet caused a significant change in the salivary glands lipid composition, especially with respect to PH and TG, but not DAG or FFAs, classes. The observed reduction in PH concentration is an interesting phenomenon frequently signifying the atrophy and malfunctions in the saliva secreting organs. On the other hand, the increased accumulation of TG in the glands may be an important clinical manifestation of metabolic syndrome and type 2 diabetes mellitus. PMID:27471733

  5. WATER RESISTANCE AND SOME MECHANICAL PROPERTIES OF RICE STRAW FIBERBOARDS AFFECTED BY THERMAL MODIFICATION

    Directory of Open Access Journals (Sweden)

    Mingzhu Pan

    2010-05-01

    Full Text Available Rice straw fiberboard was made using 12 wt % urea-formaldehyde (UF resin as binder and 1.0 wt % polymeric methylene diphenyl diisocyanate (pMDI and 1.2 wt % wax emulsion as water retardants. The prepared fiberboards were heat-treated at 120, 150, 185, and 210°C in the presence of steam in a high-temperature dry kiln, respectively for 90 min. The effect of water retardants and heat treatment on the water resistant and some mechanical properties of the fiberboards were investigated. It was found that the water resistance of the rice straw fiberboard could not be improved by adding wax emulsion. The use of pMDI to the system significantly increased the interfacial strength and reduced 24-h thickness swelling (TS compared to the boards with or without wax emulsion. After heat treatment, the TS was significantly decreased due to the decrease in the free reactive hydroxyl group content of rice straw fiber. Some mechanical properties of the fiberboards, such as the internal bonding strength, modulus of elasticity, and modulus of rapture were dramatically reduced with increasing temperature from 120°C to 210°C.

  6. Insulin Resistance and Obesity Affect Lipid Profile in the Salivary Glands

    Directory of Open Access Journals (Sweden)

    Jan Matczuk

    2016-01-01

    Full Text Available In today’s world wrong nutritional habits together with a low level of physical activity have given rise to the development of obesity and its comorbidity, insulin resistance. More specifically, many researches indicate that lipids are vitally involved in the onset of a peripheral tissue (e.g., skeletal muscle, heart, and liver insulin resistance. Moreover, it seems that diabetes can also induce changes in respect of lipid composition of both the salivary glands and saliva. However, judging by the number of research articles, the salivary glands lipid profile still has not been sufficiently explored. In the current study we aim to assess the changes in the main lipid fractions, namely, triacylglycerols, phospholipids, free fatty acids, and diacylglycerols, in the parotid and the submandibular salivary glands of rats exposed to a 5-week high fat diet regimen. We observed that the high caloric fat diet caused a significant change in the salivary glands lipid composition, especially with respect to PH and TG, but not DAG or FFAs, classes. The observed reduction in PH concentration is an interesting phenomenon frequently signifying the atrophy and malfunctions in the saliva secreting organs. On the other hand, the increased accumulation of TG in the glands may be an important clinical manifestation of metabolic syndrome and type 2 diabetes mellitus.

  7. Increasing frequency of penicillin-resistant pneumococci: epidemiological aspects and case-control study.

    Science.gov (United States)

    Amitai, Y; Rotenberg, M; Wirtschafter, D; Haas, H; Michel, J

    1985-04-01

    At the Hadassah University Hospital, Mt. Scopus, Jerusalem, the frequency of patients with relatively penicillin-resistant pneumococci (RPRP) isolates has increased from 0.9 to 10.8% during the years 1979-82. Infants and children were particularly involved. Significantly more RPRP isolates were found in those less than 14 years old than in those who were older (P less than 0.005). The determination of susceptibility or relative resistance to penicillin was based on the disk sensitivity method, which remained unchanged throughout the study period. The minimal inhibitory concentration (MIC) to penicillin G was also determined for 20 RPRP isolates and was found to be in the range of relative resistance to penicillin (0.25 to 0.50 micrograms/ml) in all 20 isolates. A case-control study of 16 index patients examined antibiotic usage during the 60 days preceding pneumococcal isolation. Total antibiotic usage was high in both groups (18.8 vs. 8.8 days, P = 0.2); beta-lactam antibiotic usage was significantly higher in the RPRP group than in the control group (13.3 vs. 4.2 days, 0.01 less than P less than 0.02). General prescribing practices, even in nonisolated areas where there is no need for public health programs to dispense prophylactic antibiotics, may produce sufficiently high antibiotic exposures to aid the emergence of RPRP strains. PMID:3846591

  8. Catering ESBL resistance challenge through strategic combination of Ceftriaxone, Sulbactam and Ethylenediaminetetraacetic Acid

    Directory of Open Access Journals (Sweden)

    Manu Chaudhary

    2012-03-01

    Full Text Available Resistant development in ESBLs producing bacteria to third generation cephalosporin has emerged with alarming rapidity in recent years and become major cause of concern world wide. Therefore, in order to cater growing resistance problem, combination of third generation cephalosporin with beta-lactam inhibitors and Ethylenediaminetetraacetic acid, was studied. The in vitro antibacterial efficacy of various concentration of ceftriaxone +sulbactam and effective dose determination study of EDTA against various ESBLs producing micro organisms such as Escherichia coli (MTCC -739, Klebsiella pneumoniae(MTCC-109,Pseudomonas aeruginosa (MTCC-1688, and Staphylococcus aureus (MTCC-737 were investigated. From the AST and MIC report it was found that the 2:1 ratio has very good bactericidal activity in comparison to other ratios under study. It was found that ceftriaxone and sulbactam combination along with 3mg/ml of Disodium EDTA has significant (p8 fold and possess synergy against the most ESBL producing micro organisms. The combination was found to have beneficial property against troublesome strains and might be considered as a promising therapy for severe infections to overcome resistance.

  9. Biochemical resistance of pyrogenic organic matter in fire-affected mineral soils of Southern Europe

    Science.gov (United States)

    Knicker, H.; González Vila, F. J.; Clemente Salas, L.

    2012-04-01

    Incorporated into the soil, naturally formed pyrogenic organic matter (PyOM) is considered as highly recalcitrant, but direct estimation of PyOM decomposition rates are scarce. With this aim in mind, we subjected organic matter (OM) of fire-affected and unaffected soils to biochemical degradation under laboratory conditions and monitored CO2 production over a period of seven months. The soils derived from fire affected and unaffected areas of the Sierra de Aznalcóllar and the Doñana National Park, Southern Spain. Virtual fractionation of the solid-state 13C nuclear magnetic resonance (NMR) spectra of the fire affected soils into fire-unaffected soil organic matter (SOM) and PyOM yielded charcoal C contributions of 30 to 50% to the total organic C (Corg) of the sample derived from the Aznalcóllar region. Fitting the respiration data with a double exponential decay model revealed a fast carbon flush during the first three weeks of the experiment. Solid-state 13C NMR spectroscopy evidenced the contribution of aromatic moieties of the PyOM to this initial carbon release and to the biosynthesis of new microbial biomass. The input of PyOM resulted in an increase of the mean residence time (MRT) of the slow OM pool of the soil by a factor of 3 to 4 to approximately 40 years which rises doubts rises doubts about the presumed big influence of PyOM as an additional C-sink in soils. On the other hand, although being small the difference in turnover rates is evident and has some major implication with respect to long-term alteration of the chemical composition of OM in fire-affected soils. Based on the obtained results and the analysis of PyOM in other soil systems, a conceptual model is presented which can explain the different behavior of PyOM under different soil conditions.

  10. Optimizing the management of community-acquired respiratory tract infections in the age of antimicrobial resistance.

    Science.gov (United States)

    Doern, Gary V

    2006-10-01

    Community-acquired respiratory tract infections (CARTIs) are the most common reason for prescribing antibiotics in the primary care setting. However, over the last decade, the management of CARTIs has become increasingly complicated by the steady increase in prevalence of drug-resistant pathogens responsible for these infections. As a result, significant attention has been directed at understanding the mechanisms of pathogen acquisition of resistance, drivers of resistance and methods for preventing the development of resistance. Data from recent surveillance studies suggest a slowing or decline in resistance rates to agents, such as beta-lactams, macrolides, tetracyclines and folic acid metabolism inhibitors. However, resistance to one antimicrobial family--the fluoroquinolones--while still low, appears to be on the increase. This is of significant concern given the rapid increase in resistance noted with older antibiotics in recent history. While the clinical implications of antibacterial resistance are poorly understood, the overall rates of antimicrobial resistance, as reported in recent surveillance studies, do not correspond to current rates of failure in patients with CARTIs. This disconnection between laboratory-determined resistance and clinical outcome has been termed the in vitro-in vivo paradox and several explanations have been offered to explain this phenomenon. Solving the problem of antimicrobial resistance will be multifactorial. Important factors in this effort include the education of healthcare providers, patients and the general healthcare community regarding the hazards of inappropriate antibiotic use, prevention of infections through vaccination, development of accurate, inexpensive and timely point-of-care diagnostic tests to aid in patient assessment, institution of objective treatment guidelines and use of more potent agents, especially those with a focused spectrum of activity, earlier in the treatment of CARTIs as opposed to reserving

  11. Resistant starch and arabinoxylan augment SCFA absorption, but affect postprandial glucose and insulin responses differently - CORRIGENDUM

    DEFF Research Database (Denmark)

    Ingerslev, Anne Krog; Theil, Peter Kappel; Hedemann, Mette Skou;

    2015-01-01

    glucose was observed in RSD fed pigs (203 mmol/h, P = 0.02). The NPF of total SCFA, acetate, propionate, and butyrate were high, intermediate, and low (P < 0.01) in AXD, RSD, and WSD fed pigs, respectively, with the largest relative increase for butyrate in response to arabinoxylan supplementation. In......The effects of increased colonic fermentation of dietary fibres (DF) on net portal flux (NPF) of carbohydrate-derived metabolites (glucose, SCFA and especially butyrate), hormones (insulin, C-peptide, GLP-1, GIP) and NEFA were studied in a healthy catheterised pig model. Six 59 ± 3.8 kg pigs were...... conclusion, RSD and AXD had different effects on net portal insulin and glucose flux, suggesting different impact of arabinoxylan and resistant starch on human health....

  12. CD38 expression and complement inhibitors affect response and resistance to daratumumab therapy in myeloma.

    Science.gov (United States)

    Nijhof, Inger S; Casneuf, Tineke; van Velzen, Jeroen; van Kessel, Berris; Axel, Amy E; Syed, Khaja; Groen, Richard W J; van Duin, Mark; Sonneveld, Pieter; Minnema, Monique C; Zweegman, Sonja; Chiu, Christopher; Bloem, Andries C; Mutis, Tuna; Lokhorst, Henk M; Sasser, A Kate; van de Donk, Niels W C J

    2016-08-18

    The anti-CD38 monoclonal antibody daratumumab is well tolerated and has high single agent activity in heavily pretreated relapsed and refractory multiple myeloma (MM). However, not all patients respond, and many patients eventually develop progressive disease to daratumumab monotherapy. We therefore examined whether pretreatment expression levels of CD38 and complement-inhibitory proteins (CIPs) are associated with response and whether changes in expression of these proteins contribute to development of resistance. In a cohort of 102 patients treated with daratumumab monotherapy (16 mg/kg), we found that pretreatment levels of CD38 expression on MM cells were significantly higher in patients who achieved at least partial response (PR) compared with patients who achieved less than PR. However, cell surface expression of the CIPs, CD46, CD55, and CD59, was not associated with clinical response. In addition, CD38 expression was reduced in both bone marrow-localized and circulating MM cells, following the first daratumumab infusion. CD38 expression levels on MM cells increased again following daratumumab discontinuation. In contrast, CD55 and CD59 levels were significantly increased on MM cells only at the time of progression. All-trans retinoic acid increased CD38 levels and decreased CD55 and CD59 expression on MM cells from patients who developed daratumumab resistance, to approximately pretreatment values. This resulted in significant enhancement of daratumumab-mediated complement-dependent cytotoxicity. Together, these data demonstrate an important role for CD38 and CIP expression levels in daratumumab sensitivity and suggest that therapeutic combinations that alter CD38 and CIP expression levels should be investigated in the treatment of MM. These trials were registered at www.clinicaltrials.gov as #NCT00574288 (GEN501) and #NCT01985126 (SIRIUS). PMID:27307294

  13. Environmental Conditions Influence Induction of Key ABC-Transporter Genes Affecting Glyphosate Resistance Mechanism in Conyza canadensis

    Science.gov (United States)

    Tani, Eleni; Chachalis, Demosthenis; Travlos, Ilias S.; Bilalis, Dimitrios

    2016-01-01

    Conyza canadensis has been reported to be the most frequent weed species that evolved resistance to glyphosate in various parts of the world. The objective of the present study was to investigate the effect of environmental conditions (temperature and light) on the expression levels of the EPSPS gene and two major ABC-transporter genes (M10 and M11) on glyphosate susceptible (GS) and glyphosate resistant (GR) horseweed populations, collected from several regions across Greece. Real-time PCR was conducted to determine the expression level of the aforementioned genes when glyphosate was applied at normal (1×; 533 g·a.e.·ha−1) and high rates (4×, 8×), measured at an early one day after treatment (DAT) and a later stage (four DAT) of expression. Plants were exposed to light or dark conditions, at three temperature regimes (8, 25, 35 °C). GR plants were made sensitive when exposed to 8 °C with light; those sensitized plants behaved biochemically (shikimate accumulation) and molecularly (expression of EPSPS and ABC-genes) like the GS plants. Results from the current study show the direct link between the environmental conditions and the induction level of the above key genes that likely affect the efficiency of the proposed mechanism of glyphosate resistance. PMID:27104532

  14. Rapid experimental evolution of pesticide resistance in C. elegans entails no costs and affects the mating system.

    Directory of Open Access Journals (Sweden)

    Patricia C Lopes

    Full Text Available Pesticide resistance is a major concern in natural populations and a model trait to study adaptation. Despite the importance of this trait, the dynamics of its evolution and of its ecological consequences remain largely unstudied. To fill this gap, we performed experimental evolution with replicated populations of Caenorhabditis elegans exposed to the pesticide Levamisole during 20 generations. Exposure to Levamisole resulted in decreased survival, fecundity and male frequency, which declined from 30% to zero. This was not due to differential susceptibility of males. Rather, the drug affected mobility, resulting in fewer encounters, probably leading to reduced outcrossing rates. Adaptation, i.e., increased survival and fecundity, occurred within 10 and 20 generations, respectively. Male frequency also increased by generation 20. Adaptation costs were undetected in the ancestral environment and in presence of Ivermectin, another widely-used pesticide with an opposite physiological effect. Our results demonstrate that pesticide resistance can evolve at an extremely rapid pace. Furthermore, we unravel the effects of behaviour on life-history traits and test the environmental dependence of adaptation costs. This study establishes experimental evolution as a powerful tool to tackle pesticide resistance, and paves the way to further investigations manipulating environmental and/or genetic factors underlying adaptation to pesticides.

  15. Environmental Conditions Influence Induction of Key ABC-Transporter Genes Affecting Glyphosate Resistance Mechanism in Conyza canadensis.

    Science.gov (United States)

    Tani, Eleni; Chachalis, Demosthenis; Travlos, Ilias S; Bilalis, Dimitrios

    2016-01-01

    Conyza canadensis has been reported to be the most frequent weed species that evolved resistance to glyphosate in various parts of the world. The objective of the present study was to investigate the effect of environmental conditions (temperature and light) on the expression levels of the EPSPS gene and two major ABC-transporter genes (M10 and M11) on glyphosate susceptible (GS) and glyphosate resistant (GR) horseweed populations, collected from several regions across Greece. Real-time PCR was conducted to determine the expression level of the aforementioned genes when glyphosate was applied at normal (1×; 533 g·a.e.·ha(-1)) and high rates (4×, 8×), measured at an early one day after treatment (DAT) and a later stage (four DAT) of expression. Plants were exposed to light or dark conditions, at three temperature regimes (8, 25, 35 °C). GR plants were made sensitive when exposed to 8 °C with light; those sensitized plants behaved biochemically (shikimate accumulation) and molecularly (expression of EPSPS and ABC-genes) like the GS plants. Results from the current study show the direct link between the environmental conditions and the induction level of the above key genes that likely affect the efficiency of the proposed mechanism of glyphosate resistance. PMID:27104532

  16. Developing mutant rice high in resistant starch fighting for diabetes-affected people

    International Nuclear Information System (INIS)

    Diabetes is a major socio-economic cost and is a predisposing factor for early onset coronary heart disease and peripheral vascular disease. Type II diabetes reflects a failure of blood glucose regulation, leading to sustained high blood glucose concentrations that have numbers of metabolic effects predisposing to pathology. The risk of Type II diabetes is related to diet, especially the availability of readily digested, highly refined foods and excess energy intake. In the case of diabetes, the ready digestion of carbohydrates (particularly starches) leads to a rapid rise in blood glucose and a greater demand on the pancreas for insulin to normalize concentrations. Starch that is not absorbed in the small intestine but passes into the large bowel (Resistant starch, RS) is a key protector against serious disease (including cancer) in the latter region of the intestines, being fermented by the large bowel microflora yielding short chain fatty acids (SCFA) that promote normal colonic function. Multiple approaches were suggested to obtain high amounts of resistant starch, and most of is to physically modify starch structure through processing technology. Diabetes is also increasing in the Third World and Least Developed Countries (LDCs). The current rice varieties low in resistant starch available to these individuals are not low in GI and the production of high resistant starch rices will be an attractive consumer option to this section of the population. The ability of subsistence farmers to be able sell high-RS rice lines will enable such farmers to continue to survive in those in these countries. The largest producers in the world are China and India with production at 120 and 80 million tonnes per annum respectively. The contents of RS in the hot cooked and processed rice are always below 3% by the traditionally domestic manners. This might lead to a higher glycemic index (GI) and lower butyrate content, subsequently increase the potential risk of metabolic

  17. Is colistin effective in the treatment of infections caused by multidrug-resistant (MDR) or extremely drug-resistant (XDR) gram-negative microorganisms in children?

    Science.gov (United States)

    Ozsurekci, Yasemin; Aykac, Kubra; Cengiz, Ali Bulent; Bayhan, Cihangul; Sancak, Banu; Karadag Oncel, Eda; Kara, Ates; Ceyhan, Mehmet

    2016-06-01

    The increasing incidence of infections caused by multidrug-resistant (MDR) or extremely drug-resistant (XDR) gram-negative organisms has led to the reemergence of colistin use. Clinical and demographic data were collected on 94 pediatric patients diagnosed with MDR or XDR gram-negative infections and treated with either a colistin-containing regimen (colistin group) or at least one antimicrobial agent other than colistin (noncolistin group). The overall clinical response rates were 65.8% in the colistin group and 70.0% in the noncolistin group (P = 0.33). The infection-related mortality rates were 11% in the colistin group and 13.3% in the noncolistin group (P = 0.74). There was no statistically significant difference in nephrotoxicity in the colistin and noncolistin groups. Colistin therapy was at least as effective and as safe as beta-lactam antibiotics or quinolones, with or without aminoglycosides, in the treatment of infections caused by gram-negative organisms and may be a therapeutic option in children. PMID:27041107

  18. Grassland management affects belowground carbon allocation in mountain grasslands and its resistance and resilience to drought

    Science.gov (United States)

    Karlowsky, Stefan; Augusti, Angela; Ingrisch, Johannes; Hasibeder, Roland; Bahn, Michael; Gleixner, Gerd

    2015-04-01

    Future climate scenarios do not only forecast increased extreme events during summer, but also more frequent drought events in the early season. In mountain grasslands, different land uses may contribute to the response of the ecosystem to climate changes, like drought in May and June. In this study, we examined the drought response of two differently managed grasslands, 1) a more intensive used meadow and 2) a less intensive used abandoned area. Our aim was to highlight differences in both resistance and resilience of ecosystem functioning, based on carbon (C) belowground allocation as a key function in the plant-rhizosphere continuum. Therefore, we used an isotopic approach and in particular, we used 13C pulse labelling to track the fate of newly assimilated C from leaves, to roots and to soil, up to different microbial communities. We performed two 13C pulse labellings, the first during the acute phase of drought, when the water status of soil was drastically decreased compared to the control; and the second during the recovery phase, when the soil water status was restored to control level. We followed the kinetics of 13C incorporation in above- and below-ground bulk material as well as non-structural sugars, in general soil microbial biomass, in different soil microbial communities and in CO2 respired from roots, up to 5 days from each labelling. Preliminary results from the 13C analyses of bulk phytomass material and soil microbial biomass indicate, as expected, different kinetics of aboveground 13C incorporation and its belowground allocation. During the acute phase of drought, 13C incorporation shows a decrease compared to the control for both land uses, with generally higher reductions in meadow treatments. Root 13C tracer dynamics follow the leaf 13C enrichment with a delay. High label amounts are found in leaves directly after labelling, whereas in roots high 13C incorporation is found first after 24 hours, accompanied by a fast decrease of 13C label in

  19. Multidrug resistance in Salmonella enterica serotype Typhimurium from humans in France (1993 to 2003).

    Science.gov (United States)

    Weill, François-Xavier; Guesnier, Françoise; Guibert, Véronique; Timinouni, Mohammed; Demartin, Marie; Polomack, Lucette; Grimont, Patrick A D

    2006-03-01

    The aim of this study was to determine the distribution of the antimicrobial resistance phenotypes (R types), the phage types and XbaI-pulsed-field gel electrophoresis (PFGE) types, the genes coding for resistance to beta-lactams and to quinolones, and the class 1 integrons among a representative sample of Salmonella enterica serotype Typhimurium isolates collected from humans in 2002 through the French National Reference Center for Salmonella (NRC-Salm) network. The trends in the evolution of antimicrobial resistance of serotype Typhimurium were reviewed by using NRC-Salm data from 1993, 1997, 2000, and 2003. In 2002, 3,998 isolates of serotype Typhimurium were registered at the NRC-Salm among 11,775 serotyped S. enterica isolates (34%). The most common multiple antibiotic resistance pattern was resistance to amoxicillin, chloramphenicol, streptomycin and spectinomycin, sulfonamides, and tetracycline (ACSSpSuTe R type), with 156 isolates (48.8%). One isolate resistant to extended-spectrum cephalosporins due to the production of TEM-52 extended-spectrum beta-lactamase was detected (0.3%), and one multidrug-resistant isolate was highly resistant to ciprofloxacin (MIC > 32 mg/liter). We found that 57.2% of the isolates tested belonged to the DT104 clone. The main resistance pattern of DT104 isolates was R type ACSSpSuTe (83.2%). However, evolutionary changes have occurred within DT104, involving both loss (variants of Salmonella genomic island 1) and acquisition of genes for drug resistance to trimethoprim or to quinolones. PFGE profile X1 was the most prevalent (74.5%) among DT104 isolates, indicating the need to use a more discriminatory subtyping method for such isolates. Global data from the NRC-Salm suggested that DT104 was the main cause of multidrug resistance in serotype Typhimurium from humans from at least 1997 to 2003, with a roughly stable prevalence during this period. PMID:16517842

  20. Occurrence of Ambler Class B Metallo-β-Lactamase Gene in Imipenem-Resistant Pseudomonas Aeruginosa Strains Isolated from Clinical Samples

    Directory of Open Access Journals (Sweden)

    Zeynab Golshani

    2014-02-01

    Full Text Available Background: 5TMetallo-β-lactamase (MBLs can hydrolyze a broad spectrum of beta-lactams, including penicillins, cephalosporins, and carbapenems. Genes encoding these enzymes are located on the plasmid that can easily be transferred to other bacteria. The aim of this study was to isolate and identify the Pseudomonas aeruginosa strains encoding VIM1 gene, in clinical samples, using the PCR technique. Materials and Methods: During a 4 month period, 100 strains of Pseudomonas aeruginosa from clinical specimens were collected. Standard tests were performed to identify strains of Pseudomonas aeruginosa. Resistance to antibiotics was examined and then the PCR was used to detect VIM1gene. Results:In this study, the highest rates of resistance to antibiotics, amikacin and cefotaxime was observed (65% and 62%, the lowest resistance to antibiotics piperacillin (48% and imipenem and cefepime with 55% resistance was reported. DDST method was performed for 37 strains for the MBl detection. Among the 37 isolate, 30 strains were MBL-producing with imipenem-EDTA method. Twelve strains (18% were carriers of VIM1 gene using the PCR method. Conclusion: In the present study, the prevalence of strains producing MBL genes in strains of hospitals is a growing trend; correct prescription of medications can prevent the spread of resistant pathogens. It is suggested that molecular methods for rapid detection of resistance genes can be used to prevent the spread of this genes.

  1. Aquaculture changes the profile of antibiotic resistance and mobile genetic element associated genes in Baltic Sea sediments.

    Science.gov (United States)

    Muziasari, Windi I; Pärnänen, Katariina; Johnson, Timothy A; Lyra, Christina; Karkman, Antti; Stedtfeld, Robert D; Tamminen, Manu; Tiedje, James M; Virta, Marko

    2016-04-01

    Antibiotics are commonly used in aquaculture and they can change the environmental resistome by increasing antibiotic resistance genes (ARGs). Sediment samples were collected from two fish farms located in the Northern Baltic Sea, Finland, and from a site outside the farms (control). The sediment resistome was assessed by using a highly parallel qPCR array containing 295 primer sets to detect ARGs, mobile genetic elements and the 16S rRNA gene. The fish farm resistomes were enriched in transposon and integron associated genes and in ARGs encoding resistance to antibiotics which had been used to treat fish at the farms. Aminoglycoside resistance genes were also enriched in the farm sediments despite the farms not having used aminoglycosides. In contrast, the total relative abundance values of ARGs were higher in the control sediment resistome and they were mainly genes encoding efflux pumps followed by beta-lactam resistance genes, which are found intrinsically in many bacteria. This suggests that there is a natural Baltic sediment resistome. The resistome associated with fish farms can be from native ARGs enriched by antibiotic use at the farms and/or from ARGs and mobile elements that have been introduced by fish farming. PMID:26976842

  2. Factors affecting gas migration and contaminant redistribution in heterogeneous porous media subject to electrical resistance heating

    Science.gov (United States)

    Munholland, Jonah L.; Mumford, Kevin G.; Kueper, Bernard H.

    2016-01-01

    A series of intermediate-scale laboratory experiments were completed in a two-dimensional flow cell to investigate gas production and migration during the application of electrical resistance heating (ERH) for the removal of dense non-aqueous phase liquids (DNAPLs). Experiments consisted of heating water in homogeneous silica sand and heating 270 mL of trichloroethene (TCE) and chloroform (CF) DNAPL pools in heterogeneous silica sands, both under flowing groundwater conditions. Spatial and temporal distributions of temperature were measured using thermocouples and observations of gas production and migration were collected using front-face image capture throughout the experiments. Post-treatment soil samples were collected and analyzed to assess DNAPL removal. Results of experiments performed in homogeneous sand subject to different groundwater flow rates showed that high groundwater velocities can limit subsurface heating rates. In the DNAPL pool experiments, temperatures increased to achieve DNAPL-water co-boiling, creating estimated gas volumes of 131 and 114 L that originated from the TCE and CF pools, respectively. Produced gas migrated vertically, entered a coarse sand lens and subsequently migrated laterally beneath an overlying capillary barrier to outside the heated treatment zone where 31-56% of the original DNAPL condensed back into a DNAPL phase. These findings demonstrate that layered heterogeneity can potentially facilitate the transport of contaminants outside the treatment zone by mobilization and condensation of gas phases during ERH applications. This underscores the need for vapor phase recovery and/or control mechanisms below the water table during application of ERH in heterogeneous porous media during the co-boiling stage, which occurs prior to reaching the boiling point of water.

  3. A narrow quantitative trait locus in C. elegans coordinately affects longevity, thermotolerance, and resistance to paraquat

    Directory of Open Access Journals (Sweden)

    Anthony eVertino

    2011-09-01

    Full Text Available By linkage mapping of quantitative trait loci, we previously identified at least 11 natural genetic variants that significantly modulate C. elegans lifespan, many of which would have eluded discovery by knockdown or mutation screens. A region on chromosome IV between markers stP13 and stP35 had striking effects on longevity in three interstrain crosses (each P < 1E–9. In order to define the limits of that interval, we have now constructed two independent lines by marker-based selection during 20 backcross generations, isolating the stP13–stP35 interval from strain Bergerac-BO in a CL2a background. These congenic lines differed significantly from CL2a in lifespan, assayed in two environments (each P<0.001. We then screened for exchange of flanking markers to isolate recombinants that partition this region, because fine mapping the boundaries for overlapping heteroallelic spans can greatly narrow the implicated interval. Recombinants carrying the CL2a allele at stP35 were consistently long-lived compared to those retaining the Bergerac-BO allele (P<0.001, and more resistant to temperature elevation and paraquat (each ~1.7-fold, P<0.0001, but gained little protection from ultraviolet or peroxide stresses. Two rounds of recombinant screening, followed by fine-mapping of break-points and survival testing, narrowed the interval to 0.18 Mb (13.35–13.53 Mb containing 26 putative genes and 6 small-nuclear RNAs – a manageable number of targets for functional assessment.

  4. Phenotypic instability of Arabidopsis alleles affecting a disease Resistance gene cluster

    Directory of Open Access Journals (Sweden)

    Richards Eric J

    2008-04-01

    Full Text Available Abstract Background Three mutations in Arabidopsis thaliana strain Columbia – cpr1, snc1, and bal – map to the RPP5 locus, which contains a cluster of disease Resistance genes. The similar phenotypes, gene expression patterns, and genetic interactions observed in these mutants are related to constitutive activation of pathogen defense signaling. However, these mutant alleles respond differently to various conditions. Exposure to mutagens, such as ethyl methanesulfonate (EMS and γ-irradiation, induce high frequency phenotypic instability of the bal allele. In addition, a fraction of the bal and cpr1 alleles segregated from bal × cpr1 F1 hybrids also show signs of phenotypic instability. To gain more insight into the mechanism of phenotypic instability of the bal and cpr1 mutations, we systematically compared the behavior of these unusual alleles with that of the missense gain-of-function snc1 allele in response to DNA damage or passage through F1 hybrids. Results We found that the cpr1 allele is similar to the bal allele in its unstable behavior after EMS mutagenesis. For both the bal and cpr1 mutants, destabilization of phenotypes was observed in more than 10% of EMS-treated plants in the M1 generation. In addition, exceptions to simple Mendelian inheritance were identified in the M2 generation. Like cpr1 × bal F1 hybrids, cpr1 × snc1 F1 hybrids and bal × snc1 F1 hybrids exhibited dwarf morphology. While only dwarf F2 plants were produced from bal × snc1 F1 hybrids, about 10% wild-type F2 progeny were produced from cpr1 × snc1 F1 hybrids, as well as from cpr1 × bal hybrids. Segregation analysis suggested that the cpr1 allele in cpr1 × snc1 crosses was destabilized during the late F1 generation to early F2 generation. Conclusion With exposure to EMS or different F1 hybrid contexts, phenotypic instability is induced for the bal and cpr1 alleles, but not for the snc1 allele. Our results suggest that the RPP5 locus can adopt different

  5. Seasonal variations in antibiotic resistance gene transport in the Almendares River, Havana, Cuba

    Directory of Open Access Journals (Sweden)

    Charles W Knapp

    2012-11-01

    Full Text Available Numerous studies have quantified antibiotic resistance genes (ARG in rivers and streams around the world, and significant relationships have been shown that relate different pollutant outputs and increased local ARG levels. However, most studies have not considered ambient flow conditions, which can vary dramatically especially in tropical countries. Here, ARG were quantified in water-column and sediment samples during the dry-and wet-seasons to assess how seasonal and other factors influence ARG transport down the Almendares River (Havana, Cuba. Eight locations were sampled and stream flow estimated during both seasons; qPCR was used to quantify four tetracycline, two erythromycin, and three beta-lactam resistance genes. ARG concentrations were higher in wet-season versus dry-season samples, which combined with higher flows, indicated greater ARG transport downstream during the wet season. Water-column ARG levels were more spatially variable in the dry-season than the wet-season, with the proximity of waste outfalls strongly influencing local ARG levels. Results confirm that dry-season sampling provides a useful picture of the impact of individual waste inputs on local stream ARG levels, whereas, the majority of ARGs in this tropical river were transported downstream during the wet season, possibly due to re-entrainment of ARG from sediments.

  6. PARP1 gene knock-out increases resistance to retinal degeneration without affecting retinal function.

    Directory of Open Access Journals (Sweden)

    Ayse Sahaboglu

    Full Text Available Retinitis pigmentosa (RP is a group of inherited neurodegenerative diseases affecting photoreceptors and causing blindness in humans. Previously, excessive activation of enzymes belonging to the poly-ADP-ribose polymerase (PARP group was shown to be involved in photoreceptor degeneration in the human homologous rd1 mouse model for RP. Since there are at least 16 different PARP isoforms, we investigated the exact relevance of the predominant isoform - PARP1 - for photoreceptor cell death using PARP1 knock-out (KO mice. In vivo and ex vivo morphological analysis using optic coherence tomography (OCT and conventional histology revealed no major alterations of retinal phenotype when compared to wild-type (wt. Likewise, retinal function as assessed by electroretinography (ERG was normal in PARP1 KO animals. We then used retinal explant cultures derived from wt, rd1, and PARP1 KO animals to test their susceptibility to chemically induced photoreceptor degeneration. Since photoreceptor degeneration in the rd1 retina is triggered by a loss-of-function in phosphodiesterase-6 (PDE6, we used selective PDE6 inhibition to emulate the rd1 situation on non-rd1 genotypes. While wt retina subjected to PDE6 inhibition showed massive photoreceptor degeneration comparable to rd1 retina, in the PARP1 KO situation, cell death was robustly reduced. Together, these findings demonstrate that PARP1 activity is in principle dispensable for normal retinal function, but is of major importance for photoreceptor degeneration under pathological conditions. Moreover, our results suggest that PARP dependent cell death or PARthanatos may play a major role in retinal degeneration and highlight the possibility to use specific PARP inhibitors for the treatment of RP.

  7. Characterization of Multidrug Resistant Extended-Spectrum Beta-Lactamase-Producing Escherichia coli among Uropathogens of Pediatrics in North of Iran

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    Mohammad Sadegh Rezai

    2015-01-01

    Full Text Available Escherichia coli remains as one of the most important bacteria causing infections in pediatrics and producing extended-spectrum beta-lactamases (ESBLs making them resistant to beta-lactam antibiotics. In this study we aimed to genotype ESBL-producing E. coli isolates from pediatric patients for ESBL genes and determine their association with antimicrobial resistance. One hundred of the E. coli isolates were initially considered ESBL producing based on their MIC results. These isolates were then tested by polymerase chain reaction (PCR for the presence or absence of CTX, TEM, SHV, GES, and VEB beta-lactamase genes. About 30.5% of isolated E. coli was ESBL-producing strain. The TEM gene was the most prevalent (49% followed by SHV (44%, CTX (28%, VEB (8%, and GES (0% genes. The ESBL-producing E. coli isolates were susceptible to carbapenems (66% and amikacin (58% and showed high resistance to cefixime (99%, colistin (82%, and ciprofloxacin (76%. In conclusion, carbapenems were the most effective antibiotics against ESBl-producing E. coli in urinary tract infection in North of Iran. The most prevalent gene is the TEM-type, but the other resistant genes and their antimicrobial resistance are on the rise.

  8. Characterization of Multidrug Resistant Extended-Spectrum Beta-Lactamase-Producing Escherichia coli among Uropathogens of Pediatrics in North of Iran.

    Science.gov (United States)

    Rezai, Mohammad Sadegh; Salehifar, Ebrahim; Rafiei, Alireza; Langaee, Taimour; Rafati, Mohammadreza; Shafahi, Kheironesa; Eslami, Gohar

    2015-01-01

    Escherichia coli remains as one of the most important bacteria causing infections in pediatrics and producing extended-spectrum beta-lactamases (ESBLs) making them resistant to beta-lactam antibiotics. In this study we aimed to genotype ESBL-producing E. coli isolates from pediatric patients for ESBL genes and determine their association with antimicrobial resistance. One hundred of the E. coli isolates were initially considered ESBL producing based on their MIC results. These isolates were then tested by polymerase chain reaction (PCR) for the presence or absence of CTX, TEM, SHV, GES, and VEB beta-lactamase genes. About 30.5% of isolated E. coli was ESBL-producing strain. The TEM gene was the most prevalent (49%) followed by SHV (44%), CTX (28%), VEB (8%), and GES (0%) genes. The ESBL-producing E. coli isolates were susceptible to carbapenems (66%) and amikacin (58%) and showed high resistance to cefixime (99%), colistin (82%), and ciprofloxacin (76%). In conclusion, carbapenems were the most effective antibiotics against ESBl-producing E. coli in urinary tract infection in North of Iran. The most prevalent gene is the TEM-type, but the other resistant genes and their antimicrobial resistance are on the rise. PMID:26064896

  9. Determination antimicrobial resistance profile of Pseudomonas aeruginosa strains isolated from hospitalized patients in Taleghani Hospital (Ahvaz, Iran from 2011-2012

    Directory of Open Access Journals (Sweden)

    Jalal Mardaneh

    2013-09-01

    Full Text Available Background & Objective: Pseudomonas aeruginosa is a rod-shaped, Gram-negative, glucose-nonfermenting aerobic bacterium. It is widespread in natural environments and it is an opportunistic pathogen for humans that can lead to a broad spectrum of disease such as urinary, burn, respiratory infections, and septicemia. The aim of this study was to determe antibiotic resistance profile of P. aeruginosa strains isolated from hospitalized patients in Taleghani hospital (Ahvaz, Iran. Materials & Methods: This cross-sectional study was conducted on 111 P. aeruginosa strains isolated from hospitalized patients. Clinical specimens were cultured on microbiological media. Subsequently, drug susceptibility test was performed using the disc diffusion method according to CLSI recommendations. Results: The more P. aeruginosa strains were from wound specimens (48.6%. In antimicrobial susceptibility testing, colistin exhibited the greatest anti-Pseudomonas activity (78.3%. Isolates demonstrated resistance to beta-lactam antimicrobials such as antipseudomonal penicillins, including piperacillin and carbenicillin. Conclusion: The spread of these bacteria in hospital personnel and wet areas could be a suitable reservoir of resistance genes. Therefore, it is necessary to evaluate the antimicrobial resistance profile and the effect of hospital equipment and personnel in the dissemination route of resistance genes.

  10. Modified expression of alternative oxidase in transgenic tomato and petunia affects the level of tomato spotted wilt virus resistance

    Directory of Open Access Journals (Sweden)

    Ma Hao

    2011-10-01

    Full Text Available Abstract Background Tomato spotted wilt virus (TSWV has a very wide host range, and is transmitted in a persistent manner by several species of thrips. These characteristics make this virus difficult to control. We show here that the over-expression of the mitochondrial alternative oxidase (AOX in tomato and petunia is related to TSWV resistance. Results The open reading frame and full-length sequence of the tomato AOX gene LeAox1au were cloned and introduced into tomato 'Healani' and petunia 'Sheer Madness' using Agrobacterium-mediated transformation. Highly expressed AOX transgenic tomato and petunia plants were selfed and transgenic R1 seedlings from 10 tomato lines and 12 petunia lines were used for bioassay. For each assayed line, 22 to 32 tomato R1 progeny in three replications and 39 to 128 petunia progeny in 13 replications were challenged with TSWV. Enzyme-Linked Immunosorbent Assays showed that the TSWV levels in transgenic tomato line FKT4-1 was significantly lower than that of wild-type controls after challenge with TSWV. In addition, transgenic petunia line FKP10 showed significantly less lesion number and smaller lesion size than non-transgenic controls after inoculation by TSWV. Conclusion In all assayed transgenic tomato lines, a higher percentage of transgenic progeny had lower TSWV levels than non-transgenic plants after challenge with TSWV, and the significantly increased resistant levels of tomato and petunia lines identified in this study indicate that altered expression levels of AOX in tomato and petunia can affect the levels of TSWV resistance.

  11. The global problem of antibiotic resistance.

    Science.gov (United States)

    Gootz, Thomas D

    2010-01-01

    Amid the recent attention justly focused on the potential problem of microbial sources for weapons of bioterrorism, it is also apparent that human pathogens frequently isolated from infections in patients from community and hospital sources have been growing more resistant to commonly used antibiotics. Much of the growth of multiple-drug-resistant (MDR) bacterial pathogens can be contributed to the overuse of broad-spectrum antimicrobial products. However, an equally troubling and often overlooked component of the problem involves the elegant ways in which pathogenic bacteria continually evolve complex genetic systems for acquiring and regulating an endless array of antibiotic-resistance mechanisms. Efforts to develop new antimicrobials have over the past two decades been woefully behind the rapid evolution of resistance genes developing among both gram-positive and gram-negative pathogens. Several new agents that are best suited for use in the hospital environment have been developed to combat staphylococci resistant to beta-lactam antimicrobials following acquisition of the mecA gene. However, the dramatic spread in the US of the now common community strain of Staphylococcus aureus USA300 has shifted the therapeutic need for new antibiotics useful against MRSA to the community. As the pharmaceutical industry focused on discovering new agents for use against MRSA, hospitals in many parts of the world have seen the emergence of gram-negative pathogens such as Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae that are clinically resistant to almost all available antimicrobials. Such MDR isolates usually contain multiple-resistance determinants, including loss of outer membrane porins via gene inactivation by chromosomally encoded insertion sequences, up-regulation of inate efflux pumps, as well as acquisition of drug-inactivating enzymes whose genes are encoded on self-transmissible plasmids, integrons, and complex transposable elements

  12. Different Levels of Eccentric Resistance during Eight Weeks of Training Affect Muscle Strength and Lean Tissue Mass

    Science.gov (United States)

    English, K. L.; Loehr, J. A.; Lee, S. M. C.; Laughlin, M. S.; Hagan, R. D.

    2008-01-01

    .3%) groups. All groups significantly increased HR strength pre- to posttraining (33%: 7.5 +/- 6.1%; 66%: 6.6 +/- 3.7%; 100%: 12.2 +/- 1.8%; 138%: 11.0 +/- 6.4%) except for the 0% (4.9 +/- 9.1%) group. There were no differences between groups. LLM increased significantly pre- to post-training in only the 138% group; there were no differences between groups. CONCLUSIONS: Eight wks of lower body resistive exercise training with eccentric overload resulted in greater increases in LP strength than training with eccentric loads of 66% or less. Post-training HR strength was not affected by eccentric training load, perhaps because of the predominance of Type I fibers typical in the gastrocnemius. Only 138% eccentric training significantly increased LLM. PRACTICAL APPLICATIONS: For athletes or others desiring to maximize muscle strength and hypertrophy gains, training with eccentric loads greater than 100% of concentric resistance will provide greater increases in muscle strength and lean tissue mass in some muscle groups. In a rehabilitation or geriatric exercise setting that places primary emphasis on program adherence and moderate strength gains, training with an eccentric underload may provide strength increases comparable to those of traditional 1:1 training but with less muscle soreness and physiologic insult to the patient, but this has yet to be proven.

  13. Prevalence of beta-lactamases among ampicillin-resistant Escherichia coli and Salmonella isolated from food animals in Denmark

    DEFF Research Database (Denmark)

    Olesen, Inger; Hasman, Henrik; Aarestrup, Frank Møller

    2004-01-01

    The genetic background for beta-lactamase-mediated resistance to beta-lactam antibiotics was examined by PCR and sequencing in 160 ampicillin-resistant isolates (109 Escherichia coli and 51 Salmonella) obtained from healthy and diseased food animals in Denmark. Sequencing revealed three different...... variants of bla(TEM-1), of which bla(TEM-1b) was the most frequently detected (80 E. coli and 47 Salmonella), followed by bla(TEM-1a) (eight E. coli, one Salmonella) and bla(TEM-1c) (seven E. coli). A few isolates were found to express OXA, TEM-30, or PSE beta-lactamases. Mutations in the ampC promoter...... leading to increased production of the AmpC beta-lactamase were demonstrated in 11 cefoxitin-resistant or intermediate E. coli isolates. Nine of these isolates did not contain any bla(TEM) genes, whereas the remaining two did. No genes encoding SHV or extended-spectrum beta-lactamases were detected. Two...

  14. Monitoring and evaluation of antibiotic resistance genes in four municipal wastewater treatment plants in Harbin, Northeast China.

    Science.gov (United States)

    Wen, Qinxue; Yang, Lian; Duan, Ruan; Chen, Zhiqiang

    2016-05-01

    The development and proliferation of antibiotic resistance in pathogenic and environmental microorganisms is of great concern for public health. In this study, the distribution and removal efficiency of intI1 and eight subtypes of antibiotic resistance genes (ARGs) for tetracycline, sulfonamides, beta-lactams resistance in four municipal wastewater treatment plants (WWTPs) in Harbin, which locates in Songhua River basin in cold areas of China, were monitored by real-time fluorescent quantitative PCR. The results showed that intI1 and 6 ARGs except for blaTEM and blaSHV were detected in wastewater and sludge samples and 0.3-2.7 orders of magnitude of ARGs removal efficiency in the four WWTPs were observed. The investigation on the removal of ARGs of different treatment units in one WWTP showed that the biological treatment unit played the most important role in ARGs removal (1.2-1.8 orders of magnitude), followed by UV disinfection, while primary physical treatment units can hardly remove any ARGs. Although all the WWTPs can remove ARGs effectively, ARGs concentrations are still relatively high in the effluent, their further attenuation should be investigated. PMID:26840514

  15. Biosynthesis of monobactam compounds: origin of the carbon atoms in the beta-lactam ring.

    OpenAIRE

    O'Sullivan, J; Gillum, A M; Aklonis, C A; Souser, M L; Sykes, R. B.

    1982-01-01

    The biosynthesis of monobactams by strains of Chromobacterium violaceum, Acetobacter sp., and Agrobacterium radiobacter was studied. Monobactams were produced during logarithmic growth by C. violaceum and Acetobacter sp. and during late log growth on glycerol and in stationary phase by A. radiobacter. The addition of various amino acids failed to significantly stimulate monobactam production in any of the producing organisms. Several 14C-amino acids and pyruvate were incorporated in vivo into...

  16. Mass Spectral Profile for Rapid Differentiating Beta-Lactams from Their Ring-Opened Impurities.

    Science.gov (United States)

    Wang, Hecheng; Huang, Haiwei; Cao, Jin; Chui, Dehua; Xiao, Shengyuan

    2015-01-01

    High performance liquid chromatography tandem mass spectrometry (HPLC MS) has been widely used for β-lactam antibiotics determination. However, its application to identify impurities of these frequently used drugs is not sufficient at present. In this job, characteristic profiles of the collision induced dissociation (CID) spectra of both β-lactams and ring-opened β-lactams were extracted from the MS data of six β-lactam antibiotics and their forty-five impurities, and were confirmed by the MS data reported in the literature. These characteristics have been successfully applied to rapid differentiation of β-lactam and ring-opened β-lactam impurities in cefixime, cefdinir, and cefaclor. However, these characteristic profiles can only be obtained under low activating voltage. They did not display in the high energy activated CID spectra. Diagnostic fragmentations for determining the localization of double bond and substituents on the thiazine ring and the side chain were also observed. In addition, several characteristic fragmentations are hopeful to be used to differentiate the configurations of C-2 on the thiazine ring of ring-opened impurities, which is generally disadvantageous of mass spectrometry. Taken together, forty-five impurities were identified from the capsules of cefixime, cefdinir, and cefaclor. PMID:26090434

  17. 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. Pol

  18. Synthesis and biological activity of some heterocyclic compounds containing benzimidazole and beta-lactam moiety

    Indian Academy of Sciences (India)

    K F Ansari; C Lal

    2009-11-01

    A number of 1-substituted-2-methyl benzimidazole derivatives have been synthesized and tested for their antibacterial activities. The chemical structures of the newly synthesized compounds were verified on the basis of spectral and elemental methods of analyses. Investigation of antimicrobial activity of the compounds was done by disc diffusion method using Gram-positive (S. aureus, S. mutans and B. subtilis), Gram-negative (E. coli, S. typhi and P. aeruginosa) bacteria and fungi (C. albicans, A. flavus and A. niger). Among the compounds tested 5a, 5b, 5d, 5i, 5j and 5k exhibited good antibacterial activities against Gram positive bacteria, while 5d and 5i also showed notable antifungal activity. Specially compounds 5a and 5b exhibited appreciable activity against S. aureus and B. subtilis comparable to reference drugs.

  19. Behavioural responses in rats; modulation with beta-lactam antibiotics and antioxidants

    OpenAIRE

    ŞAVLI, Evren

    2014-01-01

    N-Acetylcysteine (NAC) has been in clinical practice for several decades as a mucolytic agent and has been used also for the treatment of paracetamol intoxication, doxorubicin- induced cardiotoxicity, stable angina pectoris, ischemia-reperfusion cardiac injury, acute respiratory distress syndrome bronchitis, chemotherapy-induced toxicity, HIV/AIDS, radio contrastinduced nephropathy, heavymetal toxicity and psychiatric disorders including schizophrenia, bipolar disorder and addiction. It has b...

  20. Virulence and plasmidic resistance determinants of Escherichia coli isolated from municipal and hospital wastewater treatment plants.

    Science.gov (United States)

    Calhau, Vera; Mendes, Catarina; Pena, Angelina; Mendonça, Nuno; Da Silva, Gabriela Jorge

    2015-06-01

    Escherichia coli is simultaneously an indicator of water contamination and a human pathogen. This study aimed to characterize the virulence and resistance of E. coli from municipal and hospital wastewater treatment plants (WWTPs) in central Portugal. From a total of 193 isolates showing reduced susceptibility to cefotaxime and/or nalidixic acid, 20 E. coli with genetically distinct fingerprint profiles were selected and characterized. Resistance to antimicrobials was determined using the disc diffusion method. Extended spectrum β-lactamase and plasmid-mediated quinolone resistance genes, phylogroups, pathogenicity islands (PAIs) and virulence genes were screened by polymerase chain reaction (PCR). CTX-M producers were typed by multilocus sequence typing. Resistance to beta-lactams was associated with the presence of bla(TEM), bla(SHV), bla(CTX-M-15) and bla(CTX-M-32). Plasmid-mediated quinolone resistance was associated with qnrA, qnrS and aac(6')-Ib-cr. Aminoglycoside resistance and multidrug-resistant phenotypes were also detected. PAI IV(536), PAI II(CFT073), PAI II(536) and PAI I(CFT073), and uropathogenic genes iutA, papAH and sfa/foc were detected. With regard to the clinical ST131 clone, it carried bla(CTX-M-15), blaTEM-type, qnrS and aac(6')-lb-cr; IncF and IncP plasmids, and virulence factors PAI IV(536), PAI I(CFT073), PAI II(CFT073), iutA, sfa/foc and papAH were identified in the effluent of a hospital plant. WWTPs contribute to the dissemination of virulent and resistant bacteria in water ecosystems, constituting an environmental and public health risk. PMID:26042965

  1. Impact of an Urban Effluent on Antibiotic Resistance of Riverine Enterobacteriaceae and Aeromonas spp.

    Science.gov (United States)

    Goñi-Urriza, Marisol; Capdepuy, Michèle; Arpin, Corinne; Raymond, Nathalie; Caumette, Pierre; Quentin, Claudine

    2000-01-01

    In order to evaluate the impact of an urban effluent on antibiotic resistance of freshwater bacterial populations, water samples were collected from the Arga river (Spain), upstream and downstream from the wastewater discharge of the city of Pamplona. Strains of Enterobacteriaceae (representative of the human and animal commensal flora) (110 isolates) and Aeromonas (typically waterborne bacteria) (118 isolates) were selected for antibiotic susceptibility testing. Most of the Aeromonas strains (72%) and many of the Enterobacteriaceae (20%) were resistant to nalidixic acid. Singly nalidixic acid-resistant strains were frequent regardless of the sampling site for Aeromonas, whereas they were more common upstream from the discharge for enterobacteria. The most common resistances to antibiotics other than quinolones were to tetracycline (24.3%) and beta-lactams (20.5%) for Enterobacteriaceae and to tetracycline (27.5%) and co-trimoxazole (26.6%) for Aeromonas. The rates of these antibiotic resistances increased downstream from the discharge at similar degrees for the two bacterial groups; it remained at high levels for enterobacteria but decreased along the 30-km study zone for Aeromonas. Genetic analysis of representative strains demonstrated that these resistances were mostly (enterobacteria) or exclusively (Aeromonas) chromosomally mediated. Moreover, a reference strain of Aeromonas caviae (CIP 7616) could not be transformed with conjugative R plasmids of enterobacteria. Thus, the urban effluent resulted in an increase of the rates of resistance to antibiotics other than quinolones in the riverine bacterial populations, despite limited genetic exchanges between enterobacteria and Aeromonas. Quinolone resistance probably was selected by heavy antibiotic discharges of unknown origin upstream from the urban effluent. PMID:10618213

  2. Distribution and possible transmission of ampicillin- and nalidixic acid-resistant Escherichia coli within the broiler industry.

    Science.gov (United States)

    Bortolaia, Valeria; Bisgaard, Magne; Bojesen, Anders Miki

    2010-05-19

    This study was performed to determine the origin and transmission of beta-lactam- and (fluoro)quinolone-resistant Escherichia coli in healthy, untreated broiler flocks. We focused on the dynamics of bacteria resistant to critically important antimicrobials for public and veterinary health in view of the possible link between antimicrobial resistant bacteria in farm animals and humans. By processing faecal samples collected with the sock method in broiler parent and broiler flocks, E. coli resistant to ampicillin and nalidixic acid were frequently isolated, while resistance to ciprofloxacin was detected at a very low frequency, and resistance to cephalosporins was not detected. Similarly, resistance to ampicillin and nalidixic acid were the only phenotypes detected in a collection of clinical E. coli isolates associated with first-week-mortality in broiler parent chicks. Although antimicrobial resistant E. coli were genetically diverse by means of amplified fragment length polymorphism (AFLP) typing, indistinguishable isolates were present in different flocks, including isolates from broiler parent chicks, broiler parents and broilers. In the absence of apparent selective pressure, the genotypic heterogeneity that we describe is likely the consequence of multiple introductions of antimicrobial resistant bacteria into the production system. The confinement under which broilers are raised limits the possibilities of bacterial transmission among different flocks. Our findings are consistent with vertical transmission of ampicillin- and nalidixic acid-resistant E. coli through the broiler production system. The persistence of antimicrobial resistant E. coli in healthy, untreated chicken flocks emphasises the need of careful evaluation of therapeutic options at any level of the broiler production. PMID:19945232

  3. Sublethal Ciprofloxacin Treatment Leads to Rapid Development of High-Level Ciprofloxacin Resistance during Long-Term Experimental Evolution of Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Jørgensen, Karin Meinike; Wassermann, Tina; Jensen, Peter Østrup;

    2013-01-01

    The dynamics of occurrence and the genetic basis of ciprofloxacin resistance were studied in a long-term evolution experiment (940 generations) in wild-type, reference strain (PAO1) and hypermutable (PAOΔmutS and PAOMY-Mgm) P. aeruginosa populations continuously exposed to sub-MICs (1/4) of...... ciprofloxacin. A rapid occurrence of ciprofloxacin-resistant mutants (MIC of ≥12 μg/ml, representing 100 times the MIC of the original population) were observed in all ciprofloxacin-exposed lineages of PAOΔmutS and PAOMY-Mgm populations after 100 and 170 generations, respectively, and in one of the PAO1...... lineages after 240 generations. The genetic basis of resistance was mutations in gyrA (C248T and G259T) and gyrB (C1397A). Cross-resistance to beta-lactam antibiotics was observed in the bacterial populations that evolved during exposure to sublethal concentrations of ciprofloxacin. Our study shows that...

  4. Staphylococcus aureus methicillin-resistance mechanisms

    Directory of Open Access Journals (Sweden)

    Petrović-Jeremić Ljiljana

    2008-01-01

    Full Text Available Background/Aim. In many hospitals in the world and in our country, the spread of methicillin-resistant Staphylococcus aureus (MRSA is so wide that nowdays vancomycin is recommended for empiric treatment of staphylococcal life threatening infections (sepsis, pneumonia instead of beta-lactam antibiotics. The aim of this study was to determine the production of beta-lactamases in hospital and community isolates of staphyloococus aureus, i. e. hospital associated MRSA (HA-MRSA and community associated MRSA (CA-MRSA, the presence of homogeneous and heterogeneous type of methicillin resistance, and border-line resistance in Staphylococcus aureus (BORSA. The aim of this study was also to determine if there was a statistically significant difference between mechanisms of resistance in HA-MRSA and CA-MRSA. Methods. A total 216 clinical Staphylococcus aureus isolates from the General Hospital in the town of Cuprija and 186 ambulance Staphylococcus aureus isolates from the community were examined for the presence of methicillin-resistance using disk-diffusion test with penicillin disk (10 ij, oxacillin disk (1 μg and cefoxitin disk (30 μg. Betalactamases production was detected by nitrocefin disk and betalactamase tablets. Determination of oxacillin minimum inhibitory concentracion (MIC was done by agar-dilution method. Results. The prevalence of HA-MRSA was 57.4%, and CA-MRSA was 17.7% (p < 0.05. There was a higher rate of heterogeneous type of resistance among clinical MRSA isolates (11.1% compared with ambulance ones (3.8% (p < 0.05. The rates of beta-lactamases production were similar among hospital associated isolates (97.5%, as well as in the community associated isolates (95.5% (p > 0.05. There were 4.6 % of BORSA hospital isolates and 3.3 % of BORSA ambulance isolates (p > 0.05. Conclusion. The frequency of MRSA isolates in hospital was significantly higher than in community, as well as the heterogeneous type of resistance. The frequency of BORSA

  5. Longer resistance of some DNA traits from BT176 maize to gastric juice from gastrointestinal affected patients.

    Science.gov (United States)

    Ferrini, A M; Mannoni, V; Pontieri, E; Pourshaban, M

    2007-01-01

    The presence of antibiotic resistance marker genes in genetically engineered plants is one of the most controversial issues related to Genetically Modified Organism (GMO)-containing food, raising concern about the possibility that these markers could increase the pool of antibiotic resistance genes. This study investigates the in vitro survival of genes bla and cryIA(b) of maize Bt176 in human gastric juice samples. Five samples of gastric juice were collected from patients affected by gastro-esophageal reflux or celiac disease and three additional samples were obtained by pH modification with NaHCO3. DNA was extracted from maize Bt176 and incubated with samples of gastric juices at different times. The survival of the target traits (bla gene, whole 1914 bp gene cry1A(b), and its 211 bp fragment) was determined using PCR. The stability of the target genes was an inverse function of their lengths in all the samples. Survival in samples from untreated subjects was below the normal physiological time of gastric digestion. On the contrary, survival time in samples from patients under anti-acid drug treatment or in samples whose pH was modified, resulted strongly increased. Our data indicate the possibility that in particular cases the survival time could be so delayed that, as a consequence, some traits of DNA could reach the intestine. In general, this aspect must be considered for vulnerable consumers (people suffering from gastrointestinal diseases related to altered digestive functionality, physiological problems or drug side-effects) in the risk analysis usually referred to healthy subjects. PMID:17346434

  6. Novel TetR family transcriptional factor regulates expression of multiple transport-related genes and affects rifampicin resistance in Mycobacterium smegmatis.

    Science.gov (United States)

    Liu, Huicong; Yang, Min; He, Zheng-Guo

    2016-01-01

    Transport-related genes significantly affect bacterial antibiotic resistance. However, the effects of these genes and their regulation of bacterial drug resistance in several mycobacterial species, including the fast-growing Mycobacterium smegmatis, the pathogen M. tuberculosis and M. avium have not been clearly characterized. We identified Ms4022 (MSMEG_4022) as a novel TetR family regulator that activates the expression of seven transport-related genes and affects drug resistance in M. smegmatis. Overexpression of Ms4022 inhibited M. smegmatis growth and enhanced mycobacterial resistance to the anti-tuberculosis drug rifampicin (RIF). By contrast, the Ms4022-deleted mycobacterial strain has shown sensitive to RIF. Ms4022 recognized three 19 bp non-palindromic motifs containing a 9 bp conserved region at their 5' end and it directly regulated seven transport-related genes, which affects mycobacterial resistance to RIF. Overexpression of three of seven transport-related genes (Ms1448, Ms1613, and Ms5278) inhibited the growth of M. smegmatis. This study improves our understanding of the function of mycobacterial transport-related genes and their regulation of bacterial drug resistance. PMID:27271013

  7. Prevalence of multi-drug resistant uropathogenic Escherichia coli in Potohar region of Pakistan

    Institute of Scientific and Technical Information of China (English)

    Ihsan Ali; Zara Rafaque; Safia Ahmed; Sajid Malik; Javid Iqbal Dasti

    2016-01-01

    Objective: To scrutinize patterns of multi-drug-resistant uropathogenic Escherichia coli (UPEC) strains and particularly of fluoroquinolone-resistance this is an alternative choice for the treatment of urinary tract infections. Methods: Bacterial samples (n = 250) were collected from out-patients from August 2012 to August 2014 Islamabad. Antibiotic susceptibility profiling and determination of mini-mum inhibitory concentrations (MICs) and minimum bactericidal concentrations were performed according to the guidelines of Clinical and Laboratory Standards Institute (CLSI, 2012). Genes, qnrA, qnrB and qnrS were identified by DNA amplification and sequencing. Results: The highest percentage of UPEC isolates were resistant to co-trimoxazole (82%) followed by cephalothin (80%), 2nd Gen, 3rd Gen and 4th Gen cephalosporins, respectively. Resistance against gentamicin, amikacin remained 29% and 4%. For other drugs including nitrofurantoin, tetracycline, carbapenem and beta-lactam inhibitors remained below 10%. Altogether, 59% of the isolates were resistant to at least three antibiotics including one fluoroquinolone. Overall, MICs for ciprofloxacin remained (MIC≥256 mg/mL) and for levofloxacin (MIC≥16 mg/mL and 32 mg/mL). No significant differences were observed regarding MIC values of extended spectrum b-lactamase (ESBL) and non-ESBL producers. For qnrS and qnrB positive isolates MICs remained above 32 mg/mL. Prevalence of UPEC was significantly higher among females and 40% of the isolates were ESBL producers. Conclusions: Higher percentages of ESBL producing UPEC were associated with uri-nary tract infections. Moreover, the majority of these isolates were multi-drug resistant and fluoroquinolone-resistant.

  8. Fighting infections due to multidrug-resistant Gram-positive pathogens.

    Science.gov (United States)

    Cornaglia, G

    2009-03-01

    Growing bacterial resistance in Gram-positive pathogens means that what were once effective and inexpensive treatments for infections caused by these bacteria are now being seriously questioned, including penicillin and macrolides for use against pneumococcal infections and-in hospitals-oxacillin for use against staphylococcal infections. As a whole, multidrug-resistant (MDR) Gram-positive pathogens are rapidly becoming an urgent and sometimes unmanageable clinical problem. Nevertheless, and despite decades of research into the effects of antibiotics, the actual risk posed to human health by antibiotic resistance has been poorly defined; the lack of reliable data concerning the outcomes resulting from antimicrobial resistance stems, in part, from problems with study designs and the methods used in resistence determination. Surprisingly little is known, too, about the actual effectiveness of the many types of intervention aimed at controlling antibiotic resistance. New antibiotics active against MDR Gram-positive pathogens have been recently introduced into clinical practice, and the antibiotic pipeline contains additional compounds at an advanced stage of development, including new glycopeptides, new anti-methicillin-resistant Staphylococcus aureus (MRSA) beta-lactams, and new diaminopyrimidines. Many novel antimicrobial agents are likely to be niche products, endowed with narrow antibacterial spectra and/or targeted at specific clinical problems. Therefore, an important educational goal will be to change the current, long-lasting attitudes of both physicians and customers towards broad-spectrum and multipurpose compounds. Scientific societies, such as the European Society of Clinical Microbiology and Infectious Diseases (ESCMID), must play a leading role in this process. PMID:19335367

  9. Antimicrobial resistance of abnormal vaginal discharges microorganisms in Ouagadougou, Burkina Faso

    Institute of Scientific and Technical Information of China (English)

    Simplice D Karou; Virginio Pietra; Salvatore Pignatelli; Jacques Simpore; Florencia Djigma; Tani Sagna; Christelle Nadembega; Moctar Zeba; Aboudoulaye Kabre; Kokou Anani; Djeneba Ouermi; Charlemagne Gnoula

    2012-01-01

    Objective: To assess the prevalence of bacterial strains and fungal strains infecting the vaginal tract and test their sensitivity to antibiotics in women attending Saint Camille Medical Centre in Ouagadougou. Methods: From January 2008 to December 2009, a total of 2000 vaginal swabs were cultivated for bacterial and fungal identification and isolation. Furthermore, bacterial strains were tested for their susceptibility to several antibiotics used in routine in the centre.Results:1536/2000 sample, a positivity rate of 76.80%. Candida albicans (48.76%), followed by Escherichiacoli The results revealed that microbial isolation and identification was attempted for (16.67%), Streptococcus agalactiae (8.14%) and Staphylococcus aureus (7.55%) were the major agents of genital tract infections in patients. Mycoplasma hominis and Ureaplasma urealyticum combined accounted for less than 7%. Trichomonas vaginalis was identified in 1.04% cases. The antimicrobial tests revealed that the microorganisms developed resistance to several antibiotics including beta lactams. However, antibiotics such as cefamenzol, ciprofloxacin and norfloxacin were still active on these bacteria. Conclusions: The results reveal that many sexually active women are infected by one or more microbial pathogens, probably because of the lack of hygiene or the adoption of some risky behaviors, such as not using condoms or having multiple sexual partners. Efforts should be made to address these points in the country.

  10. Antimicrobial resistance of abnormal vaginal discharges microorganisms in Ouagadougou, Burkina Faso

    Science.gov (United States)

    Karou, Simplice D; Djigma, Florencia; Sagna, Tani; Nadembega, Christelle; Zeba, Moctar; Kabre, Aboudoulaye; Anani, Kokou; Ouermi, Djeneba; Gnoula, Charlemagne; Pietra, Virginio; Pignatelli, Salvatore; Simpore, Jacques

    2012-01-01

    Objective To assess the prevalence of bacterial strains and fungal strains infecting the vaginal tract and test their sensitivity to antibiotics in women attending Saint Camille Medical Centre in Ouagadougou. Methods From January 2008 to December 2009, a total of 2 000 vaginal swabs were cultivated for bacterial and fungal identification and isolation. Furthermore, bacterial strains were tested for their susceptibility to several antibiotics used in routine in the centre. Results The results revealed that microbial isolation and identification was attempted for 1 536/2 000 sample, a positivity rate of 76.80%. Candida albicans (48.76%), followed by Escherichia coli (16.67%), Streptococcus agalactiae (8.14%) and Staphylococcus aureus (7.55%) were the major agents of genital tract infections in patients. Mycoplasma hominis and Ureaplasma urealyticum combined accounted for less than 7%. Trichomonas vaginalis was identified in 1.04% cases. The antimicrobial tests revealed that the microorganisms developed resistance to several antibiotics including beta lactams. However, antibiotics such as cefamenzol, ciprofloxacin and norfloxacin were still active on these bacteria. Conclusions The results reveal that many sexually active women are infected by one or more microbial pathogens, probably because of the lack of hygiene or the adoption of some risky behaviors, such as not using condoms or having multiple sexual partners. Efforts should be made to address these points in the country. PMID:23569916

  11. Nosocomial infections caused by multidrug-resistant isolates of pseudomonas putida producing VIM-1 metallo-beta-lactamase.

    Science.gov (United States)

    Lombardi, Gianluigi; Luzzaro, Francesco; Docquier, Jean-Denis; Riccio, Maria Letizia; Perilli, Mariagrazia; Colì, Alessandra; Amicosante, Gianfranco; Rossolini, Gian Maria; Toniolo, Antonio

    2002-11-01

    Successful carbapenem-based chemotherapy for the treatment of Pseudomonas infections has been seriously hindered by the recent appearance of IMP- and VIM-type metallo-beta-lactamases, which confer high-level resistance to carbapenems and most other beta-lactams. Recently, multidrug-resistant Pseudomonas putida isolates for which carbapenem MICs were >/=32 micro g/ml were recovered from cultures of urine from three inpatients in the general intensive care unit of the Ospedale di Circolo, Varese, Italy. Enzyme assays revealed production of a metallo-beta-lactamase activity, while molecular analysis detected in each isolate a bla(VIM-1) determinant carried by an apparently identical medium-sized plasmid. Conjugation experiments were unsuccessful in transferring the beta-lactamase determinant to Escherichia coli or Pseudomonas aeruginosa. Macrorestriction analysis by pulsed-field gel electrophoresis demonstrated that the isolates were of clonal origin. PCR mapping and sequencing of the variable region of the plasmid-borne class 1 integron carrying the bla(VIM-1) determinant (named In110) showed that the bla(VIM-1)-containing cassette was identical to that previously found in strains of different species from other Italian hospitals and that the cassette array of In110 was not identical but clearly related to that of In70 (a bla(VIM-1)-containing plasmid-borne integron from an Achromobacter xylosoxidans isolate), pointing to a common origin of this cassette and to a related evolutionary history of their cognate integrons. PMID:12409373

  12. Phenotypes and gene expression profiles of Saccharopolyspora erythraea rifampicin-resistant (rif mutants affected in erythromycin production

    Directory of Open Access Journals (Sweden)

    Bicciato Silvio

    2009-03-01

    Full Text Available Abstract Background There is evidence from previous works that bacterial secondary metabolism may be stimulated by genetic manipulation of RNA polymerase (RNAP. In this study we have used rifampicin selection as a strategy to genetically improve the erythromycin producer Saccharopolyspora erythraea. Results Spontaneous rifampicin-resistant (rif mutants were isolated from the parental strain NRRL2338 and two rif mutations mapping within rpoB, S444F and Q426R, were characterized. With respect to the parental strain, S444F mutants exhibited higher respiratory performance and up to four-fold higher final erythromycin yields; in contrast, Q426R mutants were slow-growing, developmental-defective and severely impaired in erythromycin production. DNA microarray analysis demonstrated that these rif mutations deeply changed the transcriptional profile of S. erythraea. The expression of genes coding for key enzymes of carbon (and energy and nitrogen central metabolism was dramatically altered in turn affecting the flux of metabolites through erythromycin feeder pathways. In particular, the valine catabolic pathway that supplies propionyl-CoA for biosynthesis of the erythromycin precursor 6-deoxyerythronolide B was strongly up-regulated in the S444F mutants, while the expression of the biosynthetic gene cluster of erythromycin (ery was not significantly affected. In contrast, the ery cluster was down-regulated ( Conclusion Rifampicin selection is a simple and reliable tool to investigate novel links between primary and secondary metabolism and morphological differentiation in S. erythraea and to improve erythromycin production. At the same time genome-wide analysis of expression profiles using DNA microarrays allowed information to be gained about the mechanisms underlying the stimulatory/inhibitory effects of the rif mutations on erythromycin production.

  13. Factors that affect transfer of the IncI1 β-lactam resistance plasmid pESBL-283 between E. coli strains.

    Directory of Open Access Journals (Sweden)

    Nadine Händel

    Full Text Available The spread of antibiotic resistant bacteria worldwide presents a major health threat to human health care that results in therapy failure and increasing costs. The transfer of resistance conferring plasmids by conjugation is a major route by which resistance genes disseminate at the intra- and interspecies level. High similarities between resistance genes identified in foodborne and hospital-acquired pathogens suggest transmission of resistance conferring and transferrable mobile elements through the food chain, either as part of intact strains, or through transfer of plasmids from foodborne to human strains. To study the factors that affect the rate of plasmid transfer, the transmission of an extended-spectrum β-lactamase (ESBL plasmid from a foodborne Escherichia coli strain to the β-lactam sensitive E. coli MG1655 strain was documented as a function of simulated environmental factors. The foodborne E. coli isolate used as donor carried a CTX-M-1 harboring IncI1 plasmid that confers resistance to β-lactam antibiotics. Cell density, energy availability and growth rate were identified as factors that affect plasmid transfer efficiency. Transfer rates were highest in the absence of the antibiotic, with almost every acceptor cell picking up the plasmid. Raising the antibiotic concentrations above the minimum inhibitory concentration (MIC resulted in reduced transfer rates, but also selected for the plasmid carrying donor and recombinant strains. Based on the mutational pattern of transconjugant cells, a common mechanism is proposed which compensates for fitness costs due to plasmid carriage by reducing other cell functions. Reducing potential fitness costs due to maintenance and expression of the plasmid could contribute to persistence of resistance genes in the environment even without antibiotic pressure. Taken together, the results identify factors that drive the spread and persistence of resistance conferring plasmids in natural isolates

  14. Mechanisms of antibiotic resistance of Enterobacteriaceae family representatives

    Directory of Open Access Journals (Sweden)

    K. R. Kotsyuba

    2014-04-01

    Full Text Available The paper deals with the basic medical scheme of antibiotics use for treatment of lesions caused by enterobacteria and mechanisms of resistance of Enterobacteriaceae to different classes of antibiotics. It is known that the main mechanisms of resistance to antibiotics are enzymatic inactivation, modification of the target, efflux, violation of conduct through the membrane and formation of metabolic shunt. The most common cases of resistance to beta-lactams among Enterobacteriaceae relate to production of plasmid and chromosomal beta-lactamases, violation of the permeability of the outer membrane, and modification of target penicillin binding proteins. Active release of antibiotics from the cell, or efflux, in Enterobacteriaceae is used for maintaining resistance to tetracyclines, macrolides, carbapenems. Genes of efflux system are localized on plasmids and contribute to rapid spreading among Enterobacteriaceae. Mutations are the basis of resistance to novobiocinum and rifampicinum. Enzymatic inactivation by modifying is typical for resistance to aminoglycosides. Three groups of enzymes are engaged in the process, by adding the molecule of acetic acid, phosphate or adenine. Joining of these groups is irreversible and leads to complete loss of biological activity of the antibiotic. Resistance to aminoglycosides appears also due to inhibition of drug penetration, that is associated with genetically determined mechanisms of electron transport through the membrane. Resistance to quinolones and fluoroquinolones is associated with the modification of topoisomerase II and IV which are targets of these groups of antibiotics. Resistance is possible as a result of changes in the structure of the target, breaching of penetration into the cell, and active release from the cell. The highest level of resistance is develope in the case of two- or three-stage mutations in one or the other, or both, subunits in different genes. At the same time, for breaching of

  15. Activity of tigecycline tested against a global collection of Enterobacteriaceae, including tetracycline-resistant isolates.

    Science.gov (United States)

    Fritsche, Thomas R; Strabala, Patty A; Sader, Helio S; Dowzicky, Michael J; Jones, Ronald N

    2005-07-01

    Steadily increasing resistance among the Enterobacteriaceae to beta-lactams, fluoroquinolones, aminoglycosides, tetracyclines, and trimethoprim/sulfamethoxazole has compromised the utility of these commonly used antimicrobial classes for many community- or hospital-acquired infections. The development of tigecycline, the sentinel representative of a novel class of broad-spectrum agents (the glycylcyclines), represents an important milestone in addressing this critical need. Resistance to tigecycline might be expected to occur via the same mechanisms that produce tetracycline resistance; however, tigecycline remains stable and largely unaffected by the commonly occurring efflux and ribosomal protection resistance mechanisms. In this study, an international collection of Enterobacteriaceae (11327 isolates; 32.8% tetracycline-resistant) from global surveillance studies (2000-2004) were evaluated against tigecycline and other comparator antimicrobials. Although the most active agents were the carbapenems and aminoglycosides (97.5-99.7% susceptible), tigecycline displayed high potency (MIC50 and MIC90, 0.25 and 1 microg/mL) with 95.7% of all strains being inhibited at agglomerans; and up to 4-fold for Klebsiella spp., Enterobacter spp., and Citrobacter spp.). Among E. coli (263 isolates) and Klebsiella spp. (356) that meet recognized screening definitions for extended-spectrum beta-lactamase production, 100.0% and 94.4% were inhibited by tigecycline at 2 microg/mL, respectively. These findings confirm that tigecycline exhibits potency, breadth of spectrum, and stability to the commonly occurring resistance mechanisms found in contemporary Enterobacteriaceae isolates, attributes that make this parenteral agent an attractive candidate for use against serious infections produced by these species. PMID:16105566

  16. Identification of quantitative trait loci affecting resistance to gastro-intestinal parasites in a double backcross population of Red Maasai and Dorper sheep

    Science.gov (United States)

    A genome-wide scan for quantitative trait loci (QTL) affecting gastrointestinal (GI) nematode resistance was completed using a double backcross sheep population derived from Red Maasai and Dorper ewes bred to F1 rams. These breeds were chosen, because Red Maasai sheep are known to be more tolerant ...

  17. [Effect of immunomodulators on resistance to gas gangrene. The enhanced resistance of white mice to perfringens toxin type A as affected by prodigiozan].

    Science.gov (United States)

    Konikova, R E; Stepanov, A V; Sviridov, L P

    1986-02-01

    Experiments on 575 noninbred white mice have revealed that the nonspecific resistance of the animals to type A C. perfringens toxin can be enhanced by the administration of Prodigiosan, a commercial immunostimulating agent. Prodigiosan, introduced in 3-4 injections (the last one made 24 hours before intoxication) has been found to enhance the resistance of the animals to the subcutaneous injection of type A C. perfringens toxin by 40-60% and to its intraperitoneal injection by 60-97%. PMID:2870596

  18. Occurrence and persistence of antibiotic resistance genes in river biofilms after wastewater inputs in small rivers.

    Science.gov (United States)

    Proia, Lorenzo; von Schiller, Daniel; Sànchez-Melsió, Alexandre; Sabater, Sergi; Borrego, Carles M; Rodríguez-Mozaz, Sara; Balcázar, José Luis

    2016-03-01

    The extensive use of antibiotics in human and veterinary medicine and their subsequent release into the environment may have direct consequences for autochthonous bacterial communities, especially in freshwater ecosystems. In small streams and rivers, local inputs of wastewater treatment plants (WWTPs) may become important sources of organic matter, nutrients and emerging pollutants, such as antibiotic resistance genes (ARGs). In this study, we evaluated the effect of WWTP effluents as a source of ARGs in river biofilms. The prevalence of genes conferring resistance to main antibiotic families, such as beta-lactams (blaCTX-M), fluoroquinolones (qnrS), sulfonamides (sul I), and macrolides (ermB), was determined using quantitative PCR (qPCR) in biofilm samples collected upstream and downstream WWTPs discharge points in four low-order streams. Our results showed that the WWTP effluents strongly modified the hydrology, physico-chemistry and biological characteristics of the receiving streams and favoured the persistence and spread of antibiotic resistance in microbial benthic communities. It was also shown that the magnitude of effects depended on the relative contribution of each WWTP to the receiving system. Specifically, low concentrations of ARGs were detected at sites located upstream of the WWTPs, while a significant increase of their concentrations was observed in biofilms collected downstream of the WWTP discharge points (particularly ermB and sul I genes). These findings suggest that WWTP discharges may favour the increase and spread of antibiotic resistance among streambed biofilms. The present study also showed that the presence of ARGs in biofilms was noticeable far downstream of the WWTP discharge (up to 1 km). It is therefore reasonable to assume that biofilms may represent an ideal setting for the acquisition and spread of antibiotic resistance determinants and thus be considered suitable biological indicators of anthropogenic pollution by active

  19. Evidence of major genes affecting bacterial cold water disease resistance in rainbow trout using Bayesian methods of complex segregation analysis

    Science.gov (United States)

    Bacterial cold water disease (BCWD) causes significant economic loss in salmonid aquaculture. We previously detected genetic variation for BCWD resistance in our rainbow trout population, and a family-based selection program to improve resistance was initiated at the NCCCWA in 2005. The main objec...

  20. Evidence of major genes affecting resistance to bacterial cold water disease in rainbow trout using Bayesian methods of segregation analysis

    Science.gov (United States)

    Bacterial cold water disease (BCWD) causes significant economic loss in salmonid aquaculture. We previously detected genetic variation for BCWD resistance in our rainbow trout population, and a family-based selection program to improve resistance was initiated at the National Center for Cool and Col...

  1. Bacterial profile and patterns of antimicrobial drug resistance in intra-abdominal infections: Current experience in a teaching hospital

    Directory of Open Access Journals (Sweden)

    Neetu Shree

    2013-01-01

    Full Text Available Context: Bacterial isolates from intra-abdominal infections, in particular, peritonitis and their unpredictable antimicrobial resistance patterns, continue to be a matter of concern not only globally but regionally too. Aim: An attempt in the present study was made to study the patterns of drug resistance in bacterial isolates, especially gram negative bacilli in intra-abdominal infections (IAI in our hospital. Materials and Methods: From 100 cases of peritonitis, identification of isolates was done as per recommended methods. Antimicrobial susceptibility and extended-spectrum beta-lactamase (ESBL testing were performed following the CLSI guidelines. Results: A total of 133 clinical isolates were obtained, of which 108 were aerobes and 22 anaerobes. Fungal isolates were recovered in only three cases. Escherichia coli (47/108 emerged as the most predominant pathogen followed by Klebsiella spp. (27/108, while Bacteroides fragilis emerged as the predominant anaerobe (12/22. Among coliforms, 61.7% E. coli and 74.1% Klebsiella spp. were ESBL positive. A high level of resistance was observed for beta lactams, ciprofloxacin, amikacin, and ertapenem. Ertapenem resistance (30-41% seen in coliforms, appears as an important issue. Imipenem, tigecycline, and colistin were the most consistently active agents tested against ESBL producers. Conclusion: Drug resistance continues to be a major concern in isolates from intra-abdominal infections. Treatment with appropriate antibiotics preceded by antimicrobial resistance testing aided by early diagnosis, adequate surgical management, and knowledge of antibiotic - resistant organisms appears effective in reducing morbidity and mortality in IAI cases.

  2. Clinical Characteristics of Pediatric Patients Hospitalized with Methicillin-Resistant Staphylococcus aureus in Canadian Hospitals from 2008 To 2010

    Directory of Open Access Journals (Sweden)

    Kirk Ryan Leifso

    2013-01-01

    Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA infections were uncommon in children in Canada until the 1990s. Using a standardized case report form, treating physicians reported children hospitalized due to MRSA infections in Canadian hospitals through the Canadian Pediatric Surveillance Program in a 24-month period (2008 to 2010. Of 155 cases reported, 70% were ≤4 years of age and approximately one-third had an underlying medical condition. The most common clinical infections involved skin and soft tissue (69%, the lower respiratory tract (12%, and bone and joint (10%. Almost one-third had had contact with the health care environment in the previous year and 18% had a known household member with MRSA. Initial therapy with a beta-lactam alone occurred in 65%, while 22% included vancomycin. No child in this cohort died but 14% required admission to the intensive care unit. Of 143 reports of individual isolates, 93% were reported susceptible to trimethoprim-sulfamethoxazole, 63% to clindamycin and 50% to mupirocin.

  3. Prevalence of CTX-M Genes in Bacterial Strain Isolated from Patients Hospitalized in ICUs in The City of Qom, Iran

    OpenAIRE

    Yaser Sharifi; Abbas Morovvati; Azadeh Abedzadeh; Ali Javadi

    2015-01-01

    Background: Pathogenic bacteria because of beta-lactam antibiotic resistance genes are dangerous to society. This resistance due to ESBL genes, plasmids and transposons that by receiving or mutation occurs. The most important factor beta-lactam antibiotic resistance is beta lactamase enzymes. The purpose of this study was to evaluate the frequency of hospital opportunistic pathogenic bacteria producing ESBL and CTX-M genes identified are molecular methods.Methods : In this study, 500 isolates...

  4. Incidence of community-acquired methicillin-resistant Staphylococcus aureus carrying Pantone-Valentine leucocidin gene at a referral hospital in United Arab Emirates.

    Science.gov (United States)

    Dash, Nihar; Panigrahi, Debadatta; Al Zarouni, Mansour; Yassin, Faten; Al-Shamsi, Moza

    2014-04-01

    Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is an emerging pathogen in hospitalized patients worldwide. The present study was undertaken to identify CA-MRSA in hospitalized patients in a 350-bed tertiary care hospital in Sharjah, UAE over a 2-year period from January 2011 to December 2012. CA-MRSA was defined based on identification within first 48 h of admission in the hospital. Staphylococcal cassette chromosome (SCC) mec typing of the CA-MRSA isolates was carried out by multiplex polymerase chain reaction (PCR). Detection of PVL and mecA genes was done by PCR using the GenoType(®) MRSA test system (Hain Lifescience). Patient's clinical data and antimicrobial susceptibility pattern of the CA-MRSA isolates were also evaluated. Fifty seven of the 187 MRSA isolates were identified as CA-MRSA. All the CA-MRSA strains in our study belonged to SCCmecIV type and were positive for both PVL and mecA genes. The patients with CA-MRSA infections were young (median age, 32 years) and the majority of infections involved the skin and soft tissue (36%). Antimicrobial susceptibility pattern of the CA-MRSA isolates showed a better susceptibility profile to the non-beta-lactam antimicrobials with the exception of ciprofloxacin having 28% resistance. This study evidently strengthens the recent observation of an increase in CA-MRSA emergence among hospitalized patients in the UAE. PMID:23919760

  5. Inter-electrode tissue resistance is not affected by tissue oedema when electrically stimulating the lower limb of sepsis patients.

    Science.gov (United States)

    Durfee, William K; Young, Joseph R; Ginz, Hans F

    2014-05-01

    ICU patients typically are given large amounts of fluid and often develop oedema. The purpose of this study was to evaluate whether the oedema would change inter-electrode resistance and, thus, require a different approach to using non-invasive electrical stimulation of nerves to assess muscle force. Inter-electrode tissue resistance in the lower leg was measured by applying a 300 µs constant current pulse and measuring the current through and voltage across the stimulating electrodes. The protocol was administered to nine ICU patients with oedema, eight surgical patients without oedema and eight healthy controls. No significant difference in inter-electrode resistance was found between the three groups. For all groups, resistance decreased as stimulation current increased. In conclusion, inter-electrode resistance in ICU patients with severe oedema is the same as the resistance in regular surgical patients and healthy controls. This means that non-invasive nerve stimulation devices do not need to be designed to accommodate different resistances when used with oedema patients; however, surface stimulation does require higher current levels with oedema patients because of the increased distance between the skin surface and the targeted nerve or muscle. PMID:24758395

  6. Risk factors affecting nasal colonization of methicillin-resistant Staphylococcus aureus when admitted in intensive care unit

    Institute of Scientific and Technical Information of China (English)

    Li Qiang; Zhuang Taifeng; Lin Ying; Xi Jingjing; Yao Gaiqi

    2014-01-01

    Background Colonization with methicillin-resistant Staphylococcus aureus (MRSA) is a risk factor for subsequent invasive MRSA infection,particularly in patients admitted for critical care.The purpose of this study was to investigate the risk factors affecting nasal colonization of MRSA in patients admitted to intensive care units (ICU).Methods Between August 1,2011 and June 30,2012,we screened for MRSA nasal colonization in 350 patients by Real-time PCR within 24 hours of admission by means of swab samples taken from the anterior nares.According to the results of PCR,the patients were divided into 2 groups:the positive group with nasal MRSA colonization and the negative group without nasal MRSA colonization.The 31 (8.86%) patients were MRSA positive.The risk factors evaluated included thirteen variables,which were analyzed by t test for continuous variables and X2 test for discrete variables.The variables with significance (P <0.05) were analyzed with stepwise Logistic regression.Results There were differences (P <0.05) in four variables between two groups.The duration of stay in hospital prior to ICU admission in the positive group was (35.7±16.1) days,vs.(4.5±3.1) days in the negative group.The average blood albumin level was (28.4±2.9) g/L in the positive group,vs.(30.5±4.3) g/L in the negative group.Of 31 patients in the positive group,seven had been treated with antibiotics longer than seven days vs.34 of 319 patients in the negative group.In the positive group,four of 31 patients received treatment with more than two classes of antibiotics prior to admission in ICU,contrasted to 13 of 319 patients in the negative group.Furthermore,stepwise Logistic regression analysis for these four variables indicates that the duration of stay in hospital prior to ICU admission may be an independent risk factor.Conclusions MRSA colonization in ICU admission may be related to many factors.The duration of stay in hospital prior to ICU admission is an independent risk

  7. [Guidelines for treatment of pneumonia in intensive care units].

    Science.gov (United States)

    Emmi, V

    2005-01-01

    Patients affected by pneumonia can be admitted in Intensive Care Units (ICUs) independently by the setting where the infection has been acquired (community, hospital, long-term care facilities); even more frequently pneumonia can develop in patients already hospitalized in ICU especially in those requiring mechanical ventilation for different reasons. Within the severe community acquired pneumonia requiring admission in ICU, the most frequently responsible micro-organisms are mainly represented by Streptococcus pneumoniae, but also by Legionella and Haemophilus. Pseudomonas aeruginona, anyway, cannot be excluded. The most recent Canadian and American guidelines for treatment of the above mentioned infections suggest the use of a combination therapy with beta-lactams (ceftriaxone, cefotaxime, ampicillin/sulbactam, piperacillin/tazobactam) and a new generation macrolide or respiratory fluoroquinolone. In case of allergy to beta-lactams, the association fluoroquinolone-clindamycin should be preferred. Whenever a Pseudomonas etiology is suspected because of the presence of risk factors such as COPD, cystic fibrosis, bronchiectasis, previous and/or frequent therapies with antibiotics and/or steroids, the same guidelines suggest the use of an anti-pseudomonas beta-lactam (such as piperacillin/tazobactam, carbapenems, cefepime) associated with an anti-pseudomonas fluoroquinolone (high doses ciprofloxacin). An anti-pseudomonas beta-lactam plus an aminoglycoside or aminoglicosyde plus fluoroquinolone can be an alternative. Early onset Hospital Acquired Pneumonia (HAP) and early onset Ventilator Associated Pneumonia (VAP) in patients without risk factors for multi-resistant etiological agents are generally sustained by S. pneumoniae, H. influenzae, methicillin-susceptible Staphylocccus aureus e Gram negative enteric rods. These infections can be treated with one of the following antibiotics: ceftriaxone or fluoroquinolones (moxifloxacin or ciprofloxacin or levofloxacin) or

  8. JNK1 in hematopoietically derived cells contributes to diet-induced inflammation and insulin resistance without affecting obesity.

    Science.gov (United States)

    Solinas, Giovanni; Vilcu, Cristian; Neels, Jaap G; Bandyopadhyay, Gautam K; Luo, Jun-Li; Naugler, Willscott; Grivennikov, Sergei; Wynshaw-Boris, Anthony; Scadeng, Miriam; Olefsky, Jerrold M; Karin, Michael

    2007-11-01

    Obesity-induced insulin resistance is a major factor in the etiology of type 2 diabetes, and Jun kinases (JNKs) are key negative regulators of insulin sensitivity in the obese state. Activation of JNKs (mainly JNK1) in insulin target cells results in phosphorylation of insulin receptor substrates (IRSs) at serine and threonine residues that inhibit insulin signaling. JNK1 activation is also required for accumulation of visceral fat. Here we used reciprocal adoptive transfer experiments to determine whether JNK1 in myeloid cells, such as macrophages, also contributes to insulin resistance and central adiposity. Our results show that deletion of Jnk1 in the nonhematopoietic compartment protects mice from high-fat diet (HFD)-induced insulin resistance, in part through decreased adiposity. By contrast, Jnk1 removal from hematopoietic cells has no effect on adiposity but confers protection against HFD-induced insulin resistance by decreasing obesity-induced inflammation. PMID:17983584

  9. Metagenomic Evidence of the Prevalence and Distribution Patterns of Antimicrobial Resistance Genes in Dairy Agroecosystems.

    Science.gov (United States)

    Pitta, Dipti W; Dou, Zhengxia; Kumar, Sanjay; Indugu, Nagaraju; Toth, John Daniel; Vecchiarelli, Bonnie; Bhukya, Bhima

    2016-06-01

    Antimicrobial resistance (AR) is a global problem with serious implications for public health. AR genes are frequently detected on animal farms, but little is known about their origin and distribution patterns. We hypothesized that AR genes can transfer from animal feces to the environment through manure, and to this end, we characterized and compared the resistomes (collections of AR genes) of animal feces, manure, and soil samples collected from five dairy farms using a metagenomics approach. Resistomes constituted only up to 1% of the total gene content, but were variable by sector and also farm. Broadly, the identified AR genes were associated with 18 antibiotic resistances classes across all samples; however, the most abundant genes were classified under multidrug transporters (44.75%), followed by resistance to vancomycin (12.48%), tetracycline (10.52%), bacitracin (10.43%), beta-lactam resistance (7.12%), and MLS efflux pump (6.86%) antimicrobials. The AR gene profiles were variable between farms. Farm 09 was categorized as a high risk farm, as a greater proportion of AR genes were common to at least three sectors, suggesting possible horizontal transfer of AR genes. Taxonomic characterization of AR genes revealed that a majority of AR genes were associated with the phylum Proteobacteria. Nonetheless, there were several members of Bacteroidetes, particularly Bacteroides genus and several lineages from Firmicutes that carried similar AR genes in different sectors, suggesting a strong potential for horizontal transfer of AR genes between unrelated bacterial hosts in different sectors of the farms. Further studies are required to affirm the horizontal gene transfer mechanisms between microbiomes of different sectors in animal agroecosystems. PMID:27046731

  10. Development of a Geo-Referenced Database for Weed Mapping and Analysis of Agronomic Factors Affecting Herbicide Resistance in Apera spica-venti L. Beauv. (Silky Windgrass

    Directory of Open Access Journals (Sweden)

    Dario Massa

    2013-01-01

    Full Text Available In this work, we evaluate the role of agronomic factors in the selection for herbicide resistance in Apera spica-venti L. Beauv. (silky windgrass. During a period of three years, populations were collected in more than 250 conventional fields across Europe and tested for resistance in the greenhouse. After recording the field history of locations, a geo-referenced database has been developed to map the distribution of herbicide-resistant A. spica-venti populations in Europe. A Logistic Regression Model was used to assess whether and to what extent agricultural and biological factors (crop rotation, soil tillage, sowing date, soil texture and weed density affect the probability of resistance selection apart from the selection pressure due to herbicide application. Our results revealed that rotation management and soil tillage are the factors that have the greatest influence on the model. In addition, first order interactions between these two variables were highly significant. Under conventional tillage, a percentage of winter crops in the rotation exceeding 75% resulted in a 1280-times higher risk of resistance selection compared to rotations with less than 50% of winter crops. Under conservation tillage, the adoption of >75% of winter crops increased the risk of resistance 13-times compared to rotations with less than 50% of winter crops. Finally, early sowing and high weed density significantly increased the risk of resistance compared to the reference categories (later sowing and low weed density, respectively. Soil texture had no significant influence. The developed model can find application in management programs aimed at preventing the evolution and spread of herbicide resistance in weed populations.

  11. Modulation of HIV-1 Gag NC/p1 cleavage efficiency affects protease inhibitor resistance and viral replicative capacity

    Czech Academy of Sciences Publication Activity Database

    Maarseveen van, N. M.; Andersson, Dan; Lepšík, Martin; Fun, A.; Schipper, P. J.; Jong de, D.; Boucher, Ch. A. B.; Nijhuis, M.

    2012-01-01

    Roč. 9, č. 29 (2012), s. 1-7. ISSN 1742-4690 EU Projects: European Commission(XE) 37693 - HIV PI RESISTANCE Grant ostatní: Dutch AIDS Fund(XE) 2006028; (NWO) VIDI(XE) 91796349 Institutional research plan: CEZ:AV0Z40550506 Keywords : HIV -1 * protease * Gag * resistance * cleavage Subject RIV: CE - Biochemistry Impact factor: 5.657, year: 2012

  12. Pitting corrosion resistance of high-alloy OCTG in CO2 environment as affected by chlorides and sulfides

    International Nuclear Information System (INIS)

    High general corrosion resistance of high-alloy OCTG (oil country tubular goods) to CO2 may be limited by pitting corrosion in presence of chlorides and sulfides. The pitting resistance of 13% Cr steel, duplex and high Ni austenitic stainless steels have been examined by electrochemical measurements in a high temperature, high pressure autoclave simulating the well conditions. Each steel shows the pitting potential in CO2-NaCl-H2O system, the value of which being less noble as the Cl- concentration and the temperature increase. The presence of H2S is also detrimental. High alloying additions of Cr and Mo enhance pitting resistance whether or not H2S is present. The corrosion potentials of these steels in the simulating well conditions in which oxygen is absent do not exceed the pitting potential. Therefore, pitting corrosion can not occur by the passivity break through mechanism

  13. Molecular epidemiology of hybrid CTX-M type beta-lactamases among Escherichia coli isolates from human and animals

    OpenAIRE

    Liu, Chunjiao; 刘春娇

    2014-01-01

    A novel and effective mechanism of forming resistance to beta-lactam antibiotics by producing hybrid CTX-M-type beta-lactamases through genetic recombination was reported recently, albeit sporadically. Its primary introductory factor is the horizontal resistant gene transfer that occurs within the 876 bp 〖bla〗_(CTX-M) gene in Escherichia coli isolates, followed by the extensive application of beta-lactam antimicrobials. 〖bla〗_(CTX-M) originated from the nonpathogenic commensal Kluyvera spp., ...

  14. First identification of class A carbapenemase-producing Klebsiella pneumoniae in the Republic of Ireland.

    LENUS (Irish Health Repository)

    Roche, C

    2009-04-02

    The Klebsiella pneumoniae carbapenemase (KPC) was detected in a carbapenem-resistant respiratory isolate of Klebsiella pneumoniae in an Irish hospital. This is the first report of a KPC-producing isolate in the Republic of Ireland. The isolate was resistant to all beta-lactams. Furthermore, it had reduced susceptibility to three other classes of non-beta-lactam antibiotics. The isolate was not associated with travel abroad. Detection of KPC-producing bacteria has important infection control and public health implications.

  15. Experimental Simulation of the Effects of an Initial Antibiotic Treatment on a Subsequent Treatment after Initial Therapy Failure

    Directory of Open Access Journals (Sweden)

    Yanfang Feng

    2014-02-01

    Full Text Available Therapy failure of empirical antibiotic treatments prescribed by primary care physicians occurs commonly. The effect of such a treatment on the susceptibility to second line antimicrobial drugs is unknown. Resistance to amoxicillin was rapidly induced or selected in E. coli at concentrations expected in the patient’s body. Strains with reduced susceptibility outcompeted the wild-type whenever antibiotics were present, even in low concentrations that did not affect the growth rates of both strains. Exposure of E. coli to amoxicillin caused moderate resistance to cefotaxime. The combined evidence suggests that initial treatment by amoxicillin has a negative effect on subsequent therapy with beta-lactam antibiotics.

  16. Paromomycin affects translation and vesicle-mediated trafficking as revealed by proteomics of paromomycin -susceptible -resistant Leishmania donovani.

    Directory of Open Access Journals (Sweden)

    Bhavna Chawla

    Full Text Available Leishmania donovani is a protozoan parasite that causes visceral leishmaniasis (VL and is responsible for significant mortality and morbidity. Increasing resistance towards antimonial drugs poses a great challenge in chemotherapy of VL. Paromomycin is an aminoglycosidic antibiotic and is one of the drugs currently being used in the chemotherapy of cutaneous and visceral leishmaniasis. To understand the mode of action of this antibiotic at the molecular level, we have investigated the global proteome differences between the wild type AG83 strain and a paromomycin resistant (PRr strain of L. donovani. Stable isotope labeling of amino acids in cell culture (SILAC followed by quantitative mass spectrometry of the wild type AG83 strain and the paromomycin resistant (PRr strain identified a total of 226 proteins at ≥ 95% confidence. Data analysis revealed upregulation of 29 proteins and down-regulation of 21 proteins in the PRr strain. Comparative proteomic analysis of the wild type and the paromomycin resistant strains showed upregulation of the ribosomal proteins in the resistant strain indicating role in translation. Elevated levels of glycolytic enzymes and stress proteins were also observed in the PRr strain. Most importantly, we observed upregulation of proteins that may have a role in intracellular survival and vesicular trafficking in the PRr strain. Furthermore, ultra-structural analysis by electron microscopy demonstrated increased number of vesicular vacuoles in PRr strain when compared to the wild-type strain. Drug affinity pull-down assay followed by mass spectrometery identified proteins in L. donovani wild type strain that were specifically and covalently bound to paromomycin. These results provide the first comprehensive insight into the mode of action and underlying mechanism of resistance to paromomycin in Leishmania donovani.

  17. Virulence and antimicrobial resistance of common urinary bacteria from asymptomatic students of Niger Delta University, Amassoma, Bayelsa State, Nigeria

    Science.gov (United States)

    Onanuga, Adebola; Selekere, Tamaradobra Laurretta

    2016-01-01

    Background: Asymptomatic bacteriuria frequently occurs among all ages with the possibility of developing into urinary tract infections, and the antimicrobial resistance patterns of the etiologic organisms are essential for appropriate therapy. Thus, we investigated the virulence and antimicrobial resistance patterns of common urinary bacteria in asymptomatic students of Niger Delta University, Amassoma, Bayelsa State, Nigeria in a cross-sectional study. Materials and Methods: Clean catch mid-stream early morning urine samples collected from 200 asymptomatic University students of aged ranges 15–30 years were cultured, screened and common bacteria were identified using standard microbiological procedures. The isolates were screened for hemolysin production and their susceptibility to antibiotics was determined using standard disc assay method. Results: A total prevalence rate of 52.0% significant bacteriuria was detected and it was significantly higher among the female with a weak association (χ2 = 6.01, phi = 0.173, P = 0.014). The Klebsiella pneumoniae and Staphylococcus aureus isolates were most frequently encountered among the isolated bacteria and 18 (12.7%) of all the bacterial isolates produced hemolysins. All the bacterial isolates exhibited 50–100% resistance to the tested beta-lactam antibiotics, tetracycline and co-trimoxazole. The isolated bacteria were 85-100% multi-drug resistant. However, most of the isolates were generally susceptible to gentamicin and ofloxacin. The phenotypic detection of extended-spectrum beta-lactamases was 9 (9.6%) among the tested Gram-negative bacterial isolates. Conclusions: The observed high proportions of multidrug resistant urinary bacteria among asymptomatic University students call for the need of greater control of antibiotic use in this study area. PMID:26957865

  18. Current Antibiotic Resistance Trend in Clinical Isolates of Staphylococcus aureus from a Tertiary Care Hospital

    Directory of Open Access Journals (Sweden)

    Zahra Ravesh-Barakzai

    2015-10-01

    Full Text Available Background: Staphylococcus aureus (S. aureus has remained always an important pathogen of common infections acquired in community and as  well as serious nosocomial infections. With advent of penicillins and cephalosporins, infections could be effectively treated, but with the global emergence of Methicillin Resistant Staphylococcus aureus strains (MRSA physicians were  again left  with limited treatment options. This scenario of increasing resistance is even more intense and challenging for developing countries like Pakistan. Hence with this background the study was carried out to establish the frequency of MRSA in clinical specimens and look into the available antibiotic treatment options.Methods: Samples of  pus, blood, urine, body fluids and catheter tips submitted for culture  in  Microbiology department between  August  to  September  2012,  from outdoor and indoor adult patients of Pakistan Institute of Medical Sciences Islamabad, yielding growth of S. aureus were included in the study. After identification by  standard  methods, antibiotic susceptibility of  the  isolates  was performed by Kirby Baeur disc diffusion method. The study was retrospective descriptive and observational.Results: Total  106  S.  aureus  were  isolated. 45.3%  of  them  were  MRSA  and majorities were from pus samples of hospitalized patients. All MRSA were 100% sensitive to vancomycin, whereas 87.5% to chloramphenicol. To rest of the non – beta lactam drugs, resistance of 80% or more was noted.Conclusion: S. aureus is a common clinical isolate from patients in this region ofPakistan and significant number were MRSA especially from hospitalized patients. Treatment options are limited to vancomycin and chloramphenicol.

  19. High-throughput profiling of antibiotic resistance genes in drinking water treatment plants and distribution systems.

    Science.gov (United States)

    Xu, Like; Ouyang, Weiying; Qian, Yanyun; Su, Chao; Su, Jianqiang; Chen, Hong

    2016-06-01

    Antibiotic resistance genes (ARGs) are present in surface water and often cannot be completely eliminated by drinking water treatment plants (DWTPs). Improper elimination of the ARG-harboring microorganisms contaminates the water supply and would lead to animal and human disease. Therefore, it is of utmost importance to determine the most effective ways by which DWTPs can eliminate ARGs. Here, we tested water samples from two DWTPs and distribution systems and detected the presence of 285 ARGs, 8 transposases, and intI-1 by utilizing high-throughput qPCR. The prevalence of ARGs differed in the two DWTPs, one of which employed conventional water treatments while the other had advanced treatment processes. The relative abundance of ARGs increased significantly after the treatment with biological activated carbon (BAC), raising the number of detected ARGs from 76 to 150. Furthermore, the final chlorination step enhanced the relative abundance of ARGs in the finished water generated from both DWTPs. The total enrichment of ARGs varied from 6.4-to 109.2-fold in tap water compared to finished water, among which beta-lactam resistance genes displayed the highest enrichment. Six transposase genes were detected in tap water samples, with the transposase gene TnpA-04 showing the greatest enrichment (up to 124.9-fold). We observed significant positive correlations between ARGs and mobile genetic elements (MGEs) during the distribution systems, indicating that transposases and intI-1 may contribute to antibiotic resistance in drinking water. To our knowledge, this is the first study to investigate the diversity and abundance of ARGs in drinking water treatment systems utilizing high-throughput qPCR techniques in China. PMID:26890482

  20. The Prevalence Of Nosocomial Infections Caused By Enterobacter Cloacae And Antibiotic Resistant Patterns In Samples Isolated From Patients In Two Hospitals In Tehran

    Directory of Open Access Journals (Sweden)

    S Soleymanzadeh

    2012-06-01

    Full Text Available Background: The increasing use of β-lactam antibiotics in clinics for the treatment of different bacterial infections since early 1980s has led to increased rates of resistant bacteria isolated from patients. One of the problems in the treatment of nosocomial infections is related to resistant bacteria such as Enterobacter cloacae due to cross resistance through extended-spectrum beta-lactamase production. The aim of this study was to determine the prevalence of extended-spectrum beta-lactamase producing E. cloacae from different clinical specimens collected from hospitalized patients. Methods: In the present study, 101 E. cloacae confirmed by standard specific microbiologic tests were collected from different specimens in Milad and Motahri hospitals in Tehran, Iran during February 2010 and September 2011. Antibiotic susceptibility tests were conducted according to the process recommended by the Clinical and Laboratory Standards Institute for 13 antibiotics of choice. Extended-spectrum beta-lactamase producing strains were screened for by combined disk method as a phenotypic diagnostic test. Results: From a total of 101 E. cloacae, 33 (33% were shown to produce extended-spectrum beta-lactamase by phenotypic tests; 5% of the bacteria were resistant to imipenem too. Conclusion: This study clearly showed the high prevalence of resistance to broad-spectrum beta-lactam antibiotics in the isolated E. cloacae among which 5% were multi drug resistant. All the isolated E. cloacae were susceptible to Colistin. These results can be alarming for physicians treating resistant E. cloacae infections, especially extended-spectrum beta-lactamase producing species.

  1. Evolution of linked avirulence effectors in Leptosphaeria maculans is affected by genomic environment and exposure to resistance genes in host plants.

    Directory of Open Access Journals (Sweden)

    Angela P Van de Wouw

    Full Text Available Brassica napus (canola cultivars and isolates of the blackleg fungus, Leptosphaeria maculans interact in a 'gene for gene' manner whereby plant resistance (R genes are complementary to pathogen avirulence (Avr genes. Avirulence genes encode proteins that belong to a class of pathogen molecules known as effectors, which includes small secreted proteins that play a role in disease. In Australia in 2003 canola cultivars with the Rlm1 resistance gene suffered a breakdown of disease resistance, resulting in severe yield losses. This was associated with a large increase in the frequency of virulence alleles of the complementary avirulence gene, AvrLm1, in fungal populations. Surprisingly, the frequency of virulence alleles of AvrLm6 (complementary to Rlm6 also increased dramatically, even though the cultivars did not contain Rlm6. In the L. maculans genome, AvrLm1 and AvrLm6 are linked along with five other genes in a region interspersed with transposable elements that have been degenerated by Repeat-Induced Point (RIP mutations. Analyses of 295 Australian isolates showed deletions, RIP mutations and/or non-RIP derived amino acid substitutions in the predicted proteins encoded by these seven genes. The degree of RIP mutations within single copy sequences in this region was proportional to their proximity to the degenerated transposable elements. The RIP alleles were monophyletic and were present only in isolates collected after resistance conferred by Rlm1 broke down, whereas deletion alleles belonged to several polyphyletic lineages and were present before and after the resistance breakdown. Thus, genomic environment and exposure to resistance genes in B. napus has affected the evolution of these linked avirulence genes in L. maculans.

  2. Eight Weeks of Phosphatidic Acid Supplementation in Conjunction with Resistance Training Does Not Differentially Affect Body Composition and Muscle Strength in Resistance-Trained Men

    Directory of Open Access Journals (Sweden)

    Thomas L. Andre, Joshua J. Gann, Sarah K. McKinley-Barnard, Joon J. Song, Darryn S. Willoughby

    2016-09-01

    Full Text Available This study attempted to determine the effects of eight weeks of resistance training (RT combined with phosphatidic acid (PA supplementation at a dose of either 250 mg or 375 mg on body composition and muscle size and strength. Twenty-eight resistance-trained men were randomly assigned to ingest 375 mg [PA375 (n = 9] or 250 mg [PA250 (n = 9] of PA or 375 mg of placebo [PLC (n = 10] daily for eight weeks with RT. Supplements were ingested 60 minutes prior to RT and in the morning on non-RT days. Participants’ body composition, muscle size, and lower-body muscle strength were determined before and after training/supplementation. Separate group x time ANOVAs for each criterion variable were used employing an alpha level of ≤ 0.05. Magnitude- based inferences were utilized to determine the likely or unlikely impact of PA on each criterion variable. A significant main effect for time was observed for improvements in total body mass (p = 0.003, lean mass (p = 0.008, rectus femoris cross-sectional area [RF CSA (p = 0.011], and lower-body strength (p 0.05. Collectively, magnitude-based inferences determined both doses of PA to have a likely impact of increasing body mass (74.2%, lean mass (71.3%, RF CSA (92.2%, and very likely impact on increasing lower-body strength (98.1% beneficial. When combined with RT, it appears that PA has a more than likely impact on improving lower-body strength, whereas a likely impact exists for increasing muscle size and lean mass.

  3. Cabozantinib Inhibits Growth of Androgen-Sensitive and Castration-Resistant Prostate Cancer and Affects Bone Remodeling

    OpenAIRE

    Nguyen, Holly M.; Nazanin Ruppender; Xiaotun Zhang; Lisha G. Brown; Gross, Ted S.; Colm Morrissey; Roman Gulati; Vessella, Robert L.; Frauke Schimmoller; Aftab, Dana T.; Eva Corey

    2013-01-01

    Cabozantinib is an inhibitor of multiple receptor tyrosine kinases, including MET and VEGFR2. In a phase II clinical trial in advanced prostate cancer (PCa), cabozantinib treatment improved bone scans in 68% of evaluable patients. Our studies aimed to determine the expression of cabozantinib targets during PCa progression and to evaluate its efficacy in hormone-sensitive and castration-resistant PCa in preclinical models while delineating its effects on tumor and bone. Using immunohistochemis...

  4. Cabozantinib inhibits growth of androgen-sensitive and castration-resistant prostate cancer and affects bone remodeling.

    Science.gov (United States)

    Nguyen, Holly M; Ruppender, Nazanin; Zhang, Xiaotun; Brown, Lisha G; Gross, Ted S; Morrissey, Colm; Gulati, Roman; Vessella, Robert L; Schimmoller, Frauke; Aftab, Dana T; Corey, Eva

    2013-01-01

    Cabozantinib is an inhibitor of multiple receptor tyrosine kinases, including MET and VEGFR2. In a phase II clinical trial in advanced prostate cancer (PCa), cabozantinib treatment improved bone scans in 68% of evaluable patients. Our studies aimed to determine the expression of cabozantinib targets during PCa progression and to evaluate its efficacy in hormone-sensitive and castration-resistant PCa in preclinical models while delineating its effects on tumor and bone. Using immunohistochemistry and tissue microarrays containing normal prostate, primary PCa, and soft tissue and bone metastases, our data show that levels of MET, P-MET, and VEGFR2 are increasing during PCa progression. Our data also show that the expression of cabozantinib targets are particularly pronounced in bone metastases. To evaluate cabozantinib efficacy on PCa growth in the bone environment and in soft tissues we used androgen-sensitive LuCaP 23.1 and castration-resistant C4-2B PCa tumors. In vivo, cabozantinib inhibited the growth of PCa in bone as well as growth of subcutaneous tumors. Furthermore, cabozantinib treatment attenuated the bone response to the tumor and resulted in increased normal bone volume. In summary, the expression pattern of cabozantinib targets in primary and castration-resistant metastatic PCa, and its efficacy in two different models of PCa suggest that this agent has a strong potential for the effective treatment of PCa at different stages of the disease. PMID:24205338

  5. Cabozantinib inhibits growth of androgen-sensitive and castration-resistant prostate cancer and affects bone remodeling.

    Directory of Open Access Journals (Sweden)

    Holly M Nguyen

    Full Text Available Cabozantinib is an inhibitor of multiple receptor tyrosine kinases, including MET and VEGFR2. In a phase II clinical trial in advanced prostate cancer (PCa, cabozantinib treatment improved bone scans in 68% of evaluable patients. Our studies aimed to determine the expression of cabozantinib targets during PCa progression and to evaluate its efficacy in hormone-sensitive and castration-resistant PCa in preclinical models while delineating its effects on tumor and bone. Using immunohistochemistry and tissue microarrays containing normal prostate, primary PCa, and soft tissue and bone metastases, our data show that levels of MET, P-MET, and VEGFR2 are increasing during PCa progression. Our data also show that the expression of cabozantinib targets are particularly pronounced in bone metastases. To evaluate cabozantinib efficacy on PCa growth in the bone environment and in soft tissues we used androgen-sensitive LuCaP 23.1 and castration-resistant C4-2B PCa tumors. In vivo, cabozantinib inhibited the growth of PCa in bone as well as growth of subcutaneous tumors. Furthermore, cabozantinib treatment attenuated the bone response to the tumor and resulted in increased normal bone volume. In summary, the expression pattern of cabozantinib targets in primary and castration-resistant metastatic PCa, and its efficacy in two different models of PCa suggest that this agent has a strong potential for the effective treatment of PCa at different stages of the disease.

  6. The Staphylococcus aureus Chaperone PrsA Is a New Auxiliary Factor of Oxacillin Resistance Affecting Penicillin-Binding Protein 2A.

    Science.gov (United States)

    Jousselin, Ambre; Manzano, Caroline; Biette, Alexandra; Reed, Patricia; Pinho, Mariana G; Rosato, Adriana E; Kelley, William L; Renzoni, Adriana

    2015-01-01

    Expression of the methicillin-resistant S. aureus (MRSA) phenotype results from the expression of the extra penicillin-binding protein 2A (PBP2A), which is encoded by mecA and acquired horizontally on part of the SCCmec cassette. PBP2A can catalyze dd-transpeptidation of peptidoglycan (PG) because of its low affinity for β-lactam antibiotics and can functionally cooperate with the PBP2 transglycosylase in the biosynthesis of PG. Here, we focus upon the role of the membrane-bound PrsA foldase protein as a regulator of β-lactam resistance expression. Deletion of prsA altered oxacillin resistance in three different SCCmec backgrounds and, more importantly, caused a decrease in PBP2A membrane amounts without affecting mecA mRNA levels. The N- and C-terminal domains of PrsA were found to be critical features for PBP2A protein membrane levels and oxacillin resistance. We propose that PrsA has a role in posttranscriptional maturation of PBP2A, possibly in the export and/or folding of newly synthesized PBP2A. This additional level of control in the expression of the mecA-dependent MRSA phenotype constitutes an opportunity to expand the strategies to design anti-infective agents. PMID:26711778

  7. Limitation of nocturnal ATP import into chloroplasts seems to affect hormonal crosstalk, prime defense, and enhance disease resistance in Arabidopsis thaliana.

    Science.gov (United States)

    Schmitz, Gudrun; Reinhold, Thomas; Göbel, Cornelia; Feussner, Ivo; Neuhaus, H Ekkehard; Conrath, Uwe

    2010-12-01

    When grown under short-day conditions at low light, leaves of an Arabidopsis thaliana (accession Col-0) mutant with defects in the two genes encoding plastid ATP/ADP antiporters (so-called ntt1-2 null mutants) display a variety of physiological changes. These include the formation of necrotic lesions and the accumulation of hydrogen peroxide in the leaves. Here, we show that, under short-day conditions, leaves of the ntt1-2 mutant display enhanced resistance to Hyaloperonospora arabidopsidis, Botrytis cinerea, and Pseudomonas syringae pv. tomato DC3000. Resistance to these pathogens was associated with constitutively elevated levels of the plant hormone salicylic acid and, eventually, jasmonic acid, and constitutive or primed activation after pathogen attack of various defense genes that are dependent on these hormones. In addition, the antagonistic crosstalk between the salicylic acid and jasmonic acid signaling pathways seems to be affected in ntt1-2. Because the enhanced resistance of ntt1-2 to H. arabidopsidis was not seen when the mutant was grown under long-day conditions, our findings argue that nocturnal ATP import into chloroplasts is crucial to keep A. thaliana from runaway activation of pathogen resistance. PMID:21039274

  8. Virulence Characterisation of Salmonella enterica Isolates of Differing Antimicrobial Resistance Recovered from UK Livestock and Imported Meat Samples

    Science.gov (United States)

    Card, Roderick; Vaughan, Kelly; Bagnall, Mary; Spiropoulos, John; Cooley, William; Strickland, Tony; Davies, Rob; Anjum, Muna F.

    2016-01-01

    Salmonella enterica is a foodborne zoonotic pathogen of significant public health concern. We have characterized the virulence and antimicrobial resistance gene content of 95 Salmonella isolates from 11 serovars by DNA microarray recovered from UK livestock or imported meat. Genes encoding resistance to sulphonamides (sul1, sul2), tetracycline [tet(A), tet(B)], streptomycin (strA, strB), aminoglycoside (aadA1, aadA2), beta-lactam (blaTEM), and trimethoprim (dfrA17) were common. Virulence gene content differed between serovars; S. Typhimurium formed two subclades based on virulence plasmid presence. Thirteen isolates were selected by their virulence profile for pathotyping using the Galleria mellonella pathogenesis model. Infection with a chicken invasive S. Enteritidis or S. Gallinarum isolate, a multidrug resistant S. Kentucky, or a S. Typhimurium DT104 isolate resulted in high mortality of the larvae; notably presence of the virulence plasmid in S. Typhimurium was not associated with increased larvae mortality. Histopathological examination showed that infection caused severe damage to the Galleria gut structure. Enumeration of intracellular bacteria in the larvae 24 h post-infection showed increases of up to 7 log above the initial inoculum and transmission electron microscopy (TEM) showed bacterial replication in the haemolymph. TEM also revealed the presence of vacuoles containing bacteria in the haemocytes, similar to Salmonella containing vacuoles observed in mammalian macrophages; although there was no evidence from our work of bacterial replication within vacuoles. This work shows that microarrays can be used for rapid virulence genotyping of S. enterica and that the Galleria animal model replicates some aspects of Salmonella infection in mammals. These procedures can be used to help inform on the pathogenicity of isolates that may be antibiotic resistant and have scope to aid the assessment of their potential public and animal health risk. PMID:27199965

  9. Daytime pattern of post-exercise protein intake affects whole-body protein turnover in resistance-trained males

    OpenAIRE

    Moore Daniel R; Areta Jose; Coffey Vernon G; Stellingwerff Trent; Phillips Stuart M; Burke Louise M; Cléroux Marilyn; Godin Jean-Philippe; Hawley John A

    2012-01-01

    Abstract Background The pattern of protein intake following exercise may impact whole-body protein turnover and net protein retention. We determined the effects of different protein feeding strategies on protein metabolism in resistance-trained young men. Methods Participants were randomly assigned to ingest either 80g of whey protein as 8x10g every 1.5h (PULSE; n=8), 4x20g every 3h (intermediate, INT; n=7), or 2x40g every 6h (BOLUS; n=8) after an acute bout of bilateral knee extension exerci...

  10. Local Collagen-Gentamicin for Prevention of Sternal Wound Infections

    OpenAIRE

    Friberg, Örjan

    2006-01-01

    In cardiac surgery, sternal wound infection (SWI) continues to be one of the most serious postoperative complications. Coagulase-negative staphylococci (CoNS) have become the most common causative agents of SWI. Prophylaxis with intravenous beta-lactam antibiotics (cephalosporins or in Sweden most commonly isoxazolyl penicillins) is routinely practised. However, many CoNS species are resistant to beta-lactam antibiotics. Vancomycin is often the only effective antibiotic available for treatmen...

  11. Chromosomal beta-lactamase is packaged into membrane vesicles and secreted from Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Ciofu, O; Beveridge, T J; Kadurugamuwa, J; Walther-Rasmussen, J; Høiby, N

    2000-01-01

    Membrane vesicles were isolated from one beta-lactam-sensitive and three beta-lactam-resistant Pseudomonas aeruginosa clinical isolates from patients with cystic fibrosis. The presence of the chromosomally encoded beta-lactamase in the membrane vesicles was shown by electron microscopy and...... enzymatic studies. This is the first report of extracellular secretion of beta-lactamase in P. aeruginosa and it seems that the enzyme is packaged into membrane vesicles....

  12. Endurance and Resistance Training Affect High Fat Diet-Induced Increase of Ceramides, Inflammasome Expression, and Systemic Inflammation in Mice

    Directory of Open Access Journals (Sweden)

    Cornelia Mardare

    2016-01-01

    Full Text Available The study aimed to investigate the effects of differentiated exercise regimes on high fat-induced metabolic and inflammatory pathways. Mice were fed a standard diet (ST or a high fat diet (HFD and subjected to regular endurance training (ET or resistance training (RT. After 10 weeks body weight, glucose tolerance, fatty acids (FAs, circulating ceramides, cytokines, and immunological mediators were determined. The HFD induced a significant increase in body weight and a disturbed glucose tolerance (p<0.05. An increase of plasma FA, ceramides, and inflammatory mediators in adipose tissue and serum was found (p<0.05. Both endurance and resistance training decreased body weight (p<0.05 and reduced serum ceramides (p<0.005. While RT attenuated the increase of NLRP-3 (RT expression in adipose tissue, ET was effective in reducing TNF-α and IL-18 expression. Furthermore, ET reduced levels of MIP-1γ, while RT decreased levels of IL-18, MIP-1γ, Timp-1, and CD40 in serum (p<0.001, respectively. Although both exercise regimes improved glucose tolerance (p<0.001, ET was more effective than RT. These results suggest that exercise improves HFD-induced complications possibly through a reduction of ceramides, the reduction of inflammasome activation in adipose tissues, and a systemic downregulation of inflammatory cytokines.

  13. Host age only partially affects resistance to primary and secondary infections with Ascaridia galli (Schrank, 1788) in chickens.

    Science.gov (United States)

    Idi, A; Permin, A; Murrell, K D

    2004-07-14

    Two experiments were conducted to compare the effect of chickens' age on resistance to primary and secondary infections with Ascaridia galli. In Experiment I, three groups, each of 80 female Lohman Brown chickens, aged one day, one month, or four months were compared. Within each group, 54 chickens were infected orally with 500 embryonated eggs and 26 were kept as non-infected controls. Weights were recorded weekly and five chickens in each group were slaughtered every 2 weeks for worm counts. At week 10 post-infection, 17 of the infected chickens and 18 of the controls were challenged with 500 eggs. In a replicate experiment (Experiment II), 35 one-day-old and 53 one-month-old female Lohman Brown chickens were infected orally with 500 A. galli eggs. Weights and fecal egg counts were recorded every week and infected chickens were necropsied every two weeks for determination of the worm burden. Chickens infected at one month of age excreted significantly fewer A. galli eggs when measured at 14 weeks of inoculation. The worms recovered from the one-month-old age group were significantly shorter than those from the chickens infected at one day of age in the first experiment. Worm burden and female fecundity values, however, were not significantly different between age groups in both Experiments I and II. Weight gains of infected chickens were not significantly different from the controls' and only a few chickens exhibited occasional slight diarrhea in both experiments. The results from these experiments demonstrate that the chickens' age only partially influences resistance to A. galli infection. PMID:15219363

  14. Rec-8 dimorphism affects longevity, stress resistance and X-chromosome nondisjunction in C. elegans, and replicative lifespan in yeast

    Directory of Open Access Journals (Sweden)

    Srinivas eAyyadevara

    2014-08-01

    Full Text Available A quantitative trait locus (QTL in the nematode C. elegans, lsq4, was recently implicated by mapping longevity genes. QTLs for lifespan and 3 stress-resistance traits coincided within a span of <300 kbp, later narrowed to <200 kbp. A single gene in this interval is now shown to modulate all lsq4-associated traits. Full-genome analysis of transcript levels indicates that lsq4 contains a dimorphic gene governing expression of sperm-specific genes, suggesting effects on spermatogenesis. Quantitation of allele-specific transcripts encoded within the lsq4 interval revealed significant, 2- to 15-fold expression differences for 10 of 33 genes. Fourteen genes, implicated by both position and expression, were tested for RNA-interference effects on QTL-linked traits. In a strain carrying the shorter-lived allele, knockdown of rec-8 (encoding a meiotic cohesin reduced its transcripts 4-fold, to a level similar to the longer-lived strain, and extended lifespan 25–26% whether begun before fertilization or at maturity. The short-lived lsq4 allele also conferred sensitivity to oxidative and thermal stresses, and lower male frequency, traits reversed uniquely by rec-8 knockdown. A strain bearing the longer-lived lsq4 allele, differing from the short-lived strain at <0.3% of its genome, derived no lifespan or stress-survival benefit from rec-8 knockdown. We consider two possible explanations: high rec-8 expression may include increased leaky expression in mitotic cells, leading to deleterious destabilization of somatic genomes; or REC-8 may act entirely in germ-line meiotic cells to reduce aberrations such as nondisjunction, thereby blunting a stress-resistance response mediated by innate immunity. Replicative lifespan was extended 20% in haploid S. cerevisiae (BY4741 by deletion of REC8, orthologous to nematode rec-8, implying that REC8 disruption of mitotic-cell survival is widespread, reflecting antagonistic pleiotropy and/or balancing selection.

  15. Post-translational regulation of acid invertase activity by vacuolar invertase inhibitor affects resistance to cold-induced sweetening of potato tubers.

    Science.gov (United States)

    McKenzie, Marian J; Chen, Ronan K Y; Harris, John C; Ashworth, Matthew J; Brummell, David A

    2013-01-01

    Cold-induced sweetening (CIS) is a serious post-harvest problem for potato tubers, which need to be stored cold to prevent sprouting and pathogenesis in order to maintain supply throughout the year. During storage at cold temperatures (below 10 °C), many cultivars accumulate free reducing sugars derived from a breakdown of starch to sucrose that is ultimately cleaved by acid invertase to produce glucose and fructose. When affected tubers are processed by frying or roasting, these reducing sugars react with free asparagine by the Maillard reaction, resulting in unacceptably dark-coloured and bitter-tasting product and generating the probable carcinogen acrylamide as a by-product. We have previously identified a vacuolar invertase inhibitor (INH2) whose expression correlates both with low acid invertase activity and with resistance to CIS. Here we show that, during cold storage, overexpression of the INH2 vacuolar invertase inhibitor gene in CIS-susceptible potato tubers reduced acid invertase activity, the accumulation of reducing sugars and the generation of acrylamide in subsequent fry tests. Conversely, suppression of vacuolar invertase inhibitor expression in a CIS-resistant line increased susceptibility to CIS. The results show that post-translational regulation of acid invertase by the vacuolar invertase inhibitor is an important component of resistance to CIS. PMID:22734927

  16. Relationships between antimicrobial resistance, distribution of virulence factor genes and the origin of Trueperella pyogenes isolated from domestic animals and European bison (Bison bonasus).

    Science.gov (United States)

    Rzewuska, Magdalena; Czopowicz, Michał; Gawryś, Marta; Markowska-Daniel, Iwona; Bielecki, Wojciech

    2016-07-01

    Trueperella pyogenes is an opportunistic pathogen causing suppurative infections in livestock and wild animals. Although this bacterium is known for a long time, our knowledge about its pathogenicity is still insufficient. In this study the relationships between antimicrobial resistance profiles, distribution of virulence factor genes and the origin of T. pyogenes isolates were investigated. Isolates (n = 97) from various infections in domestic animals and European bison were studied. Minimal inhibitory concentrations of 12 antimicrobials were determined by a strip diffusion method, and PCR was used for detection of genes encoding seven putative virulence factors. All strains were susceptible to tested beta-lactams, and a statistically significant correlation between the resistance to enrofloxacin, tetracycline, macrolides, clindamycin, and a strain origin was found. The isolates from European bison were more susceptible than those from livestock, however the resistance to tetracycline and fluoroquinolones was observed. The plo and fimA genes were detected in all strains. There was no statistically significant association between the distribution of particular virulence factor genes and the type of infection, but the nanH, nanP and fimG genes were less frequently found in the isolates from European bison. The presence of three genes, nanP, nanH and cbpA, was found to be related to the resistance to tetracycline and ciprofloxacin. In conclusion, the resistance patterns of T. pyogenes were correlated with an isolate origin, but our findings did not allow to indicate which of the putative virulence factors may play a crucial role in the pathogenesis of particular types of T. pyogenes infection. PMID:27154538

  17. TRENDS IN ANTIMICROBIAL RESISTANCE AMONG UROPATHOGENS WITH SPECIAL REFERENCE TO ESCHERICHIA COLI IN COMMUNITY ACQUIRED PEDIATRIC URINARY TRACT INFECTIONS FROM KERALA

    Directory of Open Access Journals (Sweden)

    Nisha

    2015-07-01

    Full Text Available CONTEXT: Resistance of uropathogens to commonly used antibiotics is increasingly reported from India in adults. There is little data on resistance patterns in childhood community acquired urinary tract infections (UTI. AIMS: To study antibiotic resistanc e trends of uropathogens isolated in community acquired UTI in children from a geographic area. SETTINGS AND DESIGN: Prospective study conducted in a northern Kerala tertiary pediatric centre between November 2012 and October 2014. METHODS : Urine samples were obtained by clean catch midstream, bladder catheterization or supra - pubic aspiration. Bacterial growth, when significant were identified by standard biochemical reactions with antibiogram by Kirby Bauers disc diffusion method. STATISTICAL ANALYSIS : P roportions were calculated and statistical significance obtained by Chi - square. RESULTS : Of the 1387 cultures with suspected community acquired UTI, 274 (19.75% were positive. Mean age of study group was 28.52 months and 64.6% were boys. Escherichia coli (E.coli was the predominant pathogen [189(69%] followed by Klebsiella 50(18.2%. Citrobacter, Enterococcus, Proteus and Pseudomonas constituted less than 6%. All urinary isolates showed high combined resistance to most commonly used antimicrobials inclu ding beta - lactam antibiotics (84.3% to cefotaxime, 83.2% to cefixime, 74.5% to ampicillin, quinolones (54.2% to ciprofloxacin, 46.4% to norfloxacin, 32.8% to levofloxacin, 52.9% to co - trimoxazole, 30.2% to gentamicin, 24.1% to nitrofurantoin and 14.2% to netilmicin. E.coli was highly resistant tocephalosporins and ampicillin (>80%. CONCLUSIONS: There is increasing resistance amongst E.coli coli and Klebsiella to third generation cephalosporins in pediatric age group. It is important to generate regional data on antibiogram pattern to guide therapy.

  18. Isolation and identification of Enterococcus faecium from seafoods: antimicrobial resistance and production of bacteriocin-like substances.

    Science.gov (United States)

    Valenzuela, Antonio Sánchez; Benomar, Nabil; Abriouel, Hikmate; Cañamero, Magdalena Martínez; Gálvez, Antonio

    2010-10-01

    A collection of isolates from uncooked seafoods (molluscs, fish, and fish fillets) were identified as Enterococcus faecium species and studied in further detail. Isolates were clustered in well-defined genomic groups according to food origin after ERIC-PCR analysis. Four isolates (FR 1-2, FB 1-3-B, FB 3-1, FTA 1-2) decarboxylated lysine, ornithine, and tyrosine. Isolate FR 1-2 also decarboxylated histidine. Most isolates were sensitive to antibiotics of clinical use, but resistance was detected more frequently towards nitrofurantoin (50%), erythromycin (33.33%) or rifampicin (33.33%) to quinupristin/dalfopristin (12.5%). Resistance to beta-lactams or vancomycin was not detected. The enterococcal antigen A was the presumed virulence trait detected most frequently. None of isolates carried haemolysin/cytolysin genes. Twelve isolates produced anti-listerial activity. Among them, seven isolates also produced bacteriocin-like inhibitory substances against other enterococci, and one isolate was also able to inhibit Staphylococcus aureus. Three isolates only were active against Listeria monocytogenes, and two only were active against enterococci. One bacteriocinogenic isolate carried the enterocin A structural gene, but genes corresponding to other enterocins (EntB, EntP, EntQ, Ent1071, EntL50A/EntL50B, and Ent31) were not detected. Bacteriocin-producing enterococci lacking undesirable traits (such as antibiotic resistance or biogenic amine production) or their produced bacteriocins could be potential candidates to aid in preservation of seafoods and other food products as well. PMID:20688238

  19. TEM-1 AND ROB-1 PRESENCE AND ANTIMICROBIAL RESISTANCE IN HAEMOPHILUS INFLUENZAE STRAINS, ISTANBUL, TURKEY.

    Science.gov (United States)

    Kuvat, Nuray; Nazik, Hasan; Berkiten, Rahmiye; Öngen, Betigül

    2015-03-01

    Resistance of 235 Haemophilus influenzae clinical isolates from Istanbul Medical Faculty Hospital, Turkey were determined against 19 antibiotics by disc diffusion method, and minimum inhibitory concentrations (MICs) of those found resistant to ampicillin, cefuroxim, chloramphenicol and meropenem were measured using E-test. Ampicillin-resistant isolates producing beta-lactamase as demonstrated by a nitrocefin assay were analyzed for the presence of TEM-1 and ROB-1 genes by PCR. Eleven percent of the isolates were resistant to ampicillin (10 µg/ml), of which 73% were beta-lactamase positive and carried TEM-1 gene, but none were positive for ROB-1 gene. All isolates susceptible to amoxicillin-clavulanate (20/10 µg/ml), azithromycin (15 µg/ml), aztreonam (30 µg/ml), cefotaxime (30 µg/ml), ceftriaxone (30 µg/ml), ciprofloxacin (5 µg/ml), levofloxacin (5 µg/ml), and telithromycin (15 µg/ml) but 24%, 15%, 4%, 4%, 2%, 1%, 1%, 0.5%, 0.5% and 0.5% were resistant to trimethoprim-sulfamethoxazole (1.25/23.75 µg/ml), tetracycline (30 µg/ml), cefaclor (30 µg/ml), clarithromycin (15 µg/ml), cefuroxime (30 µg/ml), meropenem (10 µg/ml), chloramphenicol (30 µg/ml), ampicillin-sulbactam (10/10 µg/ml), nalidixic acid (30 µg/ml), and fosfomycin (30 µg/ml), respectively. MIC values of three cefuroxime-resistant isolates was 24, 48 and > 256 µg/ml, respectively; of two meropenem-resistant strains > 256 µg/ml; and of two chloramphenicol-susceptible isolates (by disc diffusion method) 6 µg/ml (considered as intermediate susceptible). Multiple- antibiotics resistance was detected in 15% of the strains, with resistance to 2, 3, 4, 5 and 6 antibiotics in 8.5%, 4%, 2%, 0.5% and 0.5% of the isolates, respectively. By identifying beta-lactamase-negative ampicillin-resistant H. influenzae, empirical therapy with beta-lactam/beta-lactamase inhibitor combinations and second generation cephalosporins would be inappropriate for such patients (approximately 3%). Our findings will

  20. In vivo development of daptomycin resistance in vancomycin-susceptible methicillin-resistant Staphylococcus aureus severe infections previously treated with glycopeptides.

    Science.gov (United States)

    Capone, A; Cafiso, V; Campanile, F; Parisi, G; Mariani, B; Petrosillo, N; Stefani, S

    2016-04-01

    -S heteroresistant phenotype. Daptomycin, as first-line therapy for the treatment of severe MRSA infections, should be used at optimal dosage combined with other agents such as beta-lactams, to prevent daptomycin resistance occurrence. PMID:26815434

  1. Daytime pattern of post-exercise protein intake affects whole-body protein turnover in resistance-trained males

    Directory of Open Access Journals (Sweden)

    Moore Daniel R

    2012-10-01

    Full Text Available Abstract Background The pattern of protein intake following exercise may impact whole-body protein turnover and net protein retention. We determined the effects of different protein feeding strategies on protein metabolism in resistance-trained young men. Methods Participants were randomly assigned to ingest either 80g of whey protein as 8x10g every 1.5h (PULSE; n=8, 4x20g every 3h (intermediate, INT; n=7, or 2x40g every 6h (BOLUS; n=8 after an acute bout of bilateral knee extension exercise (4x10 repetitions at 80% maximal strength. Whole-body protein turnover (Q, synthesis (S, breakdown (B, and net balance (NB were measured throughout 12h of recovery by a bolus ingestion of [15N]glycine with urinary [15N]ammonia enrichment as the collected end-product. Results PULSE Q rates were greater than BOLUS (~19%, P Conclusion We conclude that the pattern of ingested protein, and not only the total daily amount, can impact whole-body protein metabolism. Individuals aiming to maximize NB would likely benefit from repeated ingestion of moderate amounts of protein (~20g at regular intervals (~3h throughout the day.

  2. Oritavancin Combinations with β-Lactams against Multidrug-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococci.

    Science.gov (United States)

    Smith, Jordan R; Yim, Juwon; Raut, Animesh; Rybak, Michael J

    2016-04-01

    Oritavancin possesses activity against vancomycin-resistant enterococci (VRE) and methicillin-resistantStaphylococcus aureus(MRSA).In vitrodata suggest synergy between beta-lactams (BLs) and vancomycin or daptomycin, agents similar to oritavancin. We evaluated the activities of BLs combined with oritavancin against MRSA and VRE. Oritavancin MICs were determined for 30 strains, 5 each of MRSA, daptomycin-nonsusceptible (DNS) MRSA, vancomycin-intermediate MRSA (VISA), heteroresistant VISA (hVISA), vancomycin-resistantEnterococcus faecalis, and vancomycin-resistantEnterococcus faecium Oritavancin MICs were determined in the presence of subinhibitory concentrations of BLs. Oritavancin combined with ceftaroline, cefazolin, or nafcillin was evaluated for lethal synergy against MRSA, and oritavancin combined with ceftaroline, ampicillin, or ertapenem was evaluated for lethal synergy against VRE in 24-h time-kill assays. Oritavancin at 0.5× the MIC was combined with BLs at 0.5× the MIC or the biological free peak concentration, whichever one was lower. Synergy was defined as a ≥2-log10-CFU/ml difference between the killing achieved with the combination and that achieved with the most active single agent at 24 h. Oritavancin MICs were ≤0.125 μg/ml for all MRSA isolates except three VISA isolates with MICs of 0.25 μg/ml. Oritavancin MICs for VRE ranged from 0.03 to 0.125 μg/ml. Oritavancin in combination with ceftaroline was synergistic against all MRSA phenotypes and statistically superior to all other combinations against DNS MRSA, hVISA, and MRSA isolates (P< 0.02). Oritavancin in combination with cefazolin and oritavancin in combination with nafcillin were also synergistic against all MRSA strains. Synergy between oritavancin and all BLs was revealed against VRE strain 8019, while synergy between oritavancin and ampicillin or ertapenem but not ceftaroline was demonstrated against VRE strain R7164. The data support the potential use of oritavancin in combination

  3. Study on Cultural Technologies and Salt-resistance of Nitraria sibirica in Coastal Areas with Serious Salt-affected Soil

    Institute of Scientific and Technical Information of China (English)

    ZHANGJianfeng; XINGShangjun; SUNQixiang; XIJinbiao; SONGYumin

    2004-01-01

    In this research, five Nitraria sibirica provenances such as Dayilu were selected to do experiment of salt-resistance, combining fixed plots test with typical plot investigation, measuring survival rate and growth as main indicators. The experiments of main cultural technology were done on Nitraria sibirica in 4 types of site preparation, 3 types of planting, 3 designs for planting density. The Nitraria sibirica experiments for the effects of curbing salt and improving soil were done by testing soil nutrients, salt content, soil physical properties as focal points in typical site of 3-4 years woods. The experiment results showed that the Nitraria sibirica could survive well with soil salt content of 0.6%, and that survival rate declined distinctively as soil salt content exceeded 0.8%. However, high soil salt content did not influence growth in the year of planting. There were obvious differences in salt-tolerance among Nitraria sibirica provenances; Dayilu was the best on salt-tolerance, the other 4 provenances had no differences, and obviously inferior to Dayilu. The different types of site preparation clearly influenced planting survival rate, conserving rate and growth. The method of two-ploughing-two-harrowing was the best among all 4 types of site preparation. Seed forestation was largely limited, bared-rooted seedling forestation may be popularised when soil salt content was less than 1% and soil moisture content was better in spring. Forestation with container seedling was suited to coastal saline soil in rainy season. The optimum planting density of Nitraria sibirica was 2 505/ha in the Yellow River Delta area in view of coverage rate, yield of fruits and cost of planting. Generally speaking,Nitraria sibirica could effectively refrain soil from accumulation of salt in the surface soil, decrease salt content and increase soil nutrient, and heighten soil capillary pore rate.

  4. Crystallographic Studies of Two Bacterial AntibioticResistance Enzymes: Aminoglycoside Phosphotransferase (2')-Ic and GES-1\\beta-lactamase

    Energy Technology Data Exchange (ETDEWEB)

    Brynes, Laura; /Rensselaer Poly.

    2007-10-31

    Guiana Extended-Spectrum-1 (GES-1) and Aminoglycoside phosphotransferase (2')-Ic (APH(2')-Ic) are two bacteria-produced enzymes that essentially perform the same task: they provide resistance to an array of antibiotics. Both enzymes are part of a growing resistance problem in the medical world. In order to overcome the ever-growing arsenal of antibiotic-resistance enzymes, it is necessary to understand the molecular basis of their action. Accurate structures of these proteins have become an invaluable tool to do this. Using protein crystallography techniques and X-ray diffraction, the protein structure of GES-1 bound to imipenem (an inhibitor) has been solved. Also, APH(2')-Ic has been successfully crystallized, but its structure was unable to be solved using molecular replacement using APH(2')-Ib as a search model. The structure of GES-1, with bound imipenem was solved to a resolution of 1.89A, and though the inhibitor is bound with only moderate occupancy, the structure shows crucial interactions inside the active site that render the enzyme unable to complete the hydrolysis of the {beta}-lactam ring. The APH(2')-Ic dataset could not be matched to the model, APH(2')-Ib, with which it shares 25% sequence identity. The structural information gained from GES-1, and future studies using isomorphous replacement to solve the APH(2')-Ic structure can aid directly to the creation of novel drugs to combat both of these classes of resistance enzymes.

  5. Anti-hemolytic, hemagglutination inhibition and bacterial membrane disruptive properties of selected herbal extracts attenuate virulence of Carbapenem Resistant Escherichia coli.

    Science.gov (United States)

    Thakur, Pallavi; Chawla, Raman; Narula, Alka; Goel, Rajeev; Arora, Rajesh; Sharma, Rakesh Kumar

    2016-06-01

    Expression of a multitude of virulence factors by multi-drug resistant microbial strains, e.g., Carbapenem Resistant Escherichia coli (Family: Enterobacteriaceae; Class: Gammaproteobacteria), is responsible for resistance against beta-lactam antibiotics. Hemolysin production and induction of hemagglutination by bacterial surface receptors inflicts direct cytotoxicity by destroying host phagocytic and epithelial cells. We have previously reported that Berberis aristata, Camellia sinensis, Cyperus rotundus Holarrhena antidysenterica and Andrographis paniculata are promising herbal leads for targeting Carbapenem resistant Escherichia coli. These herbal leads were analyzed for their anti-hemolytic potential by employing spectrophotometric assay of hemoglobin liberation. Anti-hemagglutination potential of the extracts was assessed by employing qualitative assay of visible RBC aggregate formation. Camellia sinensis (PTRC-31911-A) exhibited anti-hemolytic potential of 73.97 ± 0.03%, followed by Holarrhena antidysenterica (PTRC-8111-A) i.e., 68.32 ± 0.05%, Berberis aristata (PTRC-2111-A) i.e., 60.26 ± 0.05% and Cyperus rotundus (PTRC-31811-A) i.e., 53.76 ± 0.03%. Comprehensive, visual analysis of hemagglutination inhibition revealed that only Berberis aristata (PTRC-2111-A) and Camellia sinensis (PTRC-31911-A) exhibited anti-hemagglutination activity. However, Andrographis paniculata (PTRC-11611-A) exhibited none of the inhibitory activities. Furthermore, the pair wise correlation analysis of the tested activities with quantitative phytochemical descriptors revealed that an increased content of alkaloid; flavonoids; polyphenols, and decreased content of saponins supported both the activities. Additionally, flow cytometry revealed that cell membrane structures of CRE were damaged by extracts of Berberis aristata (PTRC-2111-A) and Camellia sinensis (PTRC-31911-A) at their respective Minimum Inhibitory Concentrations, thereby confirming noteworthy antibacterial

  6. Prevalence of PER and VEB Type Extended Spectrum Betalactamases among Multidrug Resistant Acinetobacter baumannii Isolates in North-West of Iran

    Science.gov (United States)

    Farajnia, Safar; Azhari, Fatemeh; Alikhani, Mohammad Yousef; Hosseini, Mohammad Kazem; Peymani, Amir; Sohrabi, Nasrolah

    2013-01-01

    Objective(s): Drug resistant Acinetobacter baumannii have emerged as a major problem in many hospitals and intensive care units. Various types of extended spectrum beta-lactamases (ESBLs) are responsible for resistance to beta-lactam antibiotics in different parts of the world. The objective of this study was to determine the prevalence of integron class1 (INT 1) and ESBL types PER-1, PER-2 and VEB-1 among A. baumannii strains isolated from Tabriz, North-West of Iran. Material and Methods: A total of 100 A. baumannii isolates collected from different clinical samples were included in the study. Antimicrobial susceptibility profiles were determined using the Kirby Bauer disk diffusion method. Production of ESBL was investigated by testing resistance against ceftazidime, cefotaxime, ceftriaxone and verified by Double Disk Synergy Test. DNA was extracted from the isolates and the frequency of INT 1 and ESBL types PER-1, PER-2 and VEB-1 were determined by PCR using specific primers. Results: Among 100 A. baumannii isolates screened, 80 isolates were multidrug-resistant and 70 isolates were positive for ESBL production. PCR screening revealed that 74 % of the isolates contained class 1 integron, 51% were positive for PER-1 gene, 10% positive for VEB1 whereas none of the isolates were positive for PER2 type gene. Conclusion: This is the first report of ESBL types VEB and PER in A. baumannii from North West of Iran. The results of this study demonstrated high prevalence of PER-1 and VEB-1 type ESBLs among A. baumannii isolates in the study region and reminded the necessity of appropriate infection control strategy to prevent further spread of infection by these organisms. PMID:23997900

  7. Prevalence of PER and VEB Type Extended Spectrum Betalactamases among Multidrug Resistant Acinetobacter baumannii Isolates in North-West of Iran

    Directory of Open Access Journals (Sweden)

    Safar Farajnia

    2013-06-01

    Full Text Available   Objective(s: Drug resistant Acinetobacter baumannii have emerged as a major problem in many hospitals and intensive care units. Various types of extended spectrum beta-lactamases (ESBLs are responsible for resistance to beta- lactam antibiotics in different parts of the world. The objective of this study was to determine the prevalence of integron class1 (INT 1 and ESBL types PER-1, PER-2 and VEB-1 among A. baumannii strains isolated from Tabriz, North-West of Iran.   Material and Methods: A total of 100 A. baumannii isolates collected from different clinical samples were included in the study. Antimicrobial susceptibility profiles were determined using the Kirby Bauer disk diffusion method. Production of ESBL was investigated by testing resistance against ceftazidime, cefotaxime, ceftriaxone and verified by Double Disk Synergy Test. DNA was extracted from the isolates and the frequency of INT 1 and ESBL types PER-1, PER-2 and VEB-1 were determined by PCR using specific primers. Results: Among 100 A. baumannii isolates screened, 80 isolates were multidrug-resistant and 70 isolates were positive for ESBL production. PCR screening revealed that 74 % of the isolates contained class 1 integron, 51% were positive for PER-1 gene, 10% positive for VEB1 whereas none of the isolates were positive for PER2 type gene. Conclusion: This is the first report of ESBL types VEB and PER in A. baumannii from North West of Iran. The results of this study demonstrated high prevalence of PER-1 and VEB-1 type ESBLs among A. baumannii isolates in the study region and reminded the necessity of appropriate infection control strategy to prevent further spread of infection by these organisms.

  8. Does vancomycin prescribing intervention affect vancomycin-resistant enterococcus infection and colonization in hospitals? A systematic review

    Directory of Open Access Journals (Sweden)

    Riley Lee W

    2007-04-01

    Full Text Available Abstract Background Vancomycin resistant enterococcus (VRE is a major cause of nosocomial infections in the United States and may be associated with greater morbidity, mortality, and healthcare costs than vancomycin-susceptible enterococcus. Current guidelines for the control of VRE include prudent use of vancomycin. While vancomycin exposure appears to be a risk factor for VRE acquisition in individual patients, the effect of vancomycin usage at the population level is not known. We conducted a systematic review to determine the impact of reducing vancomycin use through prescribing interventions on the prevalence and incidence of VRE colonization and infection in hospitals within the United States. Methods To identify relevant studies, we searched three electronic databases, and hand searched selected journals. Thirteen studies from 12 articles met our inclusion criteria. Data were extracted and summarized for study setting, design, patient characteristics, types of intervention(s, and outcome measures. The relative risk, 95% confidence interval, and p-value associated with change in VRE acquisition pre- and post-vancomycin prescription interventions were calculated and compared. Heterogeneity in study results was formally explored by stratified analysis. Results No randomized clinical trials on this topic were found. Each of the 13 included studies used a quasi-experimental design of low hierarchy. Seven of the 13 studies reported statistically significant reductions in VRE acquisition following interventions, three studies reported no significant change, and three studies reported increases in VRE acquisition, one of which reported statistical significance. Results ranged from a reduction of 82.5% to an increase of 475%. Studies of specific wards, which included sicker patients, were more likely to report positive results than studies of an entire hospital including general inpatients (Fisher's exact test 0.029. The type of intervention

  9. Combination Regimens for Treatment of Carbapenem-Resistant Klebsiella pneumoniae Bloodstream Infections.

    Science.gov (United States)

    Gomez-Simmonds, A; Nelson, B; Eiras, D P; Loo, A; Jenkins, S G; Whittier, S; Calfee, D P; Satlin, M J; Kubin, C J; Furuya, E Y

    2016-06-01

    Previous studies reported decreased mortality in patients with carbapenemase-producing Klebsiella pneumoniae bloodstream infections (BSIs) treated with combination therapy but included carbapenem-susceptible and -intermediate isolates, as per revised CLSI breakpoints. Here, we assessed outcomes in patients with BSIs caused by phenotypically carbapenem-resistant K. pneumoniae (CRKP) according to the number of in vitro active agents received and whether an extended-spectrum beta-lactam (BL) antibiotic, including meropenem, or an extended-spectrum cephalosporin was administered. We retrospectively reviewed CRKP BSIs at two New York City hospitals from 2006 to 2013, where all isolates had meropenem or imipenem MICs of ≥4 μg/ml. Univariate and multivariable models were created to identify factors associated with mortality. Of 141 CRKP BSI episodes, 23% were treated with a single active agent (SAA), 26% were treated with an SAA plus BL, 28% were treated with multiple active agents (MAA), and 23% were treated with MAA plus BL. Ninety percent of isolates had meropenem MICs of ≥16 μg/ml. Thirty-day mortality was 33% overall and did not significantly differ across the four treatment groups in a multivariable model (P = 0.4); mortality was significantly associated with a Pitt bacteremia score of ≥4 (odds ratio [OR], 7.7; 95% confidence interval [CI], 3.2 to 18.1; P = 0.1), and immunosuppression was protective (OR, 0.4; 95% CI, 0.2 to 1.0; P = 0.04). Individual treatment characteristics were also not significantly associated with outcome, including use of SAAs versus MAA (26% versus 38%, P = 0.1) or BL versus no BL (26% versus 39%, P = 0.1). In summary, in patients with CRKP BSIs caused by isolates with high carbapenem MICs, the role of combination therapy remains unclear, highlighting the need for prospective studies to identify optimal treatment regimens. PMID:27044555

  10. [The first metronidazole-resistant Bacteroides species isolated at Marmara University Hospital: Bacteroides thetaiotaomicron].

    Science.gov (United States)

    Toprak Ülger, Nurver; Sayın, Elvan; Soyad, Ad; Dane, Faysal; Söyletir, Güner

    2013-10-01

    Bacteroides species, the predominant constituents of the human intestinal microbiota can cause serious intraabdominal and postoperative wound infections and bacteremia. Moreover, these bacteria are more resistant to antimicrobial agents than the other anaerobes. The limited number of the antimicrobials, such as carbapenems, beta-lactam/beta-lactamase inhibitors and nitroimidazoles are highly effective in eliminating Bacteroides. However, a few metronidazole-resistant isolates have been reported from several countries recently. The nim genes (nim A-G) are suggested to be responsible for the majority of the metronidazole resistance. Here, we describe a metronidazole-resistant Bacteroides thetaiotaomicron isolated from a blood culture. A gram-negative obligate anaerobic rod was isolated from the postoperative 5th day blood culture of a 62-year-old male patient with adenocarcinoma of the pancreas head. The strain was identified as B.thetaiotaomicron by using a combination of conventional tests and commercially available biochemical kits. Antimicrobial susceptibility testing was performed by agar dilution method. The resistance genes were investigated by means of PCR using specific primer pairs for nim gene. The purified PCR product was sequenced and analyzed by comparison of the consensus sequences with GenBank sequences. The MIC for metronidazole was 16 mg/L. Although the strain was intermediate according the CLSI criteria, it was resistant (> 4 mg/L) according to EUCAST criteria. The isolate was nim gene positive, and nucleotide sequencing of the PCR product shared 100% similarity with nimE gene (emb |AM042593.1 |). On the other hand the isolate was susceptible to carbapenems and sulbactam-ampicillin. Following administration of ampicillin-sulbactam, the patient's fever disappeared after 24 hours. The clinical condition improved considerably and he was discharged at day 8. The patient was followed up at the medical oncology clinic; however he died due to disease

  11. Emergence of quinolone resistance among extended-spectrum beta-lactamase-producing Enterobacteriaceae in the Central African Republic: genetic characterization

    Directory of Open Access Journals (Sweden)

    Frank Thierry

    2011-08-01

    Full Text Available Abstract Background Cross-resistance to quinolones and beta-lactams is frequent in Enterobacteriaceae, due to the wide use of these antibiotics clinically and in the food industry. Prescription of one of these categories of antibiotic may consequently select for bacteria resistant to both categories. Genetic mechanisms of resistance may be secondary to a chromosomal mutation located in quinolone resistance determining region of DNA gyrase or topoisomerase IV or to a plasmid acquisition. The insertion sequence ISCR1 is often associated with qnr and may favour its dissemination in Gram-negative bacteria. The aim of this study was to determine the genetic mechanism of quinolone resistance among extended-spectrum beta-lactamase-producing Enterobacteriaceae strains in the Central African Republic. Findings Among seventeen ESBL-producing Enterobacteriaceae isolated from urine, pus or stool between January 2003 and October 2005 in the Central African Republic, nine were resistant to ciprofloxacin (seven from community patients and two from hospitalized patients. The ESBL were previously characterized as CTX-M-15 and SHV-12. Susceptibility to nalidixic acid, norfloxacin and ciprofloxacin, and the minimal inhibitory concentrations of these drugs were determined by disc diffusion and agar dilution methods, respectively. The presence of plasmid-borne ISCR1-qnrA region was determined by PCR and amplicons, if any, were sent for sequencing. Quinolone resistance determining region of DNA gyrase gyrA gene was amplified by PCR and then sequenced for mutation characterization. We found that all CTX-M-producing strains were resistant to the tested quinolones. All the isolates had the same nucleotide mutation at codon 83 of gyrA. Two Escherichia coli strains with the highest MICs were shown to harbour an ISCR1-qnrA1 sequence. This genetic association might favour dissemination of resistance to quinolone and perhaps other antibiotics among Enterobacteriaceae

  12. Effects of some beta lactam antibiotics on (/sup 3/H)-methyl-yohimbine binding to intact human platelets

    Energy Technology Data Exchange (ETDEWEB)

    Borst, S.E.; Hui, K.K.; Conolly, M.E.

    1985-05-01

    Several antibiotics have been reported to cause a bleeding diathesis in man, characterized by reduced platelet aggregation. The authors investigated the effects of several of the penicillins and of moxalactam on the binding of (/sup 3/H)-methyl-yohimbine to intact human platelets. The (/sup 3/H)-methyl-yohimbine binding met the criteria for interaction at an alpha2 adrenergic binding site and showed low interindividual variability. Penicillin G, ticarcillin, carbenicillin, piperacillin and moxalactam all inhibited (/sup 3/H)-methyl-yohimbine binding, but at concentrations far in excess of clinically achievable plasma levels. They conclude that these compounds exert their antiplatelet effects by a mechanism other than competitive inhibition of catecholamine binding.

  13. 78 FR 22887 - Guidance for Industry on Non-Penicillin Beta-Lactam Drugs: A Current Good Manufacturing Practices...

    Science.gov (United States)

    2013-04-17

    ... Current Good Manufacturing Practices Framework for Preventing Cross- Contamination; Availability AGENCY... health risks associated with cross-reactivity. Although the existing current good manufacturing practices (CGMP) regulations require separation of manufacturing facilities to avoid cross-contamination, the...

  14. In vitro activities of quinolones, beta-lactams, tobramycin, and trimethoprim-sulfamethoxazole against nonfermentative gram-negative bacilli.

    OpenAIRE

    Fass, R J; Barnishan, J; M C Solomon; Ayers, L W

    1996-01-01

    From 1991 to 1995, 8,975 nonfermentative gram-negative bacilli were isolated from patients at The Ohio State University Medical Center: 71% Pseudomonas aeruginosa, 14% Stenotrophomonas maltophilia, 7.6% Acinetobacter baumannii, and < 2% each of 25 other species. The MICs of trovafloxacin (CP-99,219), ciprofloxacin, ofloxacin, ampicillin-sulbactam, piperacillin, piperacillin-tazobactam, ceftazidime, cefoperazone, ceftriaxone, imipenem, tobramycin, and trimethoprim-sulfamethoxazole (TMP-SMZ) we...

  15. Pharmacokinetic drug interactions of antimicrobial drugs : a systematic review on oxazolidinones, rifamycines, macrolides, fluoroquinolones, and Beta-lactams

    NARCIS (Netherlands)

    Bolhuis, Mathieu S; Panday, Prashant N; Pranger, Arianna D; Kosterink, Jos G W; Alffenaar, Jan-Willem C

    2011-01-01

    Like any other drug, antimicrobial drugs are prone to pharmacokinetic drug interactions. These drug interactions are a major concern in clinical practice as they may have an effect on efficacy and toxicity. This article provides an overview of all published pharmacokinetic studies on drug interactio

  16. Simultaneous pharmacodynamic analysis of the lag and bactericidal phases exhibited by beta-lactams against Escherichia coli.

    OpenAIRE

    Li, R C

    1996-01-01

    Antibiotic-bacterium interactions are complex in nature. In many cases, bacterial killing does not commence immediately after the addition of an antibiotic, and a lag period is observed. Antibiotic permeation and/or the intermediate steps that exist between antibiotic-receptor binding and expression of cell death are two major possible causes for such lag period. This study was primarily designed to determine the relationship, if any, between antibiotic concentrations and the lag periods by a...

  17. A clinical investigation of pivmecillinam. A novel beta-lactam antibiotic in the treatment of urinary tract infections.

    Science.gov (United States)

    Wise, R; Reeves, D S; Symonds, J M; Wilkinson, P J

    1976-01-01

    Pivmecillinam (FL 1039) is the pivaloyloxymethyl ester of mecillinam (FL 1060) which has considerable in vitro activity against Enterobacteriaceae. 38 hospital inpatients who had proven urinary tract infections were treated with 400 mg pivmecillinam four times daily for 5-7 days. The MIC of mecillinam to the infecting organisms was determined as were the serum and urinary concentrations of the antibiotic. The patients were followed up for 4-6 weeks after the end of treatment. Three patients were lost to follow-up. Of the 35 patients who were adequately followed up, 29 (83%) were classified as cured and there were 6 failures. Reported side effects were of a minor nature. PMID:181216

  18. Prevalence and antimicrobial susceptibility patterns of uropathogenic E. coli among people in Zakho, Iraq

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    Reem Fouad Polse

    2016-04-01

    Full Text Available Background: Antimicrobial resistance in uropathogenic E. coli is of major concern worldwide due to its increasing resistance to several commonly prescribed antibiotics. The aims of this study were to determine the prevalence and to evaluate the presence and antibiogram pattern of uropathogenic E. coli among people in Zakho city, Iraq. Methods: 1120 urine samples were collected from people. Samples were screened for E. coli isolates and their susceptibility to different antibiotics was analyzed. Results: Diagnoses tests showed that only 106 (9.4% isolates were E. coli. Females (90, 85% were more susceptible to urinary tract infections (UTIs than males (16, 15% (p <0.05. The age 11-21 years old (23, 21.7% was the most affected group (p <0.05. All isolates were resistant to penicillin, ampicillin and aztreonam. While, all these isolates were sensitive to imipenem and meropenem. Conclusions: The incidence of uropathogenic E. coli among people is comparable with reports from elsewhere. E. coli isolates are highly susceptible towards imipenem, and meropenem antibiotics, and highly resistant towards beta-lactam and cephalosporins antibiotics. Education programs and improving the hygienic measures are necessary to prevent contaminations with E. coli and minimize the use of beta-lactam and cephalosporin antibiotics. [Int J Res Med Sci 2016; 4(4.000: 1219-1223

  19. Resistance to Third-Generation Cephalosporins and Other Antibiotics by Enterobacteriaceae in Western Nigeria

    Directory of Open Access Journals (Sweden)

    A. O. Okesola

    2009-01-01

    Full Text Available Problem statement: The emergence and spread of resistance to third-generation cephalosporins are threatening to create species resistant to all currently available agents. The most common cause of bacterial resistance to beta-lactam antibiotics is the production of beta-lactamases and many of the 2nd and 3rd-generation penicillins and cephalosporins were specifically designed to resist the hydrolytic action of major ß-lactamases. However new ß-lactamases emerged against each of the new classes of ß-lactams that were introduced and caused resistance. This study was designed to determine the rate of resistance to 3rd-generation cephalosporins and other classes of antibiotics by the Enterobacteriaceae in this environment. Approach: One hundred bacteria isolates belonging to the family Enterobacteriaceae identified from different clinical specimens between October and December 2007 using standard bacteriological methods. These were subjected to antibiotic susceptibility testing to third-generation cephalosporins and other classes of antibiotics which included quinolones and an aminoglycoside using the Kirby-Bauer method of disc diffusion test. Results: Out of the total number of Enterobacteriaceae isolated in the study period, only 54.8% of the klebsiella species isolated were sensitive to ceftazidime, 48.4% to ceftriaxone and 30.7% to cefotaxime. With Escherichia coli however, the susceptibility pattern to the 3rd-generation cephalosporins was better (65.6% were sensitive to ceftazidime, 62.5% to ceftriaxone and 71.9% to cefotaxime. In proteus species, the susceptibility pattern was generally poor to the three classes of antibiotics(50% were sensitive to ceftazidime and ceftriaxone, 0% to cefotaxime, 33.3% to ciprofloxacin, 50% to gentamycin and 0% to amoxycillin/clavulanate. Conclusion/Recommendations: The poor susceptibility to amoxicillin/clavulanate demonstrated by all the isolates in this

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

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    Maike Koningstein

    Full Text Available Complicated urinary tract infections (c-UTIs are among the most common nosocomial infections and a substantial part of the antimicrobial agents used in hospitals is for the treatment of c-UTIs. Data from surveillance can be used to guide the empirical treatment choices of clinicians when treating c-UTIs. We therefore used nation-wide surveillance data to evaluate antimicrobial coverage of agents for the treatment of c-UTI in the Netherlands.We included the first isolate per patient of urine samples of hospitalised patients collected by the Infectious Disease Surveillance Information System for Antibiotic Resistance (ISIS-AR in 2012, and determined the probability of inadequate coverage for antimicrobial agents based on species distribution and susceptibility. Analyses were repeated for various patient groups and hospital settings.The most prevalent bacteria in 27,922 isolates of 23,357 patients were Escherichia coli (47%, Enterococcus spp. (14%, Proteus mirabilis (8%, and Klebsiella pneumoniae (7%. For all species combined, the probability of inadequate coverage was <5% for amoxicillin or amoxicillin-clavulanic acid combined with gentamicin and the carbapenems. When including gram-negative bacteria only, the probability of inadequate coverage was 4.0%, 2.7%, 2.3% and 1.7%, respectively, for amoxicillin, amoxicillin-clavulanic acid, a second or a third generation cephalosporin in combination with gentamicin, and the carbapenems (0.4%. There were only small variations in results among different patient groups and hospital settings.When excluding Enterococcus spp., considered as less virulent, and the carbapenems, considered as last-resort drugs, empirical treatment for c-UTI with the best chance of adequate coverage are one of the studied beta-lactam-gentamicin combinations. This study demonstrates the applicability of routine surveillance data for up-to-date clinical practice guidelines on empirical antimicrobial therapy, essential in patient

  1. Proactive infection control measures to prevent nosocomial transmission of carbapenem-resistant Enterobacteriaceae in a non-endemic area

    Institute of Scientific and Technical Information of China (English)

    CHENG Vincent Chi-Chung; CHAN Jasper Fuk-Woo; WONG Sally Cheuk-Ying; CHEN Jonathan Hon-Kwan; TAI Josepha Wai-Ming; YAN Mei-Kum; KWAN Grace See-Wai

    2013-01-01

    Background Identification of hospitalized carbapenem-resistant Enterobacteriaceae (CRE)-positive patient is important in preventing nosocomial transmission.The objective of this study was to illustrate the implementation of proactive infection control measures in preventing nosocomial transmission of CRE in a healthcare region of over 3200 beds in Hong Kong between October 1,2010 and December 31,2011.Methods The program included active surveillance culture in patients with history of medical tourism with hospitalization and surgical operation outside Hong Kong within 12 months before admission,and "added test" as an opportunistic CRE screening in all fecal specimens submitted to the laboratory.Outbreak investigation and contact tracing were conducted for CRE-positive patients.Serial quantitative culture was performed on CRE-positive patients and the duration of fecal carriage of CRE was analyzed.Results During the study period,a total of 6533 patients were screened for CRE,of which 76 patients were positive (10 from active surveillance culture,65 from "added test",and 1 secondary case from contact tracing of 223 patients with no nosocomial outbreak),resulting in an overall rate of CRE fecal carriage of 1.2%.The median time of fecal carriage of CRE was 43 days (range,13-119 days).Beta-lactam-beta-lactamase-inhibitors,cephalosporins,and fluoroquinolones were associated significantly with high fecal bacterial load when used 90 days before CRE detection,while use of cephalosporins,carbapenems,and fiuoroquinolones after CRE detection are significantly associated with longer duration of carriage.The duration of fecal carriage of CRE also correlates significantly with the initial fecal bacterial load (Pearson correlation:0.53; P=0.02).Conclusion Proactive infection control measures by enhanced surveillance program identify CRE-positive patients and data obtained are useful for the planning of and resource allocation for CRE control.

  2. Structure-based Design and In-Parallel Synthesis of Inhibitors of AmpC b-lactamase

    Energy Technology Data Exchange (ETDEWEB)

    Tondi, D.; Powers, R.A.; Negri, M.C.; Caselli, M.C.; Blazquez, J.; Costi, M.P.; Shoichet, B.K. (NWU)

    2010-03-08

    Group I {beta}-lactamases are a major cause of antibiotic resistance to {beta}-lactams such as penicillins and cephalosporins. These enzymes are only modestly affected by classic {beta}-lactam-based inhibitors, such as clavulanic acid. Conversely, small arylboronic acids inhibit these enzymes at sub-micromolar concentrations. Structural studies suggest these inhibitors bind to a well-defined cleft in the group I {beta}-lactamase AmpC; this cleft binds the ubiquitous R1 side chain of {beta}-lactams. Intriguingly, much of this cleft is left unoccupied by the small arylboronic acids. To investigate if larger boronic acids might take advantage of this cleft, structure-guided in-parallel synthesis was used to explore new inhibitors of AmpC. Twenty-eight derivatives of the lead compound, 3-aminophenylboronic acid, led to an inhibitor with 80-fold better binding (2; K{sub i} 83 nM). Molecular docking suggested orientations for this compound in the R1 cleft. Based on the docking results, 12 derivatives of 2 were synthesized, leading to inhibitors with K{sub i} values of 60 nM and with improved solubility. Several of these inhibitors reversed the resistance of nosocomial Gram-positive bacteria, though they showed little activity against Gram-negative bacteria. The X-ray crystal structure of compound 2 in complex with AmpC was subsequently determined to 2.1 {angstrom} resolution. The placement of the proximal two-thirds of the inhibitor in the experimental structure corresponds with the docked structure, but a bond rotation leads to a distinctly different placement of the distal part of the inhibitor. In the experimental structure, the inhibitor interacts with conserved residues in the R1 cleft whose role in recognition has not been previously explored. Combining structure-based design with in-parallel synthesis allowed for the rapid exploration of inhibitor functionality in the R1 cleft of AmpC. The resulting inhibitors differ considerably from {beta}-lactams but

  3. Transgenic insect-resistant corn affects the fourth trophic level: effects of Bacillus thuringiensis-corn on the facultative hyperparasitoid Tetrastichus howardi

    Science.gov (United States)

    Prütz, Gernot; Brink, Andreas; Dettner, Konrad

    2004-09-01

    As hyperparasitoids may have a considerable influence on the control of herbivorous arthropods, analyzing the host-mediated impact of Bacillus thuringiensis-plants (“Bt-plants”) on hyperparasitoids is of interest. Laboratory-scale experiments were conducted in order to assess the potential effect of Bt-corn leaf material on the facultative hyperparasitoid Tetrastichus howardi (Olliff) (Hymenoptera: Eulophidae), mediated through the herbivore Chilo partellus Swinhoe (Lepidoptera: Crambidae) and its primary parasitoid Cotesia flavipes (Cameron) (Hymenoptera: Braconidae). In the Bt-group, significantly less C. flavipes larvae per host spun cocoons and pupated than in the control, and the mean fresh weight of a single C. flavipes cocoon was significantly reduced compared to the control. All C. flavipes cocoons of one host formed cocoon clusters. T. howardi females of the Bt-group parasitized significantly less cocoon clusters than in the control. Moreover, significantly fewer C. flavipes cocoons per cocoon cluster were successfully parasitized as compared to the control. As a consequence, T. howardi females of the control had more offspring than in the Bt-group. Adult female T. howardi offspring of the Bt-group weighed significantly less than in the control, but there was no significant weight difference between males of both groups. Our results suggest that transgenic insect-resistant plants could affect hyperparasitoids indirectly. However, it remains to be determined whether facultative hyperparasitoids prefer to develop as primary or secondary parasitoids under field conditions.

  4. Identification of quantitative trait loci affecting resistance to gastrointestinal parasites in a double backcross population of Red Maasai and Dorper sheep

    International Nuclear Information System (INIS)

    Full text: A genome-wide scan for quantitative trait loci (QTL) affecting gastrointestinal nematode resistance in sheep was completed using a double backcross population derived from Red Maasai and Dorper ewes bred to F1 rams. This design provided an opportunity to map potentially unique genetic variation associated with a parasite-tolerant breed like Red Maasai, a breed developed to survive East African grazing conditions. Parasite indicator phenotypes (blood packed cell volume - PCV and faecal egg count - FEC) were collected on a weekly basis from 1064 lambs during a single 3-month post-weaning grazing challenge on infected pastures. The averages of last measurements for FEC (AVFEC) and PCV (AV-PCV), along with decline in PCV from challenge start to end (PCVD), were used to select lambs (N = 371) for genotyping that represented the tails (10% threshold) of the phenotypic distributions. Marker genotypes for 172 microsatellite loci covering 25 of 26 autosomes (1560.7 cM) were scored and corrected by GENOPROB prior to QXPAK analysis that included Box-Cox transformed AVFEC and arcsine transformed PCV statistics. Significant QTL for AVFEC and AVPCV were detected on four chromosomes, and this included a novel AVFEC QTL on chromosome 6 that would have remained undetected without Box-Cox transformation methods. The most significant P-values for AVFEC, AVPCV and PCVD overlapped the same marker interval on chromosome 22, suggesting the potential for a single causative mutation, which remains unknown. In all cases, the favourable QTL allele was always contributed from Red Maasai, providing support for the idea that future marker-assisted selection for genetic improvement of production in East Africa will rely on markers in linkage disequilibrium with these QTL. (author)

  5. Identification of quantitative trait loci affecting resistance to gastrointestinal parasites in a double backcross population of Red Maasai and Dorper sheep.

    Science.gov (United States)

    Silva, M V B; Sonstegard, T S; Hanotte, O; Mugambi, J M; Garcia, J F; Nagda, S; Gibson, J P; Iraqi, F A; McClintock, A E; Kemp, S J; Boettcher, P J; Malek, M; Van Tassell, C P; Baker, R L

    2012-02-01

    A genome-wide scan for quantitative trait loci (QTL) affecting gastrointestinal nematode resistance in sheep was completed using a double backcross population derived from Red Maasai and Dorper ewes bred to F(1) rams. This design provided an opportunity to map potentially unique genetic variation associated with a parasite-tolerant breed like Red Maasai, a breed developed to survive East African grazing conditions. Parasite indicator phenotypes (blood packed cell volume - PCV and faecal egg count - FEC) were collected on a weekly basis from 1064 lambs during a single 3-month post-weaning grazing challenge on infected pastures. The averages of last measurements for FEC (AVFEC) and PCV (AVPCV), along with decline in PCV from challenge start to end (PCVD), were used to select lambs (N = 371) for genotyping that represented the tails (10% threshold) of the phenotypic distributions. Marker genotypes for 172 microsatellite loci covering 25 of 26 autosomes (1560.7 cm) were scored and corrected by Genoprob prior to qxpak analysis that included Box-Cox transformed AVFEC and arcsine transformed PCV statistics. Significant QTL for AVFEC and AVPCV were detected on four chromosomes, and this included a novel AVFEC QTL on chromosome 6 that would have remained undetected without Box-Cox transformation methods. The most significant P-values for AVFEC, AVPCV and PCVD overlapped the same marker interval on chromosome 22, suggesting the potential for a single causative mutation, which remains unknown. In all cases, the favourable QTL allele was always contributed from Red Maasai, providing support for the idea that future marker-assisted selection for genetic improvement of production in East Africa will rely on markers in linkage disequilibrium with these QTL. PMID:22221026

  6. pbp2229-Mediated Nisin Resistance Mechanism in Listeria monocytogenes Confers Cross-Protection to Class IIa Bacteriocins and Affects Virulence Gene Expression

    OpenAIRE

    Gravesen, Anne; Kallipolitis, Birgitte; Holmstrøm, Kim; Høiby, Poul Erik; Ramnath, Manilduth; Knøchel, Susanne

    2004-01-01

    It was previously shown that enhanced nisin resistance in some mutants was associated with increased expression of three genes, pbp2229, hpk1021, and lmo2487, encoding a penicillin-binding protein, a histidine kinase, and a protein of unknown function, respectively. In the present work, we determined the direct role of the three genes in nisin resistance. Interruption of pbp2229 and hpk1021 eliminated the nisin resistance phenotype. Interruption of hpk1021 additionally abolished the increase ...

  7. Wheat bran affects the site of fermentation of resistant starch and luminal indexes related to colon cancer risk: a study in pigs

    OpenAIRE

    Govers, M; Gannon, N; Dunshea, F; Gibson, P.; J. Muir

    1999-01-01

    BACKGROUND—Recent studies suggest that resistant starch (effective in producing butyrate and lowering possibly toxic ammonia) is rapidly fermented in the proximal colon; the distal colon especially would, however, benefit from these properties of resistant starch.
AIMS—To determine whether wheat bran (a rich source of insoluble non-starch polysaccharides), known to hasten gastrointestinal transit, could carry resistant starch through to the distal colon and thus shift its site of fermentation...

  8. Prevalence of coagulase-negative staphylococci and determination of antimicrobial resistance in accompany with types of SCCmec in isolated of nosocomial infections

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    Mohammad Reza Arabestani

    2016-03-01

    Full Text Available Background: Coagulase-negative staphylococci (CoNS were considered as contaminats previously, but, during the past decade considered as one of the most common photogenic bacteria in hospital. Resistance to beta-lactams especially methicillin in staphylococcus species is being worrying in hospitals. Rapid identification of mechanisms of resistance and confirmation of their resistance to methicillin is a basic principle for antibiotic treatment. The aim of this study was to determine antibiotic resistance, frequency of mecA gene, and determination of SCCmec types in CoNS isolates from teaching hospitals in Iran. Methods: The descriptive cross-sectional study was carried out one hundred clinical samples isolated from patients with an average age of 7-69 years at teaching hospitals in Hamadan City, Iran, from September 2014 to February 2015. After confirmation of isolates by microbiological standard biochemical tests, antimicrobial susceptibility testing was performed by disk agar diffusion (DAD method. After extraction of isolated genomicm, mecA gene was detected. Then, the types of SCCmec were performed by PCR. Results: In this study, 387 clinical samples were collected which among 100 CoNS isolated, Staphylococcus epidermidis was the most prevalent species with frequency 55 (55%, followed by S. haemolyticus 40(40% and S. saprophyticus 5(5%. The highest antibiotic susceptibility was to rifampin 96(96% and the lowest resistance was detected for trimethoprim/sulfamethoxazole (TMP/SMX 47(47%. None of the strains were resistant to vancomycin. Resistance to methicillin was detected in 50% of CoNS isolates. Typing of SCCmec was performed by The polymerase chain reaction (PCR. Frequency types of SCCmec was type III with frequency 13(13%, type V 11(11%, type II 6(6%, type IV 4 (4%, type I 3(3% respectively. Thirteen isolated was not typable in this study. Conclusion: The result of this study showed that a large percentage of coagulase

  9. Extended spectrum β-lactamase and plasmid mediated quinolone resistance in Escherichia coli fecal isolates from healthy companion animals in Algeria.

    Science.gov (United States)

    Yousfi, Massilia; Mairi, Assia; Touati, Abdelaziz; Hassissene, Lila; Brasme, Lucien; Guillard, Thomas; De Champs, Christophe

    2016-07-01

    The aim of this study was to evaluate the rate of fecal carriage of Escherichia coli strains producing Extended-spectrum β-lactamases (ESBLs) and plasmid-mediated quinolone resistance (PMQR) isolated from healthy pets (dogs and cats) in Algeria. Fecal samples from 171 healthy pets (102 dogs and 69 cats) in one veterinary practice and private owners were included. After isolates identification, antibiotic susceptibility was determined by disk diffusion procedure. ESBL were detected by combination disk tests. PCR and sequencing were used to characterize genes encoding ESBLs and PMQR. Transfer of ESBL and PMQR genes was assessed by conjugation experiments. Phylogenetic groups of E. coli were determined by PCR. Of the 171 animals, 20 carried an ESBL producing E. coli giving a prevalence of ESBL fecal carriage of 11.7%. All isolates were susceptible to carbapenems, cefoxitin, piperacillin-tazobactam, amikacin and fosfomycine. For the rest of the tested β-lactams, susceptibility rates ranged from 35% to 70% for cefepime and amoxicillin-clavulanic acid respectively. Concerning the non-beta-lactams antibiotics, the rates of susceptibility ranged between 5% to trimethoprim and 95% for chloramphenicol. The beta-lactamase genes identified in E. coli isolates were blaCTX-M-15, blaCTX-M-1, blaSHV-12 and blaTEM-1. The PMQR determinants aac(6')-Ib-cr, qnrS1 and qnrB5 genes were identified in 15 isolates. Transconjugants were obtained for two isolates. Phylogenetic analysis showed that E. coli isolates belong to commensal phylogroups of A and B1. We reported here for the first time in Algeria ESBL and PMQR-producing E. coli in healthy cats and dogs. PMID:27132028

  10. Virulence and resistance gene profiles of staphylococcus aureus strains isolated from ready-to-eat foods.

    Science.gov (United States)

    Baumgartner, Andreas; Niederhauser, Isabel; Johler, Sophia

    2014-07-01

    Staphylococcal food poisoning represents the most prevalent foodborne intoxication worldwide. Oral intake of staphylococcal enterotoxins from food can result in emesis and diarrhea and can be fatal in children and the elderly. Few data have been available on the characteristics and sources of Staphylococcus aureus strains isolated from ready-to-eat (RTE) foods. In this study, we used a DNA microarray to determine virulence and antimicrobial resistance gene profiles of S. aureus from RTE foods. A total of 267 S. aureus strains isolated from 244 RTE foods were investigated. The isolates originated from precooked foods (41% of isolates), meat and fish products (17%), cheese (13%), delicatessen salads (8%), sandwiches and canapés (8%), confectionery and bakery products (6%), and various other RTE foods (7%). Eleven samples (5%), of which 9 were raw milk cheeses, contained > 10(5) CFU/g, which is considered a health risk. Four S. aureus strains were associated with intoxications; three cases were linked to consumption of cheese and one case was linked to consumption of potato salad. DNA microarray results revealed that one-third of the tested strains had at least one major enterotoxin gene (sea through see). We also detected the toxic shock syndrome gene (18% of isolates) and various genes conferring antimicrobial resistance, including genes involved in resistance to beta-lactams (blaZ, 72% of isolates), methicillin (mecA, 1% of isolates), and vancomycin (vanB, 1% of isolates). S. aureus strains were most frequently assigned to clonal complex (CC) 30 (17% of isolates), CC8 (12%), CC15 (11%), and CC45 (10%), which are commonly detected in humans colonized or infected with S. aureus. Although a large proportion of the tested food items contained milk, we did not detect CC705, the most prevalent clonal complex among S. aureus isolates from bovine mastitis milk. Our results suggest that S. aureus isolates from RTE foods do not commonly originate from animals but more

  11. How does acupuncture affect insulin sensitivity in women with polycystic ovary syndrome and insulin resistance? Study protocol of a prospective pilot study

    OpenAIRE

    Zheng, Yanhua; Stener-Victorin, Elisabet; Ng, Ernest H. Y.; Li, Juan; Wu, Xiaoke; Ma, Hongxia

    2015-01-01

    Introduction Hyperinsulinaemia and insulin resistance (IR) are key features of polycystic ovary syndrome (PCOS) and metabolic syndrome. The effect of 5 weeks of acupuncture treatment has been investigated in a completed prospective pilot trial (Clinicaltrials.gov: NCT01457209), and acupuncture with electrical stimulation applied to insulin-resistant rats with dihydrotestosterone-induced PCOS was shown to improve insulin sensitivity. Therefore, we now aim to conduct a prospective pilot study t...

  12. Apramycin treatment affects selection and spread of a multidrug-resistant Escherichia coli strain able to colonize the human gut in the intestinal microbiota of pigs

    DEFF Research Database (Denmark)

    Herrero-Fresno, Ana; Zachariasen, Camilla; Hansen, Monica Hegstad;

    2016-01-01

    The effect of apramycin treatment on transfer and selection of an Escherichia coli strain (E. coli 912) in the intestine of pigs was analyzed through an in vivo experiment. The strain was sequenced and assigned to the sequence type ST101 and serotype O11. It carried resistance genes to apramycin......-resistant E. coli. Since gentamicin is a first-choice drug for human bacteremia, this is of concern....

  13. Antibiotic innovation may contribute to slowing the dissemination of multiresistant Streptococcus pneumoniae: the example of ketolides.

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    Lulla Opatowski

    Full Text Available BACKGROUND: Despite increasingly frequent bacterial resistance to antibiotics, antibacterial innovation is rare. Ketolides constitute one of the very few new antibiotic classes active against Streptococcus pneumoniae developed during the last 25 years. Their mechanism of action resembles that of macrolides, but they are unaffected by common resistance mechanisms. However, cross-resistance to ketolides has been observed in some macrolide-resistant strains. We examined how new antibiotic exposure may affect overall pneumococcal resistance patterns in the population. The aims of this study were to assess the potential dissemination of newly emerged resistances and to control the selection of strains already multiresistant to existing antimicrobials. METHODOLOGY/PRINCIPAL FINDINGS: We developed an age-structured population model for S. pneumoniae transmission in a human community exposed to heptavalent vaccine, and beta-lactams, macrolides and ketolides. The dynamics of intra-individual selection of resistant strains under antibiotic exposure and interindividual transmission were simulated, with antibiotic-specific resistance mechanisms defining the path to co-resistances and cross-resistances, and parameters concerning the French situation. Results of this simulation study suggest that new antibiotic consumption could markedly slow the diffusion of multiresistant strains. Wider use was associated with slower progression of multiresistance. When ketolides were prescribed to all ages, resistance to them reached 10% after >15 years, while it took >40 years when they were prescribed only to adults. In the scenario according to which new antibiotics totally replaced former antimicrobials, the beta-lactam resistance rate was limited at 70%. CONCLUSIONS: In a context of widespread vaccination and rational use of antibiotics, innovative antibiotic, prescribed to all age groups, may have an added impact on multiresistant-strain dissemination in the

  14. Pseudomonas aeruginosa isolates from patients with cystic fibrosis have different beta-lactamase expression phenotypes but are homogeneous in the ampC-ampR genetic region

    DEFF Research Database (Denmark)

    Campbell, J I; Ciofu, O; Høiby, N

    1997-01-01

    Pseudomonas aeruginosa isolates from 1 of 17 cystic fibrosis patients produced secondary beta-lactamase in addition to the ampC beta-lactamase. Isolates were grouped into three beta-lactamase expression phenotypes: (i) beta-lactam sensitive, low basal levels and inducible beta-lactamase production......; (ii) beta-lactam resistant, moderate basal levels and hyperinducible beta-lactamase production; (iii) beta-lactam resistant, high basal levels and constitutive beta-lactamase production. Apart from a base substitution in the ampR-ampC intergenic region of an isolate with moderate-basal-level and...... hyperinducible beta-lactamase production, sensitive and resistant strains were identical in their ampC-ampR genetic regions. Thus, enhanced beta-lactamase expression is due to mutations in regulatory proteins other than AmpR....

  15. Evaluation of a Mixing versus a Cycling Strategy of Antibiotic Use in Critically-Ill Medical Patients: Impact on Acquisition of Resistant Microorganisms and Clinical Outcomes

    Science.gov (United States)

    Cobos-Trigueros, Nazaret; Solé, Mar; Castro, Pedro; Torres, Jorge Luis; Rinaudo, Mariano; De Lazzari, Elisa; Morata, Laura; Hernández, Cristina; Fernández, Sara; Soriano, Alex; Nicolás, José María; Mensa, Josep; Vila, Jordi; Martínez, José Antonio

    2016-01-01

    Objective To compare the effect of two strategies of antibiotic use (mixing vs. cycling) on the acquisition of resistant microorganisms, infections and other clinical outcomes. Methods Prospective cohort study in an 8-bed intensive care unit during 35- months in which a mixing-cycling policy of antipseudomonal beta-lactams (meropenem, ceftazidime/piperacillin-tazobactam) and fluoroquinolones was operative. Nasopharyngeal and rectal swabs and respiratory secretions were obtained within 48h of admission and thrice weekly thereafter. Target microorganisms included methicillin-resistant S. aureus, vancomycin-resistant enterococci, third-generation cephalosporin-resistant Enterobacteriaceae and non-fermenters. Results A total of 409 (42%) patients were included in mixing and 560 (58%) in cycling. Exposure to ceftazidime/piperacillin-tazobactam and fluoroquinolones was significantly higher in mixing while exposure to meropenem was higher in cycling, although overall use of antipseudomonals was not significantly different (37.5/100 patient-days vs. 38.1/100 patient-days). There was a barely higher acquisition rate of microorganisms during mixing, but this difference lost its significance when the cases due to an exogenous Burkholderia cepacia outbreak were excluded (19.3% vs. 15.4%, OR 0.8, CI 0.5–1.1). Acquisition of Pseudomonas aeruginosa resistant to the intervention antibiotics or with multiple-drug resistance was similar. There were no significant differences between mixing and cycling in the proportion of patients acquiring any infection (16.6% vs. 14.5%, OR 0.9, CI 0.6–1.2), any infection due to target microorganisms (5.9% vs. 5.2%, OR 0.9, CI 0.5–1.5), length of stay (median 5 d for both groups) or mortality (13.9 vs. 14.3%, OR 1.03, CI 0.7–1.3). Conclusions A cycling strategy of antibiotic use with a 6-week cycle duration is similar to mixing in terms of acquisition of resistant microorganisms, infections, length of stay and mortality. PMID:26982807

  16. Evaluation of a Mixing versus a Cycling Strategy of Antibiotic Use in Critically-Ill Medical Patients: Impact on Acquisition of Resistant Microorganisms and Clinical Outcomes.

    Directory of Open Access Journals (Sweden)

    Nazaret Cobos-Trigueros

    Full Text Available To compare the effect of two strategies of antibiotic use (mixing vs. cycling on the acquisition of resistant microorganisms, infections and other clinical outcomes.Prospective cohort study in an 8-bed intensive care unit during 35- months in which a mixing-cycling policy of antipseudomonal beta-lactams (meropenem, ceftazidime/piperacillin-tazobactam and fluoroquinolones was operative. Nasopharyngeal and rectal swabs and respiratory secretions were obtained within 48h of admission and thrice weekly thereafter. Target microorganisms included methicillin-resistant S. aureus, vancomycin-resistant enterococci, third-generation cephalosporin-resistant Enterobacteriaceae and non-fermenters.A total of 409 (42% patients were included in mixing and 560 (58% in cycling. Exposure to ceftazidime/piperacillin-tazobactam and fluoroquinolones was significantly higher in mixing while exposure to meropenem was higher in cycling, although overall use of antipseudomonals was not significantly different (37.5/100 patient-days vs. 38.1/100 patient-days. There was a barely higher acquisition rate of microorganisms during mixing, but this difference lost its significance when the cases due to an exogenous Burkholderia cepacia outbreak were excluded (19.3% vs. 15.4%, OR 0.8, CI 0.5-1.1. Acquisition of Pseudomonas aeruginosa resistant to the intervention antibiotics or with multiple-drug resistance was similar. There were no significant differences between mixing and cycling in the proportion of patients acquiring any infection (16.6% vs. 14.5%, OR 0.9, CI 0.6-1.2, any infection due to target microorganisms (5.9% vs. 5.2%, OR 0.9, CI 0.5-1.5, length of stay (median 5 d for both groups or mortality (13.9 vs. 14.3%, OR 1.03, CI 0.7-1.3.A cycling strategy of antibiotic use with a 6-week cycle duration is similar to mixing in terms of acquisition of resistant microorganisms, infections, length of stay and mortality.

  17. Polymorphisms in Plasmodium falciparum Chloroquine Resistance Transporter and Multidrug Resistance 1 Genes: Parasite Risk Factors that Affect Treatment Outcomes for P. falciparum Malaria after Artemether-Lumefantrine and Artesunate-Amodiaquine

    OpenAIRE

    Venkatesan, Meera; Gadalla, Nahla B; Stepniewska, Kasia; Dahal, Prabin; Nsanzabana, Christian; Moriera, Clarissa; Price, Ric N; Mårtensson, Andreas; Rosenthal, Philip J.; Dorsey, Grant; Sutherland, Colin J.; Guérin, Philippe; Davis, Timothy M. E.; Ménard, Didier; Adam, Ishag

    2014-01-01

    Adequate clinical and parasitologic cure by artemisinin combination therapies relies on the artemisinin component and the partner drug. Polymorphisms in the Plasmodium falciparum chloroquine resistance transporter (pfcrt) and P. falciparum multidrug resistance 1 (pfmdr1) genes are associated with decreased sensitivity to amodiaquine and lumefantrine, but effects of these polymorphisms on therapeutic responses to artesunate-amodiaquine (ASAQ) and artemether-lumefantrine (AL) have not been clea...

  18. Ectopically expressed sweet pepper ferredoxin PFLP enhances disease resistance to Pectobacterium carotovorum subsp. carotovorum affected by harpin and protease-mediated hypersensitive response in Arabidopsis.

    Science.gov (United States)

    Ger, Mang-Jye; Louh, Guan-Yu; Lin, Yi-Hsien; Feng, Teng-Yung; Huang, Hsiang-En

    2014-12-01

    Plant ferredoxin-like protein (PFLP) is a photosynthesis-type ferredoxin (Fd) found in sweet pepper. It contains an iron-sulphur cluster that receives and delivers electrons between enzymes involved in many fundamental metabolic processes. It has been demonstrated that transgenic plants overexpressing PFLP show a high resistance to many bacterial pathogens, although the mechanism remains unclear. In this investigation, the PFLP gene was transferred into Arabidopsis and its defective derivatives, such as npr1 (nonexpresser of pathogenesis-related gene 1) and eds1 (enhanced disease susceptibility 1) mutants and NAHG-transgenic plants. These transgenic plants were then infected with the soft-rot bacterial pathogen Pectobacterium carotovorum subsp. carotovorum (Erwinia carotovora ssp. carotovora, ECC) to investigate the mechanism behind PFLP-mediated resistance. The results revealed that, instead of showing soft-rot symptoms, ECC activated hypersensitive response (HR)-associated events, such as the accumulation of hydrogen peroxide (H2 O2 ), electrical conductivity leakage and expression of the HR marker genes (ATHSR2 and ATHSR3) in PFLP-transgenic Arabidopsis. This PFLP-mediated resistance could be abolished by inhibitors, such as diphenylene iodonium (DPI), 1-l-trans-epoxysuccinyl-leucylamido-(4-guanidino)-butane (E64) and benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (z-VAD-fmk), but not by myriocin and fumonisin. The PFLP-transgenic plants were resistant to ECC, but not to its harpin mutant strain ECCAC5082. In the npr1 mutant and NAHG-transgenic Arabidopsis, but not in the eds1 mutant, overexpression of the PFLP gene increased resistance to ECC. Based on these results, we suggest that transgenic Arabidopsis contains high levels of ectopic PFLP; this may lead to the recognition of the harpin and to the activation of the HR and other resistance mechanisms, and is dependent on the protease-mediated pathway. PMID:24796566

  19. Constitutive expression of McCHIT1-PAT enhances resistance to rice blast and herbicide, but does not affect grain yield in transgenic glutinous rice.

    Science.gov (United States)

    Zeng, Xiao-Fang; Li, Lei; Li, Jian-Rong; Zhao, De-Gang

    2016-01-01

    To produce new rice blast- and herbicide-resistant transgenic rice lines, the McCHIT1 gene encoding the class I chitinase from Momordica charantia and the herbicide resistance gene PAT were introduced into Lailong (Oryza sativa L. ssp. Japonica), a glutinous local rice variety from Guizhou Province, People's Republic of China. Transgenic lines were identified by ß-glucuronidase (GUS) histochemical staining, PCR, and Southern blot analyses. Agronomic traits, resistance to rice blast and herbicide, chitinase activities, and transcript levels of McCHIT1 were assessed in the T2 progeny of three transgenic lines (L1, L8, and L10). The results showed that the introduction of McCHIT1-PAT into Lailong significantly enhanced herbicide and blast resistance. After infection with the blast fungus Magnaporthe oryzae, all of the T2 progeny exhibited less severe lesion symptoms than those of wild type. The disease indices were 100% for wild type, 65.66% for T2 transgenic line L1, 59.69% for T2 transgenic line L8, and 79.80% for T2 transgenic line L10. Transgenic lines expressing McCHIT1-PAT did not show a significant difference from wild type in terms of malondialdehyde (MDA) content, polyphenol oxidase (PPO) activity, and superoxide dismutase (SOD) activity in the leaves. However, after inoculation with M. oryzae, transgenic plants showed significantly higher SOD and PPO activities and lower MDA contents in leaves, compared with those in wild-type leaves. The transgenic and the wild-type plants did not show significant differences in grain yield parameters including plant height, panicles per plant, seeds per panicle, and 1000-grain weight. Therefore, the transgenic plants showed increased herbicide and blast resistance, with no yield penalty. PMID:25639923

  20. Outer membrane alterations in multiresistant mutants of Pseudomonas aeruginosa selected by ciprofloxacin.

    OpenAIRE

    Legakis, N. J.; Tzouvelekis, L. S.; Makris, A; Kotsifaki, H

    1989-01-01

    Spontaneous mutants of Pseudomonas aeruginosa selected by ciprofloxacin were studied for outer membrane alterations. Acquisition of ciprofloxacin resistance was at least partially related to defects in lipopolysaccharide synthesis. When ciprofloxacin resistance was combined with resistance to beta-lactams and aminoglycosides, several alterations in outer membrane proteins were noted.

  1. Macrophytes may not contribute significantly to removal of nutrients, pharmaceuticals, and antibiotic resistance in model surface constructed wetlands.

    Science.gov (United States)

    Cardinal, Pascal; Anderson, Julie C; Carlson, Jules C; Low, Jennifer E; Challis, Jonathan K; Beattie, Sarah A; Bartel, Caitlin N; Elliott, Ashley D; Montero, Oscar F; Lokesh, Sheetal; Favreau, Alex; Kozlova, Tatiana A; Knapp, Charles W; Hanson, Mark L; Wong, Charles S

    2014-06-01

    Outdoor shallow wetland mesocosms, designed to simulate surface constructed wetlands to improve lagoon wastewater treatment, were used to assess the role of macrophytes in the dissipation of wastewater nutrients, selected pharmaceuticals, and antibiotic resistance genes (ARGs). Specifically, mesocosms were established with or without populations of Typha spp. (cattails), Myriophyllum sibiricum (northern water milfoil), and Utricularia vulgaris (bladderwort). Following macrophyte establishment, mesocosms were seeded with ARG-bearing organisms from a local wastewater lagoon, and treated with a single pulse of artificial municipal wastewater with or without carbamazepine, clofibric acid, fluoxetine, and naproxen (each at 7.6μg/L), as well as sulfamethoxazole and sulfapyridine (each at 150μg/L). Rates of pharmaceutical dissipation over 28d ranged from 0.073 to 3.0d(-1), corresponding to half-lives of 0.23 to 9.4d. Based on calculated rate constants, observed dissipation rates were consistent with photodegradation driving clofibric acid, naproxen, sulfamethoxazole, and sulfapyridine removal, and with sorption also contributing to carbamazepine and fluoxetine loss. Of the seven gene determinants assayed, only two genes for both beta-lactam resistance (blaCTX and blaTEM) and sulfonamide resistance (sulI and sulII) were found in sufficient quantity for monitoring. Genes disappeared relatively rapidly from the water column, with half-lives ranging from 2.1 to 99d. In contrast, detected gene levels did not change in the sediment, with the exception of sulI, which increased after 28d in pharmaceutical-treated systems. These shallow wetland mesocosms were able to dissipate wastewater contaminants rapidly. However, no significant enhancement in removal of nutrients or pharmaceuticals was observed in mesocosms with extensive aquatic plant communities. This was likely due to three factors: first, use of naïve systems with an unchallenged capacity for nutrient assimilation and

  2. Paromomycin Affects Translation and Vesicle-Mediated Trafficking as Revealed by Proteomics of Paromomycin –Susceptible –Resistant Leishmania donovani

    OpenAIRE

    Bhavna Chawla; Anupam Jhingran; Aswini Panigrahi; Stuart, Kenneth D.; Rentala Madhubala

    2011-01-01

    Leishmania donovani is a protozoan parasite that causes visceral leishmaniasis (VL) and is responsible for significant mortality and morbidity. Increasing resistance towards antimonial drugs poses a great challenge in chemotherapy of VL. Paromomycin is an aminoglycosidic antibiotic and is one of the drugs currently being used in the chemotherapy of cutaneous and visceral leishmaniasis. To understand the mode of action of this antibiotic at the molecular level, we have investigated the global ...

  3. Fish oil supplementation suppresses resistance exercise and feeding‐induced increases in anabolic signaling without affecting myofibrillar protein synthesis in young men

    OpenAIRE

    McGlory, Chris; Sophie L. Wardle; Lindsay S. Macnaughton; Oliver C. Witard; Scott, Fraser; Dick, James; Bell, J. Gordon; Phillips, Stuart M.; Stuart D. R. Galloway; Hamilton, D. Lee; Tipton, Kevin D.

    2016-01-01

    Abstract Fish oil (FO) supplementation potentiates muscle protein synthesis (MPS) in response to a hyperaminoacidemic–hyperinsulinemic infusion. Whether FO supplementation potentiates MPS in response to protein ingestion or when protein ingestion is combined with resistance exercise (RE) remains unknown. In a randomized, parallel group design, 20 healthy males were randomized to receive 5 g/day of either FO or coconut oil control (CO) for 8 weeks. After supplementation, participants performed...

  4. Changes in the Sterol Composition of the Plasma Membrane Affect Membrane Potential, Salt Tolerance and the Activity of Multidrug Resistance Pumps in Saccharomyces cerevisiae

    Czech Academy of Sciences Publication Activity Database

    Kodedová, Marie; Sychrová, Hana

    2015-01-01

    Roč. 10, č. 9 (2015), e0139306. E-ISSN 1932-6203 R&D Projects: GA MŠk(CZ) EE2.3.30.0025; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:67985823 Keywords : Saccharomyces cerevisiae * ergosterol synthesis * multidrug resistance * membrane potential * diS-C3(3) assay Subject RIV: EE - Microbiology, Virology Impact factor: 3.234, year: 2014

  5. Thirty-seven transcription factor genes differentially respond to a harpin protein and affect resistance to the green peach aphid in Arabidopsis

    Indian Academy of Sciences (India)

    Ruoxue Liu; Beibei Lü; Xiaomeng Wang; Chunling Zhang; Shuping Zhang; Jun Qian; Lei Chen; Haojie Shi; Hansong Dong

    2010-09-01

    The harpin protein HrpNEa induces Arabidopsis resistance to the green peach aphid by activating the ethylene signalling pathway and by recruiting EIN2, an essential regulator of ethylene signalling, for a defence response in the plant. We investigated 37 ethylene-inducible Arabidopsis transcription factor genes for their effects on the activation of ethylene signalling and insect defence. Twenty-eight of the 37 genes responded to both ethylene and HrpNEa, and showed either increased or inhibited transcription, while 18 genes showed increased transcription not only by ethylene but also by HrpNEa. In response to HrpNEa, transcription levels of 22 genes increased, with AtMYB44 being the most inducible, six genes had decreased transcript levels, and nine remained unchanged. When Arabidopsis mutants previously generated by mutagenicity at the 37 genes were surveyed, 24 mutants were similar to the wild type plant while four mutants were more resistant and nine mutants were more susceptible than wild type to aphid infestation. Aphid-susceptible mutants showed a greater susceptibility for atmyb15, atmyb38 and atmyb44, which were generated previously by T-DNA insertion into the exon region of AtMYB15 and the promoter regions of AtMYB38 and AtMYB44. The atmyb44 mutant was the most susceptible to aphid infestation and most compromised in induced resistance. Resistance accompanied the expression of PDF1.2, an ethylene signalling marker gene that requires EIN2 for transcription in wild type but not in atmyb15, atmyb38, and atmyb44, suggesting a disruption of ethylene signalling in the mutants. However, only atmyb44 incurred an abrogation in induced EIN2 expression, suggesting a close relationship between AtMYB44 and EIN2.

  6. Documenting Penicillin Allergy: The Impact of Inconsistency.

    Directory of Open Access Journals (Sweden)

    Nirav S Shah

    Full Text Available Allergy documentation is frequently inconsistent and incomplete. The impact of this variability on subsequent treatment is not well described.To determine how allergy documentation affects subsequent antibiotic choice.Retrospective, cohort study.232,616 adult patients seen by 199 primary care providers (PCPs between January 1, 2009 and January 1, 2014 at an academic medical system.Inter-physician variation in beta-lactam allergy documentation; antibiotic treatment following beta-lactam allergy documentation.15.6% of patients had a reported beta-lactam allergy. Of those patients, 39.8% had a specific allergen identified and 22.7% had allergic reaction characteristics documented. Variation between PCPs was greater than would be expected by chance (all p<0.001 in the percentage of their patients with a documented beta-lactam allergy (7.9% to 24.8%, identification of a specific allergen (e.g. amoxicillin as opposed to "penicillins" (24.0% to 58.2% and documentation of the reaction characteristics (5.4% to 51.9%. After beta-lactam allergy documentation, patients were less likely to receive penicillins (Relative Risk [RR] 0.16 [95% Confidence Interval: 0.15-0.17] and cephalosporins (RR 0.28 [95% CI 0.27-0.30] and more likely to receive fluoroquinolones (RR 1.5 [95% CI 1.5-1.6], clindamycin (RR 3.8 [95% CI 3.6-4.0] and vancomycin (RR 5.0 [95% CI 4.3-5.8]. Among patients with beta-lactam allergy, rechallenge was more likely when a specific allergen was identified (RR 1.6 [95% CI 1.5-1.8] and when reaction characteristics were documented (RR 2.0 [95% CI 1.8-2.2].Provider documentation of beta-lactam allergy is highly variable, and details of the allergy are infrequently documented. Classification of a patient as beta-lactam allergic and incomplete documentation regarding the details of the allergy lead to beta-lactam avoidance and use of other antimicrobial agents, behaviors that may adversely impact care quality and cost.

  7. Characterization of antimicrobial resistance in Klebsiella species isolated from chicken broilers.

    Science.gov (United States)

    Wu, Hao; Wang, Mingyu; Liu, Yuqing; Wang, Xinhua; Wang, Yunkun; Lu, Jinxing; Xu, Hai

    2016-09-01

    The prevalence of antimicrobial resistant Klebsiella pneumoniae in poultry products has been a public concern, as it severely endangers food safety and human health. In this study, we investigated 90 antimicrobial resistant Klebsiella strains that were isolated from a commercial broiler slaughter plant in Shandong province of China. Nearly all (89/90) of the isolates were identified as infectious phylogenetic group KpI-type K. pneumoniae. Out of these 90 strains, 87 (96.7%) were multidrug-resistant isolates, and 87 (96.7%) were extended-spectrum beta-lactamase (ESBL)-producing isolates. An analysis of the prevalence of quinolone resistance genes showed that 7.8%, 77.8%, 26.7%, and 2.2% of the strains carried the qnrA, qnrB, qnrS, and qepA genes, respectively. An analysis of beta-lactam resistance genes showed that a high percentage of the strains contain the blaTEM (76.7%), blaSHV (88.9%), and blaCTX-M (75.6%) genes, among which three blaSHV subtypes (blaSHV-1, n=30; blaSHV-11, n=38; blaSHV-12, n=12) and three blaCTX-M subtypes (blaCTX-M-14, n=14; blaCTX-M-15, n=35; blaCTX-M-55, n=19) were found. A further investigation of mobile genetic elements involved in horizontal multidrug resistance gene transfer showed the presence of class 1 and 2 integrons in 77 (85.6%) and five (5.6%) isolates, respectively, while no class 3 integrons were detected. Four types of class 1 integrons containing specific gene cassette arrays (dfrA12-orfF-aadA2, dfrA17-aadA5, dfrA1-aadA1, and empty) were identified. Only one gene cassette array (dfrA1-sat2-aadA1) was detected in the class 2 integrons. Furthermore, four different types of insertion sequence common region 1 (ISCR1)-mediated downstream structures were successfully identified in 46 class 1 integron-positive isolates, among which ISCR1-sapA-like-qnrB2-qacEΔ1 was the most commonly observed structure. Chi-square tests revealed a significant association between ESBL genes, plasmid-mediated quinolone resistance (PMQR) genes, and

  8. On conditions of negativity of friction resistance for non-stationary modes of blood flow and possible mechanism of affecting of environmental factors on energy effectiveness of cardio-vascular system functioning

    CERN Document Server

    Chefranov, S G

    2013-01-01

    It is shown that initiated by action of molecular viscosity impulse flow, directed usually from the moving fluid to limiting it solid surface, can, under certain conditions, turn to zero and get negative values in the case of non-stationary flow caused by alternating in time longitudinal (along the pipe axis) pressure gradient. It is noted that this non-equilibrium mechanism of negative friction resistance in the similar case of pulsating blood flow in the blood vessels, in addition to the stable to turbulent disturbances swirled blood flow structure providing, can also constitute hydro-mechanical basis of the observed but not explained yet paradoxically high energy effectiveness of the normal functioning of the cardio-vascular system (CVS). We consider respective mechanism of affecting on the stability of the normal work of CVS by environmental variable factors using shifting of hydro-dynamic mode with negative resistance realization range boundaries and variation of linear hydro-dynamic instability leading ...

  9. KPC-mediated resistance in Klebsiella pneumoniae in two hospitals in Padua, Italy, June 2009-December 2011: massive spreading of a KPC-3-encoding plasmid and involvement of non-intensive care units

    Directory of Open Access Journals (Sweden)

    Richter Sara N

    2012-07-01

    Full Text Available Abstract Background Klebsiella pneumoniae carbapenemases (KPCs producing bacteria have emerged as a cause of multidrug-resistant nosocomial infections worldwide. KPCs are plasmid-encoded enzymes capable of hydrolysing a broad spectrum of beta-lactams, including carbapenems and monobactams, therefore worryingly limiting antimicrobial treatment options. Analysis of circulating bacterial strains and KPC alleles may help understanding the route of KPC dissemination and therefore help containing the infection. Methods KPC-producing Klebsiella pneumoniae dissemination in two 1580- and 300- bed hospitals in Padua, Italy, from initial outbreak in 2009 to late 2011 was analysed. Molecular and clinical epidemiology, including bacterial strains, KPC-encoding plasmid sequences and associated resistance genes, involved hospital wards and relocation of patients were described. Routine antimicrobial susceptibility testing and MIC of carbapenems on clinical isolates were performed. Detection of resistance genes was obtained by PCR and sequencing. MLST, PFGE and ERIC were used for molecular genotyping. Plasmid analysis was obtained by digestion with restriction enzymes and deep sequencing. Results KPC-positive clinical samples were isolated from nearly 200 patients. In the initial outbreak intensive care units were almost exclusively involved, while medical, surgical and long-term wards were successively massively concerned. Analysis of KPC alleles, plasmids and bacterial sequence types (STs indicated that during the initial outbreak KPC-3 in ST258 and KPC-2 in ST147 were each confined in one of the two surveilled hospitals. While KPC-2 dissemination was effectively contained, KPC-3 in ST258 cross-spreading was observed. The simultaneous presence of two carbapenemases, VIM-1 and KPC-2, in the same isolate was also observed in three patients. Total sequencing of plasmid content of two KPC-3 strains showed novel association of resistance plasmids. Conclusions The

  10. Using steric hindrance to design new inhibitors of class C beta-lactamases

    Energy Technology Data Exchange (ETDEWEB)

    Trehan, Indi; Morandi, F.; Blaszczak, L.C.; Shoichet, Brian K. (NWU)

    2010-03-08

    {beta}-lactamases confer resistance to {beta}-lactam antibiotics such as penicillins and cephalosporins. However, {beta}-lactams that form an acyl-intermediate with the enzyme but subsequently are hindered from forming a catalytically competent conformation seem to be inhibitors of {beta}-lactamases. This inhibition may be imparted by specific groups on the ubiquitous R1 side chain of {beta}-lactams, such as the 2-amino-4-thiazolyl methoxyimino (ATMO) group common among third-generation cephalosporins. Using steric hindrance of deacylation as a design guide, penicillin and carbacephem substrates were converted into effective {beta}-lactamase inhibitors and antiresistance antibiotics. To investigate the structural bases of inhibition, the crystal structures of the acyl-adducts of the penicillin substrate amoxicillin and the new analogous inhibitor ATMO-penicillin were determined. ATMO-penicillin binds in a catalytically incompetent conformation resembling that adopted by third-generation cephalosporins, demonstrating the transferability of such sterically hindered groups in inhibitor design.

  11. Adaptation of Campylobacter jejuni to biocides used in the food industry affects biofilm structure, adhesion strength, and cross-resistance to clinical antimicrobial compounds.

    Science.gov (United States)

    Techaruvichit, Punnida; Takahashi, Hajime; Kuda, Takashi; Miya, Satoko; Keeratipibul, Suwimon; Kimura, Bon

    2016-08-01

    The emergence of biocide-adapted Campylobacter jejuni strains that developed into biofilms and their potential to develop clinical resistance to antimicrobial compounds was studied. C. jejuni was grown in sub-lethal concentrations of five biocides used in the food industry. C. jejuni exhibited adaptation to these biocides with increased minimum inhibitory concentrations. The 3-D structures of the biofilms produced by the biocide-adapted cells were investigated by atomic force microscopy (AFM). The results revealed marked variability in biofilm architecture, including ice-crystal-like structures. Adaptation to the biocides enhanced biofilm formation, with significant increases in biovolume, surface coverage, roughness, and the surface adhesion force of the biofilms. Adaptation to commercial biocides induced resistance to kanamycin and streptomycin. This study suggests that the inappropriate use of biocides may lead to cells being exposed to them at sub-lethal concentrations, which can result in adaptation of the pathogens to the biocides and a subsequent risk to public health. PMID:27353218

  12. Physiologic cold shock of Moraxella catarrhalis affects the expression of genes involved in the iron acquisition, serum resistance and immune evasion

    Directory of Open Access Journals (Sweden)

    Schaller André

    2011-08-01

    Full Text Available Abstract Background Moraxella catarrhalis, a major nasopharyngeal pathogen of the human respiratory tract, is exposed to rapid downshifts of environmental temperature when humans breathe cold air. It was previously shown that the prevalence of pharyngeal colonization and respiratory tract infections caused by M. catarrhalis are greatest in winter. The aim of this study was to investigate how M. catarrhalis uses the physiologic exposure to cold air to upregulate pivotal survival systems in the pharynx that may contribute to M. catarrhalis virulence. Results A 26°C cold shock induces the expression of genes involved in transferrin and lactoferrin acquisition, and enhances binding of these proteins on the surface of M. catarrhalis. Exposure of M. catarrhalis to 26°C upregulates the expression of UspA2, a major outer membrane protein involved in serum resistance, leading to improved binding of vitronectin which neutralizes the lethal effect of human complement. In contrast, cold shock decreases the expression of Hemagglutinin, a major adhesin, which mediates B cell response, and reduces immunoglobulin D-binding on the surface of M. catarrhalis. Conclusion Cold shock of M. catarrhalis induces the expression of genes involved in iron acquisition, serum resistance and immune evasion. Thus, cold shock at a physiologically relevant temperature of 26°C induces in M. catarrhalis a complex of adaptive mechanisms that enables the bacterium to target their host cellular receptors or soluble effectors and may contribute to enhanced growth, colonization and virulence.

  13. Changes in ganglioside content affect the binding of Clostridium perfringens epsilon-toxin to detergent-resistant membranes of Madin-Darby canine kidney cells.

    Science.gov (United States)

    Shimamoto, Seiko; Tamai, Eiji; Matsushita, Osamu; Minami, Junzaburo; Okabe, Akinobu; Miyata, Shigeru

    2005-01-01

    Epsilon-toxin (ET) of Clostridium perfringens, which causes fatal enterotoxemia in ungulates, was previously shown to bind to and form a heptameric pore within the detergent-resistant membranes (DRMs) of MDCK cells. Depletion of cholesterol has also been shown to decrease the cytotoxicity of ET and its heptamerization. In this study, we investigated the effects of changes in sphingolipids, other DRM components of MDCK cells, on the cells' susceptibility to ET. Treatment with fumonisin B1 and PDMP, inhibitors of sphingolipid and glycosphingolipid syntheses, respectively, increased the susceptibility, while D609, a sphingomyelin synthesis inhibitor, had the opposite effect. The exogenous addition of ganglioside G(M1) dramatically decreased the ET binding, heptamerization and cytotoxicity. These effects were shown not to be due to ET binding to G(M1) or to denaturation of ET. We also found that the ET cytotoxicity towards MDCK cells decreased with an increase in culture time. In accordance with the resistance observed for prolonged cultured cells, G(M3), a major ganglioside component, increased and sialidase treatment increased their susceptibility. These results suggest that membrane-anchored sialic acid of G(M3) within DRMs inhibits ET binding, leading to prevention of the heptamerization of ET and cell death. It is also suggested that sialidase produced by this organism aids the targeting of ET to MDCK cells. PMID:15781998

  14. Long-term field application of sewage sludge increases the abundance of antibiotic resistance genes in soil.

    Science.gov (United States)

    Chen, Qinglin; An, Xinli; Li, Hu; Su, Jianqiang; Ma, Yibing; Zhu, Yong-Guan

    2016-01-01

    Sewage sludge and manure are common soil amendments in crop production; however, their impact on the abundance and diversity of the antibiotic resistome in soil remains elusive. In this study, by using high-throughput sequencing and high-throughput quantitative PCR, the patterns of bacterial community and antibiotic resistance genes (ARGs) in a long-term field experiment were investigated to gain insights into these impacts. A total of 130 unique ARGs and 5 mobile genetic elements (MGEs) were detected and the long-term application of sewage sludge and chicken manure significantly increased the abundance and diversity of ARGs in the soil. Genes conferring resistance to beta-lactams, tetracyclines, and multiple drugs were dominant in the samples. Sewage sludge or chicken manure applications caused significant enrichment of 108 unique ARGs and MGEs with a maximum enrichment of up to 3845 folds for mexF. The enrichment of MGEs suggested that the application of sewage sludge or manure may accelerate the dissemination of ARGs in soil through horizontal gene transfer (HGT). Based on the co-occurrence pattern of ARGs subtypes revealed by network analysis, aacC, oprD and mphA-02, were proposed to be potential indicators for quantitative estimation of the co-occurring ARGs subtypes abundance by power functions. The application of sewage sludge and manure resulted in significant increase of bacterial diversity in soil, Proteobacteria, Acidobacteria, Actinobacteria and Chloroflexi were the dominant phyla (>10% in each sample). Five bacterial phyla (Chloroflexi, Planctomycetes, Firmicutes, Gemmatimonadetes and Bacteroidetes) were found to be significantly correlated with the ARGs in soil. Mantel test and variation partitioning analysis (VPA) suggested that bacterial community shifts, rather than MGEs, is the major driver shaping the antibiotic resistome. Additionally, the co-occurrence pattern between ARGs and microbial taxa revealed by network analysis indicated that four

  15. Hygiene quality and presence of ESBL-producing Escherichia coli in raw food diets for dogs

    Directory of Open Access Journals (Sweden)

    Oskar Nilsson

    2015-10-01

    CMY-2 group and only one of them was also resistant to a non-beta-lactam antibiotic. Conclusion: The results of this study indicate that raw food diets could be a source of ESC-resistant E. coli to dogs and highlight the need for maintaining good hygiene when handling these products to prevent infection.

  16. Self-harm history predicts resistance to inpatient treatment of body shape aversion in women with eating disorders: The role of negative affect.

    Science.gov (United States)

    Olatunji, Bunmi O; Cox, Rebecca; Ebesutani, Chad; Wall, David

    2015-06-01

    Although self-harm has been observed among patients with eating disorders, the effects of such tendencies on treatment outcomes are unclear. The current study employed structural equation modeling to (a) evaluate the relationship between self-harm and changes in body dissatisfaction and drive for thinness in a large sample of patients (n = 2061) who underwent inpatient treatment, and (b) to examine whether the relationship between self-harm and changes in body dissatisfaction and drive for thinness during inpatient treatment remains significant when controlling for change in negative affect during treatment. Results revealed that patients with a history of self-harm reported significantly less reduction in body dissatisfaction and drive for thinness following treatment. Patients experiencing less change in negative affect also reported significantly less reduction in body dissatisfaction and drive for thinness after discharge from treatment. However, the association between history of self-harm and reduction in body dissatisfaction and drive for thinness after treatment became non-significant when controlling for change in negative affect. This pattern of findings was also replicated among patients with a primary diagnosis of anorexia nervosa (n = 845), bulimia nervosa (n = 565), and eating disorder not otherwise specified (n = 651). The implications of these findings for delineating the specific role of self-harm in the nature and treatment of eating disorders are discussed. PMID:25868550

  17. Detection of violations in thermal cycle of electric arc welding of heat resistant steel 12Kh1MF using magnetic properties of a heat affected zone

    International Nuclear Information System (INIS)

    The studies on the magnetic characteristics of the 12Kh1M1F heat resistant steel are carried out in the zones of melting and thermal effect by different modes of the electric are welding and the new approach to calculating and forecasting the longevity of service of the steam pipe welded joints is proposed on the basis of the magnetic structuroscopy. The local step-by-step (with the 1-2 mm interval) measurement of the metal residual magnetization after magnetization through the point pole method is accomplished in the welded joint area after the removal of the weld reinforcement. The evaluating of the welding modes violations and the joint longevity forecast are given in the basis of the maximum and minimum measurement results or their distribution along the measurement line

  18. [CHANGES IN LIFESTYLE FACTORS AFFECT THE LEVELS OF NEUROPEPTIDES, INVOLVED IN THE CONTROL OF EATING BEHAVIOR, INSULIN RESISTANCE AND LEVEL OF CHRONIC SYSTEMIC INFLAMMATION IN YOUNG OVERWEIGHT PERSONS].

    Science.gov (United States)

    Shevchenko, Yu; Mamontova, T; Baranova, A; Vesnina, L; Kaidashev, I

    2015-11-01

    The continuous rise of overweight and obesity is a major concern for present and future healthcare management. The aim of our study was to evaluate the influence of lifestyle changes on central regulatory mechanisms of maintaining energy homeostasis, insulin resistance and chronic systemic inflammation in 18-25 year old overweight patients. The anthropometric measurements were done for each patient, including body weight, height, waist circumference (WC), hip circumference (HC), waist to hip ratio, and body mass index (BMI). Patients were divided into two groups according to their BMI. 20 males and 21 females with BMI > 25 kg/m2 were included in the first, study, group. The second, control, group consisted of 16 males and 11 females with BMI - 18.5 - 24.9 kg/m 2. Lipid profile, fasting glucose and insulin levels, HOMA-IR, TNF-α, ceruloplasmin, neuropeptides Agouti-related protein - AgRP and kokain- and amphetamine-mediated transcript - CART were examined at the beginning of the study (Day 1) and after 10 week treatment period (Day 70). During the 10 week treatment period, people in the study group underwent physical exercise programs of 40-60 minute duration three times per week, and brisk walking during the remaining days. The mean calorie expenditure during the exercise was 500 kcal/day. Each patient in the study group was given balanced, healthy diet with 20% calorie restriction from baseline diet. Our study reveled that negative energy balance caused a statistically significant decrease in AgRP, reduction of visceral fat stores, increase of HDL, reduction of TNF-α and dissolution of insulin resistance signs. Significant but not statistically significant reduction of CART level was observed after increased physical activity program and calorie restriction diet, which might play an important role in the mechanism of decreasing weight. However, further investigations are required in order to determine its place in body weight regulation. PMID:26656551

  19. Early Onset Inflammation in Pre-Insulin-Resistant Diet-Induced Obese Rats Does Not Affect the Vasoreactivity of Isolated Small Mesenteric Arteries

    DEFF Research Database (Denmark)

    Blædel, Martin; Raun, Kirsten; Boonen, Harrie C M;

    2012-01-01

    myography, we tested the vascular function of isolated small mesenteric arteries. Results: DIO animals had significantly (p <0.05) increased body weight (721.2 ± 6.3 g) compared to age- and sex-matched controls (643.4 ± 14.6 g), as well as a significant increase (p <0.01) in body fat percentage (29.7 ± 1....... Our study aimed to investigate signs of inflammation and their relation to vascular dysfunction in rats receiving a high fat diet. Methods: Diet-induced obese (DIO) rats were used as a model since these rats exhibit a human pre-diabetic pathology. Oral glucose and insulin tolerance tests were......Background: Obesity is an increasing burden affecting developed and emerging societies since it is associated with an increased risk of diabetes and consequent cardiovascular complications. Increasing evidence points towards a pivotal role of inflammation in the etiology of vascular dysfunction...

  20. High-Intensity Resistance Exercise Promotes Postexercise Hypotension Greater than Moderate Intensity and Affects Cardiac Autonomic Responses in Women Who Are Hypertensive.

    Science.gov (United States)

    de Freitas Brito, Aline; Brasileiro-Santos, Maria do S; Coutinho de Oliveira, Caio V; Sarmento da Nóbrega, Thereza K; Lúcia de Moraes Forjaz, Cláudia; da Cruz Santos, Amilton

    2015-12-01

    The purpose of this study was to evaluate the effect of high-intensity resistance exercise (RE) sessions on blood pressure (BP), heart rate (HR), cardiac autonomic modulation, and forearm blood flow (FBF). Sixteen trained hypertensive women (n = 16, 56 ± 3 years) completed the following 3 experimental sessions: control (CS), RE at 50% (EX50%), and RE at 80% (EX80%) of 1 repetition maximum (1RM). Both EX50% and EX80% comprised a set of 10 repetitions of 10 exercises, with an interval of 90 seconds between exercises. Measurements were taken preintervention and postintervention (at 10, 30, 50, 70, and 90 minutes of recovery). Reductions in systolic/diastolic BP after exercise were greater in EX80% (largest declines, -29 ± 4/-14 ± 5 mm Hg) than EX50% (largest declines, -18 ± 6/-8 ± 5 mm Hg, p ≤ 0.05). Heart rate and cardiac sympathovagal balance (LF/HF) increased more in relation to pre-exercise values in EX80% than EX50% (largest increases 96 ± 3 vs. 90 ± 4 b·min, LF/HF = 1.77 ± 0.25 vs. 1.40 ± 0.20, respectively, p ≤ 0.05). Increases in FBF and hyperemia was also higher in EX80% than EX50% compared with pre-exercise (4.97 ± 0.28 vs. 4.36 ± 0.27 ml·min·100 ml and 5.90 ± 0.20 vs. 5.38 ± 0.25 ml·min·100 ml; p ≤ 0.05, respectively). These results suggest that RE of higher intensity promoted greater postexercise hypotension accompanied by greater increases in FBF, vasodilator response, HR, and cardiac sympathovagal balance. PMID:25992658

  1. Constitutive expression of pathogen-inducible OsWRKY31 enhances disease resistance and affects root growth and auxin response in transgenic rice plants

    Institute of Scientific and Technical Information of China (English)

    Juan Zhang; Youliang Peng; Zejian Guo

    2008-01-01

    WRKY transcription factors have many regulatory roles in response to biotic and abiotic stresses. In this study, we isolated a rice WRKY gene (OsWRKY31) that is induced by the rice blast fungus Magnaporthe grisea and auxin. This gene encodes a polypeptide of 211 amino-acid residues and belongs to a subgroup of the rice WRKY gene family that probably originated after the divergence of monocot and dicot plants. OsWRKY31 was found to be localized to the nucleus of onion epidermis cells to transiently express OsWRKY31-eGFP fusion protein. Analysis of 0sWRKY31 and its mutants fused with a Cal4 DNA-binding domain indicated that OsWRKY31 has transactivation activity in yeast. Overexpression of the OsWRKY31 gene was found to enhance resistance against infection with M. grisea, and the transgenic lines exhibited reduced lateral root formation and elongation compared with wild-type and RNAi plants. The lines with overexpression showed constitutive expression of many defense-related genes, such as PBZ1 and OsSci2, as well as early auxin-response genes, such as OsIAA4 and OsCrll genes. Furthermore, the plants with overexpression were less sensitive to exogenously supplied IBA, NAA and 2,4-D at high concentrations, suggesting that overexpression of the OsWRKY31 gene might alter the auxin response or transport. These results also suggest that OsWRKY31 might be a common component in the signal transduction pathways of the auxin response and the defense response in rice.

  2. L-Alanylglutamine inhibits signaling proteins that activate protein degradation, but does not affect proteins that activate protein synthesis after an acute resistance exercise.

    Science.gov (United States)

    Wang, Wanyi; Choi, Ran Hee; Solares, Geoffrey J; Tseng, Hung-Min; Ding, Zhenping; Kim, Kyoungrae; Ivy, John L

    2015-07-01

    Sustamine™ (SUS) is a dipeptide composed of alanine and glutamine (AlaGln). Glutamine has been suggested to increase muscle protein accretion; however, the underlying molecular mechanisms of glutamine on muscle protein metabolism following resistance exercise have not been fully addressed. In the present study, 2-month-old rats climbed a ladder 10 times with a weight equal to 75 % of their body mass attached at the tail. Rats were then orally administered one of four solutions: placebo (PLA-glycine = 0.52 g/kg), whey protein (WP = 0.4 g/kg), low dose of SUS (LSUS = 0.1 g/kg), or high dose of SUS (HSUS = 0.5 g/kg). An additional group of sedentary (SED) rats was intubated with glycine (0.52 g/kg) at the same time as the ladder-climbing rats. Blood samples were collected immediately after exercise and at either 20 or 40 min after recovery. The flexor hallucis longus (FHL), a muscle used for climbing, was excised at 20 or 40 min post exercise and analyzed for proteins regulating protein synthesis and degradation. All supplements elevated the phosphorylation of FOXO3A above SED at 20 min post exercise, but only the SUS supplements significantly reduced the phosphorylation of AMPK and NF-kB p65. SUS supplements had no effect on mTOR signaling, but WP supplementation yielded a greater phosphorylation of mTOR, p70S6k, and rpS6 compared with PLA at 20 min post exercise. However, by 40 min post exercise, phosphorylation of mTOR and rpS6 in PLA had risen to levels not different than WP. These results suggest that SUS blocks the activation of intracellular signals for MPB, whereas WP accelerates mRNA translation. PMID:25837301

  3. Prolonged extracorporeal membrane oxygenation therapy for severe acute respiratory distress syndrome in a child affected by rituximab-resistant autoimmune hemolytic anemia: a case report

    Directory of Open Access Journals (Sweden)

    Beretta Chiara

    2009-04-01

    Full Text Available Abstract Introduction Autoimmune hemolytic anemia in children younger than 2 years of age is usually characterized by a severe course, with a mortality rate of approximately 10%. The prolonged immunosuppression following specific treatment may be associated with a high risk of developing severe infections. Recently, the use of monoclonal antibodies (rituximab has allowed sustained remissions to be obtained in the majority of pediatric patients with refractory autoimmune hemolytic anemia. Case presentation We describe the case of an 8-month-old Caucasian girl affected by a severe form of autoimmune hemolytic anemia, which required continuous steroid treatment for 16 months. Thereafter, she received 4 weekly doses of rituximab (375 mg/m2/dose associated with steroid therapy, which was then tapered over the subsequent 2 weeks. One month after the last dose of rrituximab, she presented with recurrence of severe hemolysis and received two more doses of rrituximab. The patient remained in clinical remission for 7 months, before presenting with a further relapse. An alternative heavy immunosuppressive therapy was administered combining cyclophosphamide 10 mg/kg/day for 10 days with methylprednisolone 40 mg/kg/day for 5 days, which was then tapered down over 3 weeks. While still on steroid therapy, the patient developed an interstitial pneumonia with Acute Respiratory Distress Syndrome, which required immediate admission to the intensive care unit where extracorporeal membrane oxygenation therapy was administered continuously for 37 days. At 16-month follow-up, the patient is alive and in good clinical condition, with no organ dysfunction, free from any immunosuppressive treatment and with a normal Hb level. Conclusions This case shows that aggressive combined immunosuppressive therapy may lead to a sustained complete remission in children with refractory autoimmune hemolytic anemia. However, the severe life-threatening complication presented by our

  4. Multi-drug resistance and ribotyping analysis of Acinetobacter baumanii isolated from patients in intensive care unit%鲍曼不动杆菌多重耐药性和同源性分析

    Institute of Scientific and Technical Information of China (English)

    肖红; 王雅静; 王冰姝; 陈惠珍; 钟昱文; 张里君; 柯昌文

    2011-01-01

    Objective To find out basic information on multidrug-resistant Acinetobacter baumanii in intensive care units (ICU)and compare the homology of Acinetobacter baumanii for providing basic information on treatment as well as management of nosocomial infections. Methods Nine strains of Acinetobacter baumanii were isolated from patients in ICU in some hospitala from January to March in 2009 and the DNA typing of bacterial strains was performed using ribotyping method. Results Nine multi-resistant strains were multi-resistant to beta-lactams,aminoglycosides,and fluoroquinolones. Nine strains were highly homologous by the RiboPrinter system. The homology of seven strains among nine strains were above 90%. Conclusion The drug resistance rate of Acinetobacter bawnannii isolated from ICU was high and most of the nine strains were highly homologous by ribotyping technique. In addition,the disinfection and isolation measures in ICU of hospitala should be strengthened to reduce nosocomial infections.%目的 了解重症监护病房(ICU)的多重耐药鲍曼不动杆菌的耐药谱特征及菌株同源性,为临床防治和控制院内感染提供依据.方法 收集ICU重症监护病房2009年1~3月分离出的9株鲍曼不动杆菌,研究其耐药情况,并采用自动ribotyping技术进行同源性分析.结果 9株菌对头孢菌素类,氨基甙类等抗菌素均显示出较高水平的耐药性;ribotyping分型9株菌有高度同源性,其中7株同源性达90%以上.结论 自ICU分离的鲍曼不动杆菌多重耐药率较高,且大多数菌株有高度同源性,因此,医院应加强ICU病房消毒隔离措施,降低病人院内感染的概率

  5. Disease: H01072 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available TC:J01FA] Cephalosporin [ATC:J01DB J01DC J01DD J01DE] Tetracycline [ATC:J01AA] Co-amoxyclav [DR:D06485] Moraxella catarrhalis is expe...cted to be resistant to beta-lactam antibiotics includin

  6. Killing curve activity of ciprofloxacin is comparable to synergistic effect of beta-lactam-tobramycin combinations against Haemophilus species endocarditis strains

    DEFF Research Database (Denmark)

    Westh, H; Frimodt-Møller, N; Gutschik, E;

    1992-01-01

    Nine Haemophilus species strains, all beta-lactamase negative, isolated from patients with endocarditis were tested in killing curve experiments. Antibiotics used were penicillin, amoxicillin, aztreonam alone and in combination with tobramycin, as well as ciprofloxacin alone. Synergism between beta...

  7. RELATIVE SPECIFICITIES OF A SERIES OF BETA-LACTAM-RECOGNIZING ENZYMES TOWARDS THE SIDE-CHAINS OF PENICILLINS AND OF ACYCLIC THIOLDEPSIPEPTIDES

    NARCIS (Netherlands)

    SOTO, G; ADACHI, H; VANDERLINDEN, MPG; KECK, W; PRATT, RF

    1994-01-01

    In an attempt to understand more: of the subtle differences between bacterial beta-lactamases and DD-peptidases. comparisons have been made between the specificities of these enzymes towards the phenylacetyl side chain, generally thought to be favoured by beta-lactamases, and the NN'-diacetyl-L-lysy

  8. Beta-lactam induction of ISEcp1B-mediated mobilization of the naturally occurring bla(CTX-M) beta-lactamase gene of Kluyvera ascorbata

    OpenAIRE

    Nordmann, Patrice; Lartigue, Marie-Frédérique; Poirel, Laurent

    2008-01-01

    ISEcp1B is an insertion element associated with the emerging expanded-spectrum β-lactamase blaCTX-M genes in Enterobacteriaceae. Because ISEcp1B-blaCTX-M positive strains may be identified from humans and animals, the ability of this insertion sequence to mobilize the blaCTX-M-2 gene was tested from its progenitor Kluyvera ascorbata to study the effects of amoxicillin/clavulanic and cefquinome as enhancers of transposition. These β-lactam molecules are administered parenterally to treat infec...

  9. Effect of hyperproduction of TEM-1 beta-lactamase on in vitro susceptibility of Escherichia coli to beta-lactam antibiotics.

    OpenAIRE

    Wu, P J; Shannon, K; Phillips, I

    1994-01-01

    The susceptibility of 173 TEM-1-producing isolates of Escherichia coli was assessed by determination of MICs by the agar dilution method. MICs of amoxicillin, mezlocillin, cephaloridine, and, to a smaller extent, amoxicillin-clavulanic acid (but not cephalexin, cefuroxime, cefotaxime, ceftazidime, or imipenem) were higher for isolates that produced large amounts of beta-lactamase than for isolates that produced smaller amounts. The effect of fixed concentrations of clavulanic acid on resistan...

  10. Recognition of peptidoglycan and beta-lactam antibiotics by the extracellular domain of the Ser/Thr protein kinase StkP from Streptococcus pneumoniae

    Czech Academy of Sciences Publication Activity Database

    Maestro, B.; Nováková, Linda; Hesek, D.; Lee, M.; Leyva, E.; Mobashery, S.; Sanz, J.M.; Branny, Pavel

    2011-01-01

    Roč. 585, č. 2 (2011), s. 357-363. ISSN 0014-5793 R&D Projects: GA ČR GP204/07/P082; GA ČR GA204/08/0783; GA AV ČR IAA600200801 Institutional research plan: CEZ:AV0Z50200510 Keywords : Signal transduction * Penicillin-binding protein and Ser/Thr protein kinase-associated domain * Peptidoglycan Subject RIV: CE - Biochemistry Impact factor: 3.538, year: 2011

  11. 6 beta-Iodopenicillanic acid (UI-38,006), a beta-lactamase inhibitor that extends the antibacterial spectrum of beta-lactam compounds: initial bacteriological characterization.

    OpenAIRE

    Moore, B A; Brammer, K W

    1981-01-01

    UK-38,006, 6 beta-iodopenicillanic acid, was shown to be a potent inhibitor of beta-lactamase enzymes. It potentiated the antibacterial action of ampicillin in vitro against beta-lactamase-producing strains of Staphylococcus aureus, Haemophilus influenzae, Bacteroides fragilis. Neisseria gonorrhoeae, and many Enterobacteriaceae. This ability to synergize with ampicillin was also demonstrated in vivo after oral administration of UK-38,006 to experimentally infected mice. UK-38,006 was also sho...

  12. Comprehensive allergy work-up is mandatory in cystic fibrosis patients who report a history suggestive of drug allergy to beta-lactam antibiotics

    OpenAIRE

    Caimmi Silvia; Sanfiorenzo Céline; Caimmi Davide; Bousquet Philippe-Jean; Chiron Raphael; Demoly Pascal

    2012-01-01

    Abstract Background In the general population, reports on suspected ß-lactam hypersensitivity are common. After a drug allergy work-up at best 20% of the selected patients are positive. However, these considerations have not been explored in cystic fibrosis patients for whom antibiotics are even more crucial. Methods The study, part of the Drug Allergy and Hypersensitivity (DAHD) cohort, was performed in the regional cystic fibrosis center of Montpellier, France. After identifying patients wi...

  13. Evaluation of the Charm maximum residue limit beta-lactam and tetracycline test for the detection of antibiotics in ewe and goat milk

    OpenAIRE

    Beltrán Martínez, Mª Carmen; Romero Rueda, Tamara; Althaus, Rafael Lisandro; Molina Pons, Mª Pilar

    2013-01-01

    The Charm maximum residue limit P-lactam and tetracycline test (Charm MRL BLTET; Charm Sciences Inc., Lawrence, MA) is an immunoreceptor assay utilizing Rapid. One-Step Assay lateral flow technology that detects P-lactam or tetracycline drugs in raw commingled cow milk at or below European Union maximum residue levels (EU-MRL). The Charm MRL BLTET test procedure was recently modified (dilution in buffer and longer incubation) by the manufacturers to be used with raw ewe and goat milk. To asse...

  14. Comparative evaluation of a new beta-lactamase inhibitor, YTR 830, combined with different beta-lactam antibiotics against bacteria harboring known beta-lactamases.

    OpenAIRE

    Gutmann, L; Kitzis, M D; Yamabe, S; Acar, J F

    1986-01-01

    YTR 830, a new beta-lactamase inhibitor, combined with amoxicillin or carbenicillin, showed a synergistic effect similar to that observed with clavulanic acid, and generally better than that with sulbactam, against strains harboring chromosome-encoded penicillinases and broad-spectrum beta-lactamases or plasmid-determined beta-lactamases. With ampicillin, YTR 830 showed the best synergistic activity of the inhibitors against Proteus morganii, Citrobacter freundii, and Enterobacter cloacae and...

  15. A retrospective observational study on the efficacy of colistin by inhalation as compared to parenteral administration for the treatment of nosocomial pneumonia associated with multidrug-resistant Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Naesens Reinout

    2011-11-01

    Full Text Available Abstract Background Colistin is used as last treatment option for pneumonia associated with multidrug-resistant (MDR Pseudomonas spp.. Literature about the best administration mode (inhalation versus parenteral treatment is lacking. Methods A retrospective study of 20 intensive care patients with a pneumonia associated with MDR P. aeruginosa receiving colistin sulphomethate sodium (Colistineb® between 2007 and 2009 was performed. A strain was considered multidrug-resistant if it was resistant to at least 6 of the following antibiotics: piperacillin-tazobactam, ceftazidime, cefepime, meropenem, aztreonam, ciprofloxacin, and amikacin. The administration mode, predicted mortality based on the SAPS3 score, SOFA score at onset of the colistin treatment, clinical and microbiological response, and mortality during the episode of the infection were analysed. The non parametric Kruskal-Wallis and Fisher's Exact test were used for statistical analysis of respectively the predicted mortality/SOFA score and mortality rate. Results Six patients received colistin by inhalation only, 5 were treated only parenterally, and 9 by a combination of both administration modes. All patients received concomitant beta-lactam therapy. The mean predicted mortalities were respectively 72%, 68%, and 69% (p = 0.91. SOFA scores at the onset of the treatment were also comparable (p = 0.87. Clinical response was favorable in all patients receiving colistin by inhalation (6/6 and in 40% (2/5 of the patients receiving colistin parenterally (p = 0.06. In the patients with colistin administered both via inhalation and parenterally, clinical response was favorable in 78% of the patients (7/9 (p = 0.27 as compared to the treatment group receiving colistin only parenterally. When all patients with inhalation therapy were compared to the group without inhalation therapy, a favorable clinical response was present in respectively 87% and 40% (p = 0.06. In none of the patients, the

  16. Pattern of antimicrobial usage in livestock animals in south-western Nigeria: The need for alternative plans

    Directory of Open Access Journals (Sweden)

    Hezekiah K. Adesokan

    2015-02-01

    Full Text Available Resistance to antibiotics has continued to increase, placing future animal and human disease management in real danger. The developing countries characterised by widespread indiscriminate antibiotic use and in which ‘third-generation’ antibiotics are not readily available or affordable are the worst affected. A 3-year (2010–2012 retrospective survey of antibiotic usage in livestock production in three selected states of south-western Nigeria was conducted. Data obtained from eight purposively selected licensed veterinary pharmaceutical sales establishments in the area, based on keeping detailed sales records for the study period, were analysed using Stata Version 12. Results showed that tetracyclines (33.6%, fluoroquinolones (26.5% and beta-lactams/aminoglycosides (20.4% constituted the majority of the antibiotics used over the 3 years. The differences in the quantities of antibiotic types used within each antimicrobial class were statistically significant for tetracyclines (F = 59.87; p < 0.0001 and fluoroquinolones (F = 43.97; p < 0.0001 but not for beta-lactams/aminoglycosides (F = 3.21; p = 0.148. Furthermore, antibiotic consumption increased by 40.4% between 2010 and 2012. Although statistically insignificant (F = 0.277; p = 0.762, the increasing trend across the years was at rates of 23.5% between 2010 and 2011 and 13.8% between 2011 and 2012. In addition, the findings show a significantly higher consumption rate (t = 15.21; df = 5; p < 0.0001 during the rainy (52.5% than the dry (47.5% seasons. The current increasing trend in antibiotic usage holds a serious danger for the future and therefore calls for alternative plans to safeguard future livestock production, food security and human health. This becomes more imperative considering emerging resistance against tetracyclines and fluoroquinolones, the foremost remedies for livestock diseases in most developing countries.

  17. DETERMINATION OF THE SPECTRUM OF ANTIBIOTIC RESISTANCE GENES HAVE PHENOTYPIC RESISTANT STRAINS OF PARIETAL INTESTINAL MICROBIOTA IN RATS BY RT-PCR

    Directory of Open Access Journals (Sweden)

    Bukina Y.V.

    2016-06-01

    Full Text Available Introduction. The problem of formation of bacterial resistance to glycopeptides and beta-lactam antibiotics (cephalosporins and carbapenems are used worldwide for the treatment of severe community acquired and nosocomial infections, especially caused by polymicrobial flora has become global and is a major factor limiting the effectiveness of antibiotic therapy. In this regard, the study of genetic microbial resistance determinants allows not only to carry out an effective antibiotic therapy, but also to identify two main processes leading to the development of epidemiologically significant events: the introduction of the agent in the risk population from the outside and in situ pathogen (spontaneous genetic drift targeted restructuring of the population. Therefore, the aim of our study was to investigate the resistance genes to carbapenems, cephalosporins, glycopeptides have clinically important phenotype of resistant strains of microorganisms families Enterobacteriaceae, Pseudomonadaceae, Bacteroidaceae, Enterococcaceae, Peptostreptococcaceae. Materials and methods. As a material for PCR studies 712 phenotypically resistant strains of microorganisms isolated from 80 rats "Wistar" line in microbiological study microflora of the wall were used. During the investigation 474 isolates of bacteria of the family Enterobacteriaceae, 39 - Pseudomonadaceae, 71 - Bacteroidaceae, 96 - Enterococcaceae, 32 - Peptostreptococcaceae were studied. Isolation of DNA from bacteria in the study was performed using reagents "DNA-Express" ("Litekh", Russia. For the detection of resistance genes by PCR in real time (RT-PCR reagent kits "FLUOROPOL-RV" ("Litekh", Russia were used. During the experiment, the VIM genes, OXA-48, NDM, KPC, responsible for the resistance of microorganisms to carbapenems, CTX-M - resistance to cephalosporins, as well as genes Van A and van B, the development of resistance to glycopeptides (vancomycin and teicoplanin were determined. Analysis

  18. Affect Regulation

    DEFF Research Database (Denmark)

    Pedersen, Signe Holm; Poulsen, Stig Bernt; Lunn, Susanne

    2014-01-01

    Gergely and colleagues’ state that their Social Biofeedback Theory of Parental Affect Mirroring” can be seen as a kind of operationalization of the classical psychoanalytic concepts of holding, containing and mirroring. This article examines to what extent the social biofeedback theory of parenta...

  19. Táticas cotidianas e ação coletiva: a resistência das pessoas atingidas pela hanseníase Everyday tactics and collective action: how the people affected with Hansen's disease (leprosy politically resisted to the disease

    Directory of Open Access Journals (Sweden)

    Ricardo Fabrino Mendonça

    2012-06-01

    Full Text Available Apesar da existência de uma considerável literatura sobre a história da hanseníase, predominam os estudos que enfocam a opressão e a dominação a que os antigos pacientes foram submetidos. Permanecem pouco estudadas as formas de resistência e as lutas políticas geradas por esses sujeitos. O presente artigo é um esforço nessa direção, abordando como a própria vida cotidiana e as lutas organizadas permitiram o questionamento de sentidos e práticas opressoras. O estudo está embasado em um processo de observação em antigos hospitais-colônia brasileiros, 12 grupos de conversação com moradores dessas instituições, entrevistas não-estruturadas com lideranças do Movimento de Reintegração das Pessoas Atingidas pela Hanseníase (Morhan e 45 edições do Jornal do Morhan.Despite the existence of a considerable literature about the history of leprosy, most studies focus on the oppression and domination to which former patients were subjected. The resistance and political struggles produced by these individuals remain underexplored. This paper is an attempt to introduce this issue, by discussing how everyday life and organized collective struggles have allowed the systematic challenge of oppressive meanings and social practices. The study is based on a observation process in former leprosy colonies, 12 conversation groups with colony dwellers, non-structured interviews with highly ranked activists from Morhan (Movement for the Reintegration of People Affected by Leprosy, and 45 editions of Morhan's newsletter.

  20. Affective Urbanism

    DEFF Research Database (Denmark)

    Samson, Kristine

    , experience and consumption are all strategic design tools applied by planners and architects. Whereas urban design in former modernist planning served merely functional or political means, urban design has increasingly become an aesthetical mediator of ideologies embedded in the urban field of life forces...... capitalism not only changes urban life and its means of production, it specifically influences the way the city is designed and how it unfolds as events (Anderson & Harrison 2010) and affective, emotional production (Pile 2009). Through examples of urban design and events in the Carlsberg City in Copenhagen...... and The High Line in Chelsea, New York, the paper sets out to define and question these affective modes of production. Whether these productions are socio-material practices consisting of ludic designs (Stevens 2007), temporary architecture or art installations or evental practices consisting of...

  1. Drug Resistance

    Science.gov (United States)

    HIV Treatment Drug Resistance (Last updated 3/1/2016; last reviewed 3/1/2016) Key Points As HIV multiplies in the ... the risk of drug resistance. What is HIV drug resistance? Once a person becomes infected with HIV, ...

  2. Staging of unipolar affective illness

    Directory of Open Access Journals (Sweden)

    Ewa Ferensztajn

    2014-12-01

    Full Text Available In this article, a concept of staging of unipolar affective illness (recurrent depression is presented. In respective subchapters, three most important aspects of this issue have been discussed: 1 staging of unipolar affective illness; 2 staging of treatment-resistant depression; and 3 conversion of unipolar into bipolar affective illness. The evidence for so called neuroprogression of the illness, accumulated in recent years, has allowed for a classification of staging based on a concept of allostasis and allostatic load. In the course of illness, changes in neuroendocrine system (mainly hypothalamic pituitary-adrenal (HPA axis, immunological system, mechanisms of oxidative stress, neurotransmitters, neurotrophic factors as well as structural and functional changes of the brain occur. In their paper of 2007, Fava and Tossani elaborated a concept of staging of unipolar affective illness presenting a continuum model of five consecutive stages with specific clinical features. In the present paper, a concept of treatment-resistant depression and staging of treatment resistance is presented in the context of several models. An important determinant of treatment-resistant depression is so called subthreshold bipolarity which is connected with worse efficacy of antidepressant drugs. In the course of illness, there is a possibility of changing diagnosis from recurrent depression into bipolar affective illness. The studies on this issue show that frequency of such diagnostic conversion is 1,5% of depressed patients per year.

  3. Affective Maps

    DEFF Research Database (Denmark)

    Salovaara-Moring, Inka

    Recently, in human geography there has been a considerable attention paid to retheorising maps; less as a product and more as practice. This refers to the notion that rather than reading maps as fixed representations, digital mapping is by nature a dynamic, performative, and participatory practice....... In particular, mapping environmental damage, endangered species, and human made disasters has become one of the focal point of affective knowledge production. These ‘more-than-humangeographies’ practices include notions of species, space and territory, and movement towards a new political ecology...

  4. Antimicrobial Susceptibility Pattern of Clinical Isolates of Escherichia coli and Proteus mirabilis Using Cefepime in Ogbomoso, Nigeria.

    OpenAIRE

    Oladipo E Kolawole; Amao J. A.; Omomowo I. O.; Agboola J. O.; Afolabi A. Y.; Akinade B. S.

    2014-01-01

    The challenge of Cefepime resistance in developing countries is substantial and likely to grow. Emergence of Cefepime-resistant bacteria has increased and management of this has become a therapeutic challenge. The production of beta lactamases by most bacteria make them to be resistant to beta lactam antibiotics like Cefepime which is common nowadays. Forty clinical isolates of Escherichia coli and Proteus mirabilis from different clinical sites were analyzed between March and August, 2013 u...

  5. The glutamate transport inhibitor DL-Threo-β-Benzyloxyaspartic acid (DL-TBOA) differentially affects SN38- and oxaliplatin-induced death of drug-resistant colorectal cancer cells

    OpenAIRE

    Cuesta, Elena Pedraz; Christensen, Sandra; Jensen, Anders A.; Jensen, Niels Frank; Bunch, Lennart; Rømer, Maria Unni Koefoed; Brünner, Nils; Stenvang, Jan; Pedersen, Stine Helene Falsig

    2015-01-01

    Background Colorectal cancer (CRC) is a leading cause of cancer death globally and new biomarkers and treatments are severely needed. Methods Here, we employed HCT116 and LoVo human CRC cells made resistant to either SN38 or oxaliplatin, to investigate whether altered expression of the high affinity glutamate transporters Solute Carrier (SLC)-1A1 and -1A3 (EAAT3, EAAT1) is associated with the resistant phenotypes. Analyses included real-time quantitative PCR, immunoblotting and immunofluoresc...

  6. [Affective dependency].

    Science.gov (United States)

    Scantamburlo, G; Pitchot, W; Ansseau, M

    2013-01-01

    Affective dependency is characterized by emotional distress (insecure attachment) and dependency to another person with a low self-esteem and reassurance need. The paper proposes a reflection on the definition of emotional dependency and the confusion caused by various denominations. Overprotective and authoritarian parenting, cultural and socio-environmental factors may contribute to the development of dependent personality. Psychological epigenetic factors, such as early socio-emotional trauma could on neuronal circuits in prefronto-limbic regions that are essential for emotional behaviour.We also focus on the interrelations between dependent personality, domestic violence and addictions. The objective for the clinician is to propose a restoration of self-esteem and therapeutic strategies focused on autonomy. PMID:23888587

  7. 多耐药肺炎克雷伯菌获得性耐药基因检测及指标聚类分析%The investigation of acquired resistance genes and hierarchical cluster analysis in multidrug-resistant Klebsiella pneumoniae

    Institute of Scientific and Technical Information of China (English)

    陈菁; 孙桂芹

    2011-01-01

    Objective To investigate the distribution of 65 kinds of acquired resistance genes and 7 kinds of genetic markers of mobile genetic elements, and the correlation between acquired resistance genes and genetic markers of mobile genetic elements in multidrug-resistant Klebsiella pneumoniae (K. Pneumoniae). Method From October 2007 to June 2009, 20 strains of multidrug-resistant K. Pneumoniae were collected from Shaoxing People's Hospital, China. Then, 65 kinds of acquired resistance genes to beta-lactams, aminoglycosides, quinolones, and 7 kinds of genetic markers of mobile genetic elements: conjugal plasmids, transposons, insertion sequences, and integrons were analyzed by PCR. And hierarchical cluster analysis was used to investigate the correlation between acquired resistance genes and genetic markers of mobile genetic elements. Result In the 20 strains of K. Pneumoniae, 14 kinds of acquired resistance genes were detected (including 6 kinds of acquired beta-lactam-resistance genes, 6 kinds of acquired aminoglycoside-resistance genes, 2 kinsd of acquired quinolone-resistance genes) , and 6 kinds of genetic markers of mobile genetic elements were detected (including 2 kinds of conjugal plasmids, 3 kinds of transposon and insertion sequences, 1 kind of integron). The other 52 kinds of genes were not detectable. Two clusters were divided by hierarchical cluster analysis depending on positive genes. Conclusion In this group of K. Pneumoniae, acquired resistance genes played a role in resistant phenotypes of antimicrobial a-gents. Horizontal transfer of mobile genetic elements brought rapid spread of resistance of bacterial pathogens, not only a-mong the same kinds of pathogens, but among the different kinds. In addition, hierarchical cluster analysis showed that correlation might exist between OXA-1, aac(6')- Ⅰ b.qnrB, IMP, aadA5, VEB, KPC, qnrS and traA,which suggested that these genes might exist in F conjugal plasmids; correlation might exist between DHA, aph(3

  8. Missense mutations in PBP2A Affecting ceftaroline susceptibility detected in epidemic hospital-acquired methicillin-resistant Staphylococcus aureus clonotypes ST228 and ST247 in Western Switzerland archived since 1998.

    Science.gov (United States)

    Kelley, William L; Jousselin, Ambre; Barras, Christine; Lelong, Emmanuelle; Renzoni, Adriana

    2015-04-01

    The development and maintenance of an arsenal of antibiotics is a major health care challenge. Ceftaroline is a new cephalosporin with activity against methicillin-resistant Staphylococcus aureus (MRSA); however, no reports concerning MRSA ceftaroline susceptibility have been reported in Switzerland. We tested the in vitro activity of ceftaroline against an archived set of 60 MRSA strains from the University Hospital of Geneva collected from 1994 to 2003. Our results surprisingly revealed ceftaroline-resistant strains (MIC, >1 μg/ml in 40/60 strains; EUCAST breakpoints, susceptible [S], ≤1 μg/ml; resistant [R], >1 μg/ml) were present from 1998 to 2003. The detected resistant strains predominantly belonged to sequence type 228 (ST228) (South German clonotype) but also to ST247 (Iberian clonotype). A sequence analysis of these strains revealed missense mutations in the penicillin-binding protein 2A (PBP2A) allosteric domain (N146K or E239K and N146K-E150K-G246E). The majority of our ST228 PBP2A mutations (N146K or E150K) were distinct from ST228 PBP2A allosteric domain mutations (primarily E239K) recently described for MRSA strains collected in Thailand and Spain during the 2010 Assessing Worldwide Antimicrobial Resistance Evaluation (AWARE) global surveillance program. We also found that similar allosteric domain PBP2A mutations (N146K) correlated with ceftaroline resistance in an independent external ST228 MRSA set obtained from the nearby University Hospital of Lausanne, Lausanne, Switzerland, collected from 2003 to 2008. Thus, ceftaroline resistance was observed in our archived strains (including two examples of an MIC of 4 µg/ml for the Iberian ST247 clonotype with the triple mutation N146K/E150K/G246E), at least as far back as 1998, considerably predating the commercial introduction of ceftaroline. Our results reinforce the notion that unknown parameters can potentially exert selective pressure on PBP2A that can subsequently modulate ceftaroline

  9. How does real affect affect affect recognition in speech?

    NARCIS (Netherlands)

    Truong, Khiet Phuong

    2009-01-01

    The aim of the research described in this thesis was to develop speech-based affect recognition systems that can deal with spontaneous (‘real’) affect instead of acted affect. Several affect recognition experiments with spontaneous affective speech data were carried out to investigate what combinati

  10. SHV-type extended-spectrum beta-lactamase (ESBL) are encoded in related plasmids from enterobacteria clinical isolates from Mexico beta-Lactamasas de espectro extendido (BLEE) tipo SHV están codificadas en plásmidos relacionados en aislamientos clínicos de enterobacterias en México

    OpenAIRE

    Ulises Garza-Ramos; Esperanza Martínez-Romero; Jesús Silva-Sánchez

    2007-01-01

    OBJECTIVE: In this work we report the molecular characterization of beta-lactam antibiotics resistance conferred by genes contained in plasmids from enterobacteria producing extended-spectrum beta-lactamases (ESBL). MATERIAL AND METHODS: Fourteen enterobacterial clinical isolates selected from a group of strains obtained from seven different hospitals in Mexico during 1990-1992 and 1996-1998 were analyzed at the Bacterial Resistance Laboratory (National Institute Public Health, Cuernavaca). M...

  11. Antibiotic Susceptibility in Neonatal Invasive Isolates of Streptococcus agalactiae in a 2-Year Nationwide Surveillance Study in Germany

    OpenAIRE

    Fluegge, Kirsten; Supper, Sven; Siedler, Anette; Berner, Reinhard

    2004-01-01

    The antimicrobial susceptibility of 296 invasive neonatal group B streptococcus isolates from a nationwide 2-year surveillance study in Germany was investigated. All isolates were susceptible to beta-lactams, linezolid, quinupristin-dalfopristin, and vancomycin. Erythromycin and clindamycin resistance was found in 10.1 and 5.7%, respectively. The ermB, ermTR, or mefA gene was detected in all but one of the erythromycin-resistant isolates.

  12. Phenotypic detection of beta-lactamases production in enterobacteriaceae

    OpenAIRE

    Ćirković Ivana; Pavlović Ljiljana; Konstantinović Neda; Kostić Katarina; Jovanović Snežana; Đukić Slobodanka

    2014-01-01

    Introduction. Beta-lactam antibiotics are the most commonly used antibacterial drugs. However, many bacteria have developed resistance to these antibiotics, and the most common form of resistance is the production of beta-lactamase enzymes. Many members of the Enterobacteriaceae family produce different types of these enzymes. Objective. The aim of this study was to perform phenotypic detection of production and identification of beta-lactamase type in Ente...

  13. Coexistence of Extended Spectrum Beta-Lactamases, AmpC Beta-Lactamases and Metallo-Beta-Lactamases in Acinetobacter baumannii from burns patients: a report from a tertiary care centre of India

    OpenAIRE

    Gupta, V.; Garg, R.; Garg, S.; J Chander; Attri, A.K.

    2013-01-01

    Multidrug-resistant Acinetobacter baumanii is a major pathogen encountered in pyogenic infections, especially from burns patients in hospital settings. Often there is also coexistence of multiple beta-lactamase enzymes responsible for beta-lactam resistance in a single isolate, which further complicates treatment options. We conducted a study on burn wound pus samples obtained from the burns unit of our hospital. Phenotypic tests were used to determine the Extended Spectrum Beta-Lactamase, Am...

  14. Studies on New Delhi Metallo-Beta-Lactamse-1 producing Acinetobacter baumannii isolated from donor swab in a tertiary eye care centre, India and structural analysis of its antibiotic binding interactions

    OpenAIRE

    Sowmiya, Murali; Umashankar, Vetrivel; Muthukumaran, Sivashanmugan; Madhavan, Hajib Naraharirao; Malathi, Jambulingam

    2012-01-01

    Gram-negative bacilli, Enterobacteriaceae and Non-fermentors with resistance to carbapenems and metallo beta-lactams are the major cause of concern in clinical problems in current human healthcare. The most highly emerging dreadful Metallo Beta-lactamses is New Delhi metallo-beta-lactamase (blaNDM-1) which confers resistance to carbapenems; susceptible only to colistin and, less consistently to tigecycline, leading to no therapeutic options. In the present study, we demonstrate the effects of...

  15. Draft Genome Sequence of Uropathogenic Escherichia coli Strain NB8.

    Science.gov (United States)

    Weng, Xing-Bei; Mi, Zu-Huang; Wang, Chun-Xin; Zhu, Jian-Ming

    2016-01-01

    Escherichia coli NB8 is a clinical pyelonephritis isolate. Here, we report the draft genome sequence of uropathogenic E. coli NB8, which contains drug resistance genes encoding resistance to beta-lactams, aminoglycosides, quinolones, macrolides, colistin, sulfonamide-trimethoprim, and tetracycline. NB8 infects the kidney and bladder, making it an important tool for studying E. coli pathogenesis. PMID:27609920

  16. Antibiotic Resistance

    Science.gov (United States)

    Antibiotics are medicines that fight bacterial infections. Used properly, they can save lives. But there is a growing problem of antibiotic resistance. It happens when bacteria change and become able to resist the effects of an antibiotic. Using antibiotics can lead to resistance. ...

  17. Missense mutations in PBP2A Affecting ceftaroline susceptibility detected in epidemic hospital-acquired methicillin-resistant Staphylococcus aureus clonotypes ST228 and ST247 in Western Switzerland archived since 1998

    OpenAIRE

    Kelley, William; Jousselin, Ambre; Barras, Christine; Lelong, Emmanuelle; Renzoni, Adriana Maria

    2015-01-01

    The development and maintenance of an arsenal of antibiotics is a major health care challenge. Ceftaroline is a new cephalosporin with activity against methicillin-resistant Staphylococcus aureus (MRSA); however, no reports concerning MRSA ceftaroline susceptibility have been reported in Switzerland. We tested the in vitro activity of ceftaroline against an archived set of 60 MRSA strains from the University Hospital of Geneva collected from 1994 to 2003. Our results surprisingly revealed cef...

  18. Inhibition of AmpC beta-lactamase through a destabilizing interaction in the active site

    Energy Technology Data Exchange (ETDEWEB)

    Trehan, I.; Beadle, B.M.; Shoichet, B.K. (NWU)

    2010-03-08

    {beta}-Lactamases hydrolyze {beta}-lactam antibiotics, including penicillins and cephalosporins; these enzymes are the most widespread resistance mechanism to these drugs and pose a growing threat to public health. {beta}-Lactams that contain a bulky 6(7){alpha} substituent, such as imipenem and moxalactam, actually inhibit serine {beta}-lactamases and are widely used for this reason. Although mutant serine {beta}-lactamases have arisen that hydrolyze {beta}-lactamase resistant {beta}-lactams (e.g., ceftazidime) or avoid mechanism-based inhibitors (e.g., clavulanate), mutant serine {beta}-lactamases have not yet arisen in the clinic with imipenemase or moxalactamase activity. Structural and thermodynamic studies suggest that the 6(7){alpha} substituents of these inhibitors form destabilizing contacts within the covalent adduct with the conserved Asn152 in class C {beta}-lactamases (Asn132 in class A {beta}-lactamases). This unfavorable interaction may be crucial to inhibition. To test this destabilization hypothesis, we replaced Asn152 with Ala in the class C {beta}-lactamase AmpC from Escherichia coli and examined the mutant enzyme's thermodynamic stability in complex with imipenem and moxalactam. Consistent with the hypothesis, the Asn152 {yields} Ala substitution relieved 0.44 and 1.10 kcal/mol of strain introduced by imipenem and moxalactam, respectively, relative to the wild-type complexes. However, the kinetic efficiency of AmpC N152A was reduced by 6300-fold relative to that of the wild-type enzyme. To further investigate the inhibitor's interaction with the mutant enzyme, the X-ray crystal structure of moxalactam in complex with N152A was determined to a resolution of 1.83 {angstrom}. Moxalactam in the mutant complex is significantly displaced from its orientation in the wild-type complex; however, moxalactam does not adopt an orientation that would restore competence for hydrolysis. Although Asn152 forces {beta}-lactams with 6(7){alpha

  19. Dynamics and spatial distribution of beta-lactamase expression in Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Bagge, N.; Hentzer, Morten; Andersen, Jens Bo; Ciofu, O.; Givskov, Michael Christian; Høiby, N.

    2004-01-01

    The development of resistance to beta-lactam antibiotics is a problem in the treatment of chronic Pseudomonas aeruginosa infection in the lungs of patients with cystic fibrosis. The main resistance mechanism is high-level expression of the chromosomally encoded AmpC beta-lactamase of P. aeruginosa...... cells growing in biofilms. Several genes have been shown to influence the level of ampC expression, but little is known about the regulation of ampC expression in P. aeruginosa biofilms. To study the expression of ampC in P. aeruginosa biofilms, we constructed a reporter that consisted of the fusion of...... the ampC promoter to gfp(ASV) encoding an unstable version of the green fluorescent protein. In vitro biofilms of P. aeruginosa were exposed to the beta-lactam antibiotics imipenem and ceftazidime. Sub-MICs of imipenem significantly induced the monitor system of the biofilm bacteria in the peripheries...

  20. The real threat of Klebsiella pneumoniae carbapenemase-producing bacteria.

    Science.gov (United States)

    Nordmann, Patrice; Cuzon, Gaelle; Naas, Thierry

    2009-04-01

    From early this decade, Enterobacteriaceae that produce Klebsiella pneumoniae carbapenemases (KPC) were reported in the USA and subsequently worldwide. These KPC-producing bacteria are predominantly involved in nosocomial and systemic infections; although they are mostly Enterobacteriaceae, they can also be, rarely, Pseudomonas aeruginosa isolates. KPC beta lactamases (KPC-1 to KPC-7) confer decreased susceptibility or resistance to virtually all beta lactams. Carbapenems (imipenem, meropenem, and ertapenem) may thus become inefficient for treating enterobacterial infections with KPC-producing bacteria, which are, in addition, resistant to many other non-beta-lactam molecules, leaving few available therapeutic options. Detection of KPC-producing bacteria may be difficult based on routine antibiotic susceptibility testing. It is therefore crucial to implement efficient infection control measures to limit the spread of these pathogens. PMID:19324295

  1. In vitro activity of 79 antimicrobial agents against Corynebacterium group D2.

    OpenAIRE

    García-Rodriguez, J A; García Sánchez, J E; Muñoz Bellido, J L; Nebreda Mayoral, T; García Sánchez, E; García García, I

    1991-01-01

    Corynebacterium group D2 (CGD2) is involved in urinary tract infections in patients with underlying predisposing factors. This microorganism is highly resistant to a number of antimicrobial agents. We tested the activities of 79 antimicrobial agents against CGD2. beta-Lactams, aminoglycosides, and macrolides were ineffective. Fluorinated quinolones showed irregular activities, ofloxacin being the most active one. Doxycycline, rifampin, and mainly glycopeptides (vancomycin and teicoplanin) wer...

  2. Evaluation of an Immunochromatographic Assay for Rapid Detection of Penicillin-Binding Protein 2a in Human and Animal Staphylococcus intermedius Group, Staphylococcus lugdunensis, and Staphylococcus schleiferi Clinical Isolates.

    Science.gov (United States)

    Arnold, A R; Burnham, C-A D; Ford, B A; Lawhon, S D; McAllister, S K; Lonsway, D; Albrecht, V; Jerris, R C; Rasheed, J K; Limbago, B; Burd, E M; Westblade, L F

    2016-03-01

    The performance of a rapid penicillin-binding protein 2a (PBP2a) detection assay, the Alere PBP2a culture colony test, was evaluated for identification of PBP2a-mediated beta-lactam resistance in human and animal clinical isolates of Staphylococcus intermedius group, Staphylococcus lugdunensis, and Staphylococcus schleiferi. The assay was sensitive and specific, with all PBP2a-negative and PBP2a-positive strains testing negative and positive, respectively. PMID:26677248

  3. Drug: D08307 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D08307 Drug Oxacillin ... (INN); Oxacilina (TN) C19H19N3O5S 401.1045 401.4363 D08307.gif Antibiotic, ... J01CF Beta-lactamase resistant penicillins J01CF04 Oxacillin ... D08307 Oxacillin ... (INN) USP drug classification [BR ... :br08302] Antibacterials Beta-lactam, Penicillins Oxacillin ... D08307 Oxacillin ... (INN) Antiinfectives [BR:br08307] ...

  4. Drug: D00929 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D00929 Drug Oxacillin ... sodium (JAN/USP); Oxacillin ... sodium hydrate; Bactocill (TN) C19H18N3O5S. Na ... J01CF Beta-lactamase resistant penicillins J01CF04 Oxacillin ... D00929 Oxacillin ... sodium (JAN/USP) USP drug classif ... R:br08302] Antibacterials Beta-lactam, Penicillins Oxacillin ... D00929 Oxacillin ... sodium (JAN/USP) Antiinfectives [ ...

  5. Novel plasmid-mediated beta-lactamase from Escherichia coli that inactivates oxyimino-cephalosporins.

    OpenAIRE

    Matsumoto, Y; Ikeda, F; Kamimura, T.; Yokota, Y.; Mine, Y

    1988-01-01

    A highly cephem-resistant Escherichia coli strain, FP1546, isolated from the fecal flora of laboratory dogs previously administered beta-lactam antibiotics was found to produce a beta-lactamase, FEC-1, of 48-kilodalton size and pI 8.2. FEC-1 hydrolyzed cefuroxime, cefotaxime, cefmenoxime, and ceftriaxone, as well as the enzymatically less-stable antibiotics cephaloridine, cefotiam, and cefpiramide. Of the oxyimino-cephalosporins, ceftizoxime was fairly stable to FEC-1. FEC-1 differed notably ...

  6. TEM-4, a new plasmid-mediated beta-lactamase that hydrolyzes broad-spectrum cephalosporins in a clinical isolate of Escherichia coli.

    OpenAIRE

    Paul, G C; Gerbaud, G; Bure, A; Philippon, A M; B. Pangon; Courvalin, P.

    1989-01-01

    A clinical isolate of Escherichia coli, strain CB-134, recovered in 1986 from an abdominal abscess, exhibited resistance to penams, oxyimino-beta-lactams including broad-spectrum cephalosporins (cefotaxime, ceftriaxone, ceftazidime), and aztreonam but remained susceptible to cephamycins (cefoxitin, cefotetan) and to moxalactam and imipenem. Clavulanate (2 micrograms/ml) restored the susceptibility of the strain to broad-spectrum cephalosporins and aztreonam. A beta-lactamase with an isoelectr...

  7. Iron limitation induces SpoT-dependent accumulation of ppGpp in Escherichia coli.

    OpenAIRE

    Vinella, Daniel; Albrecht, Christian; Cashel, Michael; D'Ari, Richard

    2005-01-01

    In Escherichia coli the beta-lactam mecillinam specifically inhibits penicillin-binding protein 2 (PBP2), a peptidoglycan transpeptidase essential for maintaining rod shape. We have previously shown that PBP2 inactivation results in a cell division block and that an increased concentration of the nucleotide ppGpp, effector of the RelA-dependent stringent response, confers mecillinam resistance and allows cells to divide as spheres in the absence of PBP2 activity. In this study we have charact...

  8. Prevalence of AmpC and ESBL Producing E. coli and Antibacterial Effect of Allim sativum on Clinical Isolates Collected from Zahedan Hospitals

    OpenAIRE

    Mohammad Bokaeian; Sara Shayan; Shahram Shahraki; Saeide Saeidi

    2014-01-01

    Background: AmpC beta-lactamases are capable to hydrolyse all beta-lactam antibiotics except cefepime and carbapenems. Herbal medicines have been important sources of products for the developing countries in treating common infectious diseases and overcome the problems of resistance and side effects of the currently available antimicrobial agents. Materials and Methods: Total 410 non repetitive clinical E. coli strains recovered during 7 month, were screened for AmpC production by disc dif...

  9. In vitro activities of moxalactam and cefotaxime against aerobic gram-negative bacilli.

    OpenAIRE

    Jorgensen, J H; Crawford, S. A.; Alexander, G A

    1980-01-01

    The in vitro activities of two new beta-lactam antibiotics, moxalactam disodium (LY 127935) and cefotaxime (HR-756), were compared with cefoxitin, cefamandole, cefuroxime, cephalothin, and, in some instances, carbenicillin, gentamicin, and amikacin against aerobic gram-negative bacilli. Test isolates included normally cephalosporin-resistant members of the Enterobacteriaceae and Pseudomonas spp. and a variety of nonfermentative or oxidase-positive bacteria. Both moxalactam and cefotaxime demo...

  10. Evaluation of aztreonam in experimental bacterial meningitis and cerebritis.

    OpenAIRE

    Scheld, W. M.; Brodeur, J P; Gratz, J C; Foresman, P; Rodeheaver, G

    1983-01-01

    Aztreonam (SQ 26,776), a new monocyclic beta-lactam agent, was compared with ampicillin, ampicillin plus chloramphenicol, and gentamicin in rabbits with experimental meningitis induced by, respectively, ampicillin-susceptible Haemophilus influenzae, ampicillin-resistant H. influenzae, and Escherichia coli. Aztreonam was also compared with gentamicin in experimentally induced E. coli cerebritis in rats. Doses of the various agents were delivered that produced near-peak concentrations in serum ...

  11. Resistant Hypertension.

    Science.gov (United States)

    Doroszko, Adrian; Janus, Agnieszka; Szahidewicz-Krupska, Ewa; Mazur, Grzegorz; Derkacz, Arkadiusz

    2016-01-01

    Resistant hypertension is a severe medical condition which is estimated to appear in 9-18% of hypertensive patients. Due to higher cardiovascular risk, this disorder requires special diagnosis and treatment. The heterogeneous etiology, risk factors and comorbidities of resistant hypertension stand in need of sophisticated evaluation to confirm the diagnosis and select the best therapeutic options, which should consider lifestyle modifications as well as pharmacological and interventional treatment. After having excluded pseudohypertension, inappropriate blood pressure measurement and control as well as the white coat effect, suspicion of resistant hypertension requires an analysis of drugs which the hypertensive patient is treated with. According to one definition - ineffective treatment with 3 or more antihypertensive drugs including diuretics makes it possible to diagnose resistant hypertension. A multidrug therapy including angiotensin - converting enzyme inhibitors, angiotensin II receptor blockers, beta blockers, diuretics, long-acting calcium channel blockers and mineralocorticoid receptor antagonists has been demonstrated to be effective in resistant hypertension treatment. Nevertheless, optional, innovative therapies, e.g. a renal denervation or baroreflex activation, may create a novel pathway of blood pressure lowering procedures. The right diagnosis of this disease needs to eliminate the secondary causes of resistant hypertension e.g. obstructive sleep apnea, atherosclerosis and renal or hormonal disorders. This paper briefly summarizes the identification of the causes of resistant hypertension and therapeutic strategies, which may contribute to the proper diagnosis and an improvement of the long term management of resistant hypertension. PMID:26935512

  12. Antimicrobial Resistance

    Science.gov (United States)

    ... others. For example, the emergence of Plasmodium falciparum multidrug resistance, including resistance to ACTs in the Greater Mekong subregion is an urgent public health concern that is threatening global efforts to reduce the burden of malaria. Although MDR-TB is a growing concern, it is still ...

  13. Anticoagulant Resistance

    DEFF Research Database (Denmark)

    Heiberg, Ann-Charlotte

    specific PCR to verify this genetic form of resistance, but in contrast to animals tested from various surface populations, we could not confirm the Y139C mutation in any of the sewer rats. Our findings could indicate that resistance in surface and sewer population may be caused by different mechanism or...

  14. Camptothecin resistance

    DEFF Research Database (Denmark)

    Brangi, M; Litman, Thomas; Ciotti, M; Nishiyama, K; Kohlhagen, G; Takimoto, C; Robey, R; Pommier, Y; Fojo, T; Bates, S E

    1999-01-01

    after camptothecin treatment. In addition to topotecan and SN-38, MXR-overexpressing cells are highly resistant to mitoxantrone and epirubicin. Because these compounds are susceptible to glucuronidation, we examined UDP-glucurono-syltransferase (UGT) activity in parental and resistant cells by TLC...

  15. 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...

  16. Antimicrobial resistance in Libya: 1970-2011

    OpenAIRE

    Ghenghesh, Khalifa Sifaw; Rahouma, Amal; Tawil, Khaled; Zorgani, Abdulaziz; Franka, Ezzedin

    2013-01-01

    Resistance to antimicrobial agents is a major health problem that affects the whole world. Providing information on the past state of antimicrobial resistance in Libya may assist the health authorities in addressing the problem more effectively in the future. Information was obtained mainly from Highwire Press (including PubMed) search for the period 1970-2011 using the terms ‘antibiotic resistance in Libya’, ‘antimicrobial resistance in Libya’, ‘tuberculosis in Libya’, and ‘primary and acqui...

  17. Genetic Resources for Disease Resistance in Wheat

    OpenAIRE

    Hysing, Shu-Chin

    2007-01-01

    Bread wheat is affected by many diseases that cause yield and quality losses. The incorporation of resistance genes is a user- and environmentally friendly method to manage disease. It is highly desirable that the resistance is durable and that the genes have a positive or no influence on agronomic performance. The characterization of genetic resources for resistance is a prerequisite for their utilization in plant breeding. The aim of the present thesis was to characterize resistance against...

  18. Neutron Diffraction Studies of a Class A beta-Lactamase Toho-1 E166A/R274N/R276N Triple Mutant

    Energy Technology Data Exchange (ETDEWEB)

    Blakeley, Matthew P. [Institut Laue-Langevin (ILL); Chen, Yu [ORNL; Afonine, Pavel [Lawrence Berkeley National Laboratory (LBNL)

    2010-01-01

    beta-Lactam antibiotics have been used effectively over several decades against many types of bacterial infectious diseases. However, the most common cause of resistance to the beta-lactam antibiotics is the production of beta-lactamase enzymes that inactivate beta-lactams by rapidly hydrolyzing the amide group of the beta-lactam ring. Specifically, the class A extended-spectrum beta-lactamases (ESBLs) and inhibitor-resistant enzymes arose that were capable of hydrolyzing penicillins and the expanded-spectrum cephalosporins and monobactams in resistant bacteria, which lead to treatment problems in many clinical settings. A more complete understanding of the mechanism of catalysis of these ESBL enzymes will impact current antibiotic drug discovery efforts. Here, we describe the neutron structure of the class A, CTX-M-type ESBL Toho-1 E166A/R274N/R276N triple mutant in its apo form, which is the first reported neutron structure of a beta-lactamase enzyme. This neutron structure clearly reveals the active-site protonation states and hydrogen-bonding network of the apo Toho-1 ESBL prior to substrate binding and subsequent acylation. The protonation states of the active-site residues Ser70, Lys73, Ser130, and Lys234 in this neutron structure are consistent with the prediction of a proton transfer pathway from Lys73 to Ser130 that is likely dependent on the conformation of Lys73, which has been hypothesized to be coupled to the protonation state of Glu166 during the acylation reaction. Thus, this neutron structure is in agreement with a proposed mechanism for acylation that identifies Glu166 as the general base for catalysis.

  19. Neutron Diffraction Studies of a Class A beta-Lactamase Toho-1 E166A/R274N/R276N Triple Mutant

    International Nuclear Information System (INIS)

    beta-Lactam antibiotics have been used effectively over several decades against many types of bacterial infectious diseases. However, the most common cause of resistance to the beta-lactam antibiotics is the production of beta-lactamase enzymes that inactivate beta-lactams by rapidly hydrolyzing the amide group of the beta-lactam ring. Specifically, the class A extended-spectrum beta-lactamases (ESBLs) and inhibitor-resistant enzymes arose that were capable of hydrolyzing penicillins and the expanded-spectrum cephalosporins and monobactams in resistant bacteria, which lead to treatment problems in many clinical settings. A more complete understanding of the mechanism of catalysis of these ESBL enzymes will impact current antibiotic drug discovery efforts. Here, we describe the neutron structure of the class A, CTX-M-type ESBL Toho-1 E166A/R274N/R276N triple mutant in its apo form, which is the first reported neutron structure of a beta-lactamase enzyme. This neutron structure clearly reveals the active-site protonation states and hydrogen-bonding network of the apo Toho-1 ESBL prior to substrate binding and subsequent acylation. The protonation states of the active-site residues Ser70, Lys73, Ser130, and Lys234 in this neutron structure are consistent with the prediction of a proton transfer pathway from Lys73 to Ser130 that is likely dependent on the conformation of Lys73, which has been hypothesized to be coupled to the protonation state of Glu166 during the acylation reaction. Thus, this neutron structure is in agreement with a proposed mechanism for acylation that identifies Glu166 as the general base for catalysis.

  20. Hydraulic resistance of biofilms

    KAUST Repository

    Dreszer, C.

    2013-02-01

    Biofilms may interfere with membrane performance in at least three ways: (i) increase of the transmembrane pressure drop, (ii) increase of feed channel (feed-concentrate) pressure drop, and (iii) increase of transmembrane passage. Given the relevance of biofouling, it is surprising how few data exist about the hydraulic resistance of biofilms that may affect the transmembrane pressure drop and membrane passage. In this study, biofilms were generated in a lab scale cross flow microfiltration system at two fluxes (20 and 100Lm-2h-1) and constant cross flow (0.1ms-1). As a nutrient source, acetate was added (1.0mgL-1 acetate C) besides a control without nutrient supply. A microfiltration (MF) membrane was chosen because the MF membrane resistance is very low compared to the expected biofilm resistance and, thus, biofilm resistance can be determined accurately. Transmembrane pressure drop was monitored. As biofilm parameters, thickness, total cell number, TOC, and extracellular polymeric substances (EPS) were determined, it was demonstrated that no internal membrane fouling occurred and that the fouling layer actually consisted of a grown biofilm and was not a filter cake of accumulated bacterial cells. At 20Lm-2h-1 flux with a nutrient dosage of 1mgL-1 acetate C, the resistance after 4 days reached a value of 6×1012m-1. At 100Lm-2h-1 flux under the same conditions, the resistance was 5×1013m-1. No correlation of biofilm resistance to biofilm thickness was found; Biofilms with similar thickness could have different resistance depending on the applied flux. The cell number in biofilms was between 4×107 and 5×108 cellscm-2. At this number, bacterial cells make up less than a half percent of the overall biofilm volume and therefore did not hamper the water flow through the biofilm significantly. A flux of 100Lm-2h-1 with nutrient supply caused higher cell numbers, more biomass, and higher biofilm resistance than a flux of 20Lm-2h-1. However, the biofilm thickness

  1. Continuous and Prolonged Intravenous β-Lactam Dosing: Implications for the Clinical Laboratory.

    Science.gov (United States)

    Grupper, Mordechai; Kuti, Joseph L; Nicolau, David P

    2016-10-01

    Beta-lactam antibiotics serve as a cornerstone in the management of bacterial infections because of their wide spectrum of activity and low toxicity. Since resistance rates among bacteria are continuously on the rise and the pipeline for new antibiotics does not meet this trend, an optimization of current beta-lactam treatment is needed. This review provides an overview of optimization through use of prolonged- and continuous-infusion dosing strategies compared with more traditional intermittent infusions. Included is an overview of the scientific basis for using these nontraditional prolonged- and continuous-infusion-based regimens, with a focus on major areas in which the clinical laboratory can support the clinical use of these regimens. PMID:27413094

  2. Antibiotic Resistance

    Science.gov (United States)

    ... Radiation-Emitting Products Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products For Consumers Home For Consumers Consumer Information by Audience For Women Antibiotic Resistance Share Tweet Linkedin Pin it More ...

  3. MSMA resistance studies.

    Science.gov (United States)

    Camper, N D; Keese, R J; Coker, P S

    2004-05-01

    Monosodium methanearsonate (MSMA)-resistant and -susceptible common cocklebur (Xanthium strumarium L.) and cotton (Gossypium hirsutum L.) were treated with MSMA. Plant parameters analyzed were: glutathione synthetase activity, selected amino acid (arginine, glutamic acid, alanine, citrulline, glutamine, and glutathione) content and arsenic content (MSMA, total arsenic, and arsonate). No reduction of arsenic from the parent pentavalent form present in MSMA to the trivalent form was detected. Arginine, glutamic acid, and glutamine content increased in tissue three days after MSMA treatment. Glutathione content decreased during the first three days after treatment; however, five days after treatment the resistant biotype of cocklebur and cotton had elevated glutathione levels (8-20 times greater, respectively). Glutathione Synthetase activity was higher in cotton than in either of the cocklebur biotypes; MSMA did not affect its activity in cotton or either cocklebur biotype. Resistant biotypes have a slightly higher activity than the susceptible biotype. Tolerance of cotton to MSMA may be related to glutathione synthetase activity and possibly to the presence of phytochelatins. Also, increased glutathione levels in the resistant biotype may implicate phytochelatin involvement in the resistance mechanism. PMID:15473645

  4. Experiencing affective interactive art

    NARCIS (Netherlands)

    Bialoskorski, Leticia S.S.; Westerink, Joyce H.D.M.; Broek, van den Egon L.

    2010-01-01

    The progress in the field of affective computing enables the realization of affective art. This paper describes the affective interactive art system Mood Swings, which interprets and visualizes affect expressed by a person. Mood Swings is founded on the integration of a framework for affective move

  5. The effect of electrode contact resistance and capacitive coupling on Complex Resistivity measurements

    DEFF Research Database (Denmark)

    Ingeman-Nielsen, Thomas

    2006-01-01

    The effect of electrode contact resistance and capacitive coupling on complex resistivity (CR) measurements is studied in this paper. An equivalent circuit model for the receiver is developed to describe the effects. The model shows that CR measurements are severely affected even at relatively lo...... the contact resistance artificially increased by resistors. The results emphasize the importance of keeping contact resistance low in CR measurements....

  6. [Resistant fungi].

    Science.gov (United States)

    Vehreschild, M J G T; Cornely, O A

    2015-11-01

    Particularly in the area of hematology/oncology and intensive care medicine, infections due to resistant fungi are to be expected. Emergence of resistance in fungi is a less dynamic process than in bacteria; it can, however, have an equally important impact on treatment strategies. In the following article, the most important resistance patterns of yeasts and molds (Candida albicans , Aspergillus fumigatus, the order Mucorales and the genus Fusarium) will be presented and discussed. Their diagnosis mostly being based on blood cultures, resistance testing for yeasts is usually readily available. Culture-based therapeutic adjustments in mold infections are, however, only rarely possible, as most antifungal therapies for these infections are initiated on an empirical basis after identification of typical infiltrates on a CT scan. Response to therapy is then evaluated on the basis of clinical signs and symptoms in combination with follow-up CT scans. In case of therapeutic failure or appearance of suspicious infiltrates under antifungal prophylaxis, an open or CT-guided biopsy is recommended to allow efficient adaptation of antifungal treatment. In individual cases, particularly in patients diagnosed with mucormycosis, resection of the focus of infection may be necessary to achieve a satisfactory treatment response. PMID:26432089

  7. Resisting "Reason"

    DEFF Research Database (Denmark)

    Merrild, Camilla Hoffmann; Andersen, Rikke Sand; Risør, Mette Bech;

    2016-01-01

    Social differences in health and illness are well documented in Denmark. However, little is known about how health practices are manifested in the everyday lives of different social classes. We propose acts of resistance and formation of health subjectivities as helpful concepts to develop our un...

  8. Tumor Resistance Explained by Hormesis

    OpenAIRE

    Calabrese, Edward J.; Nascarella, Marc A.

    2010-01-01

    Enhanced drug (GDC 0449) resistance in a mouse model for human medulloblastoma is shown in the present paper to act via an hormetic response. This has significant implications, imposing constraints on the quantitative features of the dose response of the chemotherapeutic agent, affecting optimal study design, mechanism assessment strategy, potential for tumor rebound, patient relapse and disease outcome.

  9. Addressing viral resistance through vaccines

    Science.gov (United States)

    Laughlin, Catherine; Schleif, Amanda; Heilman, Carole A

    2015-01-01

    Antimicrobial resistance is a serious healthcare concern affecting millions of people around the world. Antiviral resistance has been viewed as a lesser threat than antibiotic resistance, but it is important to consider approaches to address this growing issue. While vaccination is a logical strategy, and has been shown to be successful many times over, next generation viral vaccines with a specific goal of curbing antiviral resistance will need to clear several hurdles including vaccine design, evaluation and implementation. This article suggests that a new model of vaccination may need to be considered: rather than focusing on public health, this model would primarily target sectors of the population who are at high risk for complications from certain infections. PMID:26604979

  10. Influence of the adipate and dissolved oxygen concentrations on the beta-lactam production during continuous cultivations of a Penicillium chrysogenum strain expressing the expandase gene from Streptomyces clavuligerus

    DEFF Research Database (Denmark)

    Robin, Jarno Jacky Christian; Bonneau, S.; Schipper, D.;

    2003-01-01

    The influence of adipate concentration and dissolved oxygen on production of adipoyl-7-aminodeacetoxycephalosporanic acid (ad-7-ADCA) by a recombinant strain of Penicillium chrysogenum expressing the expandase gene from Streptomyces clavuligerus was studied in glucose-limited continuous cultures....... decreased from 15 to 7%AS, r(p) (total) increased to 25 mumol g DW-1 h(-1), mainly due to a two-fold increase in the adipoyl-6-aminopenicillanic acid (ad-6-APA) specific productivity....

  11. Involvement of penicillin-binding protein 2 with other penicillin-binding proteins in lysis of Escherichia coli by some beta-lactam antibiotics alone and in synergistic lytic effect of amdinocillin (mecillinam).

    OpenAIRE

    Gutmann, L; Vincent, S; Billot-Klein, D; Acar, J F; Mrèna, E; Williamson, R.

    1986-01-01

    Compared with cefotaxime, ceftazidime, moxalactam, and aztreonam, ceftriaxone produced the best lytic and bactericidal effects when each was added at about 10 times the MIC to Escherichia coli W7. When each of these antibiotics was added at its MIC, only bacteriostasis occurred, but the simultaneous addition of amdinocillin (mecillinam) was synergistic in causing rapid lysis and bactericidal effects. Induction of lysis of two E. coli mutants containing either a thermosensitive penicillin-bind...

  12. Multiple Breed Validation of Five QTL Affecting Mastitis Resistance

    DEFF Research Database (Denmark)

    Vilkki, Johanna; Dolezal, Marlies A; Sahana, Goutam;

    Ayrshire (SCC, clinical mastitis, udder conformation) and Valdostana (SCC, milk bacteriological results). Furthermore, association analysis across the regions was performed with a linear mixed model using imputed sequence for 845 Danish Red sires with nine mastitis phenotypes. Associations in five regions...

  13. Resistance welding

    DEFF Research Database (Denmark)

    Bay, Niels; Zhang, Wenqi; Rasmussen, Mogens H.;

    2003-01-01

    Resistance welding comprises not only the well known spot welding process but also more complex projection welding operations, where excessive plastic deformation of the weld point may occur. This enables the production of complex geometries and material combinations, which are often not possible...... to weld by traditional spot welding operations. Such joining processes are, however, not simple to develop due to the large number of parameters involved. Development has traditionally been carried out by large experimental investigations, but the development of a numerical programme system has...... changed this enabling prediction of the welding performance in details. The paper describes the programme in short and gives examples on industrial applications. Finally investigations of causes for failure in a complex industrial joint of two dissimilar metals are carried out combining numerical...

  14. Pain, Affect, and Attachment

    OpenAIRE

    Carl Eduard Scheidt; Elisabeth Waller

    2015-01-01

    Various psychodynamic processes may underlie the development of psychogenic pain disorder such as conversion, the displacement of affect, or narcissistic defenses. However, many of the processes suggested are related to a disorder of affect regulation. The term affect regulation in psychoanalytic literature refers to phenomena which are often described by the concept of alexithymia. Empirical observations suggest that alexithymia is correlated to insecure attachment, especially an insecure di...

  15. The affect structure revisited

    OpenAIRE

    Elefant-Yanni, Véronique Rica; Victoria-Feser, Maria-Pia

    2005-01-01

    In affective psychology, there is a persistent controversy about the number, the nature and the definition of the affect structure dimensions. Responding to the methodological criticisms addressed to the preceding studies, we conciliated the principal theories regarding the affect structure with the same experimental setting. In particular, using the semantic items all around the circumplex we found three bipolar independent dimensions and using only the PANAS semantic items, we found two uni...

  16. Identification and evolution of drug efflux pump in clinical Enterobacter aerogenes strains isolated in 1995 and 2003.

    Directory of Open Access Journals (Sweden)

    Jacqueline Chevalier

    Full Text Available BACKGROUND: The high mortality impact of infectious diseases will increase due to accelerated evolution of antibiotic resistance in important human pathogens. Development of antibiotic resistance is a evolutionary process inducing the erosion of the effectiveness of our arsenal of antibiotics. Resistance is not necessarily limited to a single class of antibacterial agents but may affect many unrelated compounds; this is termed 'multidrug resistance' (MDR. The major mechanism of MDR is the active expulsion of drugs by bacterial pumps; the treatment of gram negative bacterial infections is compromised due to resistance mechanisms including the expression of efflux pumps that actively expel various usual antibiotics (beta-lactams, quinolones, .... METHODOLOGY/PRINCIPAL FINDINGS: Enterobacter aerogenes has emerged among Enterobacteriaceae associated hospital infections during the last twenty years due to its faculty of adaptation to antibiotic stresses. Clinical isolates of E. aerogenes belonging to two strain collections isolated in 1995 and 2003 respectively, were screened to assess the involvement of efflux pumps in antibiotic resistance. Drug susceptibility assays were performed on all bacterial isolates and an efflux pump inhibitor (PAbetaN previously characterized allowed to decipher the role of efflux in the resistance. Accumulation of labelled chloramphenicol was monitored in the presence of an energy poison to determine the involvement of active efflux on the antibiotic intracellular concentrations. The presence of the PAbetaN-susceptible efflux system was also identified in resistant E. aerogenes strains. CONCLUSIONS/SIGNIFICANCE: For the first time a noticeable increase in clinical isolates containing an efflux mechanism susceptible to pump inhibitor is report within an 8 year period. After the emergence of extended spectrum beta-lactamases in E. aerogenes and the recent characterisation of porin mutations in clinical isolates, this study

  17. Susceptibility to antimicrobial agents and plasmid carrying in Aeromonas hydrophila isolated from two estuarine systems.

    Science.gov (United States)

    Montoya, R; Dominguez, M; Gonzalez, C; Mondaca, M A; Zemelman, R

    1992-01-01

    Susceptibility to various antimicrobial agents and the presence of plasmids was investigated in eleven strains of Aeromonas hydrophila isolated from samples of sea water and these strains isolated from Aulacomya ater. Transference of resistance to Escherichia coli was attempted by conjugation and transformation experiments. The strains showed multiple resistance toward beta-lactam antibiotics and susceptibility to other antimicrobial agents. Five strains harboured plasmids with molecular weights below 5.7 MD. It was not possible to relate the resistance of the strains with the presence of their plasmids. PMID:1593967

  18. Affectivity and race

    DEFF Research Database (Denmark)

    This book presents new empirical studies of social difference in the Nordic welfare states, in order to advance novel theoretical perspectives on the everyday practices and macro-politics of race and gender in multi-ethnic societies. With attention to the specific political and cultural landscapes...... of the Nordic countries, Affectivity and Race draws on a variety of sources, including television programmes, news media, fictional literature, interviews, ethnographic observations, teaching curricula and policy documents, to explore the ways in which ideas about affectivity and emotion afford new...... insights into the experience of racial difference and the unfolding of political discourses on race in various social spheres. Organised around the themes of the politicisation of race through affect, the way that race produces affect and the affective experience of race, this interdisciplinary collection...

  19. Affectivity in the Liminal

    DEFF Research Database (Denmark)

    Thomassen, Bjørn

    alternative interpretations of what liminality is, or could be, taking it to territories distant from its place of origin, quite the contrary: we are moving the concept back to its rightful place in intellectual history and back to the core of its significance, back to the centre of human emotions trembling......In this paper I propose a return to the work of Arnold van Gennep, in order to briefly discuss how the terms of liminality and affectivity were always already connected. By linking the concept of liminality that van Gennep made famous to affectivity, we are actually not proposing new and...... at the threshold. The paper contains three sections: a) liminality and affectivity in van Gennep’s life; b) liminality and affectivity as a theme in his work; c) liminality and affectivity as developed in the early reception of his work....

  20. X100抗大变形管线钢焊接热影响区的显微组织与冲击功%Microstructure and Impact Energy of Heat Affected Zone for X100 Pipeline Steel with High Deformation Resistance

    Institute of Scientific and Technical Information of China (English)

    李光; 李雪萍; 徐学利; 张骁勇; 高惠临; 刘彦明

    2015-01-01

    采用部分再结晶区加速冷却的方法获得了 X100抗大变形管线钢,利用焊接热模拟技术制备了不同热影响区试样并研究了其冲击功和显微组织.结果表明:X100抗大变形管线钢具有较强的极限应变能力,其组织为粒状贝氏体和多边形铁素体;模拟热影响区试样的冲击功随热循环峰值温度的升高而下降,当峰值温度为1300℃时,冲击功为247.9 J,比母材的降低了17.3%,冲击断裂方式也从韧性断裂转为解理断裂;热循环峰值温度升高使热影响区组织发生再结晶,并且晶粒粗化,降低了其韧性.%The X100 pipeline steel with high deformation resistance was obtained by the critical region accelerated cooling method.The impact energy and microstructures of the heat affected zone (HAZ)specimens prepared by means of welding thermal simulation technology were investigated.The results show that the ultimate strain capability of the X100 pipeline steel with high deformation resistance was strong and the microstructure was composed of bainite and ferrite.The impact energy of the HAZ specimens prepared by weld simulation decreased with the rise of the thermal cycle peak temperature.When the peak temperature was 1 300 ℃,the impact energy reached the lowest value of 247.9 J,which was reduced by 1 7.3% comparing to that of base material,and then the fracture mode changed from ductile fracture to cleavage fracture.The rise of the thermal cycle peak temperature resulted in the recrystallization and grain coarseness in HAZ microstructure,and then decreased the toughness.

  1. Resistance training and sarcopenia.

    Science.gov (United States)

    Giallauria, Francesco; Cittadini, Antonio; Smart, Neil Andrew; Vigorito, Carlo

    2016-01-01

    Aging is inexorably accompanied by a progressive decline of muscle mass, quality and strength. The resulting condition has been termed sarcopenia. Age-related sarcopenia can be accelerated by a variety of factors including changes in the hormonal milieu, inactivity, poor nutrition, chronic illness, and loss of integrity and function in the peripheral and central nervous systems. The downstream mechanisms by which these risk factors cause sarcopenia are not completely understood. Exercise training (particularly resistance training) has long been identified as the most promising method for increasing muscle mass and strength among older people. New interventions aimed at preventing muscle atrophy, promoting muscle growth and ultimately, maintaining muscle functions during aging are discussed. Understanding how age affects muscle-related gene expression, protein recycling and resynthesis, post-translational modification and turnover will be crucial to identify new treatment options. PMID:27374049

  2. Animation of Antimicrobial Resistance

    Medline Plus

    Full Text Available ... use of antimicrobial drugs will result in the development of resistant strains of bacteria, complicating clinician's efforts ... More in Antimicrobial Resistance National Antimicrobial Resistance Monitoring System About NARMS Bacteria (NARMS) NARMS at Work Reports ...

  3. Animation of Antimicrobial Resistance

    Medline Plus

    Full Text Available ... 08 Animation of Antimicrobial Resistance (text version) Arabic Translation - Animation of Antimicrobial Resistance (WMV - 19.2MB) Chinese Translation - Animation of Antimicrobial Resistance (WMV - 19.2MB) French ...

  4. HIV Resistance Testing

    Science.gov (United States)

    ... 14, 2016 Select a Language: Fact Sheet 126 HIV Resistance Testing WHAT IS RESISTANCE? HOW DOES RESISTANCE ... ARVs. If you miss doses of your medications, HIV will multiply more easily. More mutations will occur. ...

  5. Animation of Antimicrobial Resistance

    Medline Plus

    Full Text Available ... Veterinary Home Animal & Veterinary Safety & Health Antimicrobial Resistance Animation of Antimicrobial Resistance Share Tweet Linkedin Pin it ... Veterinary Medicine is cited as the corporate author. Animation Animation of Antimicrobial Resistance (WMV - 19.2MB) 9: ...

  6. Pain, Affect, and Attachment

    Directory of Open Access Journals (Sweden)

    Carl Eduard Scheidt

    2015-03-01

    Full Text Available Various psychodynamic processes may underlie the development of psychogenic pain disorder such as conversion, the displacement of affect, or narcissistic defenses. However, many of the processes suggested are related to a disorder of affect regulation. The term affect regulation in psychoanalytic literature refers to phenomena which are often described by the concept of alexithymia. Empirical observations suggest that alexithymia is correlated to insecure attachment, especially an insecure dismissing representation of attachment. Psychodynamic psychotherapy in psychogenic pain disorder should focus on the reintegration of split-off affects which may provoke intensive counter-transference and which in order to be used therapeutically must be linked to attachment experiences within and outside of the therapeutic relationship.

  7. Colors Can Affect Us!

    Institute of Scientific and Technical Information of China (English)

    张俊斌

    2006-01-01

    Different colors affect us differently.The following will show us how they work. Experiment proves that math problems worked on yellow paper have fewer mistakes than problems written on other colors of paper.

  8. Animation of Antimicrobial Resistance

    Medline Plus

    Full Text Available ... More in Antimicrobial Resistance National Antimicrobial Resistance Monitoring System ... Note: If you need help accessing information in different file formats, see Instructions for Downloading ...

  9. Salt Concentration Differences Alter Membrane Resistance in Reverse Electrodialysis Stacks

    KAUST Repository

    Geise, Geoffrey M.

    2014-01-14

    Membrane ionic resistance is usually measured by immersing the membrane in a salt solution at a single, fixed concentration. While salt concentration is known to affect membrane resistance when the same concentration is used on both sides of the membrane, little is known about membrane resistance when the membrane is placed between solutions of different concentrations, such as in a reverse electrodialysis (RED) stack. Ionic resistance measurements obtained using Selemion CMV and AMV that separated sodium chloride and ammonium bicarbonate solutions of different concentrations were greater than those measured using only the high-concentration solution. Measured RED stack resistances showed good agreement with resistances calculated using an equivalent series resistance model, where the membranes accounted for 46% of the total stack resistance. The high area resistance of the membranes separating different salt concentration solutions has implications for modeling and optimizing membranes used in RED systems.

  10. Affective responses to dance.

    Science.gov (United States)

    Christensen, Julia F; Pollick, Frank E; Lambrechts, Anna; Gomila, Antoni

    2016-07-01

    The objective of the present work was the characterization of mechanisms by which affective experiences are elicited in observers when watching dance movements. A total of 203 dance stimuli from a normed stimuli library were used in a series of independent experiments. The following measures were obtained: (i) subjective measures of 97 dance-naïve participants' affective responses (Likert scale ratings, interviews); and (ii) objective measures of the physical parameters of the stimuli (motion energy, luminance), and of the movements represented in the stimuli (roundedness, impressiveness). Results showed that (i) participants' ratings of felt and perceived affect differed, (ii) felt and perceived valence but not arousal ratings correlated with physical parameters of the stimuli (motion energy and luminance), (iii) roundedness in posture shape was related to the experience of more positive emotion than edgy shapes (1 of 3 assessed rounded shapes showed a clear effect on positiveness ratings while a second reached trend level significance), (iv) more impressive movements resulted in more positive affective responses, (v) dance triggered affective experiences through the imagery and autobiographical memories it elicited in some people, and (vi) the physical parameters of the video stimuli correlated only weakly and negatively with the aesthetics ratings of beauty, liking and interest. The novelty of the present approach was twofold; (i) the assessment of multiple affect-inducing mechanisms, and (ii) the use of one single normed stimulus set. The results from this approach lend support to both previous and present findings. Results are discussed with regards to current literature in the field of empirical aesthetics and affective neuroscience. PMID:27235953

  11. Embodied Resistance to Persuasion in Advertising

    Science.gov (United States)

    Lewinski, Peter; Fransen, Marieke L.; Tan, Ed S.

    2016-01-01

    From the literature on resistance to persuasion in advertising, much is known about how people can resist advertising by adopting resistance strategies, such as avoidance, counter-arguing, and selective attention (e.g., Fransen et al., 2015b). However, the role of emotion regulation and bodily expression in resisting persuasion is so far underexplored. This is a surprising observation if one considers that at least 40% of advertisements use positive emotions (i.e., happiness) to persuade people to like the ad, brand, and product (Weinberger et al., 1995). In this article we present a framework in which we apply previous knowledge and theories on emotion regulation and embodiment to the process of resistance to persuasion. In doing so, we specifically address the role of facial expression in the course of resistance. The literature and findings from our own research lead us to propose that people can resist persuasion by controlling their facial expression of emotion when exposed to an advertisement. Controlling the expression of emotions elicited by an ad (for example refusing to smile) might be a fruitful way to resist the ad’s persuasive potential. Moreover, we argue that co-viewers can affect embodied resistance to persuasion. Showing the viability of embodied resistance to persuasion is relevant in view of the fact that ads trying to persuade us by addressing our positive emotions are ubiquitous. Embodied resistance might help people to cope with these induced positive emotions in order to resist advertisements and might therefore work as a novel and effective strategy to resist persuasion. PMID:27574512

  12. Embodied Resistance to Persuasion in Advertising.

    Science.gov (United States)

    Lewinski, Peter; Fransen, Marieke L; Tan, Ed S

    2016-01-01

    From the literature on resistance to persuasion in advertising, much is known about how people can resist advertising by adopting resistance strategies, such as avoidance, counter-arguing, and selective attention (e.g., Fransen et al., 2015b). However, the role of emotion regulation and bodily expression in resisting persuasion is so far underexplored. This is a surprising observation if one considers that at least 40% of advertisements use positive emotions (i.e., happiness) to persuade people to like the ad, brand, and product (Weinberger et al., 1995). In this article we present a framework in which we apply previous knowledge and theories on emotion regulation and embodiment to the process of resistance to persuasion. In doing so, we specifically address the role of facial expression in the course of resistance. The literature and findings from our own research lead us to propose that people can resist persuasion by controlling their facial expression of emotion when exposed to an advertisement. Controlling the expression of emotions elicited by an ad (for example refusing to smile) might be a fruitful way to resist the ad's persuasive potential. Moreover, we argue that co-viewers can affect embodied resistance to persuasion. Showing the viability of embodied resistance to persuasion is relevant in view of the fact that ads trying to persuade us by addressing our positive emotions are ubiquitous. Embodied resistance might help people to cope with these induced positive emotions in order to resist advertisements and might therefore work as a novel and effective strategy to resist persuasion. PMID:27574512

  13. WHEAT PATHOGEN RESISTANCE AND CHITINASE PROFILE

    OpenAIRE

    Zuzana Gregorová; Peter Socha; Marína Maglovski; Jana Moravčíková; Jana Libantová; Roman Kuna; Pavol Hauptvogel; Matušíková Ildikó

    2015-01-01

    The powdery mildew and leaf rust caused by Blumeria graminis and Puccinia recondita (respectively) are common diseases of wheat throughout the world. These fungal diseases greatly affect crop productivity. Incorporation of effective and durable disease resistance is an important breeding objective for wheat improvement. We have evaluated resistance of four bread wheat (Triticum aestivum) and four spelt wheat (Triticum spelta) cultivars. Chitinases occurrence as well as their activity was dete...

  14. Neuromodulation for treatment-resistant depression

    OpenAIRE

    Holtzheimer, Paul E.; Mayberg, Helen S

    2012-01-01

    Treatment-resistant depression affects at least 1-3% of the US population. This article reviews the current state of focal neuromodulation therapies for treatment-resistant depression, focusing on those treatments published clinical data. These include transcranial magnetic stimulation, transcranial direct current stimulation, magnetic seizure therapy, vagus nerve stimulation, direct cortical stimulation, and deep brain stimulation among others. Of these, only two (transcranial magnetic stimu...

  15. Monitoring forest soil properties with electrical resistivity

    OpenAIRE

    Paillet, Y.; Cassagne, N.; Brun, J.J.

    2010-01-01

    Maintenance and monitoring of soil fertility is a key issue for sustainable forest management. Vital ecosystem processes may be affected by management practices which change the physical, chemical and biological properties of the soil. This study is the first in Europe to use electrical resistivity as a non-invasive method to determine forest soil properties rapidly in the field in a monitoring purpose. We explored the correlations between electrical resistivity and forest soil properties on ...

  16. Inducible cephalosporinase production in clinical isolates of Enterobacter cloacae is controlled by a regulatory gene that has been deleted from Escherichia coli.

    OpenAIRE

    Honoré, N; Nicolas, M H; Cole, S T

    1986-01-01

    Cephalosporin hyper-resistant Enterobacter cloacae strains are isolated with increasing frequency from hospital infections. Resistance is principally due to the chromosomal ampC gene encoding a cephalosporinase. In contrast to Escherichia coli which expresses ampC constitutively from a promoter located in the upstream frdD gene, E. cloacae displays inducible ampC expression. By cloning the ampC gene it was shown that a linked genetic locus, ampR, mediated the induction by beta-lactams. In the...

  17. The Affective Turn

    Directory of Open Access Journals (Sweden)

    Alí Lara

    2013-11-01

    Full Text Available In the last decade studies on affect and emotions have become relevant in the social sciences. This is not just a fad guideline, but instead a simultaneous reader of public life changes and subjective experience, from which it is also being transformed the knowledge production. Such a trend has been known as ‘The Affective Turn’ within the Anglophone Academy. Here we will translate it as ‘El Giro Afectivo’. This turn, so far, has not dabbled in the social science literature that is written in Spanish. This paper draws on a singular panorama of discussions about contemporary social studies of affect and emotion, and it’s vertebrate by some of its expressions in the contemporary academy.

  18. The Affective Turn

    DEFF Research Database (Denmark)

    Carnera, Alexander

    2012-01-01

    This paper confronts biopolitics with modern labour addressing questions of ‘governmentality’, ‘self-management’ and ‘social innovation’. It argues that the new modes of production within immaterial labour involve a new complex relation between on the one hand the ‘Art of Governance......-management that human individuation ties together modes of productions with affects and emotions. Introducing Spinoza's concept of ‘affect’, and Gilles Deleuze's reading of Spinoza's ethics focusing on the ‘affective turn’ in relation to the new economy and society, the paper argues for a more positive notion of...... biopolitics that surpasses that of governmentality. The affective self-relation is used as a research tool to analyse the creation of social and economic values in our new modes of productions, for instance, within free labour of the cultural industry. The movie The Five Obstructions is used to show how...

  19. Affected in the nightclub

    DEFF Research Database (Denmark)

    Demant, Jakob Johan

    2013-01-01

    experiences within a club as a way of understanding the complexities of pleasure. The study does so by addressing experiences through the concept of affects, which is situated within a framework of a non-representational theory of space. Anxiety, pride, anger, shame and embarrassment are embodied...

  20. Resistance patterns, prevalence, and predictors of fluoroquinolones resistance in multidrug resistant tuberculosis patients

    OpenAIRE

    Nafees Ahmad; Arshad Javaid; Syed Azhar Syed Sulaiman; Long Chiau Ming; Izaz Ahmad; Amer Hayat Khan

    2016-01-01

    Abstract Background Fluoroquinolones are the backbone of multidrug resistant tuberculosis treatment regimens. Despite the high burden of multidrug resistant tuberculosis in the country, little is known about drug resistance patterns, prevalence, and predictors of fluoroquinolones resistance among multidrug resistant tuberculosis patients from Pakistan. Objective To evaluate drug resistance patterns, prevalence, and predictors of fluoroquinolones resistance in multidrug resistant tuberculosi...

  1. Neurotransmitters affecting time perception

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    BACKGROUND:It has been demonstrated that dopamine and acetylcholine are the main neurotransmitters that affect time perception,which is also affected by other neurotransmitters.OBJECTIVE:To summarize how the neurotransmitter affect the time perception,and put forward the perspectives for further study on time perception.RETRIEVE STRATEGY:An online search for related literatures published in English was conducted in Elsevier SDOL(ScienceDirect Online)database from May 1990 to March 2007 using key words of "timing neurotransmitter".Totally 69 literatures were collected,and they were primarily checked.Inclusive criteria:Reviews and experimental studies;correlative studies of timing neurotransmitter.Exclusive criteria:Repeated studies.LITERATURE EVALUATION:The literatures were mainly sourced from Cognitive Brain Research and Neuroscience,and they were analyzed according to the inclusive criteria.Nineteen of them were involved,and all were experimental studies and reviews.DATA SYNTHESIS:The studies on time perception are developed mainly concentrating on dopamine and acetylcholine.Dopamine D2 receptors mainly affect the speed of internal clock.Dopamine receptors play an important role in both timing excitation and inhibition,which suggests the bi-directional regulation of dopamine.Injection of dopamine agonist can affect the attention to timing information.Injection of BW813U(antagonist of acetylcholine) can induce memory disorder,which indicates the effect of acetylcholine on timing memory,and further study shows that it is the effect of acetylcholine in precentral medial area.In a word,the study on the neurotransmitters affecting time perception is still at the primary stage.CONCLUSION:Dopamine and acetylcholine are the neurotransmitters known to be related to time perception.Dopamine in the basal ganglia is related to internal-clock in the range of seconds and minutes;Acetylcholine in prefrontal cortex is related to the mechanisms of temporal memory and attention

  2. Breakdown of resistance to grapevine downy mildew upon limited deployment of a resistant variety

    Directory of Open Access Journals (Sweden)

    Bellin Diana

    2010-07-01

    Full Text Available Abstract Background Natural disease resistance is a cost-effective and environmentally friendly way of controlling plant disease. Breeding programmes need to make sure that the resistance deployed is effective and durable. Grapevine downy mildew, caused by the Oomycete Plasmopara viticola, affects viticulture and it is controlled with pesticides. Downy mildew resistant grapevine varieties are a promising strategy to control the disease, but their use is currently restricted to very limited acreages. The arising of resistance-breaking isolates under such restricted deployment of resistant varieties would provide valuable information to design breeding strategies for the deployment of resistance genes over large acreages whilst reducing the risks of the resistance being defeated. The observation of heavy downy mildew symptoms on a plant of the resistant variety Bianca, whose resistance is conferred by a major gene, provided us with a putative example of emergence of a resistance-breaking isolate in the interaction between grapevine and P. viticola. Results In this paper we describe the emergence of a P. viticola isolate (isolate SL that specifically overcomes Rpv3, the major resistance gene carried by Bianca at chromosome 18. We show that isolate SL has the same behaviour as two P. viticola isolates avirulent on Bianca (isolates SC and SU when inoculated on susceptible plants or on resistant plants carrying resistances derived from other sources, suggesting there is no fitness cost associated to the virulence. Molecular analysis shows that all three isolates are genetically closely related. Conclusions Our results are the first description of a resistance-breaking isolate in the grapevine/P. viticola interaction, and show that, despite the reduced genetic variability of P. viticola in Europe compared to its basin of origin and the restricted use of natural resistance in European viticulture, resistance-breaking isolates overcoming monogenic

  3. Affects and assemblages

    DEFF Research Database (Denmark)

    Samson, Kristine

    happens to aesthetics and how does it change the existing social and geographical understanding of urban space? The paper sets out to reintroduce aesthetical aspects of affects and assemblages in relation to urban space and urban planning. It presupposes urban space as a continuous state of becoming where...... ‘throwntogetherness’ (Massey 2005) or assemblage (Farias & Bender 2010) of perspectives bridging for instance the social and cultural experienced space investigated by the geographer and urban sociologist with the material and formal aesthetics of the architect and urban planner....... cultural geopgraphy. On this backdrop the paper states that affects and assemblages could serve as key notions for the reassembling the aesthetics of urban space. Thus, the paper suggest a less formal understanding of urban space and aesthetics, proposing an understanding of aesthetics as a...

  4. Comfortable bodies: sedentary affects

    OpenAIRE

    David Bissell

    2008-01-01

    Whilst to be comfortable is often equated with conservatism and complacency, this paper considers the various and often complex configurations of comfort as a desirable corporeal sensibility. Subsequently, this paper considers what corporeal comfort as an affective sensibility is and can do to theorisations of the sedentary body. The sensibility of corporeal comfort induced through the relationality between bodies and proximate objects is explored to trace through some of the affectual circul...

  5. Cytoplasm Affects Embryonic Development

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Recent studies by CAS researchers furnish strong evidence that a fertilized egg's nucleus isn't the sole site of control for an embryo's development. A research team headed by Prof. Zhu Zuoyan from the CAS Institute of Hydrobiology in Wuhan discovered that cytoplasm affects the number of vertebrae in cloned offspring created when nuclei from one fish genus were transplanted to enucleated eggs of another.

  6. Factors Affecting Wound Healing

    OpenAIRE

    Guo, S; DiPietro, L. A.

    2010-01-01

    Wound healing, as a normal biological process in the human body, is achieved through four precisely and highly programmed phases: hemostasis, inflammation, proliferation, and remodeling. For a wound to heal successfully, all four phases must occur in the proper sequence and time frame. Many factors can interfere with one or more phases of this process, thus causing improper or impaired wound healing. This article reviews the recent literature on the most significant factors that affect cutane...

  7. Bacterial resistance to antimicrobial peptides: an evolving phenomenon.

    Science.gov (United States)

    Fleitas, Osmel; Agbale, Caleb M; Franco, Octavio L

    2016-01-01

    Bacterial resistance to conventional antibiotics is currently a real problem all over the world, making novel antimicrobial compounds a real research priority. Some of the most promising compounds found to date are antimicrobial peptides (AMPs). The benefits of these drugs include their broad spectrum of activity that affects several microbial processes, making the emergence of resistance less likely. However, bacterial resistance to AMPs is an evolving phenomenon that compromises the therapeutic potential of these compounds. Therefore, it is mandatory to understand bacterial mechanisms of resistance to AMPs in depth, in order to develop more powerful AMPs that overcome the bacterial resistance response. PMID:27100488

  8. Affective Image Colorization

    Institute of Scientific and Technical Information of China (English)

    Xiao-Hui Wang; Jia Jia; Han-Yu Liao; Lian-Hong Cai

    2012-01-01

    Colorization of gray-scale images has attracted many attentions for a long time.An important role of image color is the conveyer of emotions (through color themes).The colorization with an undesired color theme is less useful,even it is semantically correct.However this has been rarely considered.Automatic colorization respecting both the semantics and the emotions is undoubtedly a challenge.In this paper,we propose a complete system for affective image colorization.We only need the user to assist object segmentation along with text labels and an affective word.First,the text labels along with other object characters are jointly used to filter the internet images to give each object a set of semantically correct reference images.Second,we select a set of color themes according to the affective word based on art theories.With these themes,a generic algorithm is used to select the best reference for each object,balancing various requirements.Finally,we propose a hybrid texture synthesis approach for colorization.To the best of our knowledge,it is the first system which is able to efficiently colorize a gray-scale image semantically by an emotionally controllable fashion.Our experiments show the effectiveness of our system,especially the benefit compared with the previous Markov random field (MRF) based method.

  9. Effect of physiological age on radiation resistance of some bacteria that are highly radiation resistant

    International Nuclear Information System (INIS)

    Physiological age-dependent variation in radiation resistance was studied for three bacteria that are highly radiation resistant: Micrococcus radiodurans, Micrococcus sp. isolate C-3, and Moraxella sp. isolate 4. Stationary-phase cultures of M. radiodurans and isolate C-3 were much more resistant to gamma radiation than were log-phase cultures. This pattern of relative resistance was reversed for isolate 4. Resistance of isolate 4 to UV light was also greater during log phase, although heat resistance and NaCl tolerance after heat stresses were greater during stationary phase. Radiation-induced injury of isolate 4 compared with injury of Escherichia coli B suggested that the injury process, as well as the lethal process, was affected by growth phase. The hypothesis that growth rate affects radiation resistance was tested, and results were interpreted in light of the probable confounding effect of methods used to alter growth rates of bacteria. These results indicate that dose-response experiments should be designed to measure survival during the most resistant growth phase of the organism under study. The timing is particularly important when extrapolations of survival results might be made to potential irradiation processes for foods. 17 references

  10. Sensibilidade a antimicrobianos de bactérias isoladas do trato respiratório de pacientes com infecções respiratórias adquiridas na comunidade: resultados brasileiros do Programa SENTRY de Vigilância de Resistência a Antimicrobianos dos anos de 1997 e 1998 Susceptibility to respiratory tract isolated bacteria to antimicrobial agents in patients with community-acquired respiratory tract infections: 1997 and 1998 Brazilian data of the SENTRY surveillance program of resistance to antimicrobial agents

    Directory of Open Access Journals (Sweden)

    HÉLIO S. SADER

    2001-01-01

    surveillance network of sentinel laboratories. Three sites in Brazil participated in the 1997 and 1998 SENTRY Program. Methods: A total of 344 bacterial isolates, collected from patients with CARTI in 1997 and 1998, were tested against more than 20 antimicrobial agents by the broth microdilution method. Results: Among S. pneumoniae (176 isolates, 71.6% were susceptible to penicillin. High level resistance to penicillin and resistance to cefotaxime was found in 2.3 and 4.0%, respectively. The newer quinolones, levofloxacin, (MIC90 of 2 mug/mL and gatifloxacin (MIC90 of 0.5 mug/mL were active against 100% of the isolates tested. Among the other non-beta-lactam drugs tested, the rank order of pneumococci activity was (% susceptible: chloramphenicol (97.5% > clindamycin (94.0% > azithromycin (90.3% > clarithromycin (89.4% > tetracycline (76.4% > trimethoprim/sulfamethoxazole (60.2%. The percentage of Haemophilus influenzae (101 isolates susceptible to amoxicillin was 90.1%, whereas among Moraxella catarrhalis (67 isolates only 9.0% were susceptible. Clavulanic acid restored the activity of amoxicillin against both H. influenzae and M. catarrhalis. However, H. influenzae showed increased levels of resistance to trimethoprim/sulfametoxazole (55.1% susceptibility, clarithromycin (80.4% susceptibility, and cefaclor (88.2% susceptibility. All H. influenzae and M. catarrhalis isolates were susceptible to levofloxacin (MIC90, < 0.5 mug/mL for both and gatifloxacin (MIC90, < 0.06 mug/mL for both with very low MICs. Conclusion: Results indicate that the rate of S. pneumoniae showing high-level penicillin resistance is still low in Brazil. However, intermediate resistance to penicillin associated with resistance to other classes of antimicrobial agents was relatively high. On the other hand, the new quinolones were highly active against 100% of the respiratory pathogens tested.

  11. Nanomolar Inhibitors of AmpC [beta]-Lactamase

    Energy Technology Data Exchange (ETDEWEB)

    Morandi, Federica; Caselli, Emilia; Morandi, Stefania; Focia, Pamela J.; Blazquez, Jesus; Shoichet, Brian K.; Prati, Fabio (Degali); (NIH); (NWU); (UCSF)

    2010-03-08

    {beta}-lactamases are the most widespread resistance mechanism to {beta}-lactam antibiotics, such as the penicillins and the cephalosporins. In an effort to combat these enzymes, a combination of stereoselective organic synthesis, enzymology, microbiology, and X-ray crystallography was used to design and evaluate new carboxyphenyl-glycylboronic acid transition-state analogue inhibitors of the class C {beta}-lactamase AmpC. The new compounds improve inhibition by over 2 orders of magnitude compared to analogous glycylboronic acids, with K{sub i} values as low as 1 nM. On the basis of the differential binding of different analogues, the introduced carboxylate alone contributes about 2.1 kcal/mol in affinity. This carboxylate corresponds to the ubiquitous C3(4)' carboxylate of {beta}-lactams, and this energy represents the first thermodynamic measurement of the importance of this group in molecular recognition by class C {beta}-lactamases. The structures of AmpC in complex with two of these inhibitors were determined by X-ray crystallography at 1.72 and 1.83 {angstrom} resolution. These structures suggest a structural basis for the high affinity of the new compounds and provide templates for further design. The highest affinity inhibitor was 5 orders of magnitude more selective for AmpC than for characteristic serine proteases, such as chymotrypsin. This inhibitor reversed the resistance of clinical pathogens to the third generation cephalosporin ceftazidime; it may serve as a lead compound for drug discovery to combat bacterial resistance to {beta}-lactam antibiotics.

  12. The Affective Turn

    OpenAIRE

    Alí Lara; Giazú Enciso

    2013-01-01

    En la última década los estudios del afecto y las emociones han cobrado relevancia en las ciencias sociales. Esto no es simplemente una directriz de moda, es un indicador simultáneo de las modificaciones en la vida pública y de la experiencia subjetiva; a partir del cual se está transformando la producción de conocimiento. Tal tendencia ha sido conocida en la academia sajona como The Affective Turn, aquí traducido como “El giro afectivo” y que hasta el momento no ha incursionado como tal en l...

  13. Visual affect recognition

    CERN Document Server

    Stathopoulou, I-O

    2010-01-01

    It is generally known that human faces, as well as body motions and gestures, provide a wealth of information about a person, such as age, race, sex and emotional state. This monograph primarily studies the perception of facial expression of emotion, and secondarily of motion and gestures, with the purpose of developing a fully automated visual affect recognition system for use in modes of human/computer interaction. The book begins with a survey of the literature on emotion perception, followed by a description of empirical studies conducted with human participants and the construction of a '

  14. Animation of Antimicrobial Resistance

    Medline Plus

    Full Text Available ... More in Antimicrobial Resistance National Antimicrobial Resistance Monitoring System About NARMS Bacteria (NARMS) NARMS at Work Reports ... Emergency Preparedness International Programs News & Events Training & Continuing Education Inspections & Compliance Federal, State & Local Officials Consumers Health ...

  15. HIV Genotypic Resistance Testing

    Science.gov (United States)

    ... of the disease progression and to minimize viral replication and mutation. However, a person may be initially infected with a drug-resistant HIV strain or drug resistance may develop during treatment, ...

  16. Animation of Antimicrobial Resistance

    Medline Plus

    Full Text Available ... how antimicrobial resistance both emerges and proliferates among bacteria. Over time, the use of antimicrobial drugs will result in the development of resistant strains of bacteria, complicating clinician's efforts to select the appropriate antimicrobial ...

  17. Oxidation-resistant cermet

    Science.gov (United States)

    Phillips, W. M.

    1977-01-01

    Chromium metal alloys and chromium oxide ceramic are combined to produce cermets with oxidation-resistant properties. Application of cermets includes use in hot corrosive environments requiring strong resistive materials.

  18. Pneumococcal resistance to antibiotics.

    OpenAIRE

    Klugman, K P

    1990-01-01

    The geographic distribution of pneumococci resistant to one or more of the antibiotics penicillin, erythromycin, trimethoprim-sulfamethoxazole, and tetracycline appears to be expanding, and there exist foci of resistance to chloramphenicol and rifampin. Multiply resistant pneumococci are being encountered more commonly and are more often community acquired. Factors associated with infection caused by resistant pneumococci include young age, duration of hospitalization, infection with a pneumo...

  19. The fitness of drug-resistant malaria parasites in a rodent model: multiplicity of infection

    OpenAIRE

    Huijben, Silvie; Sim, Derek G.; Nelson, William; Read, Andrew F.

    2011-01-01

    Malaria infections normally consist of more than one clonally-replicating lineage. Within-host interactions between sensitive and resistant parasites can have profound effects on the evolution of drug resistance. Here, using the Plasmodium chabaudi mouse malaria model, we ask whether the costs and benefits of resistance are affected by the number of co-infecting strains competing with a resistant clone. We found strong competitive suppression of resistant parasites in untreated infections and...

  20. Ghrelin- and GH-induced insulin resistance

    DEFF Research Database (Denmark)

    Vestergaard, Esben Thyssen; Krag, Morten B; Poulsen, Morten M;

    2013-01-01

    Supraphysiological levels of ghrelin and GH induce insulin resistance. Serum levels of retinol-binding protein-4 (RBP4) correlate inversely with insulin sensitivity in patients with type 2 diabetes. We aimed to determine whether ghrelin and GH affect RBP4 levels in human subjects....