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Sample records for oxytetracycline resistance determinants

  1. Tetracycline and oxytetracycline resistance determinants detected in Bacillus cereus strains isolated from honey samples Detección de determinantes de resistencia a tetraciclina y oxitetraciclina en cepas de Bacillus cereus aisladas de muestras de miel

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    A. C. López

    2008-12-01

    Full Text Available The aim of this study was to investigate the presence of tetracycline and oxytetracycline resistance determinants in Bacillus cereus strains isolated from honey samples. Of a total of 77 isolates analyzed, 30 (39% exhibited resistance to tetracyclines according to the results of a disk diffusion method. Resistant strains (n=30 were screened by PCR for the presence of the resistant determinants tetK, tetL, tetM, tetO, tetW, otrA and otrB and their MIC values for tetracycline, oxytetracycline and minocycline were assessed. According to the PCR results, 23 isolates (77% presented at least one tetracycline or oxytetracycline resistance determinant. The tetK genotype was present in 10 isolates while the tetL, tetM, and otrA genotypes were present in 3, 2, and 5 isolates, respectively. In addition, 2 isolates of the tetK plus tetM genotype, 1 of the tetK plus tetL genotype, and 1 of the tetK plus otrA genotype were found. All isolates were tetW, tetO and otrB negatives. On the other hand, 7 isolates (23% showed a tetracycline-resistant and/or minocyclineresistant phenotype (MIC but did not carry any of the tet or otr determinants investigated in this study. This research has shown that B. cereus isolates from honey samples contain a variety of tetracycline and oxytetracycline resistance genes, including the tetK and tetL determinants which encode for efflux proteins, and tetM and otrA, which encode for ribosomal protection proteins. These findings indicate that strains isolated from honeys could represent a reservoir for tetracycline resistance genes. To our knowledge, this is the first report of tetracycline-resistant and oxytetracyclineresistant B. cereus strains carrying the tetK determinant, and also the first report of oxytetracycline-resistant and tetracycline- resistant Bacillus species carrying the otrA determinant.El objetivo del presente estudio ha sido investigar la presencia de diversos determinantes de resistencia a tetraciclina y

  2. In vitro development of resistance to enrofloxacin, erythromycin, tylosin, tiamulin and oxytetracycline in Mycoplasma gallisepticum, Mycoplasma iowae and Mycoplasma synoviae.

    Science.gov (United States)

    Gautier-Bouchardon, A V; Reinhardt, A K; Kobisch, M; Kempf, I

    2002-08-02

    The in vitro emergence of resistance to enrofloxacin, erythromycin, tylosin, tiamulin, and oxytetracycline in three avian Mycoplasma species, Mycoplasma gallisepticum, Mycoplasma synoviae and Mycoplasma iowae was studied. Mutants were selected stepwise and their MICs were determined after 10 passages in subinhibitory concentrations of antibiotic. High-level resistance to erythromycin and tylosin developed within 2-6 passages in the three Mycoplasma species. Resistance to enrofloxacin developed more gradually. No resistance to tiamulin or oxytetracycline could be evidenced in M. gallisepticum or M. synoviae after 10 passages whereas, resistant mutants were obtained with M. iowae. Cross-sensitivity tests performed on mutants demonstrated that mycoplasmas made resistant to tylosin were also resistant to erythromycin, whereas mutants made resistant to erythromycin were not always resistant to tylosin. Some M. iowae tiamulin-resistant mutants were also resistant to both macrolide antibiotics. Enrofloxacin and oxytetracycline did not induce any cross-resistance to the other antibiotics tested. These results show that Mycoplasma resistance to macrolides can be quickly selected in vitro, and thus, providing that similar results could be obtained under field conditions, that development of resistance to these antibiotics in vivo might also be a relatively frequent event.

  3. Determination of optimal conditions of oxytetracyclin production from streptomyces rimosus

    International Nuclear Information System (INIS)

    Zouaghi, Atef

    2007-01-01

    Streptomyces rimosus is an oxytetracycline (OTC) antibiotic producing bacteria that exhibited activities against gram positive and negative bacteria. OTC is used widely not only in medicine but also in production industry. The antibiotic production of streptomyces covers a very wide range of condition. However, antibiotic producers are particularly fastidious cultivated by proper selection of media such as carbon source. In present study we have optimised conditions of OTC production (Composition of production media, p H, shaking and temperature). The results have been shown that bran barley is the optimal media for OTC production at 28C pH5.8 at 150rpm for 5 days. For antibiotic determination, OTC was extracted with different organic solvent. Thin-layer chromatography system was used for separation and identification of OTC antibiotic. High performance liquid chromatographic (HPLC) method with ultraviolet detection for the analysis of OTC is applied to the determination of OTC purification. (Author). 24 refs

  4. PCR detection of oxytetracycline resistance genes from diverse habitats in total community DNA and in streptomycete isolates.

    NARCIS (Netherlands)

    Nikolakopoulou, T.L.; Egan, S.; Overbeek, van L.S.; Guillaume, G.; Heuer, H.; Wellington, E.M.H.; Elsas, van J.D.; Collard, J.M.; Smalla, K.; Karagouni, A.D.

    2005-01-01

    A range of European habitats was screened by PCR for detection of the oxytetracycline resistance genes otr(A) and otr(B), found in the oxytetracycline-producing strain Streptomyces rimosus. Primers were developed to detect these otr genes in tetracycline-resistant (TcR) streptomycete isolates from

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

    DEFF Research Database (Denmark)

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

    2017-01-01

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

  6. Detection and determination of Oxytetracycline and Penicillin G ...

    African Journals Online (AJOL)

    Concentrations of oxytetracycline and penicillin G in all samples were between ranges of 45 -192 μg/l and 0-28 μg/l, respectively. The antibiotic residue positive samples which showed residues of oxytetracycline above the WTO/FAO/ CAC established maximum residue limit of 100μg/l were 40 (83.33%). For penicillin G, the ...

  7. Determination of oxytetracycline residues in cattle meat marketed in the Kilosa district, Tanzania

    Directory of Open Access Journals (Sweden)

    Zuhura I. Kimera

    2015-11-01

    Full Text Available Oxytetracycline is used to treat various diseases in cattle. However, its use may be associated with unacceptable residue levels in food. Oxytetracycline residues in tissues from indigenous cattle were determined in a cross-sectional study conducted in the Kilosa district, Tanzania, between November 2012 and April 2013. A total of 60 tissue samples, including muscle, liver and kidney, were collected from slaughterhouses and butchers and analysed for oxytetracycline using high-performance liquid chromatography. Oxytetracycline residues were found in 71.1% of the samples, of which 68.3% were above acceptable regulatory levels. The mean concentration of oxytetracycline across tissues was 3401.1 μg/kg ± 879.3 μg/kg; concentrations in muscle, liver and kidney were 2604.1 μg/kg ± 703.7 μg/kg, 3434.4 μg/kg ± 606.4 μg/kg and 3533.1 μg/kg ± 803.6 μg/kg, respectively. High levels of oxytetracycline residue in meat from indigenous cattle may pose a health threat to consumers in Kilosa. The findings possibly reflect a general lack of implementation of recommended withdrawal periods, ignorance about drug use and lack of extension services. Strict regulation of the use of antimicrobial drugs in the livestock industry and associated testing of animal-derived food sources prior to marketing are required.

  8. Determination of oxytetracycline residues in cattle meat marketed in the Kilosa district, Tanzania.

    Science.gov (United States)

    Kimera, Zuhura I; Mdegela, Robinson H; Mhaiki, Consolatha J N; Karimuribo, Esron D; Mabiki, Faith; Nonga, Hezron E; Mwesongo, James

    2015-11-27

    Oxytetracycline is used to treat various diseases in cattle. However, its use may be associated with unacceptable residue levels in food. Oxytetracycline residues in tissues from indigenous cattle were determined in a cross-sectional study conducted in the Kilosa district, Tanzania, between November 2012 and April 2013. A total of 60 tissue samples, including muscle, liver and kidney, were collected from slaughterhouses and butchers and analysed for oxytetracycline using high-performance liquid chromatography. Oxytetracycline residues were found in 71.1% of the samples, of which 68.3% were above acceptable regulatory levels. The mean concentration of oxytetracycline across tissues was 3401.1 μg/kg ± 879.3 μg/kg; concentrations in muscle, liver and kidney were 2604.1 μg/kg ± 703.7 μg/kg, 3434.4 μg/kg ± 606.4 μg/kg and 3533.1 μg/kg ± 803.6 μg/kg, respectively. High levels of oxytetracycline residue in meat from indigenous cattle may pose a health threat to consumers in Kilosa. The findings possibly reflect a general lack of implementation of recommended withdrawal periods, ignorance about drug use and lack of extension services. Strict regulation of the use of antimicrobial drugs in the livestock industry and associated testing of animal-derived food sources prior to marketing are required.

  9. PCR detection of oxytetracycline resistance genes otr(A) and otr(B) in tetracycline-resistant streptomycete isolates from diverse habitats

    NARCIS (Netherlands)

    Nikolakopoulou, T; Egan, S; van Overbeek, L; Guillaume, G; Heuer, H; Wellington, EMH; van Elsas, JD; Collard, JM; Smalla, K; Karagouni, A

    2005-01-01

    A range of European habitats was screened by PCR for detection of the oxytetracycline resistance genes otr(A) and otr(B), found in the oxytetracycline-producing strain Streptomyces rimosus. Primers were developed to detect these otr genes in tetracycline-resistant (Tc-R) streptomycete isolates from

  10. Detection and determination of Oxytetracycline and Penicillin G ...

    African Journals Online (AJOL)

    Antibiotic residues are small amounts of drugs or their active metabolites ... able daily intake and maximum residue limits in foods (FAO and WHO, 1995). Regulatory limits for antibiotic residues have been imposed on the dairy in- dustry in many ... Methods for oxytetracycline and penicillin G residue analysis. The milk ...

  11. Diversity and antimicrobial susceptibility of oxytetracycline-resistant isolates of Stenotrophomonas sp. and Serratia sp. associated with Costa Rican crops.

    Science.gov (United States)

    Rodríguez, C; Wachlin, A; Altendorf, K; García, F; Lipski, A

    2007-12-01

    To ameliorate the identification, evaluate the diversity, and determine the antimicrobial sensitivity of 19 oxytetracycline-resistant isolates of Stenotrophomonas sp. and Serratia sp. associated with Costa Rican crops. Phenotypical, chemotaxonomical, and molecular data allocated most isolates to the species Sten. maltophilia and Ser. marcescens. The API profiles, antimicrobial resistance patterns (ATB system), and BOX-polymerase chain reaction (PCR) genomic fingerprints of isolates of Stenotrophomonas sp. exhibited a higher degree of heterogeneity than those obtained for the isolates of Serratia sp. The former group of bacteria exhibited multiresistance to antimicrobials. In contrast, isolates of Serratia sp. were sensitive to the majority of the drugs tested. Changes in the results of the antibiograms throughout incubation, which indicate an induction of tolerance, were observed for isolates of both the species. Minimum inhibitory concentration of oxytetracycline, determined using E-test stripes, were rather elevated. The occurrence of two species of opportunistic pathogens in crop-associated materials poses a risk to consumers in the community. The phenotypic and genotypic data presented could support epidemiologist and physicians dealing with infections caused by environmental strains of these taxa.

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

    Czech Academy of Sciences Publication Activity Database

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

    2013-01-01

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

  13. Short communication: Determination of withdrawal time for oxytetracycline in different types of goats for milk consumption.

    Science.gov (United States)

    Attaie, Rahmat; Bsharat, Mohammed; Mora-Gutierrez, Adela; Woldesenbet, Sela

    2015-07-01

    Antibiotics are widely used in animal husbandry and the presence of antibiotics in milk is a health hazard. The objective of this study was to determine residual amounts of oxytetracycline in fresh, aged, and pasteurized milk of 3 breeds of goats using HPLC analysis. It was also essential to determine the safe withdrawal period of oxytetracycline in lactating goats. The quantitative results obtained using the HPLC system were compared with the tolerance limit of oxytetracycline in milk in the United States. Fifteen milking does, 5 Nubians, 5 Alpines, and 5 LaManchas were randomly selected from the milking herd at the International Goat Research Center at Prairie View A&M University. A simple sample preparation and isocratic HPLC method using ultraviolet detection was used for analysis of milk samples. The HPLC results indicated that the withdrawal period of oxytetracycline in treated Alpine does was 82h (7 milking), whereas for Nubian does the period was 58h (5 milking), and for LaManchas the period was 72h (6 milking) after drug administration. The overall withdrawal period for all the treated goats of 3 breeds was 72h. Although these results indicated that the depletion rate of this antibiotic was faster in goats than the reported data for cows, the 96-h withdrawal period that is currently used for lactating cows is still necessary for these 3 breeds of goats. Additionally, our results indicated that oxytetracycline is not stable in goat milk at refrigeration temperature or during pasteurization and will decrease significantly. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  14. Occurrence of tetracycline resistance genes in aquaculture facilities with varying use of oxytetracycline

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    Seyfried, Erin E.; Newton, Ryan J.; Rubert, Kennedy F.; Pedersen, Joel A.; McMahon, Katherine D.

    2014-01-01

    The contribution of human activities to environmental reservoirs of antibiotic resistance is poorly understood. The purpose of this study was to determine if oxytetracycline (OTC) use in aquaculture facilities increased the detection frequency (i.e. prevalence) of tetracycline resistance genes relative to facilities with no recent OTC treatment. We used PCR to screen water and sediment from four non-commercial fish farms in northwestern Wisconsin for the presence of ten tetracycline resistance determinants (tetR): tet(A), tet(B), tet(D), tet(E), tet(G), tet(M), tet(O), tet(Q), tet(S) and tet(W). Water from farms with recent OTC use had significantly higher tetR detection frequencies than did water from farms without recent OTC use, with prevalence in raceways and rearing ponds of farms with recent OTC use exceeded by more than two-fold that of farms not using OTC. Effluent from all farms, regardless of treatment regime, had higher tetR detection frequencies than their corresponding influent for all genes, but the specific combinations of tetR genes detected in a sample were not different from their corresponding influent. Although OTC use was associated with the increased occurrence and diversity of tetR genes in water samples, it was not found to relate to tetR gene occurrence in sediment samples. Sediment samples from facilities with no recent OTC use had significantly higher frequencies of tetR gene detection than did samples from facilities with recent OTC use. All of the tetR genes were detected in both the medicated and non-medicated feed samples analyzed in this study. These findings suggest that both OTC treatment in aquaculture facilities, and the farms themselves, may be sources of tetR gene introduction to the environment. To our knowledge, this is the first study to use genotypic and cultivation-independent methods to examine tetR gene occurrence associated with OTC use in aquaculture. PMID:20217406

  15. Effect of variation in oxytetracycline treatment of Lawsonia intracellularis diahrea in nursery pigs on treatment-efficacy and resistance development

    DEFF Research Database (Denmark)

    Larsen, I.; Mellerup, Anders; Zachariasen, C.

    2015-01-01

    A Danish research project, MINIRESIST, investigated the consequences of varying doses and treatment strategies for oxytetracycline treatment of Lawsonia intracellularis diarrhea in nursery pigs. Batches of nursery pigs in five herds were randomly allocated to one of five treatment protocols (batch...... scores, which have low sensitivity for diarrhea. Simulation studies suggested that resistance development was mostly dependent on the duration of the treatment and the total amount of oxytetracycline used per pig. Ongoing field testing has been initiated to confirm this conclusion, since no field...

  16. Improvement of oxytetracycline production mediated via cooperation of resistance genes in Streptomyces rimosus.

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    Yin, Shouliang; Wang, Xuefeng; Shi, Mingxin; Yuan, Fang; Wang, Huizhuan; Jia, Xiaole; Yuan, Fang; Sun, Jinliang; Liu, Tiejun; Yang, Keqian; Zhang, Yuxiu; Fan, Keqiang; Li, Zilong

    2017-09-01

    Increasing the self-resistance levels of Streptomyces is an effective strategy to improve the production of antibiotics. To increase the oxytetracycline (OTC) production in Streptomyces rimosus, we investigated the cooperative effect of three co-overexpressing OTC resistance genes: one gene encodes a ribosomal protection protein (otrA) and the other two express efflux proteins (otrB and otrC). Results indicated that combinational overexpression of otrA, otrB, and otrC (MKABC) exerted a synergetic effect. OTC production increased by 179% in the recombinant strain compared with that of the wild-type strain M4018. The resistance level to OTC was increased by approximately two-fold relative to the parental strain, thereby indicating that applying the cooperative effect of self-resistance genes is useful to improve OTC production. Furthermore, the previously identified cluster-situated activator OtcR was overexpressed in MKABC in constructing the recombinant strain MKRABC; such strain can produce OTC of approximately 7.49 g L -1 , which represents an increase of 19% in comparison with that of the OtcR-overexpressing strain alone. Our work showed that the cooperative overexpression of self-resistance genes is a promising strategy to enhance the antibiotics production in Streptomyces.

  17. Oxytetracycline as a new analytical reagent for the spectrophotometric determination of boron

    Energy Technology Data Exchange (ETDEWEB)

    Narayana, G L

    1984-05-01

    Oxytetracycline hydrochloride, Terramycin, is introduced as a new reagent for the spectrophotometric determination of trace quantities of boron in concentrated sulphuric acid medium. The reagent has an absorption maximum at 430 nm, and that of the boron complex at 520 nm. The colored system conformed to Beer's law between 2 and 10 ..mu..g of boron at 520 nm. The molar absorptivity calculated on the basis of boron is 10,800 1 mol/sup -1/ cm/sup -1/. The composition of the complex has been shown to be 1:1 both by the slope ratio and molar ratio methods. 16 references.

  18. Oxytetracycline as a new analytical reagent for the spectrophotometric determination of boron

    International Nuclear Information System (INIS)

    Narayana, G.L.

    1984-01-01

    Oxytetracycline hydrochloride, Terramycin, is introduced as a new reagent for the spectrophotometric determination of trace quantities of boron in concentrated sulphuric acid medium. The reagent has an absorption maximum at 430 nm, and that of the boron complex at 520 nm. The coloured system conformed to Beer's law between 2 and 10 μg of boron at 520 nm. The molar absorptivity calculated on the basis of boron is 10,800 1 mol -1 cm -1 . The composition of the complex has been shown to be 1:1 both by the slope ratio and molar ratio methods. (author)

  19. Determination of optimal conditions of oxytetracyclin production from streptomyces rimosus; Optimisation de la production de l'oxytetracycline par Streptomyces rimosus

    Energy Technology Data Exchange (ETDEWEB)

    Zouaghi, Atef [Institut National des Sciences Appliquees et de Technologie (Tunisia)

    2007-07-01

    Streptomyces rimosus is an oxytetracycline (OTC) antibiotic producing bacteria that exhibited activities against gram positive and negative bacteria. OTC is used widely not only in medicine but also in production industry. The antibiotic production of streptomyces covers a very wide range of condition. However, antibiotic producers are particularly fastidious cultivated by proper selection of media such as carbon source. In present study we have optimised conditions of OTC production (Composition of production media, p H, shaking and temperature). The results have been shown that bran barley is the optimal media for OTC production at 28C pH5.8 at 150rpm for 5 days. For antibiotic determination, OTC was extracted with different organic solvent. Thin-layer chromatography system was used for separation and identification of OTC antibiotic. High performance liquid chromatographic (HPLC) method with ultraviolet detection for the analysis of OTC is applied to the determination of OTC purification. (Author). 24 refs.

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

    Science.gov (United States)

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

    2017-09-01

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

  1. The tetracycline resistance determinant Tet 39 and the sulphonamide resistance gene sulII are common among resistant Acinetobacter spp. isolated from integrated fish farms in Thailand

    DEFF Research Database (Denmark)

    Agersø, Yvonne; Petersen, Andreas

    2007-01-01

    Objectives: To determine the genetic basis for tetracycline and sulphonamide resistance and the prevalence of class I and II integrons in oxytetracycline-resistant Acinetobacter spp. from integrated fish farms in Thailand. Methods: A total of 222 isolates were screened for tetracycline resistance...... and Southern blots with sulII and tet(39) probes were performed on selected isolates. Results: The recently identified tetracycline resistance gene tet(39) was demonstrated in 75% (166/222) of oxytetracycline-resistant Acinetobacter spp. from integrated fish farms in Thailand. Isolates that were also...

  2. Oxytetracycline in Pyoderma

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    A K Sharma

    1983-01-01

    Full Text Available One hundred patients with moderate to severe pyoderma were treated with oral oxytetracycline. The most common organism isolated were coagulase positive Staph pyogenes and Str betahemolyticus. Of 100 patients; 87 showed a successful therapeutic response. The predictive value of in vitro test for bacterial susceptibility to oxytetracycline (30 mcg disc was 88% for "sensitive" reports but 17% for "resistant" reports.Judged by clinical response the incidence of false sensitive reports was 12% (9/87 but that of false resistant reports was 83 (22/26.

  3. A Novel and Validated Protocol for Performing MIC Tests to Determine the Susceptibility of Piscirickettsia salmonis Isolates to Florfenicol and Oxytetracycline

    Directory of Open Access Journals (Sweden)

    Sergio Contreras-Lynch

    2017-07-01

    Full Text Available This paper presents a validated protocol, using a novel, specifically formulated medium, to perform broth microdilution antimicrobial susceptibility assays of the salmonid bacterial pathogen Piscirickettsia salmonis. The minimum inhibitory concentrations (MIC for florfenicol and oxytetracycline against 58 P. salmonis isolates recovered from various outbreaks occurred in Chilean salmonid farms were determined using this protocol. Normalized resistance interpretation (NRI analysis was applied to these data to calculate appropriate protocol-specific epidemiological cut-off values. These cut-off values allow the isolates to be categorized as either fully susceptible wild type (WT members of this species, or as manifesting reduced susceptibility non-wild type (NWT. The distribution of MIC values of florfenicol was bimodal and the distribution of the normalized values for the putative WT observation had a standard deviation of 0.896 log2 μg mL-1. This analysis calculated a cut-off value of ≤0.25 μg mL-1 and categorized 33 (56% of the isolates as manifesting reduced susceptibility to florfenicol. For the oxytetracycline MIC data the NRI analysis also treated the distribution as bimodal. The distribution of the normalized values for the putative WT observation had a standard deviation of 0.951 log2 μg mL-1. This analysis gave a cut-off value of ≤0.5 μg mL-1 and categorized five isolates (9% as manifesting reduced susceptibility to oxytetracycline. The susceptibility testing protocol developed in this study was capable of generating MIC data from all the isolates tested. On the basis of the precision of the data it generated, and the degree of separation of values for WT and NWT it achieved, it is argued that this protocol has the performance characteristics necessary for it to be considered as a standard protocol.

  4. Spectrophotometric Methods for Simultaneous Determination of Oxytetracycline HCl and Flunixin Meglumine in Their Veterinary Pharmaceutical Formulation

    Directory of Open Access Journals (Sweden)

    Hanan A. Merey

    2017-01-01

    Full Text Available Four precise, accurate, selective, and sensitive UV-spectrophotometric methods were developed and validated for the simultaneous determination of a binary mixture of Oxytetracycline HCl (OXY and Flunixin Meglumine (FLU. The first method, dual wavelength (DW, depends on measuring the difference in absorbance (ΔA 273.4–327 nm for the determination of OXY where FLU is zero while FLU is determined at ΔA 251.7–275.7 nm. The second method, first-derivative spectrophotometric method (1D, depends on measuring the peak amplitude of the first derivative selectively at 377 and 266.7 nm for the determination of OXY and FLU, respectively. The third method, ratio difference method, depends on the difference in amplitudes of the ratio spectra at ΔP 286.5–324.8 nm and ΔP 249.6–286.3 nm for the determination of OXY and FLU, respectively. The fourth method, first derivative of ratio spectra method (1DD, depends on measuring the amplitude peak to peak of the first derivative of ratio spectra at 296.7 to 369 nm and 259.1 to 304.7 nm for the determination of OXY and FLU, respectively. Different factors affecting the applied spectrophotometric methods were studied. The proposed methods were validated according to ICH guidelines. Satisfactory results were obtained for determination of both drugs in laboratory prepared mixture and pharmaceutical dosage form. The developed methods are compared favourably with the official ones.

  5. Liquid chromatographic determination of oxytetracycline in edible fish fillets from six species of fish

    Science.gov (United States)

    Meinertz, J.R.; Stehly, G.R.; Gingerich, W.H.

    1998-01-01

    The approved use of oxytetracycline (OTC) in U.S. Aquaculture is limited to specific diseases in salmonids and channel catfish. OTC may also be effective in controlling diseases in other fish species important to public aquaculture, but before approved use of OTC can be augmented, an analytical method for determining OTC in fillet tissue from multiple species of fish will be required to support residue depletion studies. The objective of this study was to develop and validate a liquid chromatographic (LC) method that is accurate, precise, and sensitive for OTC in edible fillets from multiple species of fish. Homogenized fillet tissues from walleye, Atlantic salmon, striped bass, white sturgeon, rainbow trout, and channel catfish were fortified with OTC at nominal concentrations of 10, 20, 100, 1000, and 5000 ng/g. In tissues fortified with OTC at 100, 1000, and 5000 ng/g, mean recoveries ranged from 83 to 90%, and relative standard deviations (RSDs) ranged from 0.9 to 5.8%. In all other tissues, mean recoveries ranged from 59 to 98%, and RSDs ranged from 3.3 to 20%. Method quantitation limits ranged from 6 to 22 ng/g for the 6 species. The LC parameters produced easily integratable OTC peaks without coelution of endogenous compounds. The method is accurate, precise, and sensitive for OTC in fillet tissue from 6 species of fish from 5 phylogenetically diverse groups.

  6. Determination of Oxytetracycline from Salmon Muscle and Skin by Derivative Spectrophotometry.

    Science.gov (United States)

    Toral, M Inés; Sabay, Tamara; Orellana, Sandra L; Richter, Pablo

    2015-01-01

    A method was developed for the identification and quantification of oxytetracycline residues present in salmon muscle and skin using UV-Vis derivative spectrophotometry. With this method, it was possible to reduce the number of steps in the procedure typically required for instrumental analysis of a sample. The spectral variables, order of the derivative, scale factor, smoothing factor, and analytical wavelength were optimized using standard solutions of oxytetracycline dissolved in 900 mg/L oxalic acid in methanol. The matrix effect was significant; therefore, quantification for oxytetracycline residues was carried out using drug-free salmon muscle and skin samples fortified with oxytetracycline. The LOD and LOQ were found to be 271 and 903 μg/kg, respectively. The precision and accuracy of the method were validated using drug-free salmon muscle and skin tissues fortified at three different concentrations (8, 16, and 32 mg/kg) on 3 different days. The recoveries at all fortified concentrations were between 90 and 105%, and RSDs in all cases were less than 6.5%. This method can be used to screen out compliant samples and thereby reduce the number of suspect positive samples that will require further confirmatory analysis.

  7. Use of a portable time-resolved fluorometer to determine oxytetracycline residue in four fruit crops

    Science.gov (United States)

    Worldwide, oxytetracycline (OTC) is used in fruit and vegetable crops to prevent and treat bacteria diseases. In the U.S., the Environmental Protection Agency approved its use in apple, pear, peach, and nectarine, and set tolerance at 350 ng/g. OTC residues in 12 varieties of these fruits are determ...

  8. Operating conditions influence microbial community structures, elimination of the antibiotic resistance genes and metabolites during anaerobic digestion of cow manure in the presence of oxytetracycline.

    Science.gov (United States)

    Turker, Gokhan; Akyol, Çağrı; Ince, Orhan; Aydin, Sevcan; Ince, Bahar

    2018-01-01

    The way that antibiotic residues in manure follow is one of the greatest concerns due to its potential negative impacts on microbial communities, the release of metabolites and antibiotic resistant genes (ARGs) into the nature and the loss of energy recovery in anaerobic digestion (AD) systems. This study evaluated the link between different operating conditions, the biodegradation of oxytetracycline (OTC) and the formation of its metabolites and ARGs in anaerobic digesters treating cow manure. Microbial communities and ARGs were determined through the use of quantitative real-time PCR. The biodegradation of OTC and occurrence of metabolites were determined using UV-HPLC and LC/MS/MS respectively. The maximum quantity of resistance genes was also examined at the beginning of AD tests and concentration was in the order of: tetM >tetO. The numbers of ARGs were always higher at high volatile solids (VS) content and high mixing rate. The results of the investigation revealed that relationship between mixing rate and VS content plays a crucial role for elimination of ARGs, OTC and metabolites. This can be attributed to high abundance of microorganisms due to high VS content and their increased contact with elevated mixing rate. An increased interaction between microorganisms triggers the promotion of ARGs. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Effects of biochar on reducing the abundance of oxytetracycline, antibiotic resistance genes, and human pathogenic bacteria in soil and lettuce.

    Science.gov (United States)

    Duan, Manli; Li, Haichao; Gu, Jie; Tuo, Xiaxia; Sun, Wei; Qian, Xun; Wang, Xiaojuan

    2017-05-01

    Antibiotics and antibiotic resistance genes (ARGs) in soil can affect human health via the food chain. Biochar is a soil amendment but its impacts on ARGs and the microbial communities associated with soil and vegetables are unclear. Therefore, we established three lettuce pot culture experiments, i.e., O300: 300 mg/kg oxytetracycline (OTC), BO300: 300 mg/kg OTC + 2% biochar, and a control without OTC or biochar. We found that under BO300, the relative abundances of ARGs were reduced by 51.8%, 43.4%, and 44.1% in lettuce leaves, roots, and soil, respectively, compared with O300. intI1 was highly abundant in soil and lettuce, and it co-occurred with some ARGs (tetW, ermF, and sul1). Redundancy analysis and network analysis indicated that the bacterial community succession was the main mechanism that affected the variations in ARGs and intI1. The reduction of Firmicutes due to the biochar treatment of soil and lettuce was the main factor responsible for the removal of tetracycline resistance genes in leaves. Biochar application led to the disappearance of human pathogenic bacteria (HPB), which was significantly correlated with the abundances of ermF and ermX. In summary, biochar is an effective farmland amendment for reducing the abundances of antibiotics, ARGs, and HPB in order to ensure the safety of vegetables and protect human health. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Removal of oxytetracycline and determining its biosorption properties on aerobic granular sludge.

    Science.gov (United States)

    Mihciokur, Hamdi; Oguz, Merve

    2016-09-01

    This study investigates biosorption of Oxytetracycline, a broad-spectrum antibiotic, using aerobic granular sludge as an adsorbent in aqueous solutions. A sequencing batch reactor fed by a synthetic wastewater was operated to create aerobic granular sludge. Primarily, the pore structure and surface area of granular sludge, the chemical structure and the molecular sizes of the pharmaceutical, operating conditions, such as pH, stirring rate, initial concentration of Oxytetracycline, during adsorption process was verified. Subsequently, thermodynamic and kinetic aspects of the adsorption were examined and adsorption isotherm studies were carried out. It was shown that the aerobic granular sludge was a good alternative for biosorption of this pharmaceutical. The pharmaceutical was adsorbed better at pH values of 6-8. The adsorption efficiency increased with rising ionic strength. Also, it was seen that the adsorption process was an exothermic process in terms of thermodynamics. The adsorption can be well explained by Langmuir isotherm model. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Determination of Oxytetracycline and 4-Epi-Oxytetracycline Residues in Feathers and Edible Tissues of Broiler Chickens Using Liquid Chromatography Coupled with Tandem Mass Spectrometry.

    Science.gov (United States)

    Cornejo, Javiera; Pokrant, Ekaterina; Krogh, Magdalena; Briceño, Cristóbal; Hidalgo, Héctor; Maddaleno, Aldo; Araya-Jordán, Carolina; Martín, Betty San

    2017-04-01

    Antibiotics have been widely used in poultry production for the treatment of bacterial diseases. However, drug residues can remain in products derived from animals after the cessation of the drug therapies. Feathers, in particular, have shown an affinity for antibiotics such as tetracycline, suggesting the persistence of these drugs in nonedible tissue. After the birds are slaughtered, feathers are ground into feather meals, which are used as organic fertilizer or an ingredient in animal diets, thereby entering into the food chain and becoming a potential risk for public health. To evaluate the depletion of oxytetracycline (OTC) and its metabolite 4-epi-oxytetracycline (4-epi-OTC) in the muscles, liver, and feathers, 64 broiler chickens, bred under controlled conditions, were treated orally with a commercial formulation of 10% OTC for 7 days. The analytes were quantified using liquid chromatography-tandem mass spectrometry. OTC and 4-epi-OTC were found in the feathers for 46 days, whereas they were found in the muscle and liver for only 12 and 6 days, respectively. These results prove that the analytes remain in feathers in higher concentrations than they do in edible tissues after treatment with tetracyclines. Thus, feather meals represent a potential source of antimicrobial residue contamination in the food chain.

  12. Variable effects of oxytetracycline on antibiotic resistance gene abundance and the bacterial community during aerobic composting of cow manure.

    Science.gov (United States)

    Qian, Xun; Sun, Wei; Gu, Jie; Wang, Xiao-Juan; Sun, Jia-Jun; Yin, Ya-Nan; Duan, Man-Li

    2016-09-05

    Livestock manure is often subjected to aerobic composting but little is known about the variation in antibiotic resistance genes (ARGs) during the composting process under different concentrations of antibiotics. This study compared the effects of three concentrations of oxytetracycline (OTC; 10, 60, and 200mg/kg) on ARGs and the succession of the bacterial community during composting. Very similar trends were observed in the relative abundances (RAs) of each ARG among the OTC treatments and the control during composting. After composting, the RAs of tetC, tetX, sul1, sul2, and intI1 increased 2-43 times, whereas those of tetQ, tetM, and tetW declined by 44-99%. OTC addition significantly increased the absolute abundances and RAs of tetC and intI1, while 200mg/kg OTC also enhanced those of tetM, tetQ, and drfA7. The bacterial community could be grouped according to the composting time under different treatments. The highest concentration of OTC had a more persistent effect on the bacterial community. In the present study, the succession of the bacterial community appeared to have a greater influence on the variation of ARGs during composting than the presence of antibiotics. Aerobic composting was not effective in reducing most of the ARGs, and thus the compost product should be considered as an important reservoir for ARGs. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Aptamer-functionalized magnetic nanoparticles for simultaneous fluorometric determination of oxytetracycline and kanamycin

    International Nuclear Information System (INIS)

    Liu, Changbin; Lu, Chunxia; Tang, Zonggui; Chen, Xia; Wang, Guohong; Sun, Fengxia

    2015-01-01

    This work describes a method for the simultaneous detection of oxytetracycline (OTC) and kanamycin (KMY) using aptamers acting as both recognition and separation elements, and complementary oligonucleotides labeled with a green emitting fluorophore (carboxyfluorescein, FAM) and a yellow emitting fluorophore (carboxy-X-rhodamine, ROX), respectively, as signal labels. An OTC aptamer and a KMY aptamer were immobilized on the surface of magnetic nanoparticles (MNPs) via avidin-biotin chemistry. The aptamers preferentially bind their respective targets and thereby cause the upconcentration of analytes. However, in their absence they bind fluorescently-tagged complementary oligonucleotide later added to the reaction system. This cause the NPs to become fluorescent, with emission peaks located at 520 and 608 nm, respectively. The effects of the concentration of avidin, aptamer, complementary oligonucleotide, incubation temperature and incubation time were optimized. Under the optimal conditions, linear relationships were obtained in the range of 1–50 ng∙mL −1 for OTC and KMY, with limits of detection of 0.85 ng∙mL −1 and 0.92 ng∙mL −1 , respectively. The method was applied to the analysis of pork, milk, and honey samples spiked with OTC and MKY. Recoveries ranged from 76.5 to 94.7 % and 77.8 to 93.1 %, respectively, and the relative standard deviation was <10.0 %. (author)

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

    DEFF Research Database (Denmark)

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

    2004-01-01

    2-Acetyl-2-decarboxamido-oxytetracycline (ADOTC) is a major impurity of oxytetracycline (OTC) produced as a side product during fermentation. ADOTC was isolated from OTC and other impurities using preparative HPLC. The preparative column was an Xterra MS. C-18 chromatographic column (100 mm x 19...

  15. Vaginal oxytetracycline concentrations.

    Science.gov (United States)

    Thin, R N; Al Rawi, Z H; Simmons, P D; Treharne, J; Tabaqchali, S

    1979-01-01

    Although tetracycline preparations are widely used in departments of genitourinary medicine, or sexually transmitted diseases clinics, little is known of the concentrations of these preparations in genital secretions. For this reason a microbiological method was used for estimating oxytetracycline concentrations in vaginal secretions. These concentrations varied from 0.6 to 6.5 microgram/ml in 19 women who had had sexual contact with a man with non-specific urethritis and who were taking oxytetracycline dihydrate 250 mg four times daily. They were well in excess of the minimum inhibitory concentration of oxytetracycline (0.2 microgram/ml) for the strains of Chlamydia trachomatis isolated from the patients with positive culture results. Thus, oxytetracycline 250 mg four times daily appears to be a satisfactory regimen for the treatment of chlamydial genital infection in women. PMID:509190

  16. Identification and determination of oxytetracycline, tiamulin, lincomycin, and spectinomycin in veterinary preparations by thin-layer chromatography/densitometry.

    Science.gov (United States)

    Krzek, J; Kwiecień, A; Starek, M; Kierszniewska, A; Rzeszutko, W

    2000-01-01

    A thin-layer chromatographic/densitometric method was developed for the identification and quantitation of oxytetracycline, tiamulin, lincomycin, and spectinomycin in veterinary preparations. Silica gel-coated thin layer chromatography plates and 2 mobile phases were used to separate these constituents. The appropriate compositions of the suitable mobile phases were established: 10% citric acid solution-n-hexane-ethanol (80 + 1 + 1, v/v) and n-butanol-ethanol-chloroform-25% ammonia (4 + 5 + 2 + 5, v/v). Along with Rf values and spot colors, direct UV and visual densitometric measurements were used for identification. Similar measuring ranges were used for quantitative analysis to obtain repeatable and reliable results for the preparations examined. The results of the quantitative analysis are characterized by a small confidence interval and are close to the declared contents of active constituents: oxytetracycline 30.01 +/- 0.38 g at lambda = 350 nm and 30.24 +/- 0.86 g at lambda = 430 nm; tiamulin, 10.19 +/- 0.86 g at lambda = 450 nm; lincomycin, 2.27 +/- 0.08 g at lambda = 278 nm; and spectinomycin, 2.18 +/- 0.07 g at lambda = 421 nm. The recoveries for all antibiotics ranged from 100.01 to 102.54%.

  17. Effects of oxytetracycline on archaeal community, and tetracycline resistance genes in anaerobic co-digestion of pig manure and wheat straw.

    Science.gov (United States)

    Wang, Xiaojuan; Pan, Hongjia; Gu, Jie; Qian, Xun; Gao, Hua; Qin, Qingjun

    2016-12-01

    In this study, the effects of different concentrations of oxytetracycline (OTC) on biogas production, archaeal community structure, and the levels of tetracycline resistance genes (TRGs) were investigated in the anaerobic co-digestion products of pig manure and wheat straw. PCR denaturing gradient gel electrophoresis analysis and real-time quantitative polymerase chain reaction (RT-qPCR) (PCR) were used to detect the archaeal community structure and the levels of four TRGs: tet(M), tet(Q), tet(W), and tet(C). The results showed that anaerobic co-digestion with OTC at concentrations of 60, 100, and 140 mg/kg (dry weight of pig manure) reduced the cumulative biogas production levels by 9.9%, 10.4%, and 14.1%, respectively, compared with that produced by the control, which lacked the antibiotic. The addition of OTC substantially modified the structure of the archaeal community. Two orders were identified by phylogenetic analysis, that is, Pseudomonadales and Methanomicrobiales, and the methanogen present during anaerobic co-digestion with OTC may have been resistant to OTC. The abundances of tet(Q) and tet(W) genes increased as the OTC concentration increased, whereas the abundances of tet(M) and tet(C) genes decreased as the OTC concentration increased.

  18. Assessment of oxytetracycline and tetracycline antibiotics in manure samples in different cities of Khuzestan Province, Iran.

    Science.gov (United States)

    Alavi, Nadali; Babaei, Ali Akbar; Shirmardi, Mohammad; Naimabadi, Abolfazl; Goudarzi, Gholamreza

    2015-11-01

    Tetracyclines (TCs), a class of antibiotics with a broad spectrum, are the most frequently used antibiotics in animal production. The major concern is that the widespread use of the antibiotics may lead to the emergence of new strains of bacteria that are resistant to these antibiotics. The objective of this study was to determine the residual levels of oxytetracycline and tetracycline in 80 animal manure samples that were collected from the livestock and poultry feedlots in Khuzestan Province. The residual levels of the antibiotics in the samples were extracted by using solid-phase extraction (SPE) method and subsequently were measured by liquid chromatography. Recoveries from the spiked poultry manure samples ranged from 65 to 113% for tetracycline and 86 to 132% for oxytetracycline. Relative standard deviations of the recoveries were less than 5.7% within the same day. Method detection limit (MDL) measured for oxytetracycline and tetracycline in the manure were 0.011 and 0.01 mg/kg, respectively. Analysis of the collected 50 chickens and 30 cow manure samples showed that the highest concentration of tetracycline was related to Behbahan City (5.36 mg/kg) and the lowest concentration was detected for Ramhormoz (0.05 mg/kg). The highest and lowest concentrations of oxytetracycline were respectively observed for Behbahan (13.77 mg/kg) and Ramhormoz (0.047 mg/kg). Based on the results, in chicken manure, there was significant statistical difference between the residual TC concentrations among five cities (p(value) oxytetracyclin (OTC) residual concentrations among five cities (p(value) > 0.05).

  19. Ethyl substituted β-cyclodextrin enhanced fluorimetric method for the determination of trace amounts of oxytetracycline in urine, serum, feed of chook and milk

    International Nuclear Information System (INIS)

    Wang Hongjian; Hou Faju; Jiang Chongqiu

    2005-01-01

    A simple sensitive spectrofluorimetric method was developed for the determination of oxytetracycline (OTC). Ethyl substituted β-cyclodextrin (DE-β-CD) can remarkably enhance the fluorescence intensity of the OTC-Eu 3+ complex at λ=612nm and the enhanced fluorescence intensity of Eu 3+ ion is in proportion to the concentration of OTC. Optimum conditions for the determination of OTC were also investigated. The linear range of this method for the determination of OTC is 8.28x10 -8 -1.73x10 -5 mol/L and the limit of detection is 6.76x10 -9 mol/L, respectively. The developed method is practical and relatively free interference from coexisting substances and can be successfully applied to determination of OTC in samples of urine, serum, feed of chook and milk. The enhancement of the fluorescence at λ em =612nm of Eu 3+ ion is because of the inclusion complex OTC-Eu 3+ -DE-β-CD

  20. Ethyl substituted {beta}-cyclodextrin enhanced fluorimetric method for the determination of trace amounts of oxytetracycline in urine, serum, feed of chook and milk

    Energy Technology Data Exchange (ETDEWEB)

    Hongjian, Wang [Department of Chemistry, Shandong Normal University, Jinan 250014 (China); Faju, Hou [Department of Chemistry, Shandong Normal University, Jinan 250014 (China); Chongqiu, Jiang [Department of Chemistry, Shandong Normal University, Jinan 250014 (China)

    2005-05-15

    A simple sensitive spectrofluorimetric method was developed for the determination of oxytetracycline (OTC). Ethyl substituted {beta}-cyclodextrin (DE-{beta}-CD) can remarkably enhance the fluorescence intensity of the OTC-Eu{sup 3+} complex at {lambda}=612nm and the enhanced fluorescence intensity of Eu{sup 3+} ion is in proportion to the concentration of OTC. Optimum conditions for the determination of OTC were also investigated. The linear range of this method for the determination of OTC is 8.28x10{sup -8}-1.73x10{sup -5}mol/L and the limit of detection is 6.76x10{sup -9}mol/L, respectively. The developed method is practical and relatively free interference from coexisting substances and can be successfully applied to determination of OTC in samples of urine, serum, feed of chook and milk. The enhancement of the fluorescence at {lambda}{sub em}=612nm of Eu{sup 3+} ion is because of the inclusion complex OTC-Eu{sup 3+}-DE-{beta}-CD.

  1. One pot synthesis of magnetic graphene/carbon nanotube composites as magnetic dispersive solid-phase extraction adsorbent for rapid determination of oxytetracycline in sewage water.

    Science.gov (United States)

    Sun, Yunyun; Tian, Jing; Wang, Lu; Yan, Hongyuan; Qiao, Fengxia; Qiao, Xiaoqiang

    2015-11-27

    A simple and time-saving one pot synthesis of magnetic graphene/carbon nanotube composites (M-G/CNTs) was developed that could avoid the tedious drying process of graphite oxide, and G/CNTs were modified by Fe3O4 nanoparticles in the reduction procedure. It contributed to a shorten duration of the synthesis process of M-G/CNTs. The obtained M-G/CNTs were characterized and the results indicated that CNTs and Fe3O4 nanoparticles were served as spacer distributing to the layers of graphene, which was beneficial for enlarging surface area and improving extraction efficiency. Moreover, M-G/CNTs showed good magnetic property and outstanding thermal stability. Then M-G/CNTs were applied as adsorbent of magnetic dispersive solid-phase extraction for rapid extraction and determination of oxytetracycline in sewage water. Under the optimum conditions, good linearity was obtained in the range of 20-800ngmL(-1) and the recoveries were ranged from 95.5% to 112.5% with relative standard deviations less than 5.8%. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. [Binding of tylosin, tilmicosin and oxytetracycline to proteins from honeybees, larvae and beehive products].

    Science.gov (United States)

    Reynaldi, F J; Lacunza, J; Alippi, A M; Rule, R

    2010-01-01

    American Foulbrood (AFB) caused by the spore-forming bacterium Paenibacillus larvae is the most serious disease of bacterial origin affecting larvae and pupae of honeybees. Antibiotics are used in many countries for the control of AFB in high incidence areas, but their misuse may lead to antibiotic resistance of bacterial strains and honey contamination. The objective of the present work was to determine, through a biological method, the protein binding of tylosin, tilmicosin and oxytetracycline to worker jelly; honey; pollen; adult bees and larvae in order to propose their kinetic routes. The sensitivity limit of the technique used was 0.05 μg/ml for tylosin and tilmicosin and 0.01 μg/ml for oxytetracycline, respectively. The method had intra and inter-assay correlation coefficients over 0.90, respectively and a coefficient variation of intra-and inter-assay for all antibiotics and processed samples under 5%. Tylosin and oxytetracycline presented lower percentages of protein binding in tissues and hive products (average 15%) in relation to those observed for tilmicosin (29%). In conclusion, tylosin is useful for AFB control in honey bee colonies due to its chemical characteristics, antimicrobial activity and levels of protein binding in bees, larvae, and beehive products.

  3. Integrated Control of Fire Blight with Antagonists and Oxytetracycline

    Science.gov (United States)

    In the Pacific Northwest of the United States, the antibiotic streptomycin provided excellent control of fire blight until resistant isolates of Erwinia amylovora arose. Oxytetracycline (Mycoshield) is now sprayed as an alternative antibiotic. We found that the duration of inhibitory activity of o...

  4. Integrated Control of Fire Blight with Bacterial Antagonists and Oxytetracycline

    Science.gov (United States)

    In the Pacific Northwest of the United States, the antibiotic streptomycin provided excellent control of fire blight until resistant isolates of Erwinia amylovora were prevalent. Oxytetracycline (Mycoshield) is now sprayed as an alternative antibiotic. We found that the duration of inhibitory acti...

  5. Effect of irradiation on oxytetracycline residues in poultry meat

    Energy Technology Data Exchange (ETDEWEB)

    Mazurowski, P [Warsaw Agricultural University, Faculty of Veterinary Medicine, Department of Food Hygiene, Warsaw (Poland)

    1994-12-31

    The purpose of the study was an evaluation of the effect of ionizing radiation on detection of oxytetracycline residues in poultry meat. Oxytetracycline was chosen as a representative of tetracyclines which are often applied in poultry for therapeutical reasons. The experiment was conducted using both broiler meat treated by oxytetracycline and slurry of broiler meat containing appropriate concentration of this antibiotic. A traditional microbiological method for determination of antibiotics antimicrobial activity was used. A significant decrease of oxytetracycline concentration in meat slurry as a result of irradiation was noted. A dose of 1 kGy reduced concentration of tetracycline to ca 40% and a dose of 3 kGy reduced it to ca 3%. In ground poultry meat a dose of 1 kGy reduced this antibiotic concentration to 70%, a dose of 3 kGy reduced oxytetracycline concentration to 35% and a 5 kGy dose reduced it up to ca 18% of initial concentration. It can be concluded that irradiation of poultry meat with radurization doses can cause some difficulties in detection of tetracycline residues in meat using traditional microbiological methods of detection. (author).

  6. Effect of irradiation on oxytetracycline residues in poultry meat

    International Nuclear Information System (INIS)

    Mazurowski, P.

    1994-01-01

    The purpose of the study was an evaluation of the effect of ionizing radiation on detection of oxytetracycline residues in poultry meat. Oxytetracycline was chosen as a representative of tetracyclines which are often applied in poultry for therapeutical reasons. The experiment was conducted using both broiler meat treated by oxytetracycline and slurry of broiler meat containing appropriate concentration of this antibiotic. A traditional microbiological method for determination of antibiotics antimicrobial activity was used. A significant decrease of oxytetracycline concentration in meat slurry as a result of irradiation was noted. A dose of 1 kGy reduced concentration of tetracycline to ca 40% and a dose of 3 kGy reduced it to ca 3%. In ground poultry meat a dose of 1 kGy reduced this antibiotic concentration to 70%, a dose of 3 kGy reduced oxytetracycline concentration to 35% and a 5 kGy dose reduced it up to ca 18% of initial concentration. It can be concluded that irradiation of poultry meat with radurization doses can cause some difficulties in detection of tetracycline residues in meat using traditional microbiological methods of detection. (author)

  7. Influence of oxytetracycline on carprofen pharmacodynamics and pharmacokinetics in calves.

    Science.gov (United States)

    Brentnall, C; Cheng, Z; McKellar, Q A; Lees, P

    2013-08-01

    A tissue cage model of inflammation in calves was used to determine the pharmacokinetic and pharmacodynamic properties of individual carprofen enantiomers, following the administration of the racemate. RS(±) carprofen was administered subcutaneously both alone and in combination with intramuscularly administered oxytetracycline in a four-period crossover study. Oxytetracycline did not influence the pharmacokinetics of R(-) and S(+) carprofen enantiomers, except for a lower maximum concentration (Cmax ) of S(+) carprofen in serum after co-administration with oxytetracycline. S(+) enantiomer means for area under the serum concentration-time curve (AUC0-96 h were 136.9 and 128.3 μg·h/mL and means for the terminal half-life (T(1/2) k10 ) were = 12.9 and 17.3 h for carprofen alone and in combination with oxytetracycline, respectively. S(+) carprofen AUC0-96 h in both carprofen treatments and T(1/2) k10 for carprofen alone were lower (P oxytetracycline in calves and indicate that no alteration to carprofen dosage is required when the drugs are co-administered. © 2012 John Wiley & Sons Ltd.

  8. 76 FR 17025 - New Animal Drugs; Oxytetracycline

    Science.gov (United States)

    2011-03-28

    ... [Docket No. FDA-2011-N-0003] New Animal Drugs; Oxytetracycline AGENCY: Food and Drug Administration, HHS... Pennfield Oil Co. The supplemental ANADA provides for use of oxytetracycline hydrochloride soluble powder... use of PENNOX 343 (oxytetracycline HCl) Soluble Powder for control of American and European foulbrood...

  9. 21 CFR 556.500 - Oxytetracycline.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline. 556.500 Section 556.500 Food and... Residues of New Animal Drugs § 556.500 Oxytetracycline. (a) Acceptable daily intake (ADI). The ADI for total tetracycline residues (chlortetracycline, oxytetracycline, and tetracycline) is 25 micrograms per...

  10. 21 CFR 558.450 - Oxytetracycline.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline. 558.450 Section 558.450 Food and... in Animal Feeds § 558.450 Oxytetracycline. (a) Approvals. Type A medicated articles: (1) 10, 20, 30...-alkyl (C8-C18) trimethylammonium oxytetracycline expressed in terms of an equivalent amount of...

  11. 21 CFR 529.1660 - Oxytetracycline.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline. 529.1660 Section 529.1660 Food... DRUGS, FEEDS, AND RELATED PRODUCTS CERTAIN OTHER DOSAGE FORM NEW ANIMAL DRUGS § 529.1660 Oxytetracycline. (a) Specifications—(1) Each gram of powder contains 366 milligrams (mg) oxytetracycline hydrochloride...

  12. Flow injection on-line spectrophotometric determination of thorium(IV) after preconcentration on XAD-4 resin impregnated with oxytetracycline

    Energy Technology Data Exchange (ETDEWEB)

    Shahida, Shabnam; Khan, Muhammad Haleem [Univ. of Azad Jammu and Kashmir, Muzaffarabad (Pakistan). Dept. of Chemistry; Ali, Akbar [Pakistan Institute of Nuclear Science and Technology, Islamabad (Pakistan). Chemistry Div.

    2014-02-15

    A very sensitive, selective and simple flow injection time-based method was developed for on-line preconcentration and determination of thorium(IV) at micro g L{sup -1} levels in environmental samples. The system operation was based on thorium(IV) ion retention at pH 4.0 in the minicolumn at a flow rate of 15.2 mL min{sup -1}. The trapped complex was then eluted with 3.6 mol L{sup -1} HCl at a flow rate of 4.9 mL min{sup -1}. The amount of thorium(IV) in the eluate was measured spectrophotometrically at 651 nm using arsenazo-III solution (0.05 % in 3.6 mol L{sup -1} HCl stabilized with 1 % triton X-100, 4.9 mL min{sup -1}) as colorimetric reagent. All chemical, and flow injection variables were optimized for the quantitative preconcentration of metal and a study of interference level of various ions was also carried out. The system offered low backpressure and improved sensitivity and selectivity. At a preconcentration time of 60 s and a sample frequency of 40 h{sup -1}, the enhancement factor was 97, the detection limit was 0.25 μg L{sup -1}, and the precision expressed as relative standard deviation was 1.08 % (at 50 μg L{sup -1}), whereas for 300 s of the preconcentration time and a sample frequency of 10 h{sup -1}, the enhancement factor of 357, the detection limit (3s) of 0.069 μg L{sup -1} and the precision of 1.32 % (at 10 μg L{sup -1}) was reported. The accuracy of the developed method was sufficient and evaluated by the analysis of certified reference material IAEA-SL-1 (Lake Sediment) and spiked water samples.

  13. Flow injection on-line spectrophotometric determination of thorium(IV) after preconcentration on XAD-4 resin impregnated with oxytetracycline

    International Nuclear Information System (INIS)

    Shahida, Shabnam; Khan, Muhammad Haleem; Ali, Akbar

    2014-01-01

    A very sensitive, selective and simple flow injection time-based method was developed for on-line preconcentration and determination of thorium(IV) at micro g L"-"1 levels in environmental samples. The system operation was based on thorium(IV) ion retention at pH 4.0 in the minicolumn at a flow rate of 15.2 mL min"-"1. The trapped complex was then eluted with 3.6 mol L"-"1 HCl at a flow rate of 4.9 mL min"-"1. The amount of thorium(IV) in the eluate was measured spectrophotometrically at 651 nm using arsenazo-III solution (0.05 % in 3.6 mol L"-"1 HCl stabilized with 1 % triton X-100, 4.9 mL min"-"1) as colorimetric reagent. All chemical, and flow injection variables were optimized for the quantitative preconcentration of metal and a study of interference level of various ions was also carried out. The system offered low backpressure and improved sensitivity and selectivity. At a preconcentration time of 60 s and a sample frequency of 40 h"-"1, the enhancement factor was 97, the detection limit was 0.25 μg L"-"1, and the precision expressed as relative standard deviation was 1.08 % (at 50 μg L"-"1), whereas for 300 s of the preconcentration time and a sample frequency of 10 h"-"1, the enhancement factor of 357, the detection limit (3s) of 0.069 μg L"-"1 and the precision of 1.32 % (at 10 μg L"-"1) was reported. The accuracy of the developed method was sufficient and evaluated by the analysis of certified reference material IAEA-SL-1 (Lake Sediment) and spiked water samples.

  14. Reactivities of tetracycline and oxytetracycline with OH radicals

    Energy Technology Data Exchange (ETDEWEB)

    Dziegielewski, J O; Glowacki, P [Uniwersytet Slaski, Katowice (Poland)

    1982-05-03

    Decomposition yields of tetracycline sulphate and oxytetracycline sulphate were determined in argon saturated 0.1N H/sub 2/SO/sub 4/ solutions. The decomposition yields of teracyclines decrease in the presence of the Cl/sup -/ ions. The reaction rate constants of the OH radicals with tetracyclines were also determined.

  15. Reactivities of tetracycline and oxytetracycline with OH radicals

    International Nuclear Information System (INIS)

    Dziegielewski, J.O.; Glowacki, P.

    1982-01-01

    Decomposition yields of tetracycline sulphate and oxytetracycline sulphate were determined in argon saturated 0.1N H 2 SO 4 solutions. The decomposition yields of teracyclines decrease in the presence of the Cl - ions. The reaction rate constants of the OH radicals with tetracyclines were also determined. (author)

  16. The effect of aging on sequestration and bioaccessibility of oxytetracycline in soils.

    Science.gov (United States)

    Liu, Yuxia; Bao, Yanyu; Cai, Zhang; Zhang, Zhenzihao; Cao, Peilin; Li, Xinqian; Zhou, Qixing

    2015-07-01

    Veterinary antibiotics introduced into soil environment may change the composition and functioning of soil microbial communities and promote the spreading of antibiotic resistance. Actual risks depend on the antibiotic's bioaccessibility and sequestration in soils, which may vary with contact time and soil properties. We elucidated changes in the horsebean plant's bioaccessible oxytetracycline with increasing contact time in three different soils (cinnamon, red, and brown soil) and observed discrepancy in oxytetracycline dissipation using sequential extractions with H2O-, 0.01 M CaCl2-, and Mcllvaine- in the same three soils. The results showed lower quantities of oxytetracycline with increasing contact time over 20 days than the level in freshly contaminated soils but hugely discrepant quantities among the three tested soils. In addition, aging largely reduced dissipation of H2O-, 0.01 M CaCl2-, and Mcllvaine- extracted oxytetracycline in soils before planting. However, bioturbation helped increase the H2O-, CaCl2-, and Mcllvaine- extracted oxytetracyline from cinnamon and brown soils with aging. Lastly, correlation analysis indicated that bioaccessibility of oxytetracycline significantly correlates with the total of H2O-, CaCl2-, and Mcllvaine- extracted oxytetracycline (0.676**, p oxytetracycline with aging. Overall, this study provides some basic understanding of the aging effect on sequestration and bioaccessibility of veterinary antibiotics in soils.

  17. Incidence, distribution, and spread of tetracycline resistance determinants and integron-associated antibiotic resistance genes among motile aeromonads from a fish farming environment

    DEFF Research Database (Denmark)

    Schmidt, Anja S.; Bruun, Morten Sichlau; Dalsgaard, Inger

    2001-01-01

    . Microbiol. 66:4908-4915, 2000), the predominant resistance phenotype (37%) being a combined oxytetracycline (OTC) and sulphadiazine/trimethoprim resistance. Combined sulphonamide/trimethoprim resistance (135 isolates) appeared closely related to the presence of a class 1 integron (141 strains). Among...

  18. The determinants of the antibiotic resistance process.

    Science.gov (United States)

    Franco, Beatriz Espinosa; Altagracia Martínez, Marina; Sánchez Rodríguez, Martha A; Wertheimer, Albert I

    2009-01-01

    The use of antibiotic drugs triggers a complex interaction involving many biological, sociological, and psychological determinants. Resistance to antibiotics is a serious worldwide problem which is increasing and has implications for morbidity, mortality, and health care both in hospitals and in the community. To analyze current research on the determinants of antibiotic resistance and comprehensively review the main factors in the process of resistance in order to aid our understanding and assessment of this problem. We conducted a MedLine search using the key words "determinants", "antibiotic", and "antibiotic resistance" to identify publications between 1995 and 2007 on the determinants of antibiotic resistance. Publications that did not address the determinants of antibiotic resistance were excluded. The process and determinants of antibiotic resistance are described, beginning with the development of antibiotics, resistance and the mechanisms of resistance, sociocultural determinants of resistance, the consequences of antibiotic resistance, and alternative measures proposed to combat antibiotic resistance. Analysis of the published literature identified the main determinants of antibiotic resistance as irrational use of antibiotics in humans and animal species, insufficient patient education when antibiotics are prescribed, lack of guidelines for treatment and control of infections, lack of scientific information for physicians on the rational use of antibiotics, and lack of official government policy on the rational use of antibiotics in public and private hospitals.

  19. Determining the specific electric resistance of rock

    Energy Technology Data Exchange (ETDEWEB)

    Persad' ko, V.Ia.

    1982-01-01

    Data are presented on perfecting the method of laboratory determination of the specific electric resistance of a rock formation. The average error in determining the specific electric resistance of the core at various locations is no more than two percent with low resistance values (2-5 ohms).

  20. Stability studies of oxytetracycline in methanol solution

    Science.gov (United States)

    Wang, Wei; Wu, Nan; Yang, Jinghui; Zeng, Ming; Xu, Chenshan; Li, Lun; Zhang, Meng; Li, Liting

    2018-02-01

    As one kind of typical tetracycline antibiotics, antibiotic residues of oxytetracycline have been frequently detected in many environmental media. In this study, the stability of oxytetracycline in methanol solution was investigated by high-performance liquid chromatography combined with UV-vis (HPLC-UV). The results show that the stability of oxytetracycline in methanol solution is highly related to its initial concentration and the preserved temperature. Under low temperature condition, the solution was more stable than under room temperature preservation. Under the same temperature preservation condition, high concentrations of stock solutions are more stable than low concentrations. The study provides a foundation for preserving the oxytetracycline-methanol solution.

  1. Oxytetracycline does not cause growth promotion in finfish.

    Science.gov (United States)

    Trushenski, Jesse T; Aardsma, Matthew P; Barry, Kelli J; Bowker, James D; Jackson, Christopher J; Jakaitis, Michelle; McClure, Rebecca L; Rombenso, Artur N

    2018-05-04

    Until recently, use of antibiotics to enhance terrestrial animal growth performance was a common, U.S. Food and Drug Administration (FDA)-approved, but controversial practice. There are no FDA-approved production claims for antibiotic drug use in fish, but it is a common misconception that antibiotics are widely used for this purpose in U.S. aquaculture. Antibiotics are not thought to be effective growth promoters in fish, but there is little quantitative data available to address whether there are growth-promoting effects that might incentivize the use of antibiotics in this way, despite legal prohibitions. Therefore, this study was conducted to determine if oral administration of oxytetracycline, an antibiotic with known growth-promoting effects in terrestrial livestock, has a similar effect when applied to channel catfish Ictalurus punctatus, hybrid striped bass Morone chrysops × M. saxatilis, Nile tilapia Oreochromis niloticus, or rainbow trout Oncorhynchus mykiss. Oxytetracycline products with production claims are typically applied at doses substantially lower than the approved therapeutic doses for the same products. Medication (0, 0.24, or 1.2 g oxytetracycline dihydrate kg-1 feed) and feeding rates (3% BW d-1) were selected to achieve target daily doses of 0, 16, or 80 mg kg-1 fish representing control, subtherapeutic, and therapeutic treatments. Replicate groups of fish (N = 4) were fed accordingly for 8 wk. Overall, oral administration of oxytetracycline did not affect survival or promote growth of the selected taxa, with no significant differences observed for weight gain, feed conversion ratio, or specific growth rate (P > 0.05 in all cases). Few differences were observed in organosomatic indices and in the frequency of tissue abnormalities; where present, these differences tended to suggest a negative effect of long-term dietary exposure to oxytetracycline. These data demonstrate that there is no benefit to dietary supplementation with

  2. The determinants of the antibiotic resistance process

    Directory of Open Access Journals (Sweden)

    Beatriz Espinosa Franco

    2009-04-01

    Full Text Available Beatriz Espinosa Franco1, Marina Altagracia Martínez2, Martha A Sánchez Rodríguez1, Albert I Wertheimer31Facultad de Estudios Superiores Zaragoza (UNAM, Mexico; 2Universidad Autónoma Metropolitana Unidad Xochimilco, Mexico; 3Temple University, Philadelphia, Pennsylvania, USABackground: The use of antibiotic drugs triggers a complex interaction involving many biological, sociological, and psychological determinants. Resistance to antibiotics is a serious worldwide problem which is increasing and has implications for morbidity, mortality, and health care both in hospitals and in the community.Objectives: To analyze current research on the determinants of antibiotic resistance and comprehensively review the main factors in the process of resistance in order to aid our understanding and assessment of this problem.Methods: We conducted a MedLine search using the key words “determinants”, “antibiotic”, and “antibiotic resistance” to identify publications between 1995 and 2007 on the determinants of antibiotic resistance. Publications that did not address the determinants of antibiotic resistance were excluded.Results: The process and determinants of antibiotic resistance are described, beginning with the development of antibiotics, resistance and the mechanisms of resistance, sociocultural determinants of resistance, the consequences of antibiotic resistance, and alternative measures proposed to combat antibiotic resistance.Conclusions: Analysis of the published literature identified the main determinants of antibiotic resistance as irrational use of antibiotics in humans and animal species, insufficient patient education when antibiotics are prescribed, lack of guidelines for treatment and control of infections, lack of scientific information for physicians on the rational use of antibiotics, and lack of official government policy on the rational use of antibiotics in public and private hospitals.Keywords: antibiotic drug resistance

  3. 21 CFR 520.1660 - Oxytetracycline.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline. 520.1660 Section 520.1660 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1660 Oxytetracycline. ...

  4. Pharmacodynamics of oxytetracycline administered alone and in combination with carprofen in calves.

    Science.gov (United States)

    Brentnall, C; Cheng, Z; McKellar, Q A; Lees, P

    2012-09-15

    The pharmacodynamics (PD) of oxytetracycline was investigated against a strain of Mannheimia haemolytica. In vitro measurements, comprising minimum inhibitory concentration (MIC), minimum bactericidal concentration and time-kill curves, were conducted in five matrices; Mueller Hinton Broth (MHB), cation-adjusted MHB (CAMHB) and calf serum, exudate and transudate. MICs were much higher in the biological fluids than in MHB and CAMHB. Ratios of MIC were, serum: CAMHB 19 : 1; exudate:CAMHB 16.1; transudate:CAMHB 14 : 1. Ex vivo data, generated in the tissue cage model of inflammation, demonstrated that oxytetracycline, administered to calves intramuscularly at a dose rate of 20 mg/kg, did not inhibit the growth of M haemolytica in serum, exudate and transudate, even at peak concentration. However, using in vitro susceptibility in CAMHB and in vivo-determined pharmacokinetic (PK) variables, average and minimum oxytetracycline concentrations relative to MIC (C(av)/MIC and C(min)/MIC) predicted achievement of efficacy for approximately 48 hours after dosing. Similar C(av)/MIC and C(min)/MIC data were obtained when oxytetracycline was administered in the presence of carprofen. PK-PD integration of data for oxytetracycline, based on MICs determined in the three biological fluids, suggests that it possesses, at most, limited direct killing activity against M haemolytica. These data raise questions concerning the mechanism(s) of action of oxytetracycline, when administered at clinically recommended dose rates.

  5. 21 CFR 558.455 - Oxytetracycline and neomycin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline and neomycin. 558.455 Section 558... Drugs for Use in Animal Feeds § 558.455 Oxytetracycline and neomycin. (a) Specifications. Type A medicated articles containing oxytetracycline equivalent to 50 grams per pound (g/lb) oxytetracycline...

  6. 21 CFR 520.1660b - Oxytetracycline hydrochloride capsules.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline hydrochloride capsules. 520.1660b... Oxytetracycline hydrochloride capsules. (a) Specifications. The drug is in capsule form with each capsule containing 125 or 250 milligrams of oxytetracycline hydrochloride. Oxytetracycline is the antibiotic...

  7. Convergent acquisition of antibiotic resistance determinants ...

    African Journals Online (AJOL)

    Convergent acquisition of antibiotic resistance determinants amongst the Enterobacteriaceae isolates of the Mhlathuze River, KwaZulu-Natal (RSA) ... The possibility of transmission of resistant genes between bacteria (especially pathogenic) which invade human and animal populations within this river poses a health risk ...

  8. Extraction of oxytetracycline starting from the meats of chickens and identifications by thin layer chromatography

    International Nuclear Information System (INIS)

    Elghozzi, Amira

    2007-01-01

    Use of antibiotics in the poultry also suspected as one of the cause of the emergence of resistance to antibiotics of some bacteria what causes risks on human health continuation of persistence of the residues in the foodstuffs. We were interested in detected the presence qualitatively of oxytetracyclin in samples of muscle and liver of chicken by the use of the techniques of thin layer chromatography. Although, These results are satisfactory, it is always necessary to prevent the dangers which cause the risks of the residues of oxytetracycline on health. (Author). 20 refs

  9. Applicability of Screening Tests for Oxytetracycline in the Milk of Three Breeds of Goats.

    Science.gov (United States)

    Attaie, Rahmat; Bsharat, Mohammed; Mora-Gutierrez, Adela

    2016-06-01

    Antibiotics are widely used in animal husbandry, and the presence of antibiotic residues in milk is a health hazard. The objectives of this study were to determine residual amounts of oxytetracycline in the milk of three breeds of goats using high-pressure liquid chromatography (HPLC) analysis and screening tests. It was also essential to explore the safe withdrawal period of oxytetracycline in lactating goats and examine the applicability of Charm ROSA and SNAP screening tests. The qualitative results of these tests were compared with the quantitative results of the HPLC method. Fifteen milking does, five each from the Alpine, LaMancha, and Nubian breeds, were selected from the herd at Prairie View A&M University. Milk samples containing antibiotic residues were deproteinized by HCl and acetonitrile, and then oxytetracycline was extracted from the supernatant. The residues of oxytetracycline in goat's milk up to 110 h after injection were qualitatively detected using the Charm ROSA test. Similarly, the SNAP test detected the antibiotic residues in milk up to 110 h after treatment. The HPLC results indicated that oxytetracycline residues in milk from Alpine goats were below the tolerance level (300 ng/ml) 82 h after drug treatment (72 h for LaManchas, 58 h for Nubians); however, the results of the screening tests would indicate longer withdrawal periods for milk from the breeds of goats studied, which would result in economic losses to goat's milk producers. The results of this study also indicated that oxytetracycline was not stable in raw goat's milk at refrigeration temperature or during pasteurization and that the concentrations decreased significantly. Commercial goat's milk is usually exposed to several hours of refrigeration and then to pasteurization. The results of this study indicated that, if oxytetracycline was present in raw goat's milk, the concentration would decrease significantly before it was marketed.

  10. Dissipation of oxytetracycline in soils under different redox conditions

    International Nuclear Information System (INIS)

    Yang Jigeng; Ying Guangguo; Zhou Lijun; Liu Shan; Zhao Jianliang

    2009-01-01

    This study investigated the dissipation kinetics of oxytetracycline in soils under aerobic and anoxic conditions. Laboratory experiments showed that the dissipation of oxytetracycline in soil followed first-order reaction kinetics and its dissipation rates decreased with increasing concentration. Oxytetracycline dissipated faster in soil under aerobic conditions than under anoxic conditions. The half-lives for oxytetracycline in soil under aerobic conditions ranged between 29 and 56 days for non-sterile treatments and 99-120 days for sterile treatments, while under anoxic conditions the half-lives of oxytetracycline ranged between 43 and 62 days in the non-sterile soil and between 69 and 104 days in the sterile soil. This suggests microbes can degrade oxytetracycline in agricultural soil. Abiotic factors such as strong sorption onto soil components also played a role in the dissipation of oxytetracycline in soil. - Oxytetracycline dissipation in soils is influenced by redox conditions and soil properties.

  11. Dissipation of oxytetracycline in soils under different redox conditions

    Energy Technology Data Exchange (ETDEWEB)

    Jigeng, Yang [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Department of Chemistry and Chemical Engineering, Hunan University of Arts and Sciences, Changde 415000 (China); Ying Guangguo, E-mail: guangguo.ying@gmail.co [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Lijun, Zhou; Shan, Liu; Jianliang, Zhao [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China)

    2009-10-15

    This study investigated the dissipation kinetics of oxytetracycline in soils under aerobic and anoxic conditions. Laboratory experiments showed that the dissipation of oxytetracycline in soil followed first-order reaction kinetics and its dissipation rates decreased with increasing concentration. Oxytetracycline dissipated faster in soil under aerobic conditions than under anoxic conditions. The half-lives for oxytetracycline in soil under aerobic conditions ranged between 29 and 56 days for non-sterile treatments and 99-120 days for sterile treatments, while under anoxic conditions the half-lives of oxytetracycline ranged between 43 and 62 days in the non-sterile soil and between 69 and 104 days in the sterile soil. This suggests microbes can degrade oxytetracycline in agricultural soil. Abiotic factors such as strong sorption onto soil components also played a role in the dissipation of oxytetracycline in soil. - Oxytetracycline dissipation in soils is influenced by redox conditions and soil properties.

  12. Molecular characterization and determination of antimicrobial resistance of Mycoplasma gallisepticum isolated from chickens.

    Science.gov (United States)

    Pakpinyo, Somsak; Sasipreeyajan, Jiroj

    2007-11-15

    In this study, three consecutive approaches of molecular characterization, determination of minimum inhibitory concentration (MIC) and antimicrobial tested on Mycoplasma gallisepticum (MG) isolated from chicken farms were investigated. These approaches were conducted between 2004 and 2005 to 134 MG samples collected from five different regions of the intensive farming area of Thailand. Twenty MG isolates and four reference strains including S6, F, ts-11, and 6/85 were classified according to Random Amplification of Polymorphic DNA (RAPD) patterns prior to the antimicrobial tests. These isolates exhibited 5 different genotypes (A-E). Consequently, MG isolates representing each genotype were tested on 11 registered antibiotics. The levels of MIC were determined. Three antibiotics, doxycycline (0.20 microg/ml), tiamulin (0.10 microg/ml), and tylosin (0.33 microg/ml), gave the least MICs among all effective drugs. Break point comparisons of each antimicrobial suggested that the MG isolates were most sensitive to lincomycin, oxytetracycline, tiamulin, and tylosin. Some MG isolates had an intermediate effect on josamycin and were resistant to enrofloxacin and erythromycin. Our results also indicated that MG isolated and collected from the region and nearby districts had similar RAPD patterns showing properties of antimicrobial resistance. The RAPD patterns may imply the frequent use of antibiotics and a resistant strain of MG. This is the first report of genetic characterization using RAPD reflected by the levels of MIC against MG. The information is useful to plan for prophylactic and therapeutic impacts on the poultry industry especially in the area of intensive use of antibiotics.

  13. 40 CFR 180.337 - Oxytetracycline; tolerance for residues.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Oxytetracycline; tolerance for... § 180.337 Oxytetracycline; tolerance for residues. Tolerances are established for residues of the pesticide oxytetracycline in or on the following raw agricultural commodities: Commodity Parts per million...

  14. 21 CFR 522.1662a - Oxytetracycline hydrochloride injection.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline hydrochloride injection. 522.1662a... § 522.1662a Oxytetracycline hydrochloride injection. (a)(1) Specifications. The drug contains 50 milligrams of oxytetracycline hydrochloride in each milliliter of sterile solution. (2) Sponsor. See No...

  15. 21 CFR 520.1660d - Oxytetracycline powder.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline powder. 520.1660d Section 520...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1660d Oxytetracycline... concentrations of oxytetracycline hydrochloride (independent of the various net weights) as follows: (1) Each 18...

  16. Potential enzyme toxicity of oxytetracycline to catalase

    International Nuclear Information System (INIS)

    Chi Zhenxing; Liu Rutao; Zhang Hao

    2010-01-01

    Oxytetracycline (OTC) is a kind of widely used veterinary drugs. The residue of OTC in the environment is potentially harmful. In the present work, the non-covalent toxic interaction of OTC with catalase was investigated by the fluorescence spectroscopy, UV-vis absorption and circular dichroism (CD) spectroscopy at physiological pH 7.4. OTC can interact with catalase to form a complex mainly by van der Waals' interactions and hydrogen bonds with one binding site. The association constants K were determined to be K 293K = 7.09 x 10 4 L mol -1 and K 311K = 3.31 x 10 4 L mol -1 . The thermodynamic parameters (ΔH o , ΔG o and ΔS o ) of the interaction were calculated. Based on the Foerster theory of non-radiative energy transfer, the distance between bound OTC and the tryptophan residues of catalase was determined to be 6.48 nm. The binding of OTC can result in change of the micro-environment of the tryptophan residues and the secondary structure of catalase. The activity of catalase was also inhibited for the bound OTC. This work establishes a new strategy to probe the enzyme toxicity of veterinary drug residues and is helpful for clarifying the molecular toxic mechanism of OTC in vivo. The established strategy can be used to investigate the potential enzyme toxicity of other small organic pollutants and drugs.

  17. Prevalence and determinants of resistant hypertension among ...

    African Journals Online (AJOL)

    Tropical Journal of Pharmaceutical Research ... Prevalence and determinants of resistant hypertension among hypertensive patients attending a cardiology clinic in ... Obese patients and those suffering from diabetes mellitus, ischemic heart ... By Country · List All Titles · Free To Read Titles This Journal is Open Access.

  18. Electrical resistivity determination of subsurface layers, subsoil ...

    African Journals Online (AJOL)

    Electrical resistivity determination of subsurface layers, subsoil competence and soil corrosivity at and engineering site location in Akungba-Akoko, ... The study concluded that the characteristics of the earth materials in the site would be favourable to normal engineering structures/materials that may be located on it.

  19. Anodic oxidation of oxytetracycline: Influence of the experimental conditions on the degradation rate and mechanism

    Directory of Open Access Journals (Sweden)

    Annabel Fernandes

    2014-12-01

    Full Text Available The anodic oxidation of oxytetracycline was performed with success using as anode a boron-doped diamond electrode. The experiments were conducted in batch mode, using two different electrochemical cells: an up-flow cell, with recirculation, that was used to evaluate the influence of recirculation flow rate; and a stirred cell, used to determine the influence of the applied current density. Besides oxytetracyclin electrodegradation rate and mineralization extent, oxidation by-products were also assessed. Both the flow rate and the applied current density have shown positive influence on the oxytetracycline oxidation rate. On the other hand, the mineralization degree presented the highest values at the lowest flow rate and the lowest current density tested. The main oxidation by-products detected were oxalic, oxamic and maleic acids.

  20. Efficacy of three-week oxytetracycline or rifampin monotherapy compared with a combination regimen against the filarial nematode Onchocerca ochengi.

    Science.gov (United States)

    Bah, Germanus S; Ward, Emma L; Srivastava, Abhishek; Trees, Alexander J; Tanya, Vincent N; Makepeace, Benjamin L

    2014-01-01

    Onchocerciasis (river blindness), caused by the filarial nematode Onchocerca volvulus, is a major cause of visual impairment and dermatitis in sub-Saharan Africa. As O. volvulus contains an obligatory bacterial symbiont (Wolbachia), it is susceptible to antibiotic chemotherapy, although current regimens are considered too prolonged for community-level control programs. The aim of this study was to compare the efficacies of oxytetracycline and rifampin, administered separately or in combination, against a close relative of O. volvulus (Onchocerca ochengi) in cattle. Six animals per group were treated with continuous or intermittent oxytetracycline regimens, and effects on adult worm viability, dermal microfilarial loads, and Wolbachia density in worm tissues were assessed. Subsequently, the efficacies of 3-week regimens of oxytetracycline and rifampin alone and a combination regimen were compared, and rifampin levels in plasma and skin were quantified. A 6-month regimen of oxytetracycline with monthly dosing was strongly adulticidal, while 3-week and 6-week regimens exhibited weaker adulticidal effects. However, all three regimens achieved >2-log reductions in microfilarial load. In contrast, rifampin monotherapy and oxytetracycline-rifampin duotherapy failed to induce substantive reductions in either adult worm burden or microfilarial load, although a borderline effect on Wolbachia density was observed following duotherapy. Dermal rifampin levels were maintained above the MIC for >24 h after a single intravenous dose. We conclude that oxytetracycline-rifampin duotherapy is less efficacious against O. ochengi than oxytetracycline alone. Further studies will be required to determine whether rifampin reduces oxytetracycline bioavailability in this system, as suggested by human studies using other tetracycline-rifampin combinations.

  1. Novel Cadmium Resistance Determinant in Listeria monocytogenes.

    Science.gov (United States)

    Parsons, Cameron; Lee, Sangmi; Jayeola, Victor; Kathariou, Sophia

    2017-03-01

    Listeria monocytogenes is a foodborne pathogen that can cause severe disease (listeriosis) in susceptible individuals. It is ubiquitous in the environment and often exhibits resistance to heavy metals. One of the determinants that enables Listeria to tolerate exposure to cadmium is the cadAC efflux system, with CadA being a P-type ATPase. Three different cadA genes (designated cadA1 to cadA3 ) were previously characterized in L. monocytogenes A novel putative cadmium resistance gene ( cadA4 ) was recently identified through whole-genome sequencing, but experimental confirmation for its involvement in cadmium resistance is lacking. In this study, we characterized cadA4 in L. monocytogenes strain F8027, a cadmium-resistant strain of serotype 4b. By screening a mariner-based transposon library of this strain, we identified a mutant with reduced tolerance to cadmium and that harbored a single transposon insertion in cadA4 The tolerance to cadmium was restored by genetic complementation with the cadmium resistance cassette ( cadA4C ), and enhanced cadmium tolerance was conferred to two unrelated cadmium-sensitive strains via heterologous complementation with cadA4C Cadmium exposure induced cadA4 expression, even at noninhibitory levels. Virulence assessments in the Galleria mellonella model suggested that a functional cadA4 suppressed virulence, potentially promoting commensal colonization of the insect larvae. Biofilm assays suggested that cadA4 inactivation reduced biofilm formation. These data not only confirm cadA4 as a novel cadmium resistance determinant in L. monocytogenes but also provide evidence for roles in virulence and biofilm formation. IMPORTANCE Listeria monocytogenes is an intracellular foodborne pathogen causing the disease listeriosis, which is responsible for numerous hospitalizations and deaths every year. Among the adaptations that enable the survival of Listeria in the environment are the abilities to persist in biofilms, grow in the cold, and

  2. Potential enzyme toxicity of oxytetracycline to catalase

    Energy Technology Data Exchange (ETDEWEB)

    Zhenxing, Chi; Rutao, Liu; Zhang Hao, E-mail: Trutaoliu@sdu.edu.cn [School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment and Health, Shandong Province, 27 Shanda South Road, Jinan 250100 (China)

    2010-10-15

    Oxytetracycline (OTC) is a kind of widely used veterinary drugs. The residue of OTC in the environment is potentially harmful. In the present work, the non-covalent toxic interaction of OTC with catalase was investigated by the fluorescence spectroscopy, UV-vis absorption and circular dichroism (CD) spectroscopy at physiological pH 7.4. OTC can interact with catalase to form a complex mainly by van der Waals' interactions and hydrogen bonds with one binding site. The association constants K were determined to be K{sub 293K} = 7.09 x 10{sup 4} L mol{sup -1} and K{sub 311K} = 3.31 x 10{sup 4} L mol{sup -1}. The thermodynamic parameters ({Delta}H{sup o}, {Delta}G{sup o} and {Delta}S{sup o}) of the interaction were calculated. Based on the Foerster theory of non-radiative energy transfer, the distance between bound OTC and the tryptophan residues of catalase was determined to be 6.48 nm. The binding of OTC can result in change of the micro-environment of the tryptophan residues and the secondary structure of catalase. The activity of catalase was also inhibited for the bound OTC. This work establishes a new strategy to probe the enzyme toxicity of veterinary drug residues and is helpful for clarifying the molecular toxic mechanism of OTC in vivo. The established strategy can be used to investigate the potential enzyme toxicity of other small organic pollutants and drugs.

  3. Extraction of oxytetracycline starting from the meats of chickens and identifications by thin layer chromatography; Extraction de l'oxytetracycline dans les viandes des poulet et identification par chromatographie sur couche mince

    Energy Technology Data Exchange (ETDEWEB)

    Elghozzi, Amira [Institut Superieur de Biotechnologie de Sidi Thabet (Tunisia)

    2007-07-01

    Use of antibiotics in the poultry also suspected as one of the cause of the emergence of resistance to antibiotics of some bacteria what causes risks on human health continuation of persistence of the residues in the foodstuffs. We were interested in detected the presence qualitatively of oxytetracyclin in samples of muscle and liver of chicken by the use of the techniques of thin layer chromatography. Although, These results are satisfactory, it is always necessary to prevent the dangers which cause the risks of the residues of oxytetracycline on health. (Author). 20 refs.

  4. Prevalence of Sulfonamide Resistance Genes in Bacterial Isolates from Manured Agricultural Soils and Pig Slurry in the United Kingdom▿

    OpenAIRE

    Byrne-Bailey, K. G.; Gaze, W. H.; Kay, P.; Boxall, A. B. A.; Hawkey, P. M.; Wellington, E. M. H.

    2008-01-01

    The prevalences of three sulfonamide resistance genes, sul1, sul2, and sul3 and sulfachloropyridazine (SCP) resistance were determined in bacteria isolated from manured agricultural clay soils and slurry samples in the United Kingdom over a 2-year period. Slurry from tylosin-fed pigs amended with SCP and oxytetracycline was used for manuring. Isolates positive for sul genes were further screened for the presence of class 1 and 2 integrons. Phenotypic resistance to SCP was significantly higher...

  5. COMPARATIVE PHARMACOKINETIC STUDIES ON OXYTETRACYCLINE IN CAMELS, SHEEP AND GOATS

    Directory of Open Access Journals (Sweden)

    Mohammed H. Al-Nazawi

    2003-12-01

    Full Text Available Kinetics of long-acting oxytetracycline (OTC injected intravenously (IV at a dose of 5 mg/kg was determined in each of eight camels, sheep and goats. The disposition of OTC was described by two-compartment open model. Two elimination half-lives were recorded for the camel (81 min and 46.1 h, whereas in sheep and goats these were 3.2 and 3.4 h, respectively. The peak plasma concentration was 10.2, 850 and 780 g/ml at 5 minutes in camel, sheep and goats, respectively. The values of volume of distribution were 1.4, 13.4 and 12.1 litre/kg for the camels, sheep and goats, respectively. In sheep and goats, values of t1/2, Vd and clearance were found similar but different from camel, indicating exclusive distribution and substantial storage which were consistent with oxytetracycline lipophilicity and the large fat content of camel body.

  6. Pharmacokinetics and tissue residues of an oxytetracycline/diclofenac combination in cattle.

    Science.gov (United States)

    Mestorino, N; Mariño Hernández, E; Marchetti, L; Errecalde, J O

    2007-12-01

    Eight male cattle were given a combined dose containing 20 mg/kg oxytetracycline and 0.5 mg/kg diclofenac intramuscularly. Blood samples were drawn at different times until 168 h after administration. Two experimental animals were slaughtered by humane means at weekly intervals up to 28 days after administration. Samples of muscle, injection zone tissue, liver, kidney and fat were obtained. Oxytetracycline and diclofenac concentrations were determined by high performance liquid chromatography. Kinetic analysis was performed by linear regression using the CSTRIP programme. Plasma oxytetracycline concentration showed a maximum (Cmax) of 3.89 +/- 1.48 microg/ml and a prolonged elimination half-life (T1/2beta: 47.73 +/- 18.33 h). The diclofenac plasma profile showed high Cmax (577.62 +/- 238.40 ng/ml), and its T1/2beta was also prolonged (30.48 +/- 9.42 h). Oxytetracycline concentrations were measurable in liver and adipose tissue until day 21 after administration, but all tissue samples were negative for diclofenac at 21 days. The long elimination half-life of diclofenac was an unexpected finding; its T1/2beta in humans is 1.1 h.

  7. Persistent Oxytetracycline Exposure Induces an Inflammatory Process That Improves Regenerative Capacity in Zebrafish Larvae

    Science.gov (United States)

    Barros-Becker, Francisco; Romero, Jaime; Pulgar, Alvaro; Feijóo, Carmen G.

    2012-01-01

    Background The excessive use of antibiotics in aquaculture can adversely affect not only the environment, but also fish themselves. In this regard, there is evidence that some antibiotics can activate the immune system and reduce their effectiveness. None of those studies consider in detail the adverse inflammatory effect that the antibiotic remaining in the water may cause to the fish. In this work, we use the zebrafish to analyze quantitatively the effects of persistent exposure to oxytetracycline, the most common antibiotic used in fish farming. Methodology We developed a quantitative assay in which we exposed zebrafish larvae to oxytetracycline for a period of 24 to 96 hrs. In order to determinate if the exposure causes any inflammation reaction, we evaluated neutrophils infiltration and quantified their total number analyzing the Tg(mpx:GFP)i114 transgenic line by fluorescence stereoscope, microscope and flow cytometry respectively. On the other hand, we characterized the process at a molecular level by analyzing several immune markers (il-1β, il-10, lysC, mpx, cyp1a) at different time points by qPCR. Finally, we evaluated the influence of the inflammation triggered by oxytetracycline on the regeneration capacity in the lateral line. Conclusions Our results suggest that after 48 hours of exposure, the oxytetracycline triggered a widespread inflammation process that persisted until 96 hours of exposure. Interestingly, larvae that developed an inflammation process showed an improved regeneration capacity in the mechanosensory system lateral line. PMID:22590621

  8. Pharmacokinetics of Short- and Long-acting Formulations of Oxytetracycline After Intramuscular Administration in Chickens.

    Science.gov (United States)

    Gberindyer, Aondover F; Okpeh, Ene R; Semaka, Asaaga A

    2015-12-01

    Both short- and long-acting formulations of oxytetracycline are commonly used in veterinary medicine to treat animals infected with gram-negative and gram-positive bacteria, rickettsiae, mycoplasma, and chlamydiae. To compare pharmacokinetics of short- and long-acting oxytetracycline in chickens, injectable formulations from the same pharmaceutical company were administered to healthy 6-week-old broiler chickens in accordance to the labeled instructions. Fourteen chickens were separated into 2 groups: chickens in group A (n = 7) were administered the short-acting formulation (10 mg/kg IM q24h) for 4 consecutive days, whereas those in group B (n = 7) were treated with a single dose (20 mg/kg IM) of the long-acting formulation. Blood samples were collected into heparinized tubes before and at 0.25, 0.5, 1, 1.5, 2, 4, 6, 8, 10, and 24 hours after initial treatment. Thereafter, blood samples were taken every 24 hours up to 120 hours. Plasma concentrations of oxytetracycline were determined by competitive enzyme-linked immunoabsorbent assay, and pharmacokinetic parameters were obtained. Both formulations delivered therapeutic plasma concentrations of oxytetracycline for approximately 100% of their respective dosing intervals as recommended. However, considering the additional labor, patient stress, and mortalities associated with handling, in addition to rejection of the carcass due to tissue necrosis resulting from multiple injections, we recommend use of the long-acting instead of the short-acting injectable formulation in broiler chickens.

  9. Effects of oxytetracycline and amoxicillin on development and biomarkers activities of zebrafish (Danio rerio).

    Science.gov (United States)

    Oliveira, Rhaul; McDonough, Sakchai; Ladewig, Jessica C L; Soares, Amadeu M V M; Nogueira, António J A; Domingues, Inês

    2013-11-01

    Antibiotics have been widely used in human and veterinary medicine to treat or prevent diseases. Residues of antibiotics have been found in aquatic environments, but their effects on fish have been not properly investigated. This work aimed to assess the sub-lethal effects of oxytetracycline and amoxicillin on zebrafish development and biomarkers. Embryos and adults were exposed during 96 h to amoxicillin and oxytetracycline following OECD guidelines. Tissues of adults and pools of embryos were used for catalase, glutathione-S-transferases and lactate dehydrogenase determinations. Amoxicillin caused premature hatching (48 h-EC50=132.4 mg/l) whereas oxytetracycline cause delayed hatching of embryos (72 h-EC50=127.6 mg/l). Moreover, both antibiotics inhibited catalase and induced glutathione-S-transferases in zebrafish adults. However, only oxytetracycline induced lactate dehydrogenase. Short-term effects of antibiotics were observed at high doses (mg/l) indicating that physiological impairment in fish populations is unlike to occur. However, effects of chronic exposures to low doses of ABs must be investigated. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Comparison of standardised versus non-standardised methods for testing the in vitro potency of oxytetracycline against mannheimia haemolytica and pasteurella multocida

    OpenAIRE

    Lees, P; Illambas, J; Pelligand, L; Toutain, P L

    2016-01-01

    The in vitro pharmacodynamics of oxytetracycline was established for six isolates of each of the calf pneumonia pathogens Mannheimia haemolytica and Pasteurella multocida. Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and bacterial time-kill curves were determined in two matrices, Mueller Hinton broth (MHB) and calf serum. Geometric mean MIC ratios, serum:MHB, were 25.2:1 (M. haemolytica) and 27.4:1 (P. multocida). The degree of binding of oxytetracycline to...

  11. Determining the Resistivity of Resistive Sheets Using Transmission Measurements

    National Research Council Canada - National Science Library

    Hyde, IV, Milo W

    2006-01-01

    In September 2005, radar cross section (RCS) measurements were made of resistive sheets, or R-cards, wrapped around a polystyrene foam cylinder to compare with a newly developed theoretical RCS prediction technique...

  12. 21 CFR 522.1660 - Oxytetracycline injectable dosage forms.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline injectable dosage forms. 522.1660 Section 522.1660 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... § 522.1660 Oxytetracycline injectable dosage forms. ...

  13. 21 CFR 520.1660a - Oxytetracycline and carbomycin in combination.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline and carbomycin in combination. 520....1660a Oxytetracycline and carbomycin in combination. (a) Specifications. (1) Oxytetracycline: The....600(c) of this chapter. (c) Special considerations. The quantities of oxytetracycline in paragraph (e...

  14. Determinants of Growth Hormone Resistance in Malnutrition

    Science.gov (United States)

    Fazeli, Pouneh K.; Klibanski, Anne

    2014-01-01

    States of under-nutrition are characterized by growth hormone resistance. Decreased total energy intake, as well as isolated protein-calorie malnutrition and isolated nutrient deficiencies result in elevated growth hormone levels and low levels of IGF-I. We review various states of malnutrition and a disease state characterized by chronic under-nutrition -- anorexia nervosa -- and discuss possible mechanisms contributing to the state of growth hormone resistance, including FGF-21 and SIRT1. We conclude by examining the hypothesis that growth hormone resistance is an adaptive response to states of under-nutrition, in order to maintain euglycemia and preserve energy. PMID:24363451

  15. Environmental Sciences Electrical resistivity soundings to determine ...

    African Journals Online (AJOL)

    Wood, leaves, newspaper, cloth, polythene bags, plastics, glass and metal refuse interspersed with soil exhibited resistivity of 11.6 ohm-m and layer thickness of 0.7 m as obtained from the inversion of the sounding. The unsaturated layer has a resistivity of 6.8 ohm-m and thickness of 0.6 m while leachate-saturated is ...

  16. Determination of the Drag Resistance Coefficients of Different Vehicles

    Science.gov (United States)

    Fahsl, Christoph; Vogt, Patrik

    2018-01-01

    While it has been demonstrated how air resistance could be analyzed by using mobile devices, this paper demonstrates a method of how to determine the drag resistance coefficient "c" of a commercial automobile by using the acceleration sensor of a smartphone or tablet. In an academic context, the drag resistance is often mentioned, but…

  17. Determination of electrical resistivity of dry coke beds

    Energy Technology Data Exchange (ETDEWEB)

    Eidem, P.A.; Tangstad, M.; Bakken, J.A. [NTNU, Trondheim (Norway)

    2008-02-15

    The electrical resistivity of the coke bed is of great importance when producing FeMn, SiMn, and FeCr in a submerged arc furnace. In these processes, a coke bed is situated below and around the electrode tip and consists of metallurgical coke, slag, gas, and metal droplets. Since the basic mechanisms determining the electrical resistivity of a coke bed is not yet fully understood, this investigation is focused on the resistivity of dry coke beds consisting of different carbonaceous materials, i.e., coke beds containing no slag or metal. A method that reliably compares the electrical bulk resistivity of different metallurgical cokes at 1500{sup o} C to 1600{sup o}C is developed. The apparatus is dimensioned for industrial sized materials, and the electrical resistivity of anthracite, charcoal, petroleum coke, and metallurgical coke has been measured. The resistivity at high temperatures of the Magnitogorsk coke, which has the highest resistivity of the metallurgical cokes investigated, is twice the resistivity of the Corus coke, which has the lowest electrical resistivity. Zdzieszowice and SSAB coke sort in between with decreasing resistivities in the respective order. The electrical resistivity of anthracite, charcoal, and petroleum coke is generally higher than the resistivity of the metallurgical cokes, ranging from about two to about eight times the resistivity of the Corus coke at 1450{sup o}C. The general trend is that the bulk resistivity of carbon materials decreases with increasing temperature and increasing particle size.

  18. Safety of oxytetracycline (Terramycin TM-100F) administered in feed to hybrid striped bass, walleyes, and yellow perch

    Science.gov (United States)

    Gaikowski, M.P.; Wolf, J.C.; Schleis, S.M.; Gingerich, W.H.

    2003-01-01

    Oxytetracycline (Terramycin TM-100F, a medicated premix containing oxytetracycline at 220 g/kg) is approved in the United States to control certain systemic bacterial diseases of salmon and catfish when fed at a rate of 55-82.5 mg per kilogram of bodyweight per day for 10 d. Although oxytetracycline may also control certain systemic bacterial infections in coolwater or scaled warmwater fish, no safety data for such species are available. Our objective was to determine the safety of oxytetracycline administered in feed at nominal doses of 0, 82.5, 248, or 413 mg??kg-1??d-1 to yellow perch Perca flavescens and hybrid striped bass (striped bass Morone saxatilis x white bass M. chrysops) for 10 d and to walleye Sander vitreus (formerly Stizostedion vitreum) for 20 d. Yellow perch and hybrid striped bass consumed 50% to 100% of the diet, whereas walleye feed consumption was occasionally less than 50% of the diet. Feed or fecal material was present in the gastrointestinal tract of all necropsied walleyes except for one control fish. The single growth effect was that hybrid striped bass offered a nominal dose of 413 mg??kg-1??d-1 were significantly smaller than untreated controls. Oxytetracycline-related histopathological findings were limited to walleyes and were of low severity. The histopathological findings included decreased hematopoietic-lymphopoietic (H&L) tissue in the anterior kidneys, diffuse hyperplasia of the gill filament epithelium, and a decreased prevalence of fish with eosinophilic droplets in their renal tubular epithelial cells. Although the incidence of decreased H&L tissue tended to increase in proportion to oxytetracycline dose, this finding was statistically significant only for fish that received a nominal dose of 413 mg??kg-1??d-1. Given the pathogenicity of the types of bacteria that are controlled by oxytetracycline treatment and the long history of its use in major aquaculture species, the relative risk of the minor oxytetracycline

  19. A novel reflectance-based aptasensor using gold nanoparticles for the detection of oxytetracycline.

    Science.gov (United States)

    Seo, Ho Bin; Kwon, Young Seop; Lee, Ji-eun; Cullen, David; Noh, Hongseok Moses; Gu, Man Bock

    2015-10-07

    We present a novel reflectance-based colorimetric aptasensor using gold nanoparticles for the detection of oxytetracycline for the first time. It was found that the reflectance-based measurement at two wavelengths (650 and 520 nm) can generate more stable and sensitive signals than absorbance-based sensors to determine the aggregation of AuNPs, even at high AuNP concentrations. One of the most common antibacterial agents, oxytetracycline (OTC), was detected at concentrations as low as 1 nM in both buffer solution and tap water, which was 25-fold more sensitive, compared to the previous absorbance-based colorimetric aptasensors. This reflectance-based colorimetric aptasensor using gold nanoparticles is considered to be a better platform for portable sensing of small molecules using aptamers.

  20. Waste to wealth: Production of oxytetracycline using streptomyces ...

    African Journals Online (AJOL)

    Yomi

    2012-05-29

    May 29, 2012 ... used due to high risk of sensitization (Archer et al., 2001). However, ocular ... degree of aeration at the surface favours the production of antibiotics ... the near absence of water. Oxytetracycline, a quinone antibiotic commonly.

  1. Determination of anthelmintic resistance in goats and sheep using ...

    African Journals Online (AJOL)

    Nematode parasites are known to pose a challenge to small ruminant production in Tanzania due to their fast development of resistance to the commonly used anthelmintics. The objective of this study was to determine the resistance of anthelmintics in small ruminants. A total of 30 sheep and 30 goats aged between 6 and ...

  2. Antimicrobial resistance determinant microarray for analysis of multi-drug resistant isolates

    Science.gov (United States)

    Taitt, Chris Rowe; Leski, Tomasz; Stenger, David; Vora, Gary J.; House, Brent; Nicklasson, Matilda; Pimentel, Guillermo; Zurawski, Daniel V.; Kirkup, Benjamin C.; Craft, David; Waterman, Paige E.; Lesho, Emil P.; Bangurae, Umaru; Ansumana, Rashid

    2012-06-01

    The prevalence of multidrug-resistant infections in personnel wounded in Iraq and Afghanistan has made it challenging for physicians to choose effective therapeutics in a timely fashion. To address the challenge of identifying the potential for drug resistance, we have developed the Antimicrobial Resistance Determinant Microarray (ARDM) to provide DNAbased analysis for over 250 resistance genes covering 12 classes of antibiotics. Over 70 drug-resistant bacteria from different geographic regions have been analyzed on ARDM, with significant differences in patterns of resistance identified: genes for resistance to sulfonamides, trimethoprim, chloramphenicol, rifampin, and macrolide-lincosamidesulfonamide drugs were more frequently identified in isolates from sources in Iraq/Afghanistan. Of particular concern was the presence of genes responsible for resistance to many of the last-resort antibiotics used to treat war traumaassociated infections.

  3. Marine fungi isolated from Chilean fjord sediments can degrade oxytetracycline.

    Science.gov (United States)

    Ahumada-Rudolph, R; Novoa, V; Sáez, K; Martínez, M; Rudolph, A; Torres-Diaz, C; Becerra, J

    2016-08-01

    Salmon farming is the main economic activity in the fjords area of Southern Chile. This activity requires the use of antibiotics, such as oxytetracycline, for the control and prevention of diseases, which have a negative impact on the environment. We analyzed the abilities of endemic marine fungi to biodegrade oxytetracycline, an antibiotic used extensively in fish farming. We isolated marine fungi strains from sediment samples obtained from an area of fish farming activity. The five isolated strains showed an activity on oxytetracycline and were identified as Trichoderma harzianum, Trichoderma deliquescens, Penicillium crustosum, Rhodotorula mucilaginosa, and Talaromyces atroroseus by a scanning electron microscopy and characterized by molecular techniques. Results showed significant degradation in the concentration of oxytetracycline at the first 2 days of treatment for all strains analyzed. At 21 days of treatment, the concentration of oxytetracycline was decreased 92 % by T. harzianum, 85 % by T. deliquescens, 83 % by P. crustosum, 73 % by R. mucilaginosa, and 72 % by T. atroroseus, all of which were significantly higher than the controls. Given these results, we propose that fungal strains isolated from marine sediments may be useful tools for biodegradation of antibiotics, such as oxytetracycline, in the salmon industry.

  4. Development and validation of a reversed phase liquid chromatographic method for analysis of oxytetracycline and related impurities.

    Science.gov (United States)

    Kahsay, Getu; Shraim, Fairouz; Villatte, Philippe; Rotger, Jacques; Cassus-Coussère, Céline; Van Schepdael, Ann; Hoogmartens, Jos; Adams, Erwin

    2013-03-05

    A simple, robust and fast high-performance liquid chromatographic method is described for the analysis of oxytetracycline and its related impurities. The principal peak and impurities are all baseline separated in 20 min using an Inertsil C₈ (150 mm × 4.6 mm, 5 μm) column kept at 50 °C. The mobile phase consists of a gradient mixture of mobile phases A (0.05% trifluoroacetic acid in water) and B (acetonitrile-methanol-tetrahydrofuran, 80:15:5, v/v/v) pumped at a flow rate of 1.3 ml/min. UV detection was performed at 254 nm. The developed method was validated for its robustness, sensitivity, precision and linearity in the range from limit of quantification (LOQ) to 120%. The limits of detection (LOD) and LOQ were found to be 0.08 μg/ml and 0.32 μg/ml, respectively. This method allows the separation of oxytetracycline from all known and 5 unknown impurities, which is better than previously reported in the literature. Moreover, the simple mobile phase composition devoid of non-volatile buffers made the method suitable to interface with mass spectrometry for further characterization of unknown impurities. The developed method has been applied for determination of related substances in oxytetracycline bulk samples available from four manufacturers. The validation results demonstrate that the method is reliable for quantification of oxytetracycline and its impurities. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Antibacterial activity of oxytetracycline photoproducts in marine aquaculture's water.

    Science.gov (United States)

    Leal, J F; Henriques, I S; Correia, A; Santos, E B H; Esteves, V I

    2017-01-01

    Oxytetracycline (OTC) is one of the most used antibiotics in aquaculture. The main concern related to its use is the bacterial resistance, when ineffective treatments are applied for its removal or inactivation. OTC photo-degradation has been suggested as an efficient complementary process to conventional methods used in intensive fish production (e.g.: ozonation). Despite this, and knowing that the complete mineralization of OTC is difficult, few studies have examined the antibacterial activity of OTC photoproducts. Thus, the main aim of this work is to assess whether the OTC photoproducts retain the antibacterial activity of its parent compound (OTC) after its irradiation, using simulated sunlight. For that, three Gram-negative bacteria (Escherichia coli, Vibrio sp. and Aeromonas sp.) and different synthetic and natural aqueous matrices (phosphate buffered solutions at different salinities, 0 and 21‰, and three different samples from marine aquaculture industries) were tested. The microbiological assays were made using the well-diffusion method before and after OTC has been exposed to sunlight. The results revealed a clear effect of simulated sunlight, resulting on the decrease or elimination of the antibacterial activity for all strains and in all aqueous matrices due to OTC photo-degradation. For E. coli, it was also observed that the antibacterial activity of OTC is lower in the presence of sea-salts, as demonstrated by comparison of halos in aqueous matrices containing or not sea-salts. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Antimicrobial resistance and resistance gene determinants in clinical Escherichia coli from different animal species in Switzerland.

    Science.gov (United States)

    Lanz, Roland; Kuhnert, Peter; Boerlin, Patrick

    2003-01-02

    Antimicrobial susceptibility testing was performed on a total of 581 clinical Escherichia coli isolates from diarrhea and edema disease in pigs, from acute mastitis in dairy cattle, from urinary tract infections in dogs and cats, and from septicemia in laying hens collected in Switzerland between 1999 and 2001. Among the 16 antimicrobial agents tested, resistance was most frequent for sulfonamides, tetracycline, and streptomycin. Isolates from swine presented significantly more resistance than those from the other animal species. The distribution of the resistance determinants for sulfonamides, tetracycline, and streptomycin was assessed by hybridization and PCR in resistant isolates. Significant differences in the distribution of resistance determinants for tetracycline (tetA, tetB) and sulfonamides (sulII) were observed between the isolates from swine and those from the other species. Resistance to sulfonamides could not be explained by known resistance mechanisms in more than a quarter of the sulfonamide-resistant and sulfonamide-intermediate isolates from swine, dogs and cats. This finding suggests that one or several new resistance mechanisms for sulfonamides may be widespread among E. coli isolates from these animal species. The integrase gene (intI) from class I integrons was detected in a large proportion of resistant isolates in association with the sulI and aadA genes, thus demonstrating the importance of integrons in the epidemiology of resistance in clinical E. coli isolates from animals.

  7. Determination of rolling resistance coefficient based on normal tyre stiffness

    Science.gov (United States)

    Rykov, S. P.; Tarasuyk, V. N.; Koval, V. S.; Ovchinnikova, N. I.; Fedotov, A. I.; Fedotov, K. V.

    2018-03-01

    The purpose of the article is to develop analytical dependence of wheel rolling resistance coefficient based on the mathematical description of normal tyre stiffness. The article uses the methods of non-holonomic mechanics and plane section methods. The article shows that the abscissa of gravity center of tyre stiffness expansion by the length of the contact area is the shift of normal road response. It can be used for determining rolling resistance coefficient. When determining rolling resistance coefficient using ellipsis and power function equations, one can reduce labor costs for testing and increase assessment accuracy.

  8. Antimicrobial susceptibility and tetracycline resistance determinant genotyping of Gallibacterium anatis

    DEFF Research Database (Denmark)

    Bojesen, Anders M.; Vazquez, Maria E.; Bager, Ragnhild J.

    2011-01-01

    no determinant was identified.This is the first study to determine the antimicrobial susceptibility of Gallibacterium anatis by MIC revealing that multidrug resistance is very common among G. anatis field isolates. tet(B) was by far the most common determinant identified but future work should aim at identifying......The present investigation was undertaken to assess the antimicrobial susceptibility of a collection of 58 Gallibacterium isolates. All strains were tested by the broth dilution method using the veterinary fastidious medium. A total of 46 field strains were tested, whereof 23 were clinical isolates....... Multidrug resistance (resistance towards≥three drugs) was observed for 65% of the field strains and only two strains were susceptible to all compounds. Most prominently, resistance to tetracycline and sulfamethoxazole was observed in 92% and 97% of the field strains, respectively. For comparison...

  9. Implementación, validación y aplicación de un nuevo método para la determinación de oxitetraciclina por HPLC en tejido muscular de salmonídeos Implementation, validation, and application of a new HPLC method to determine oxytetracycline in salmonid muscle tissue

    Directory of Open Access Journals (Sweden)

    Cristian Aguilera

    2010-01-01

    Full Text Available Se implementa y valida un método para identificar y cuantificar la oxitetraciclina en músculo de salmón, cuantificar los niveles de recuperación de oxitetraciclina y estudiar su fármaco cinética en diferentes órganos de salmones. La implementación correspondió a la detección y cuantificación de residuos del antibiótico en el tejido muscular de salmonídeos. El principio de la metodología HPLC incluyó la determinación de una serie de soluciones representativas de los estándares utilizados en la fortificación de las muestras. El tiempo de retención fue de 5,7 min. La validación del método, busca confirmar y documentar que los resultados entregados por el método implementado sean confiables. Para esto se llevaron a cabo análisis de parámetros tales como: selectividad, precisión, exactitud, sensibilidad e incertidumbre. Los resultados obtenidos señalan que el porcentaje de recuperación, es de un 96%. El coeficiente de correlación (R de la curva de calibrado es 0,9946 y el coeficiente de variación 1,86%.A method for identifying and quantifying oxytetracycline in salmon muscle, for quantifying oxytetracycline recovery levels, and for studying its pharmacokinetic in different organs of salmonids was implemented and validated. During implementation, antibiotic residues were detected and quantified in salmon muscle tissue. The principle of the HPLC methodology included determining a series of representative solutions of the standards, used to fortify the samples. The retention time was 5.7 min. The validation of the method sought to confirm and document the reliability of the results obtained with this method. For this, several parameters (selectivity, precision, accuracy, sensitivity, uncertainty were analyzed. The results obtained indicated 96% recovery. The coefficient of correlation (R of the calibration curve was 0.9946 and the coefficient of variation was 1.86%.

  10. Genetic determinants of heat resistance in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Ryan eMercer

    2015-09-01

    Full Text Available Escherichia coli AW1.7 is a heat resistant food isolate and the occurrence of pathogenic strains with comparable heat resistance may pose a risk to food safety. To identify the genetic determinants of heat resistance, 29 strains of E. coli that differed in their of heat resistance were analyzed by comparative genomics. Strains were classified as highly heat resistant strains, exhibiting a D60-value of more than 6 min; moderately heat resistant strains, exhibiting a D60-value of more than 1 min; or as heat sensitive. A ~14 kb genomic island containing 16 predicted open reading frames encoding putative heat shock proteins and proteases was identified only in highly heat resistant strains. The genomic island was termed the locus of heat resistance (LHR. This putative operon is flanked by mobile elements and possesses >99% sequence identity to genomic islands contributing to heat resistance in Cronobacter sakazakii and Klebsiella pneumoniae. An additional 41 LHR sequences with >87% sequence identity were identified in 11 different species of β- and γ-proteobacteria. Cloning of the full length LHR conferred high heat resistance to the heat sensitive E. coli AW1.7ΔpHR1 and DH5α. The presence of the LHR correlates perfectly to heat resistance in several species of Enterobacteriaceae and occurs at a frequency of 2% of all E. coli genomes, including pathogenic strains. This study suggests the LHR has been laterally exchanged among the β- and γ-proteobacteria and is a reliable indicator of high heat resistance in E. coli.

  11. 21 CFR 522.1660a - Oxytetracycline solution, 200 milligrams/milliliter.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline solution, 200 milligrams... FORM NEW ANIMAL DRUGS § 522.1660a Oxytetracycline solution, 200 milligrams/milliliter. (a) Specifications. Each milliliter of sterile solution contains 200 milligrams of oxytetracycline base. (b) Sponsors...

  12. 21 CFR 522.1660b - Oxytetracycline solution, 300 milligrams/milliliter.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline solution, 300 milligrams... FORM NEW ANIMAL DRUGS § 522.1660b Oxytetracycline solution, 300 milligrams/milliliter. (a) Specifications. Each milliliter (mL) of solution contains 300 milligrams (mg) oxytetracycline base. (b) Sponsor...

  13. 21 CFR 522.1662b - Oxytetracycline hydrochloride with lidocaine injection.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline hydrochloride with lidocaine... FORM NEW ANIMAL DRUGS § 522.1662b Oxytetracycline hydrochloride with lidocaine injection. (a) Specifications. The drug contains 50 or 100 milligrams of oxytetracycline hydrochloride and 2 percent lidocaine...

  14. 21 CFR 520.1660c - Oxytetracycline hydrochloride tablets/boluses.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline hydrochloride tablets/boluses. 520....1660c Oxytetracycline hydrochloride tablets/boluses. (a) Specifications. Each tablet or bolus contains 250, 500, or 1,000 milligrams of oxytetracycline hydrochloride. (b) Sponsors. For sponsors in § 510...

  15. 21 CFR 524.1662b - Oxytetracycline hydrochloride, polymyxin B sulfate ophthalmic ointment.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline hydrochloride, polymyxin B sulfate... DOSAGE FORM NEW ANIMAL DRUGS § 524.1662b Oxytetracycline hydrochloride, polymyxin B sulfate ophthalmic ointment. (a) Specifications. Each gram of the ointment contains oxytetracycline hydrochloride equivalent...

  16. 76 FR 3488 - Implantation or Injectable Dosage Form New Animal Drugs; Oxytetracycline and Flunixin

    Science.gov (United States)

    2011-01-20

    .... FDA-2010-N-0002] Implantation or Injectable Dosage Form New Animal Drugs; Oxytetracycline and Flunixin... combination drug injectable solution containing oxytetracycline and flunixin meglumine in cattle. [[Page 3489... veterinary prescription use of HEXASOL (oxytetracycline and flunixin meglumine) Injection for the treatment...

  17. 21 CFR 524.1662a - Oxytetracycline hydrochloride and hydrocortisone spray.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline hydrochloride and hydrocortisone... NEW ANIMAL DRUGS § 524.1662a Oxytetracycline hydrochloride and hydrocortisone spray. (a) Specifications. Each 3-ounce unit of oxytetracycline hydrochloride and hydrocortisone spray contains 300...

  18. Prevalence of plasmid-mediated quinolone resistance determinants among oxyiminocephalosporin-resistant Enterobacteriaceae in Argentina

    Directory of Open Access Journals (Sweden)

    Giovanna Rincon Cruz

    2013-11-01

    Full Text Available High quinolone resistance rates were observed among oxyiminocephalosporin-resistant enterobacteria. In the present study, we searched for the prevalence of plasmid-mediated quinolone resistance (PMQR genes within the 55 oxyiminocephalosporin-resistant enterobacteria collected in a previous survey. The main PMQR determinants were aac(6'-Ib-cr and qnrB, which had prevalence rates of 42.4% and 33.3%, respectively. The aac(6'-Ib-cr gene was more frequently found in CTX-M-15-producing isolates, while qnrB was homogeneously distributed among all CTX-M producers.

  19. Antimicrobial resistance determinants among anaerobic bacteria isolated from footrot.

    Science.gov (United States)

    Lorenzo, María; García, Nuria; Ayala, Juan Alfonso; Vadillo, Santiago; Píriz, Segundo; Quesada, Alberto

    2012-05-25

    Antibiotic resistance has been evaluated among 36 Gram negative and anaerobic bacilli (10 Bacteroides, 11 Prevotella, 7 Porphyromonas and 8 Fusobacterium strains) isolated from clinical cases of caprine and ovine footrot (necrotic pododermatitis). The initial analysis on this bacterial consortium evaluates the relationships existing among antimicrobial resistance determinants, phenotype expression and mobilization potential. The Bacteroides strains were generally resistant to penicillins, first-generation cephalosporins, tetracycline and erythromycin, and expressed low level of β-lactamase activity. The main determinants found among the Bacteroides strains were cepA and tetQ genes, conferring resistance to β-lactams and tetracycline, respectively. A general susceptibility to β-lactams was shown for most Prevotella, Porphyromonas and Fusobacterium strains, where none of the β-lactamase genes described in Bacteroides was detected. Resistance to tetracycline and/or erythromycin was found among the three bacterial groups. Although tetQ genes were detected for several Prevotella and Porphyromonas strains, a unique ermF positive was revealed among Prevotella strains. The expression of resistance markers was not related with the polymorphism of their coding sequences. However, the finding of sequence signatures for conjugative transposons in the vicinities of tetQ and ermF suggests a mobilization potential that might have contributed to the spread of antimicrobial resistance genes. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Determination of the drag resistance coefficients of different vehicles

    Science.gov (United States)

    Fahsl, Christoph; Vogt, Patrik

    2018-05-01

    While it has been demonstrated how air resistance could be analyzed by using mobile devices, this paper demonstrates a method of how to determine the drag resistance coefficient c of a commercial automobile by using the acceleration sensor of a smartphone or tablet. In an academic context, the drag resistance is often mentioned, but little attention is paid to quantitative measurements. This experiment was driven by the fact that this physical value is most certainly neglected because of its difficult measurability. In addition to that, this experiment gives insights on how the aerodynamic factor of an automobile affects the energy dissipation and thus how much power is required by automobile transportation.

  1. Chlortetracycline and Oxytetracycline Residues in Poultry Tissues and Eggs

    Science.gov (United States)

    Meredith, W. E.; Weiser, H. H.; Winter, A. R.

    1965-01-01

    A pad-plate method of assaying residual amounts of chlortetracycline (CTC) and oxytetracycline (OTC) using Bacillus cereus 213 was used to determine amounts of antibiotic left in tissues and eggs of poultry fed 1,000 and 200 ppm of CTC and OTC in basal feed mixtures. The effects of various methods of cooking the tissues and eggs and the potentiating effect of terephthalic acid (TPA) were studied. It was found that normal methods of roasting, frying, and autoclaving poultry tissue destroyed all residual CTC and OTC, even with the potentiating effect of TPA. The largest amounts of residual antibiotic were found in the liver, then breast, and then thigh tissue when assayed for CTC. Tissue assays for CTC revealed that it was not taken up as extensively as CTC and the largest amounts were found in the liver, then breast. OTC residue was seldom found in the thigh tissue. Terephthalic acid in 0.5% concentration increased the concentration found in all cases. Cooking by poaching and scrambling eggs did not destroy the antibiotic in all cases. PMID:14264853

  2. Genetic Determinants of High-Level Oxacillin Resistance in Methicillin-Resistant Staphylococcus aureus.

    Science.gov (United States)

    Pardos de la Gandara, Maria; Borges, Vitor; Chung, Marilyn; Milheiriço, Catarina; Gomes, João Paulo; de Lencastre, Herminia; Tomasz, Alexander

    2018-06-01

    Methicillin-resistant Staphylococcus aureus (MRSA) strains carry either a mecA - or a mecC -mediated mechanism of resistance to beta-lactam antibiotics, and the phenotypic expression of resistance shows extensive strain-to-strain variation. In recent communications, we identified the genetic determinants associated with the stringent stress response that play a major role in the antibiotic resistant phenotype of the historically earliest "archaic" clone of MRSA and in the mecC -carrying MRSA strain LGA251. Here, we sought to test whether or not the same genetic determinants also contribute to the resistant phenotype of highly and homogeneously resistant (H*R) derivatives of a major contemporary MRSA clone, USA300. We found that the resistance phenotype was linked to six genes ( fruB , gmk , hpt , purB , prsA , and relA ), which were most frequently targeted among the analyzed 20 H*R strains (one mutation per clone in 19 of the 20 H*R strains). Besides the strong parallels with our previous findings (five of the six genes matched), all but one of the repeatedly targeted genes were found to be linked to guanine metabolism, pointing to the key role that this pathway plays in defining the level of antibiotic resistance independent of the clonal type of MRSA. Copyright © 2018 American Society for Microbiology.

  3. Quantitative analysis of oxytetracycline and its impurities by LC-MS-MS

    DEFF Research Database (Denmark)

    Lykkeberg, Anne Kruse; Halling-Sørensen, Bent; Cornett, Claus

    2004-01-01

    A liquid chromatographic-tandem mass spectrometric method using an Xterra MS C(18) chromatographic column ( 100 mm x 2.1 mm i.d., 3.5microm) that allows complete separation of oxytetracycline (OTC) and the impurities: 4-epi-oxytetracycline (EOTC), tetracycline (TC), 4-epi-tetracycline (ETC), 2......-acetyl-2-decarboxamido-oxytetracycline (ADOTC), alpha-apo-oxytetracycline (alpha-AOTC) and beta-apo-oxytetracycline (beta-AOTC) was developed. Gradient elution was used and calibration curves were obtained using the scan mode selected reaction monitoring (SRM). Acceptable correlations were obtained...

  4. Determination of slope failure using 2-D resistivity method

    Science.gov (United States)

    Muztaza, Nordiana Mohd; Saad, Rosli; Ismail, Nur Azwin; Bery, Andy Anderson

    2017-07-01

    Landslides and slope failure may give negative economic effects including the cost to repair structures, loss of property value and medical costs in the event of injury. To avoid landslide, slope failure and disturbance of the ecosystem, good and detailed planning must be done when developing hilly area. Slope failure classification and various factors contributing to the instability using 2-D resistivity survey conducted in Selangor, Malaysia are described. The study on landslide and slope failure was conducted at Site A and Site B, Selangor using 2-D resistivity method. The implications of the anticipated ground conditions as well as the field observation of the actual conditions are discussed. Nine 2-D resistivity survey lines were conducted in Site A and six 2-D resistivity survey lines with 5 m minimum electrode spacing using Pole-dipole array were performed in Site B. The data were processed using Res2Dinv and Surfer10 software to evaluate the subsurface characteristics. 2-D resistivity results from both locations show that the study areas consist of two main zones. The first zone is alluvium or highly weathered with the resistivity of 100-1000 Ωm at 20-70 m depth. This zone consists of saturated area (1-100 Ωm) and boulders with resistivity value of 1200-3000 Ωm. The second zone with resistivity values of > 3000 Ωm was interpreted as granitic bedrock. The study area was characterized by saturated zones, highly weathered zone, highly contain of sand and boulders that will trigger slope failure in the survey area. Based on the results obtained from the study findings, it can be concluded that 2-D resistivity method is useful method in determination of slope failure.

  5. Oxytetracycline Delivery in Adult Female Zebrafish by Iron Oxide Nanoparticles.

    Science.gov (United States)

    Chemello, Giulia; Piccinetti, Chiara; Randazzo, Basilio; Carnevali, Oliana; Maradonna, Francesca; Magro, Massimiliano; Bonaiuto, Emanuela; Vianello, Fabio; Radaelli, Giuseppe; Fifi, Anna Paola; Gigliotti, Federica; Olivotto, Ike

    2016-12-01

    Recently, the indiscriminate use of antibiotics in the aquaculture sector has raised public concern because of possible toxic effects, development of bacterial resistance, and accumulation of residues in individual tissues. Even if several countries have developed regulations about their use, it is clear that long-term growth of the aquaculture industry requires both ecologically sound practices and sustainable resource management. Alternative strategies for better management of antibiotic administration are of primary interest to improve absorption rates and, as a consequence, to reduce their release into the aquatic environment. The present study investigates, for the first time to our knowledge, a new methodology for oxytetracycline (OTC) administration through the use of iron oxide nanoparticles (NPs) (made of maghemite γ-Fe 2 O 3 ) in zebrafish (Danio rerio). Fish were divided into 4 experimental groups: control; group A exposed to 4 mg/L OTC (through water); group B exposed to the 100 mg/L SAMNs@OTC complex (equivalent to 4 mg/L OTC), and group C exposed to bare NPs. No detoxification processes or anatomical alterations were observed in fish exposed to bare NPs. Exposure of fish to the SAMNs@OTC complex resulted in a 10 times higher OTC accumulation with respect to using water exposure. This new OTC administration method seems much more efficient with respect to the traditional way of exposure and has the potentiality to reduce antibiotic utilization and possible environmental impacts. However, the dynamics related to OTC release from the SAMNs@OTC complex are still not clear and need further investigations.

  6. "Tissue oxygen tension, a determinant of resistance to infection and ...

    African Journals Online (AJOL)

    "Tissue oxygen tension, a determinant of resistance to infection and healing" - An Inaugural Lecture. K Jönsson. Abstract. An Inaugural Lecture Given in the University of Zimbabwe on 21 June 2001. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  7. Determination of Ductile Tearing Resistance Curve in Weld Joints

    International Nuclear Information System (INIS)

    Marie, S.; Gilles, P.; Ould, P.

    2010-01-01

    Steels present in the ductile domain a tearing resistance which increase with the crack propagation up to the failure. This ductile tearing resistance is in general characterised with curves giving the variation of a global parameter (opening displacement at the crack tip delta, integral J) versus the crack extension Delta a. These global approaches depend more or less on the specimen geometry and on the type of the imposed loading. Local approaches based on the description of the ductile tearing mechanisms provide reliable solution to the transferability problem (from the lab specimen to the component) but are complex and costly to use and are not codified. These problems get worse in the case of a weld joint where no standard is available for the measurement of their ductile tearing resistance. But the welded joints are often the weak point of the structure because of greater risk of defects, the heterogeneity of the microstructure of the weld, deformation along the interface between two materials with different yield stress (mismatch).... After briefly recalling the problems of transferability of the ductile tearing resistance curves obtained on lab specimen to the case of components, this article identifies the factors complicating the determination of the toughness in the welded joints and gives recommendations for the experimental determination of ductile tearing resistance curves of welded joints

  8. Quantifying the Determinants of Evolutionary Dynamics Leading to Drug Resistance.

    Directory of Open Access Journals (Sweden)

    Guillaume Chevereau

    Full Text Available The emergence of drug resistant pathogens is a serious public health problem. It is a long-standing goal to predict rates of resistance evolution and design optimal treatment strategies accordingly. To this end, it is crucial to reveal the underlying causes of drug-specific differences in the evolutionary dynamics leading to resistance. However, it remains largely unknown why the rates of resistance evolution via spontaneous mutations and the diversity of mutational paths vary substantially between drugs. Here we comprehensively quantify the distribution of fitness effects (DFE of mutations, a key determinant of evolutionary dynamics, in the presence of eight antibiotics representing the main modes of action. Using precise high-throughput fitness measurements for genome-wide Escherichia coli gene deletion strains, we find that the width of the DFE varies dramatically between antibiotics and, contrary to conventional wisdom, for some drugs the DFE width is lower than in the absence of stress. We show that this previously underappreciated divergence in DFE width among antibiotics is largely caused by their distinct drug-specific dose-response characteristics. Unlike the DFE, the magnitude of the changes in tolerated drug concentration resulting from genome-wide mutations is similar for most drugs but exceptionally small for the antibiotic nitrofurantoin, i.e., mutations generally have considerably smaller resistance effects for nitrofurantoin than for other drugs. A population genetics model predicts that resistance evolution for drugs with this property is severely limited and confined to reproducible mutational paths. We tested this prediction in laboratory evolution experiments using the "morbidostat", a device for evolving bacteria in well-controlled drug environments. Nitrofurantoin resistance indeed evolved extremely slowly via reproducible mutations-an almost paradoxical behavior since this drug causes DNA damage and increases the mutation

  9. Method of separate determination of high-ohmic sample resistance and contact resistance

    Directory of Open Access Journals (Sweden)

    Vadim A. Golubiatnikov

    2015-09-01

    Full Text Available A method of separate determination of two-pole sample volume resistance and contact resistance is suggested. The method is applicable to high-ohmic semiconductor samples: semi-insulating gallium arsenide, detector cadmium-zinc telluride (CZT, etc. The method is based on near-contact region illumination by monochromatic radiation of variable intensity from light emitting diodes with quantum energies exceeding the band gap of the material. It is necessary to obtain sample photo-current dependence upon light emitting diode current and to find the linear portion of this dependence. Extrapolation of this linear portion to the Y-axis gives the cut-off current. As the bias voltage is known, it is easy to calculate sample volume resistance. Then, using dark current value, one can determine the total contact resistance. The method was tested for n-type semi-insulating GaAs. The contact resistance value was shown to be approximately equal to the sample volume resistance. Thus, the influence of contacts must be taken into account when electrophysical data are analyzed.

  10. Método de determinação e avaliação da depleção de oxitetraciclina em camarão marinho Method for the determination and evaluation of oxytetracycline depletion in marine shrimp

    Directory of Open Access Journals (Sweden)

    Beatriz Regina Brito de Oliveira Lavorante

    2009-07-01

    Full Text Available O objetivo deste trabalho foi validar um método para determinação de resíduos de oxitetraciclina (OTC em camarões, por meio de cromatografia líquida de alta eficiência, e avaliar, pelo método validado, a depleção de resíduos de OTC em camarões in vivo. Para a validação, foram utilizados camarões isentos de OTC e camarões adicionados de OTC in vitro. Foram estabelecidos: seletividade, tempo de retenção, linearidade (coeficiente de correlação, faixa de trabalho, recuperação relativa, limites de detecção e quantificação do método (LDM e LQM, respectivamente e repetibilidade. Para o experimento in vivo, rações com 200, 400 e 500 μg g-1 de OTC foram administradas aos camarões durante 14 dias. Foi avaliada a concentração do resíduo desse antibiótico no músculo e na carapaça até 22 dias após a suspensão da droga. O coeficiente de correlação linear foi de 0,9997 para o extrato fortificado da matriz, na faixa de trabalho de 0,02 a 0,4 μg g-1; a recuperação foi de 106±17,1% e os LDM e LQM foram de 0,006 e 0,019 μg g-1, respectivamente. O tempo de residência da droga na carapaça dos animais (de 10 a 13 dias foi maior em comparação ao tempo de residência no músculo (5 dias.This work aimed at validating a method for the determination of oxytetracycline (OTC residues in shrimp by means of high performance liquid chromatography (HPLC, and at evaluating the OTC residue depletion in shrimps in vivo using the validated method. The shrimp used for validation were either not submitted or submitted to in vitro OTC addition. Selectivity, retention time, linearity (correlation coefficient, work range, relative recovery, detection and method quantification limits and repeatability were determined. For the in vivo experiment, shrimp were fed with feed medicated with OTC at 200, 400 and 500 μg g-1 for 14 days. Oxytetracycline residue concentration in the animals' muscle and carapace was assessed for up to 22 days

  11. Characterization of microbial degradation of oxytetracycline in river ...

    African Journals Online (AJOL)

    Characterization of microbial degradation of oxytetracycline in river water and sediment using reversed phase high performance liquid chromatography. ... African Journal of Biotechnology ... The present results have shown that microbial degradation plays a major role in the removal of OTC in natural environments.

  12. Waste to wealth: Production of oxytetracycline using streptomyces ...

    African Journals Online (AJOL)

    The production of oxytetracycline by Streptomyces speibonae OXS1 in solid-state fermentation from cocoyam peels (household kitchen wastes of agricultural produce) was investigated. The proximate analyses of peels of the two cocoyam species showed that Colocasia esculenta had higher protein (1.39%) and fibre ...

  13. Antimicrobial Resistance of Hypervirulent Klebsiella pneumoniae: Epidemiology, Hypervirulence-Associated Determinants, and Resistance Mechanisms

    Directory of Open Access Journals (Sweden)

    Chang-Ro Lee

    2017-11-01

    Full Text Available Klebsiella pneumoniae is one of the most clinically relevant species in immunocompromised individuals responsible for community-acquired and nosocomial infections, including pneumonias, urinary tract infections, bacteremias, and liver abscesses. Since the mid-1980s, hypervirulent K. pneumoniae, generally associated with the hypermucoviscosity phenotype, has emerged as a clinically significant pathogen responsible for serious disseminated infections, such as pyogenic liver abscesses, osteomyelitis, and endophthalmitis, in a generally younger and healthier population. Hypervirulent K. pneumoniae infections were primarily found in East Asia and now are increasingly being reported worldwide. Although most hypervirulent K. pneumoniae isolates are antibiotic-susceptible, some isolates with combined virulence and resistance, such as the carbapenem-resistant hypervirulent K. pneumoniae isolates, are increasingly being detected. The combination of multidrug resistance and enhanced virulence has the potential to cause the next clinical crisis. To better understand the basic biology of hypervirulent K. pneumoniae, this review will provide a summarization and discussion focused on epidemiology, hypervirulence-associated factors, and antibiotic resistance mechanisms of such hypervirulent strains. Epidemiological analysis of recent clinical isolates in China warns the global dissemination of hypervirulent K. pneumoniae strains with extensive antibiotic resistance in the near future. Therefore, an immediate response to recognize the global dissemination of this hypervirulent strain with resistance determinants is an urgent priority.

  14. Determining the resistance of X-pinch plasma

    International Nuclear Information System (INIS)

    Zhao Shen; Zhu Xin-Lei; Zhang Ran; Luo Hai-Yun; Zou Xiao-Bing; Wang Xin-Xin; Xue Chuang; Ning Cheng; Ding Ning; Shu Xiao-Jian

    2013-01-01

    The current and the voltage of an X-pinch were measured. The inductance of the X-pinch was assumed to be a constant and estimated by the calculation of the magnetic field based on the well-known Biot—Savart's Law. The voltage of the inductance was calculated with L · di/dt and subtracted from the measured voltage of the X-pinch. Then, the resistance of the X-pinch was determined and the following results were obtained. At the start of the current flow the resistance of the exploding wires is several tens of Ohms, one order of magnitude, higher than the metallic resistance of the wires at room temperature, and then it falls quickly to about 1 Ω, which reflects the physical processes occurring in the electrically exploding wires, i.e., a current transition from the highly resistive wire core to the highly conductive plasma. It was shown that the inductive contribution to the voltage of the X-pinch is less than the resistive contribution. For the wires we used, the wires' material and diameter have no strong influence on the resistance of the X-pinch, which may be explained by the fact that the current flows through the plasma rather than through the metallic wire itself. As a result, the current is almost equally divided between two parallel X-pinches even though the diameter and material of the wires used for these two X-pinches are significantly different. (physics of gases, plasmas, and electric discharges)

  15. Determination of Serotypes and Antibiotic Resistance in Streptococcus Pneumoniae

    Directory of Open Access Journals (Sweden)

    Deniz Akgun Karapinar

    2016-01-01

    Full Text Available Aim: In this study, the distribution of serogroup/serotype and antibiotic susceptibility testing of Streptococcus pneumoniae strains, recovered from pediatric and adult patients were evaluated. Material and Method: A total of 80 clinical isolates recovered from 19 pediatric and 61 adult patients were performed by latex aglutination method and antibiotic susceptibility tests in Istanbul University, Istanbul Faculty of Medicine, Medical Microbiology Laboratories. Results: Sixty-two strains (76 %, were serogroup/serotyped and 18 (23 % strains couldn%u2019t serogroup/serotyped. The most frequent identified serogroups were 19, 14, 23, 6, 4 in pediatrics, and 3, 19, 23 and 9 in adults. In adults, serogroups 3, 9, 5, 8, 18, 1, 15 were determined, but these serogroups weren%u2019t found in pediatrics. Vaccine serotypes rates were found as 53 % in pediatric and as 85 % in adults. The serogroups 2, 7, 10, 11, 12, 17, 20, 22, 33 were not detected, which are available in vaccine serotypes. Only 1 (1 % strain was found to exhibit low level resistance to penicillin and high level resistance wasn%u2019t found in any strain. Resistant results for trimethoprim-sulfamethoxazole, erythromycin, chloramphenicol and ofloxacin were found as 45 (56 %, 22 (27.5 %, 7 (9 %, 2 (2.5 %, respectively. All strains were found susceptible to vancomycin, linezolid and levofloxacin. The most resistant serogroups were 19, 23, 9 and 14 in the tested antibiotics. Multidrug resistance was found in 9 (11 % strains and these strains were found as serogroups 19, 23, 9, 6 and 14. Discussion: The epidemiological studies are important that the distribution of serotype and antibiotic resistance vary depending on many factors like age, and geographic region.

  16. Quantitative aspects of recognition of the antibiotic drug oxytetracycline by bovine serum albumin: Calorimetric and spectroscopic studies

    Energy Technology Data Exchange (ETDEWEB)

    Keswani, Neelam; Choudhary, Sinjan [Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076 (India); Kishore, Nand [Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076 (India)

    2013-03-15

    Highlights: ► Thermodynamics of oxytetracycline (OTC)-bovine serum albumin (BSA) binding addressed. ► ITC and fluorescence spectroscopic analysis provide values of binding constant. ► Binding is mainly ionic, hydrophobic with minor hydrogen bonding contribution. ► Quantitative effects of OTC on BSA stability provided by DSC. ► Preferential complexation of one domain of BSA by OTC at site II is suggested. -- Abstract: A quantitative understanding of the mode of interaction of drugs with target proteins provides a guide for the synthesis of new drug molecules. The binding of the antibiotic drug oxytetracycline with serum albumin has been studied by a combination of isothermal titration calorimetry (ITC), differential scanning calorimetry (DSC), steady-state and time-resolved fluorescence spectroscopy, and circular dichroism spectroscopy. The values of the binding constant (K), enthalpy change (ΔH), entropy (ΔS), and stoichiometry of binding have been determined along with the associated conformational changes in the protein. Oxytetracycline binds to bovine serum albumin with a 1:1 stoichiometry and with a weakly temperature dependent association constant of 1.8 · 10{sup 4} at T = 298.15 K. The effect of ionic strength, tetrabutylammonium bromide, and sucrose on the thermodynamic parameters obtained from ITC and DSC measurements indicate involvement of predominantly ionic and hydrophobic interactions with a minor hydrogen bonding contribution in the drug-protein complexation. The DSC results on the binding of oxytetracycline with bovine serum albumin in the absence and presence of these additives provide quantitative information on the effect of drugs on the stability of bovine serum albumin, and suggest preferential complexation of one of the domains of the protein. The results further indicate that the drug occupies binding site II on bovine serum albumin.

  17. Quantitative aspects of recognition of the antibiotic drug oxytetracycline by bovine serum albumin: Calorimetric and spectroscopic studies

    International Nuclear Information System (INIS)

    Keswani, Neelam; Choudhary, Sinjan; Kishore, Nand

    2013-01-01

    Highlights: ► Thermodynamics of oxytetracycline (OTC)-bovine serum albumin (BSA) binding addressed. ► ITC and fluorescence spectroscopic analysis provide values of binding constant. ► Binding is mainly ionic, hydrophobic with minor hydrogen bonding contribution. ► Quantitative effects of OTC on BSA stability provided by DSC. ► Preferential complexation of one domain of BSA by OTC at site II is suggested. -- Abstract: A quantitative understanding of the mode of interaction of drugs with target proteins provides a guide for the synthesis of new drug molecules. The binding of the antibiotic drug oxytetracycline with serum albumin has been studied by a combination of isothermal titration calorimetry (ITC), differential scanning calorimetry (DSC), steady-state and time-resolved fluorescence spectroscopy, and circular dichroism spectroscopy. The values of the binding constant (K), enthalpy change (ΔH), entropy (ΔS), and stoichiometry of binding have been determined along with the associated conformational changes in the protein. Oxytetracycline binds to bovine serum albumin with a 1:1 stoichiometry and with a weakly temperature dependent association constant of 1.8 · 10 4 at T = 298.15 K. The effect of ionic strength, tetrabutylammonium bromide, and sucrose on the thermodynamic parameters obtained from ITC and DSC measurements indicate involvement of predominantly ionic and hydrophobic interactions with a minor hydrogen bonding contribution in the drug-protein complexation. The DSC results on the binding of oxytetracycline with bovine serum albumin in the absence and presence of these additives provide quantitative information on the effect of drugs on the stability of bovine serum albumin, and suggest preferential complexation of one of the domains of the protein. The results further indicate that the drug occupies binding site II on bovine serum albumin

  18. Antibiotic Resistance in Staphylococcus aureus and Coagulase Negative Staphylococci Isolated from Goats with Subclinical Mastitis

    Directory of Open Access Journals (Sweden)

    Salvatore Virdis

    2010-01-01

    Full Text Available Antimicrobial resistance patterns and gene coding for methicillin resistance (mecA were determined in 25 S. aureus and 75 Coagulase Negative Staphylococci (CNS strains isolates from half-udder milk samples collected from goats with subclinical mastitis. Fourteen (56.0% S. aureus and thirty-one (41.3% CNS isolates were resistant to one or more antimicrobial agents. S. aureus showed the highest resistance rate against kanamycin (28.0%, oxytetracycline (16.0%, and ampicillin (12.0%. The CNS tested were more frequently resistant to ampicillin (36.0% and kanamycin (6.7%. Multiple antimicrobial resistance was observed in eight isolates, and one Staphylococcus epidermidis was found to be resistant to six antibiotics. The mecA gene was not found in any of the tested isolates. Single resistance against β-lactamics or aminoglicosides is the most common trait observed while multiresistance is less frequent.

  19. Pharmacokinetic-pharmacodynamic integration and modelling of oxytetracycline administered alone and in combination with carprofen in calves.

    Science.gov (United States)

    Brentnall, C; Cheng, Z; McKellar, Q A; Lees, P

    2013-06-01

    The pharmacokinetic (PK) and pharmacodynamic (PD) profiles of oxytetracycline were investigated, when administered both alone and in the presence of carprofen, in healthy calves. The study comprised a four treatment, four sequences, and four period cross-over design and used a tissue cage model, which permitted the collection of serum, inflamed tissue cage fluid (exudate) and non-inflamed tissue cage fluid (transudate). There were no clinically relevant differences in the PK profile of oxytetracycline when administered alone and when administered with carprofen. PK-PD integration was undertaken for a pathogenic strain of Mannheimia haemolytic (A1 76/1), by correlating in vitro minimum inhibitory concentration (MIC) and time-kill data with in vivo PK data obtained in the cross-over study. Based on in vitro susceptibility in cation adjusted Mueller Hinton Broth (CAMHB) and in vivo determined PK variables, ratios of maximum concentration (Cmax) and area under curve (AUC) to MIC and time for which concentration exceeded MIC (T>MIC) were determined. The CAMHB MIC data satisfied integrated PK/PD relationships predicted to achieve efficacy for approximately 48 h after dosing; mean values for serum were 5.13 (Cmax/MIC), 49.3 h (T>MIC) and 126.6 h (AUC(96h)/MIC). Similar findings were obtained when oxytetracycline was administered in the presence of carprofen, with PK-PD indices based on MIC determined in CAMHB. However, PK-PD integration of data, based on oxytetracycline MICs determined in the biological fluids, serum, exudate and transudate, suggest that it possesses, at most, limited direct killing activity against the M. haemolytica strain A1 76/1; mean values for serum were 0.277 (Cmax/MIC), 0 h (T>MIC) and 6.84 h (AUC(96h)/MIC). The data suggest that the beneficial therapeutic effects of oxytetracycline may depend, at least in part, on actions other than direct inhibition of bacterial growth. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    The purpose of this work was to quantify retention/release of tetracycline, oxytetracycline, and chlortetracycline on two soils, paying attention to sorption kinetics and to implications of the adsorption/desorption processes on transfer of these pollutants to the various environmental compartments...... tetracycline > oxytetracycline > chlortetracycline in soil 1, with similar values for the three antibiotics and the sequence tetracycline > chlortetracycline > oxytetracycline in soil 2. The desorption sequences were oxytetracycline > tetracycline > chlortetracycline in soil 1 and oxytetracycline...... > chlortetracycline > tetracycline in soil 2. In conclusion, the SFC technique has yielded new kinetic data regarding tetracycline, oxytetracycline, and chlortetracycline adsorption/desorption on soils, indicating that it can be used to shed further light on the retention and transport processes affecting antibiotics...

  1. Determinants of foamy virus envelope glycoprotein mediated resistance to superinfection

    International Nuclear Information System (INIS)

    Berg, Angelika; Pietschmann, Thomas; Rethwilm, Axel; Lindemann, Dirk

    2003-01-01

    Little is known about the nature of foamy virus (FV) receptor molecules on target cells and their interaction with the viral glycoproteins. Similar to other viruses, cellular expression of the FV Env protein is sufficient to induce resistance to exogenous FV, a phenomenon called superinfection resistance (SIR). In this study we define determinants of the FV Env protein essential for mediating SIR. FV Env requires the extracellular domains of the SU and the TM subunits as well as membrane anchorage, efficient cell surface transport, and most probably correct subunit processing. This is in contrast to murine leukemia virus where secreted proteins comprising the receptor-binding domain in SU are sufficient to induce SIR. Furthermore, we demonstrate that cellular expression of the prototype FV envelope proteins induces SIR against pseudotypes with glycoproteins of other FV species, including of simian, feline, bovine, and equine origin. This implies that all of them use the same receptor molecules for viral entry

  2. Development of paper-based color test-strip for drug detection in aquatic environment: Application to oxytetracycline.

    Science.gov (United States)

    Gomes, Helena I A S; Sales, M Goreti F

    2015-03-15

    The wide use of antibiotics in aquaculture has led to the emergence of resistant microbial species. It should be avoided/minimized by controlling the amount of drug employed in fish farming. For this purpose, the present work proposes test-strip papers aiming at the detection/semi-quantitative determination of organic drugs by visual comparison of color changes, in a similar analytical procedure to that of pH monitoring by universal pH paper. This is done by establishing suitable chemical changes upon cellulose, attributing the paper the ability to react with the organic drug and to produce a color change. Quantitative data is also enabled by taking a picture and applying a suitable mathematical treatment to the color coordinates given by the HSL system used by windows. As proof of concept, this approach was applied to oxytetracycline (OXY), one of the antibiotics frequently used in aquaculture. A bottom-up modification of paper was established, starting by the reaction of the glucose moieties on the paper with 3-triethoxysilylpropylamine (APTES). The so-formed amine layer allowed binding to a metal ion by coordination chemistry, while the metal ion reacted after with the drug to produce a colored compound. The most suitable metals to carry out such modification were selected by bulk studies, and the several stages of the paper modification were optimized to produce an intense color change against the concentration of the drug. The paper strips were applied to the analysis of spiked environmental water, allowing a quantitative determination for OXY concentrations as low as 30ng/mL. In general, this work provided a simple, method to screen and discriminate tetracycline drugs, in aquaculture, being a promising tool for local, quick and cheap monitoring of drugs. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Production of a monoclonal antibody against oxytetracycline and its application for oxytetracycline residue detection in shrimp*

    Science.gov (United States)

    Wongtangprasert, Tossapon; Natakuathung, Wirongrong; Pimpitak, Umaporn; Buakeaw, Anumart; Palaga, Tanapat; Komolpis, Kittinan; Khongchareonporn, Nanthika

    2014-01-01

    A novel monoclonal antibody (MAb) against oxytetracycline (OTC) was generated and characterized. The MAb was used in the development of an enzyme-linked immunosorbant assay (ELISA)-based detection system. An OTC-bovine serum albumin (BSA) conjugate was prepared and used in the immunization of mice. A conventional somatic cell fusion technique was used to generate MAb-secreting hybridomas denoted 2-4F, 7-3G, and 11-11A. An indirect competitive ELISA (icELISA) was applied to measure the sensitivity and specificity of each MAb in terms of its 50% inhibitory concentration (IC50) and percentage of cross-reactivity, respectively. MAb 2-4F exhibited the highest sensitivity, with an IC50 of 7.01 ng/ml. This MAb showed strong cross-reactivity to rolitetracycline, but no cross-reactivity to other unrelated antibiotics. When MAb 2-4F was used to detect OTC from shrimp samples, the recoveries were in the range of 82%–118% for an intra-assay and 96%–113% for an inter-assay. The coefficients of variation of the assays were 3.9%–13.9% and 5.5%–14.9%, respectively. PMID:24510709

  4. Hydrolysis and photolysis of oxytetracycline in aqueous solution

    Science.gov (United States)

    Oxytetracycline ((2Z,4S,4aR,5S,5aR,6S,12aS)-2-(amino-hydroxy-methylidene)-4-dimethylamino-5,6,10,11,12a-pentahydroxy-6-methyl-4,4a,5,5a-tetrahydrotetracene-1,3,12-trione) is a member of tetracycline antibiotics family and is widely administered to farm animals for the purpose of therapeutical treatm...

  5. Tutorial: Determination of thermal boundary resistance by molecular dynamics simulations

    Science.gov (United States)

    Liang, Zhi; Hu, Ming

    2018-05-01

    Due to the high surface-to-volume ratio of nanostructured components in microelectronics and other advanced devices, the thermal resistance at material interfaces can strongly affect the overall thermal behavior in these devices. Therefore, the thermal boundary resistance, R, must be taken into account in the thermal analysis of nanoscale structures and devices. This article is a tutorial on the determination of R and the analysis of interfacial thermal transport via molecular dynamics (MD) simulations. In addition to reviewing the commonly used equilibrium and non-equilibrium MD models for the determination of R, we also discuss several MD simulation methods which can be used to understand interfacial thermal transport behavior. To illustrate how these MD models work for various interfaces, we will show several examples of MD simulation results on thermal transport across solid-solid, solid-liquid, and solid-gas interfaces. The advantages and drawbacks of a few other MD models such as approach-to-equilibrium MD and first-principles MD are also discussed.

  6. Biodegradation of oxytetracycline by Pleurotus ostreatus mycelium: a mycoremediation technique

    International Nuclear Information System (INIS)

    Migliore, Luciana; Fiori, Maurizio; Spadoni, Anna; Galli, Emanuela

    2012-01-01

    Highlights: ► Oxytetracycline uptake and degradation by Pleurotus ostreatus mycelium were measured. ► The role of extracellular laccase in degradation was evaluated. ► The almost complete OTC removal was obtained. ► A possible degradation product was identified in mycelia (ADOTC). ► The system can be considered the first step of an useful mycoremediation technique. - Abstract: Oxytetracycline (OTC) is administered in high doses to livestocks and enters the environmental compartments as a consequence of animal waste disposal. As a first step in setting up a useful mycoremediation technique, an OTC lab degradation test was performed in liquid medium using the ligninolytic fungus Pleurotus ostreatus. OTC disappearance in culture medium was clearly evident as early as the third day of exposure onwards, with an almost complete removal after 14 d. The drug removal was mediated by fungal absorption in the mycelia, where the OTC molecule underwent a degradation step, as demonstrated by mass spectrometry analyses. A putative degradation product, ADOTC (2-acetyl-2-decarboxamido-oxytetracycline) is proposed. Experimental conditions excluded OTC abiotic degradation; the degradation by extracellular laccase was also experimentally discarded.

  7. Biodegradation of oxytetracycline by Pleurotus ostreatus mycelium: a mycoremediation technique

    Energy Technology Data Exchange (ETDEWEB)

    Migliore, Luciana [Dept. Biology, Tor Vergata University, Via della Ricerca Scientifica, 00133 Rome (Italy); Fiori, Maurizio [Dept. Veterinary Public Health and Food Safety, Istituto Superiore di Sanita, Viale Regina Elena 299, 00161 Rome (Italy); Spadoni, Anna [Dept. Biology, Tor Vergata University, Via della Ricerca Scientifica, 00133 Rome (Italy); Institute of Agro-Environment and Forest Biology, National Research Council, Research Area Rome 1, Via Salaria km 29.300, 00015 Monterotondo Rome (Italy); Galli, Emanuela [Institute of Agro-Environment and Forest Biology, National Research Council, Research Area Rome 1, Via Salaria km 29.300, 00015 Monterotondo Rome (Italy)

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer Oxytetracycline uptake and degradation by Pleurotus ostreatus mycelium were measured. Black-Right-Pointing-Pointer The role of extracellular laccase in degradation was evaluated. Black-Right-Pointing-Pointer The almost complete OTC removal was obtained. Black-Right-Pointing-Pointer A possible degradation product was identified in mycelia (ADOTC). Black-Right-Pointing-Pointer The system can be considered the first step of an useful mycoremediation technique. - Abstract: Oxytetracycline (OTC) is administered in high doses to livestocks and enters the environmental compartments as a consequence of animal waste disposal. As a first step in setting up a useful mycoremediation technique, an OTC lab degradation test was performed in liquid medium using the ligninolytic fungus Pleurotus ostreatus. OTC disappearance in culture medium was clearly evident as early as the third day of exposure onwards, with an almost complete removal after 14 d. The drug removal was mediated by fungal absorption in the mycelia, where the OTC molecule underwent a degradation step, as demonstrated by mass spectrometry analyses. A putative degradation product, ADOTC (2-acetyl-2-decarboxamido-oxytetracycline) is proposed. Experimental conditions excluded OTC abiotic degradation; the degradation by extracellular laccase was also experimentally discarded.

  8. The oxidative stress response of oxytetracycline in the ciliate Pseudocohnilembus persalinus.

    Science.gov (United States)

    Wang, Chongnv; Pan, Xuming; Fan, Yawen; Chen, Ying; Mu, Weijie

    2017-12-01

    Oxytetracycline (OTC) is commonly employed in fish farms to prevent bacterial infections in China, and because of their widely and intensive use, the potential harmful effects on organisms in aquatic environment are of great concern. Ciliates play an important role in aquatic food webs as secondary producers, and Pseudocohnilembus persalinus, is one kind of them which are easily found in fish farms, surviving in polluted water. Therefore, using P. persalinus as experimental models, this study investigated the effects of oxytetracycline (OTC) on the growth, antioxidant system and morphological damage in pollution-resistant ciliates species. Our results showed that the 96-h EC 50 values for OTC of P. persalinus was 21.38mgL -1 . The increased level of SOD and GSH during 96h OTC stress was related to an adaptive response under oxidative stress induced in ciliates. Additionally, sod1, sod2 and sod3 exhibited a significant increased expression level compared to control group at 24h treatment, indicating a promoting of dense system in ciliates at this exposure time. However, only sod1 and sod2 showed raised expression level at 48h stress, showing the different sensitive of gene isoforms to some extent. With OTC treatment, damage of regular wrinkles, shrunk, twisted on the cell surface, even forming cyst of scuticociliatid ciliate cells were firstly observed by SEM (scanning electron microscope) in this study. Overall, physiological, molecular and morphological information on the toxicological studies of ciliates and more information on possibility of ciliates as indicators of contamination were provided in this study. Copyright © 2017. Published by Elsevier B.V.

  9. Bacterial Multidrug Efflux Pumps: Much More Than Antibiotic Resistance Determinants.

    Science.gov (United States)

    Blanco, Paula; Hernando-Amado, Sara; Reales-Calderon, Jose Antonio; Corona, Fernando; Lira, Felipe; Alcalde-Rico, Manuel; Bernardini, Alejandra; Sanchez, Maria Blanca; Martinez, Jose Luis

    2016-02-16

    Bacterial multidrug efflux pumps are antibiotic resistance determinants present in all microorganisms. With few exceptions, they are chromosomally encoded and present a conserved organization both at the genetic and at the protein levels. In addition, most, if not all, strains of a given bacterial species present the same chromosomally-encoded efflux pumps. Altogether this indicates that multidrug efflux pumps are ancient elements encoded in bacterial genomes long before the recent use of antibiotics for human and animal therapy. In this regard, it is worth mentioning that efflux pumps can extrude a wide range of substrates that include, besides antibiotics, heavy metals, organic pollutants, plant-produced compounds, quorum sensing signals or bacterial metabolites, among others. In the current review, we present information on the different functions that multidrug efflux pumps may have for the bacterial behaviour in different habitats as well as on their regulation by specific signals. Since, in addition to their function in non-clinical ecosystems, multidrug efflux pumps contribute to intrinsic, acquired, and phenotypic resistance of bacterial pathogens, the review also presents information on the search for inhibitors of multidrug efflux pumps, which are currently under development, in the aim of increasing the susceptibility of bacterial pathogens to antibiotics.

  10. Otimização e validação de método para determinação de resíduos de oxitetraciclina, tetraciclina e clortetraciclina em leite por cromatografia líquida de alta eficiência Optimization and validation of a method for determination of oxytetracycline, tetracycline and chlortetracycline residues in milk by high performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    Iara C. A. Ruela

    2005-03-01

    Full Text Available Um método para determinação de resíduos de oxitetraciclina, tetraciclina e clortetraciclina em leite por cromatografia líquida de alta eficiência foi otimizado e validado. Ensaios intralaboratoriais empregando soluções padrão, brancos de amostras e amostras adicionadas de soluções padrão dos antimicrobianos foram realizados para avaliação da linearidade, seletividade, exatidão, precisão, limites de detecção e de quantificação do método. As amostras foram homogeneizadas, tratadas com solução tampão de succinato de sódio pH 4,0 e centrifugadas, descartando-se o precipitado. As tetraciclinas foram removidas do sobrenadante por quelação com íons cobre reversivelmente ligados à resina quelante e eluídas com tampão McIlvaine-EDTA pH 4,0. As médias de recuperação para as tetraciclinas foram de 76,2 a 104,9% com coeficiente de variação na faixa de 1,4 a 18,9%. Limites de detecção de 10, 15 e 40ng/mL e limites de quantificação de 10, 20 e 50ng/mL foram determinados para oxitetraciclina, tetraciclina e clortetraciclina, respectivamente.A method for determination of oxytetracycline, tetracycline and chlortetracycline residues in milk by high performance liquid chromatography was optimized and validated. Linearity, selectivity, trueness, precision, limits of detection and quantitation were evaluated by in-house validation procedures employing reference materials, sample blanks and spiked samples. Milk samples were homogenized, treated with sodium succinate pH 4.0 buffer and centrifuged, discarding the precipitate. Tetracyclines were removed from the supernatant by chelating with metal ions bound to a chelating resin and eluted with McIlvaine-EDTA pH 4.0 buffer. Mean recoveries for tetracyclines ranged from 76.2 to 104.9% with coefficients of variation from 1.4 to 18.9%. Detection limits of 10, 15 and 40ng/mL and quantitation limits of 10, 20 and 50ng/mL were determined for oxytetracycline, tetracycline and

  11. 21 CFR 524.1662 - Oxytetracycline hydrochloride ophthalmic and topical dosage forms.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline hydrochloride ophthalmic and topical dosage forms. 524.1662 Section 524.1662 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... DOSAGE FORM NEW ANIMAL DRUGS § 524.1662 Oxytetracycline hydrochloride ophthalmic and topical dosage forms. ...

  12. 21 CFR 522.1662 - Oxytetracycline hydrochloride implantation or injectable dosage forms.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline hydrochloride implantation or injectable dosage forms. 522.1662 Section 522.1662 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.1662 Oxytetracycline hydrochloride implantation or injectable...

  13. Standard practice for determining rail-to-Earth resistance

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1999-01-01

    1.1 This practice covers the procedures necessary to follow for measuring resistance-to-earth of the running rails which are used as the conductors for returning the train operating current to the substation in electric mass transit systems. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  14. Synthesis and characterization of oxytetracycline imprinted magnetic polymer for application in food

    Science.gov (United States)

    Aggarwal, Sneha; Rajput, Yudhishthir Singh; Singh, Gulab; Sharma, Rajan

    2016-02-01

    Magnetic imprinted polymer was prepared by polymerization of methacrylate and ethyleneglycoldimethacrylate in the presence of oxytetracycline on the surface of iron magnetite. Selectivity of prepared polymer was calculated from ratio of partition coefficient of oxytetracycline for imprinted and non- imprinted polymer in water, acetonitrile, methanol and at different pH in aqueous buffer. pH of solvent exhibited pronounced effect on selectivity. Selectivity at pH 7.0, 6.0 and 5.0 was 36.0, 2.25 and 1.61 fold higher than at pH 4.0. Imprinted polymer was not selective for oxytetracycline in methanol. However, selectivity in water and acetonitrile was 19.42 and 2.86, respectively. Oxytetracycline did bind to imprinted polymer in water or aqueous buffer (pH 7.0) and could be eluted with methanol. Prepared polymer extracted 75-80 % oxytetracycline from water, honey and egg white.

  15. Oxytetracycline Inhibits Mucus Secretion and Inflammation in Human Airway Epithelial Cells.

    Science.gov (United States)

    Shah, Said Ahmad; Ishinaga, Hajime; Takeuchi, Kazuhiko

    2017-01-01

    Oxytetracycline is a broad-spectrum antibiotic, but its nonantibacterial effects in the human respiratory tract are unknown. In this study, the effects of oxytetracycline on mucus secretion and inflammation were examined by PCR and ELISA in the human airway epithelial cell line NCI-H292. Oxytetracycline (10 μg/mL) significantly inhibited TNF-α-induced MUC5AC gene expression and MUC5AC protein levels in NCI-H292 cells. It also downregulated IL-8 and IL-1β gene expression and IL-1β protein levels. Our findings demonstrated that oxytetracycline suppressed mucus production and inflammation in human respiratory epithelial cells, providing further evidence for the usefulness of oxytetracycline for human airway inflammatory diseases. © 2017 S. Karger AG, Basel.

  16. Crack resistance curves determination of tube cladding material

    Energy Technology Data Exchange (ETDEWEB)

    Bertsch, J. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)]. E-mail: johannes.bertsch@psi.ch; Hoffelner, W. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

    2006-06-30

    Zirconium based alloys have been in use as fuel cladding material in light water reactors since many years. As claddings change their mechanical properties during service, it is essential for the assessment of mechanical integrity to provide parameters for potential rupture behaviour. Usually, fracture mechanics parameters like the fracture toughness K {sub IC} or, for high plastic strains, the J-integral based elastic-plastic fracture toughness J {sub IC} are employed. In claddings with a very small wall thickness the determination of toughness needs the extension of the J-concept beyond limits of standards. In the paper a new method based on the traditional J approach is presented. Crack resistance curves (J-R curves) were created for unirradiated thin walled Zircaloy-4 and aluminium cladding tube pieces at room temperature using the single sample method. The procedure of creating sharp fatigue starter cracks with respect to optical recording was optimized. It is shown that the chosen test method is appropriate for the determination of complete J-R curves including the values J {sub 0.2} (J at 0.2 mm crack length), J {sub m} (J corresponding to the maximum load) and the slope of the curve.

  17. Determination of ductile tearing resistance J-R curves in welded joints; Determination de courbes de resistance a la dechirure ductile dans les joints soudes

    Energy Technology Data Exchange (ETDEWEB)

    Gilles, Ph.; Ould, P. [AREVA NP, Tour AREVA, 92086 Paris La Defense (France); Marie, St. [CEA Saclay, DM2S, 91191 Gif sur Yvette Cedex (France)

    2010-05-15

    The ductile tearing resistance of steels is generally characterized in terms of resistance curves giving the increase of a resistance parameter such as the crack driving force J or a crack opening displacement as a function of the crack extension {Delta}a. Welded joints are often the weakest part of structures because of greater risk of defects, heterogeneity of the microstructure of the weld, strain concentration along mismatched interfaces. This paper recalls the transferability issues common to all integrity assessments based on tearing resistance curves and points out the difficulties of characterization specific to welds. Several recommendations are proposed for the experimental determination of tearing resistance of welded joints. (authors)

  18. Transferable chloramphenicol resistance determinant in luminous Vibrio harveyi from penaeid shrimp Penaeus monodon larvae

    Directory of Open Access Journals (Sweden)

    Thangapalam Jawahar Abraham

    2016-12-01

    Full Text Available Antibiotic-resistant luminous Vibrio harveyi strains isolated from Penaeus monodon larvae were screened for the possession of transferable resistance determinants. All the strains were resistant to chloramphenicol and the determinant coding for chloramphenicol resistance was transferred to Escherichia coli at frequencies of 9.50x10-4 to 4.20x10-4. The results probably suggest the excessive use of chloramphenicol in shrimp hatcheries to combat luminous vibriosis.

  19. Field assessment of oxytetracycline exposure to the freshwater macrophytes Egeria densa Planch. and Ceratophyllum demersum L

    International Nuclear Information System (INIS)

    Hanson, M.L.; Knapp, C.W.; Graham, D.W.

    2006-01-01

    In a microcosm study, two aquatic macrophytes, Egeria densa and Ceratophyllum demersum were exposed to nominal concentrations of 0, 5, 20, 50, and 250 μg/L oxytetracycline (n = 3), plus 20 μg/L oxytetracycline amended with additional nitrogen (N) and phosphorus (P). Responses were monitored bi-weekly over a six-week exposure period. Both plant species exhibited a significant decline in growth in the 250 μg/L oxytetracycline and the N- and P-amended units. Decreased light penetration resulting from accumulating oxytetracycline by-products appears to be the primary modifier in the growth of these plants. Increased susceptibility to oxytetracycline exposure was noted in some paired plantings (e.g., E. densa root development), relative to individual plants in these treatments, however, no clear explanation for this response is available. Based on the toxicity data generated in this study, we estimate that current concentrations of oxytetracycline in freshwater environments do not pose a direct risk to E. densa and C. demersum. - Oxytetracycline did not pose a risk for two freshwater macrophytes

  20. Field assessment of oxytetracycline exposure to the freshwater macrophytes Egeria densa Planch. and Ceratophyllum demersum L

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, M L [Department of Environment and Geography, University of Manitoba, 118 Isbister Building, Winnipeg, Manitoba R3T 2N2 (Canada); Knapp, C W [Department of Civil, Environmental, and Architectural Engineering, University of Kansas, Lawrence, KS 66045 (United States); Graham, D W [Department of Civil, Environmental, and Architectural Engineering, University of Kansas, Lawrence, KS 66045 (United States)

    2006-06-15

    In a microcosm study, two aquatic macrophytes, Egeria densa and Ceratophyllum demersum were exposed to nominal concentrations of 0, 5, 20, 50, and 250 {mu}g/L oxytetracycline (n = 3), plus 20 {mu}g/L oxytetracycline amended with additional nitrogen (N) and phosphorus (P). Responses were monitored bi-weekly over a six-week exposure period. Both plant species exhibited a significant decline in growth in the 250 {mu}g/L oxytetracycline and the N- and P-amended units. Decreased light penetration resulting from accumulating oxytetracycline by-products appears to be the primary modifier in the growth of these plants. Increased susceptibility to oxytetracycline exposure was noted in some paired plantings (e.g., E. densa root development), relative to individual plants in these treatments, however, no clear explanation for this response is available. Based on the toxicity data generated in this study, we estimate that current concentrations of oxytetracycline in freshwater environments do not pose a direct risk to E. densa and C. demersum. - Oxytetracycline did not pose a risk for two freshwater macrophytes.

  1. Molecular screening of antibiotic-resistant determinants among ...

    African Journals Online (AJOL)

    Background: Globally, and particularly in developing countries, the menace of anti-microbial resistance is an accelerating problem. In Nigeria, increase in bacterial resistance has been phenotypically established but due to high cost, few molecular studies have been reported. Objectives: This study screened for presence of ...

  2. Genetic determinants of antifungal resistance in Candida species ...

    African Journals Online (AJOL)

    In the previous decades, it has been an increase in cases of resistance to antifungal agents used in the prophylaxis and treatment of infections caused by Candida species. The emergence of resistance to drug classes, it is usually explained by genome alterations ranging from point mutations to gain or loss of whole ...

  3. Detection of mutations in quinolone-resistant determining regions in ...

    African Journals Online (AJOL)

    Yomi

    2012-01-16

    Jan 16, 2012 ... Since the use of fluoroquinolone antibiotic in clinical practice was introduced about two decades ago, quinolone-resistant E. coli strains .... containing dehydrated antibiotics (Merlin Diagnostika, Germany) in two–fold dilution. .... alterations in parC play fundamental role in developing high level of resistance ...

  4. Electrical capacity and resistance determination of emitting electric transducer

    International Nuclear Information System (INIS)

    Alba Fernandez, J.; Ramis Soriano, J.

    2000-01-01

    In this work we calculate the electrical resistance and capacity of emitting electric transducer, which is mainly formed, in direct relationship with its properties, by a ceramic capacitor. Our aim is to motivate the students with an attractive element in order to carry out traditional measurements of the charge and discharge transients of a capacitor, implementing high resistance setups. (Author) 5 refs

  5. Determination of rust resistance genes in pakistani bread wheats

    International Nuclear Information System (INIS)

    Qamar, M.; Ahmad, S.D.; Rabbani, M.A.; Shinwari, Z.K.

    2014-01-01

    Stripe and leaf rusts are the major constraints to bread wheat production in Pakistan. Molecular markers were used to investigate the presence of leaf rust and stripe rust resistance gene cluster Lr34/Yr18 and stem rust resistance gene Sr2 in 52 Pakistani bread wheat cultivars/lines. PCR amplification of DNA fragments using DNA marker csLV-34 showed that 13 of the studied cultivars/lines, namely 03FJ26, NR 337, NR 339, NR 347, NR 350, Manthar, Margalla 99, Iqbal 2000, Saleem 2000, Wafaq 2001, Marwat 2001, Pirsabak 2004 and Fareed 2006 carry leaf rust and stripe rust resistance genes Lr34/Yr18. Stem rust resistance gene Sr2 was observed in 36 Pakistani spring wheat cultivars/lines using stm560.3tgag marker. The slow rusting gene Sr2 needs to be combined with additional stem rust resistance genes to establish durable resistance against Ug99 in modern wheat cultivars. Low frequency of Lr34/Yr18 was found in Pakistani wheats. This gene cluster needs to be incorporated into Pakistani wheats for durable rust resistance. (author)

  6. Production of oxytetracycline by Streptomyces rimosus 12,907 as an animal feed supplement

    Energy Technology Data Exchange (ETDEWEB)

    Baghlaf, A O; Abou-Zeid, A; El-Dewany, A I; Eissa, I; Fouad, M; Yassein, M

    1980-01-01

    Production of oxytetracycline by S. rimosus 12,907 as an animal feed supplement was achieved with a fermentation medium containing the following ingredients: blackstrap molasses 30, fodder yeast 20, rice bran 10, KH2PO4 0.2%, and water to 1000 mL. The dry mash, containing oxytetracycline, was 50 g/L of fermentation medium. The amount of oxytetracycline, present in the dry mash, was approximately 4.0%. The dry mash, also contained the following amino acids: L-arginine, L-histidine, L-lysine, L-isoleucine, L-leucine, L-phenylalanine, DL-methionine, and L-tryptophan.

  7. Experimental determination of fuel-cladding thermal contact resistance

    International Nuclear Information System (INIS)

    Maglic, K.; Zivotic, Z.

    1968-01-01

    Thermal resistance of the UO 2 fuel - Zr-2 cladding was measure by the same experimental apparatus which was used for measuring the thermal conductivity of ceramic fuel. Thermal resistance was measure for a series of heat flux values and the dependence of thermal resistance on the flux is given within in the range from 0.66 W/cm 2 to 13.3 W/cm 2 . The temperature drop on the contact surface was between 39 deg C and 181.7 deg C, proportional to the increase of the heat flux [sr

  8. Determination of the Resistance of Cone-Shaped Solid Electrodes

    DEFF Research Database (Denmark)

    Frandsen, Henrik Lund; Hendriksen, Peter Vang; Koch, Søren

    2017-01-01

    during processing can be avoided. Newman's formula for current constriction in the electrolyte is then used to deduce the active contact area based on the ohmic resistance of the cell, and from this the surface specific electro-catalytic activity. However, for electrode materials with low electrical......A cone-shaped electrode pressed into an electrolyte can with advantage be utilized to characterize the electro-catalytic properties of the electrode, because it is less dependent on the electrode microstructure than e.g. thin porous composite electrodes, and reactions with the electrolyte occurring...... conductivity (like Ce1-xPrxO2-δ), the resistance of the cell is significantly influenced by the ohmic resistance of the cone electrode, wherefore it must be included. In this work the ohmic resistance of a cone is modelled analytically based on simplified geometries. The two analytical models only differ...

  9. Molecular screening of antibiotic-resistant determinants among ...

    African Journals Online (AJOL)

    In Nigeria, increase in bacterial resistance has been phenotypically established but due to high cost, few molecular studies ... ocomial opportunistic infections such as urinary tract .... Twelve (20%) of these MDR isolates were from children.

  10. Insertion sequence transposition determines imipenem resistance in Acinetobacter baumannii.

    Science.gov (United States)

    Kuo, Han-Yueh; Chang, Kai-Chih; Liu, Chih-Chin; Tang, Chuan Yi; Peng, Jhih-Hua; Lu, Chia-Wei; Tu, Chi-Chao; Liou, Ming-Li

    2014-10-01

    This study employed genomewide analysis to investigate potential resistance mechanisms in Acinetobacter baumannii following imipenem exposure. Imipenem-selected mutants were generated from the imipenem-susceptible strain ATCC 17978 by multistep selection resistance. Antibiotic susceptibilities were examined, and the selected mutants originated from the ATCC 17978 strain were confirmed by pulsed-field gel electrophoresis. The genomic sequence of a resistant mutant was analyzed using a next-generation sequencing platform, and genetic recombination was further confirmed by PCR. The result showed that phenotypic resistance was observed with carbapenem upon exposure to various concentrations of imipenem. Genomewide analysis showed that ISAba1 transposition was initiated by imipenem exposure at concentrations up to 0.5 mg/L. Transposition of ISAba1 upstream of blaOXA-95 was detected in all the selected mutants. The expression of blaOXA-95 was further analyzed by quantitative PCR, and the results demonstrated that a 200-fold increase in gene expression was required for resistance to imipenem. This study concluded that imipenem exposure at a concentration of 0.5 mg/L mediated the transposition of ISAba1 upstream of the blaOXA-95 gene and resulted in the overexpression of blaOXA-95 gene, which may play a major role in the resistance to imipenem in A. baumannii.

  11. Determination of Flow Resistance Coefficient for Vegetation in Open Channel: Laboratory study

    Science.gov (United States)

    Aliza Ahmad, Noor; Ali, ZarinaMd; Arish, Nur Aini Mohd; Munirah Mat Daud, Azra; Fatin Amirah Alias, Nur

    2018-04-01

    This study focused on determination of flow resistances coefficient for grass in an open channel. Laboratory works were conducted to examine the effects of varying of roughness elements on the flume to determine flow resistance coefficient and also to determine the optimum flow resistance with five different flow rate, Q. Laboratory study with two type of vegetation which are Cow Grass and Pearl Grass were implementing to the bed of a flume. The roughness coefficient, n value is determine using Manning’s equation while Soil Conservation Services (SCS) method was used to determine the surface resistance. From the experiment, the flow resistance coefficient for Cow Grass in range 0.0008 - 0.0039 while Pearl Grass value for the flow resistance coefficient are in between 0.0013 - 0.0054. As a conclusion the vegetation roughness value in open channel are depends on density, distribution type of vegetation used and physical characteristic of the vegetation itself

  12. Crack resistance curve determination of zircaloy-4 cladding

    International Nuclear Information System (INIS)

    Bertsch, J.; Alam, A.; Zubler, R.

    2009-03-01

    Fracture mechanics properties of fuel claddings are of relevance with respect to fuel rod integrity. The integrity of a fuel rod, in turn, is important for the fuel performance, for the safe handling of fuel rods, for the prevention of leakages and subsequent dissemination of fuel, for the avoidance of unnecessary dose rates, and for safe operation. Different factors can strongly deteriorate the mechanical fuel rod properties: irradiation damage, thermo-mechanical impact, corrosion or hydrogen uptake. To investigate the mechanical properties of fuel rod claddings which are used in Swiss nuclear power plants, PSI has initiated a program for mechanical testing. A major issue was the interaction between specific loading devices and the tested cladding tube, e.g. in the form of bending or friction. Particular for Zircaloy is the hexagonal closed packed structure of the zirconium crystallographic lattice. This structure implies plastic deformation mechanisms with specific, preferred orientations. Further, the manufacturing procedure of Zircaloy claddings induces a specific texture which plays a salient role with respect to the embrittlement by irradiation or integration of hydrogen in the form of hydrides. Both, the induced microstructure as well as the plastic deformation behaviour play a role for the mechanical properties. At PSI, in a first step inactive thin walled Zircaloy tubes and, for comparison reasons, plates were tested. The validity of the mechanical testing of the non standard tube and plate geometries had to be verified. The used Zircaloy-4 cladding tube sections and small plates of the same wall thickness have been notched, fatigue pre-cracked and tensile tested to evaluate the fracture toughness properties at room temperature, 300 o C and 350 o C. The crack propagation has been determined optically. The test results of the plates have been further used to validate FEM calculations. For each sample a complete crack resistance (J-R) curve could be

  13. Crack resistance curve determination of zircaloy-4 cladding

    Energy Technology Data Exchange (ETDEWEB)

    Bertsch, J.; Alam, A.; Zubler, R

    2009-03-15

    Fracture mechanics properties of fuel claddings are of relevance with respect to fuel rod integrity. The integrity of a fuel rod, in turn, is important for the fuel performance, for the safe handling of fuel rods, for the prevention of leakages and subsequent dissemination of fuel, for the avoidance of unnecessary dose rates, and for safe operation. Different factors can strongly deteriorate the mechanical fuel rod properties: irradiation damage, thermo-mechanical impact, corrosion or hydrogen uptake. To investigate the mechanical properties of fuel rod claddings which are used in Swiss nuclear power plants, PSI has initiated a program for mechanical testing. A major issue was the interaction between specific loading devices and the tested cladding tube, e.g. in the form of bending or friction. Particular for Zircaloy is the hexagonal closed packed structure of the zirconium crystallographic lattice. This structure implies plastic deformation mechanisms with specific, preferred orientations. Further, the manufacturing procedure of Zircaloy claddings induces a specific texture which plays a salient role with respect to the embrittlement by irradiation or integration of hydrogen in the form of hydrides. Both, the induced microstructure as well as the plastic deformation behaviour play a role for the mechanical properties. At PSI, in a first step inactive thin walled Zircaloy tubes and, for comparison reasons, plates were tested. The validity of the mechanical testing of the non standard tube and plate geometries had to be verified. The used Zircaloy-4 cladding tube sections and small plates of the same wall thickness have been notched, fatigue pre-cracked and tensile tested to evaluate the fracture toughness properties at room temperature, 300 {sup o}C and 350 {sup o}C. The crack propagation has been determined optically. The test results of the plates have been further used to validate FEM calculations. For each sample a complete crack resistance (J-R) curve could

  14. Environmental pollution by antibiotics and by antibiotic resistance determinants

    International Nuclear Information System (INIS)

    Martinez, Jose Luis

    2009-01-01

    Antibiotics are among the most successful drugs used for human therapy. However, since they can challenge microbial populations, they must be considered as important pollutants as well. Besides being used for human therapy, antibiotics are extensively used for animal farming and for agricultural purposes. Residues from human environments and from farms may contain antibiotics and antibiotic resistance genes that can contaminate natural environments. The clearest consequence of antibiotic release in natural environments is the selection of resistant bacteria. The same resistance genes found at clinical settings are currently disseminated among pristine ecosystems without any record of antibiotic contamination. Nevertheless, the effect of antibiotics on the biosphere is wider than this and can impact the structure and activity of environmental microbiota. Along the article, we review the impact that pollution by antibiotics or by antibiotic resistance genes may have for both human health and for the evolution of environmental microbial populations. - The article reviews the current knowledge on the effects that pollution by antibiotics and antibiotic resistance genes may have for the microbiosphere.

  15. Environmental pollution by antibiotics and by antibiotic resistance determinants

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Jose Luis, E-mail: jlmtnez@cnb.csic.e [Departamento de Biotecnologia Microbiana, Centro Nacional de Biotecnologia, Consejo Superior de Investigaciones Cientificas, Darwin 3, Cantoblanco, 28049 Madrid, and CIBERESP (Spain)

    2009-11-15

    Antibiotics are among the most successful drugs used for human therapy. However, since they can challenge microbial populations, they must be considered as important pollutants as well. Besides being used for human therapy, antibiotics are extensively used for animal farming and for agricultural purposes. Residues from human environments and from farms may contain antibiotics and antibiotic resistance genes that can contaminate natural environments. The clearest consequence of antibiotic release in natural environments is the selection of resistant bacteria. The same resistance genes found at clinical settings are currently disseminated among pristine ecosystems without any record of antibiotic contamination. Nevertheless, the effect of antibiotics on the biosphere is wider than this and can impact the structure and activity of environmental microbiota. Along the article, we review the impact that pollution by antibiotics or by antibiotic resistance genes may have for both human health and for the evolution of environmental microbial populations. - The article reviews the current knowledge on the effects that pollution by antibiotics and antibiotic resistance genes may have for the microbiosphere.

  16. Combinations of macrolide resistance determinants in field isolates of Mannheimia haemolytica and Pasteurella multocida

    DEFF Research Database (Denmark)

    Desmolaize, Benoit; Rose, Simon; Wilhelm, Cornelia

    2011-01-01

    of these species exhibit resistance to veterinary macrolides with phenotypes that fall into three distinct classes. The first class has type I macrolide, lincosamide, and streptogramin B antibiotic resistance and, consistent with this, the 23S rRNA nucleotide A2058 is monomethylated by the enzyme product......(E) genes within an isogenic Escherichia coli background to assess their individually contributions to resistance. Our findings indicate what types of compounds might have driven the selection for these resistance determinants....

  17. Removal of oxytetracycline from aqueous solutions by hydroxyapatite as a low-cost adsorbent

    Science.gov (United States)

    Harja, Maria; Ciobanu, Gabriela

    2017-11-01

    The present paper involved a study of the adsorption process of the oxytetracycline drug from aqueous medium by using the hydroxyapatite nanopowders as adsorbent materials. The batch adsorption experiments were performed by monitoring the solution pH, contact time, adsorbent dosage and drug solution concentration. At pH 8 and ambient temperature, high oxytetracycline removal rates of about 97.58% and 89.95% for the uncalcined and calcined nanohydroxyapatites, respectively, were obtained. The kinetic studies indicate that the oxytetracycline adsorption onto nanohydroxyapatite samples follows a pseudo-second order kinetic model. The maximum adsorption capacities of 291.32 mg/g and 278.27 mg/g for uncalcined and calcined nanohydroxyapatite samples, respectively, have been found. So, the conclusion can be drawn that the hydroxyapatite shows good adsorption ability towards oxytetracycline.

  18. Removal of oxytetracycline from aqueous solutions by hydroxyapatite as a low-cost adsorbent

    Directory of Open Access Journals (Sweden)

    Harja Maria

    2017-01-01

    Full Text Available The present paper involved a study of the adsorption process of the oxytetracycline drug from aqueous medium by using the hydroxyapatite nanopowders as adsorbent materials. The batch adsorption experiments were performed by monitoring the solution pH, contact time, adsorbent dosage and drug solution concentration. At pH 8 and ambient temperature, high oxytetracycline removal rates of about 97.58% and 89.95% for the uncalcined and calcined nanohydroxyapatites, respectively, were obtained. The kinetic studies indicate that the oxytetracycline adsorption onto nanohydroxyapatite samples follows a pseudo-second order kinetic model. The maximum adsorption capacities of 291.32 mg/g and 278.27 mg/g for uncalcined and calcined nanohydroxyapatite samples, respectively, have been found. So, the conclusion can be drawn that the hydroxyapatite shows good adsorption ability towards oxytetracycline.

  19. Spectroscopic investigation of the pH controlled inclusion of doxycycline and oxytetracycline antibiotics in cationic micelles and their magnesium driven release.

    Science.gov (United States)

    Cesaretti, Alessio; Carlotti, Benedetta; Gentili, Pier Luigi; Clementi, Catia; Germani, Raimondo; Elisei, Fausto

    2014-07-24

    This work presents a steady-state and time-resolved UV-visible spectroscopic investigation of two antibiotics belonging to the family of tetracyclines (doxycycline and oxytetracycline) in the micellar medium provided by p-dodecyloxybenzyltrimethylammonium bromide (pDoTABr). The spectroscopic analysis has been performed in absorption and emission with femtosecond time resolution, and at pH 5.0 and 8.7 where doxycycline and oxytetracycline are present in their neutral-zwitterionic and monoanionic forms, respectively. The experimental data have been processed by sophisticated data mining methods such as global/target analysis and the maximum entropy method. The results unambiguously indicate that, when doxycycline and oxytetracycline are in their zwitterionic form, they are entrapped within the micelle, while when they are in their monoanionic form, they preferentially show a strong one-to-one interaction with the positively charged surfactant heads. Thus, the pH of the solution controls the inclusion of the investigated drugs into the micelle. When the drugs are entrapped inside the micelles, their spectroscopic and dynamical properties after photoexcitation change appreciably. Interestingly, the entrapped drugs are still able to strongly bind Mg(2+) cations, crucial in determining the biological functioning of tetracyclines. The femtosecond resolved measurements reveal that the drugs are efficiently pulled out of the micelles by Mg(2+). In fact, magnesium-tetracycline complexes are detected in the aqueous phase. The present study suggests the potential promising use of ammonium surfactant micelles embedding doxycycline and oxytetracycline as "smart" drug delivery systems allowing their pH controlled inclusion and Mg(2+) induced release.

  20. Determination of the Antibiotic Resistance Profile of Student Cell Phones

    Directory of Open Access Journals (Sweden)

    Lisa Ann Blankinship

    2012-08-01

    Full Text Available Sampling of common use items (e.g., student cell phones for bacterial presence, identification, and antibiotic resistance profiling helps students to recognize the need for routine cleaning of personal items and encourages thoughtful use of currently available medications. This multilab period project can be used to teach or reinforce several methods from general microbiology including aseptic technique, isolation streak, serial dilution, spread plating, Kirby Bauer testing, unknown identification, and media production. The data generated can be saved and added to each semester, thus providing a data set that reflects a local trend of antibiotic resistance.      

  1. Reduced mortality among young endangered masked bobwhite quail fed oxytetracycline-supplemented diets

    Science.gov (United States)

    Serafin, J.A.

    1982-01-01

    Two experiments were conducted to examine the effect of oxytetracycline-supplemented diets on mortality of young endangered masked bobwhite quail (Colinus virginianus ridgwayi). Inclusion of oxytetracycline at 200 g per ton in the feed for 6 weeks resulted in a marked, significant reduction in mortality of young masked bobwhite quail raised in captivity. Including the antibiotic in feed during the first week of life reduced mortality as effectively as feeding it for a longer period.

  2. Comparison of side effects of oxytetracycline and talc pleurodesis: an experimental study

    Science.gov (United States)

    2010-01-01

    Background Chemical pleurodesis is widely recommended in the treatment of refractory pleural effusion or pulmonary air leak of different etiologies. Although several agents have been used, many questions have remained unanswered about their toxicity. Talc is the most commonly used agent for the treatment, with rare, serious complications reported. Oxytetracycline pleurodesis in clinical practice has been described in a few studies, but literature reveals no experimental studies using this agent. We performed a prospective, randomized, observer-blinded, controlled study to evaluate the changes in lung histology and systemic response to pleurodesis with oxytetracycline and talc in acute and subacute phases in a rat model. Methods Forty-two male albino Wistar rats were divided into three groups and 3 subgroups with 7 animals in each. Group 1 was given oxytetracycline, 35 mg/kg; Group 2 was given talc slurry, 60 mg/kg in 0.5 mL saline solution, and Group 3 was given only 0.5 mL saline intrapleurally. In subgroups "a" the nimls were sacrificed at the postoperative 72nd hour and, in subgroups "b", on the postoperative day 7. The surfaces were graded by microscopic examination. Results Oxytetracycline produced alveolar collapse, hemorrhage, edema, inflammation at the postoperative 72nd hour and hemorrhage on the postoperative day 7, while talc produced significant edema, inflammation, proliferation, fibrosis at the postoperative 72nd hour and hemorrhage, edema, inflammation, proliferation, and fibrosis on the postoperative day 7 (p oxytetracycline on the postoperative day 7. On contralateral side, oxytetracycline and talc produced significant hemorrhage on the postoperative day 7 (p oxytetracycline were more pronounced, whereas the side effects of talc were prolonged to subacute phase. We propose that the occasional side effects in humans may be related to these changes as were observed in our rat model, and like talc, oxytetracycline must be used cautiously in patients

  3. SCC mec typing and antimicrobial resistance of methicillin-resistant Staphylococcus aureus (MRSA) from pigs of Northeast India.

    Science.gov (United States)

    Rajkhowa, S; Sarma, D K; Pegu, S R

    2016-12-01

    Staphylococcus aureus is one of the most important pathogens of both humans and animal. Methicillin-resistant Staphylococcus aureus (MRSA) is an important human pathogen that causes serious infections both in hospitals and communities due to its multidrug resistance tendency. This study was undertaken to characterize the MRSA isolates from pigs and to determine the antimicrobial resistance of these isolates. Forty nine MRSA strains (one strain per positive pig) isolated from pigs of Northeast India were characterized by SCCmec typing and antimicrobial resistance. The overall prevalence of MRSA was 7.02 % with the highest prevalence recorded in pigs aged 1-3 months (P = 0.001) and in nasal samples (P = 0.005). Two SCC mec types (type III and V) were found in Indian pigs with predominance of type V. All isolates were resistant to penicillin. Seventeen resistance groups were observed where 87.75 % isolates showed multidrug resistance (showed resistance to three or more classes of antimicrobials). The most predominant resistance pattern observed was Oxytetracycline + Penicillin + Sulfadiazine + Tetracycline accounting 12.24 % of the isolates. The present study contributes to the understanding of characteristics and antimicrobial resistance of porcine MRSA isolates which in turn will help in devising strategy for the control of this pathogen. Findings of the study also throw light on multidrug resistance MRSA and emphasize the need for judicious use of antimicrobials in animal practice.

  4. Saturation mapping of QTL region determining resistance specificity ...

    African Journals Online (AJOL)

    Genetic improvement for biotic resistance in rice involves the quantitative nature of inheritance, which reflects the additive effects of several genetic loci throughout the genome. To in silico identify putative candidate genes involved in defense response, we performed in silico anchoring of the QTL genetic marker data to the ...

  5. Two distinct classes of QTL determine rust resistance in sorghum.

    Science.gov (United States)

    Wang, Xuemin; Mace, Emma; Hunt, Colleen; Cruickshank, Alan; Henzell, Robert; Parkes, Heidi; Jordan, David

    2014-12-31

    Agriculture is facing enormous challenges to feed a growing population in the face of rapidly evolving pests and pathogens. The rusts, in particular, are a major pathogen of cereal crops with the potential to cause large reductions in yield. Improving stable disease resistance is an on-going major and challenging focus for many plant breeding programs, due to the rapidly evolving nature of the pathogen. Sorghum is a major summer cereal crop that is also a host for a rust pathogen Puccinia purpurea, which occurs in almost all sorghum growing areas of the world, causing direct and indirect yield losses in sorghum worldwide, however knowledge about its genetic control is still limited. In order to further investigate this issue, QTL and association mapping methods were implemented to study rust resistance in three bi-parental populations and an association mapping set of elite breeding lines in different environments. In total, 64 significant or highly significant QTL and 21 suggestive rust resistance QTL were identified representing 55 unique genomic regions. Comparisons across populations within the current study and with rust QTL identified previously in both sorghum and maize revealed a high degree of correspondence in QTL location. Negative phenotypic correlations were observed between rust, maturity and height, indicating a trend for both early maturing and shorter genotypes to be more susceptible to rust. The significant amount of QTL co-location across traits, in addition to the consistency in the direction of QTL allele effects, has provided evidence to support pleiotropic QTL action across rust, height, maturity and stay-green, supporting the role of carbon stress in susceptibility to rust. Classical rust resistance QTL regions that did not co-locate with height, maturity or stay-green QTL were found to be significantly enriched for the defence-related NBS-encoding gene family, in contrast to the lack of defence-related gene enrichment in multi-trait effect

  6. 30 CFR 27.41 - Test to determine resistance to moisture.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Test to determine resistance to moisture. 27.41... determine resistance to moisture. Components, subassemblies, or assemblies, the normal functioning of which might be affected by moisture, shall be tested in atmospheres of high relative humidity (80 percent or...

  7. Comparison of conventional and long-acting oxytetracyclines in prevention of induced Actinobacillus (Haemophilus) pleuropneumoniae infection of growing swine.

    OpenAIRE

    Kiorpes, A L; Bäckström, L R; Collins, M T; Kruse, G O

    1989-01-01

    These experiments tested the hypothesis that long-acting oxytetracycline (oxytetracycline-LA) was more effective than regular oxytetracycline in preventing porcine pleuropneumonia when administered either 24 or 48 h prior to experimental challenge with virulent strains of Actinobacillus pleuropneumoniae. Two experiments (1 and 2) were conducted using growing pigs (average weight 12-15 kg). Antibiotic treatments were administered once intramuscularly at 20 mg/kg body weight; controls received ...

  8. Oxytetracycline removal from water by novel microbial embedding gel beads

    Science.gov (United States)

    Wu, Nan; Pan, Peng; Zeng, Ming; Wang, Wei; Xu, Chenshan; Zhang, Zongpeng; Liu, Xinyuan; Wang, Yichao

    2018-01-01

    As a common antibiotic in aquatic environment, excessive oxytetracycline (OTC) is urgent to be removed due to its great biological toxicity. Compared with the traditional activated sludge, microbial embedding can enhance the treating efficiency. In this study, novel microbial embedding gel beads were produced with the additional agent of cyclodextrin (CD). Results show that CD could increase the mass transfer of OTC into gel beads, possibly because of its strong affinity for organic matters. In terms of OTC biodegradation, gel beads with CD were comparable to gel beads without CD, while the former’s sucrose removal efficiency was higher than the latter. The biodegradation of OTC only occurred in the presence of sucrose. The respiration test also confirmed these findings. Overall, the produced novel gel beads modified with CD could improve the removal performance of OTC.

  9. Determination of the electrical resistivity of vertically aligned carbon nanotubes by scanning probe microscopy

    Science.gov (United States)

    Ageev, O. A.; Il'in, O. I.; Rubashkina, M. V.; Smirnov, V. A.; Fedotov, A. A.; Tsukanova, O. G.

    2015-07-01

    Techniques are developed to determine the resistance per unit length and the electrical resistivity of vertically aligned carbon nanotubes (VA CNTs) using atomic force microscopy (AFM) and scanning tunneling microscopy (STM). These techniques are used to study the resistance of VA CNTs. The resistance of an individual VA CNT calculated with the AFM-based technique is shown to be higher than the resistance of VA CNTs determined by the STM-based technique by a factor of 200, which is related to the influence of the resistance of the contact of an AFM probe to VA CNTs. The resistance per unit length and the electrical resistivity of an individual VA CNT 118 ± 39 nm in diameter and 2.23 ± 0.37 μm in height that are determined by the STM-based technique are 19.28 ± 3.08 kΩ/μm and 8.32 ± 3.18 × 10-4 Ω m, respectively. The STM-based technique developed to determine the resistance per unit length and the electrical resistivity of VA CNTs can be used to diagnose the electrical parameters of VA CNTs and to create VA CNT-based nanoelectronic elements.

  10. Kinetics and mechanism investigation on the destruction of oxytetracycline by UV-254nm activation of persulfate.

    Science.gov (United States)

    Liu, Yiqing; He, Xuexiang; Fu, Yongsheng; Dionysiou, Dionysios D

    2016-03-15

    Oxytetracycline (OTC), an important broad-spectrum antibiotic, has been detected extensively in various environmental systems, which may have a detrimental impact on ecosystem and human health through the development of drug resistant bacteria and pathogens. In this study, the degradation of OTC was evaluated by UV-254nm activated persulfate (PS). The observed UV fluence based pseudo first-order rate constant (kobs) was found to be the highest at near neutral pH conditions (pH 5.5-8.5). Presence of various natural water constituents had different effects on OTC degradation, with a significant enhancement in the presence of bicarbonate or Cu(2+). Limited elimination of total organic carbon (TOC) and PS was observed during the mineralization of OTC. Transformation byproducts in the presence and absence of hydroxyl radical scavenging agent tert-butanol (t-BuOH) were identified using ultra-high definition accurate-mass quadrupole time-of-flight liquid chromatography/mass spectrometer (LC-QTOF/MS). Potential OTC degradation mechanism was subsequently proposed revealing four different reaction pathways by SO4(-) reaction including hydroxylation (+16Da), demethylation (-14Da), decarbonylation (-28Da) and dehydration (-18Da). This study suggests that UV-254nm/PS is a promising treatment technology for the control of water pollution caused by emerging contaminants such as OTC. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Resistance to hepatitis C virus: potential genetic and immunological determinants.

    Science.gov (United States)

    Mina, Michael M; Luciani, Fabio; Cameron, Barbara; Bull, Rowena A; Beard, Michael R; Booth, David; Lloyd, Andrew R

    2015-04-01

    Studies of individuals who were highly exposed but seronegative (HESN) for HIV infection led to the discovery that homozygosity for the Δ32 deletion mutation in the CCR5 gene prevents viral entry into target cells, and is associated with resistance to infection. Additionally, evidence for protective immunity has been noted in some HESN groups, such as sex workers in The Gambia. Population studies of individuals at high risk for hepatitis C virus infection suggest that an HESN phenotype exists. The body of evidence, which suggests that protective immunity allows clearance of hepatitis C virus without seroconversion is growing. Furthermore, proof-of-principle evidence from in-vitro studies shows that genetic polymorphisms can confer resistance to establishment of infection. This Review discusses the possibility that genetic mutations confer resistance against hepatitis C virus, and also explores evidence for protective immunity, including via genetically programmed variations in host responses. The data generally strengthens the notion that investigations of naturally arising polymorphisms within the hepatitis C virus interactome, and genetic association studies of well characterised HESN individuals, could identify potential targets for vaccine design and inform novel therapies. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  13. Autosomal male determination in a spinosad-resistant housefly strain from Denmark

    DEFF Research Database (Denmark)

    Højland, Dorte H; Scott, Jeffrey G; Vagn Jensen, Karl-Martin

    2014-01-01

    males in this strain. The factor responsible for spinosad resistance in the strain is unknown, but previous studies suggest a role of cytochrome P450s for detoxification of spinosad. Sex determination in the housefly is controlled by a male-determining factor (M), either located on the Y chromosome......BACKGROUND The housefly, Musca domestica L., is a global pest and has developed resistance to most insecticides applied for its control. The insecticide spinosad plays an important role in housefly control. Females of the Danish housefly strain 791spin are threefold more resistant to spinosad than...... of resistance to spinosad. Sex determination in 791spin is due to a male factor on autosome 3. CONCLUSIONS The most likely explanation for the differentiation of spinosad resistance between males and females is a recessive spinosad resistance factor on autosome III. © 2013 Society of Chemical Industry...

  14. Determination of internal series resistance of PV devices: repeatability and uncertainty

    International Nuclear Information System (INIS)

    Trentadue, Germana; Pavanello, Diego; Salis, Elena; Field, Mike; Müllejans, Harald

    2016-01-01

    The calibration of photovoltaic devices requires the measurement of their current–voltage characteristics at standard test conditions (STC). As the latter can only be reached approximately, a curve translation is necessary, requiring among others the internal series resistance of the photovoltaic device as an input parameter. Therefore accurate and reliable determination of the series resistance is important in measurement and test laboratories. This work follows standard IEC 60891 ed 2 (2009) for the determination of the internal series resistance and investigates repeatability and uncertainty of the result in three aspects for a number of typical photovoltaic technologies. Firstly the effect of varying device temperature on the determined series resistance is determined experimentally and compared to a theoretical derivation showing agreement. It is found that the series resistance can be determined with an uncertainty of better than 5% if the device temperature is stable within  ±0.1 °C, whereas the temperature range of  ±2 °C allowed by the standard leads to much larger variations. Secondly the repeatability of the series resistance determination with respect to noise in current–voltage measurement is examined yielding typical values of  ±5%. Thirdly the determination of the series resistance using three different experimental set-ups (solar simulators) shows agreement on the level of  ±5% for crystalline Silicon photovoltaic devices and deviations up to 15% for thin-film devices. It is concluded that the internal series resistance of photovoltaic devices could be determined with an uncertainty of better than 10%. The influence of this uncertainty in series resistance on the electrical performance parameters of photovoltaic devices was estimated and showed a contribution of 0.05% for open-circuit voltage and 0.1% for maximum power. Furthermore it is concluded that the range of device temperatures allowed during determination of series

  15. Linezolid-resistant enterococci in Polish hospitals: species, clonality and determinants of linezolid resistance.

    Science.gov (United States)

    Gawryszewska, I; Żabicka, D; Hryniewicz, W; Sadowy, E

    2017-07-01

    The significant increase of the linezolid-resistant enterococci (LRE) has been observed in Polish hospitals since 2012 and our study aimed at elucidating the possible reasons for this phenomenon. Polish LRE isolates were analysed by multilocus-sequence typing (MLST) and multiple locus variable-number tandem repeat (VNTR) analysis (MLVA), polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (PCR-RFLP) to establish clonal relatedness and mechanism of linezolid resistance, respectively. Fifty analysed LRE (2008-2015) included mostly Enterococcus faecium (82%) and Enterococcus faecalis (16%). Enterococcus faecium belonged to the hospital-adapted lineages 17/18 and 78, while E. faecalis isolates represented ST6, a hospital-associated type, and ST116, found in both humans and food-production animals. The G2576T 23S rRNA mutation was the most frequent (94%) mechanism of linezolid/tedizolid resistance of LRE. None of the isolates carried the plasmid-associated gene of Cfr methyltransferase, whereas optrA, encoding the ABC-type drug transporter, was identified in two E. faecalis isolates. In these isolates, optrA was located on a plasmid, transferable to both E. faecium and E. faecalis, whose partial (36.3 kb) sequence was 100% identical to the pE394 plasmid, identified previously in China in both clinical and farm animal isolates. The optrA-E. faecium transconjugant displayed a significant growth deficiency, in contrast to the optrA-E. faecalis. Our study indicates the role of mutation acquisition by hospital-adapted clones of enterococci as a major driver of increasing resistance to linezolid and tedizolid. Transferability and apparent lack of a biological cost of resistance suggest that E. faecalis may be a natural reservoir of optrA, an emerging mechanism of oxazolidinone resistance.

  16. Prevalence of genetic determinants and phenotypic resistance to ciprofloxacin in Campylobacter jejuni from lithuania

    DEFF Research Database (Denmark)

    Aksomaitiene, Jurgita; Ramonaite, Sigita; Olsen, John E.

    2018-01-01

    Recently, the number of reports on isolation of ciprofloxacin resistant Campylobacter jejuni has increased worldwide. The aim of this study was to determine the prevalence of resistance to ciprofloxacin and its genetic determinants among C. jejuni isolated from humans (n = 100), poultry products (n...... = 96) and wild birds (n = 96) in Lithuania. 91.4% of the C. jejuni isolates were phenotypically resistant to ciprofloxacin. DNA sequence analyses of the gyrA gene from 292 isolates revealed that a change in amino acid sequence, Thr86Ile, was the main substition conferring resistance to ciprofloxacin...... forty-five C. jejuni isolates showed one or more silent mutations, and 32.4% of examined isolates possessed six silent mutations. In addition to the ciprofloxacin resistant isolates harboring only Thr86Ile point mutation (110 isolates), the current study identified resistant isolates (n = 101) harboring...

  17. Immunotherapy with mutated onchocystatin fails to enhance the efficacy of a sub-lethal oxytetracycline regimen against Onchocerca ochengi.

    Science.gov (United States)

    Bah, Germanus S; Tanya, Vincent N; Makepeace, Benjamin L

    2015-08-15

    Human onchocerciasis (river blindness), caused by the filarial nematode Onchocerca volvulus, has been successfully controlled by a single drug, ivermectin, for over 25 years. Ivermectin prevents the disease symptoms of severe itching and visual impairment by killing the microfilarial stage, but does not eliminate the adult parasites, necessitating repeated annual treatments. Mass drug administration with ivermectin does not always break transmission in forest zones and is contraindicated in individuals heavily co-infected with Loa loa, while reports of reduced drug efficacy in Ghana and Cameroon may signal the development of resistance. An alternative treatment for onchocerciasis involves targeting the essential Wolbachia symbiont with tetracycline or its derivatives, which are adulticidal. However, implementation of antibiotic therapy has not occurred on a wide scale due to the prolonged treatment regimen required (several weeks). In the bovine Onchocerca ochengi system, it has been shown previously that prolonged oxytetracycline therapy increases eosinophil counts in intradermal nodules, which kill the adult worms by degranulating on their surface. Here, in an "immunochemotherapeutic" approach, we sought to enhance the efficacy of a short, sub-lethal antibiotic regimen against O. ochengi by prior immunotherapy targeting onchocystatin, an immunomodulatory protein located in the adult female worm cuticle. A key asparagine residue in onchocystatin was mutated to ablate immunomodulatory activity, which has been demonstrated previously to markedly improve the protective efficacy of this vaccine candidate when used as an immunoprophylactic. The immunochemotherapeutic regimen was compared with sub-lethal oxytetracycline therapy alone; onchocystatin immunotherapy alone; a gold-standard prolonged, intermittent oxytetracycline regimen; and no treatment (negative control) in naturally infected Cameroonian cattle. Readouts were collected over one year and comprised adult

  18. Molecular Determinants of Radio Resistance in Prostate Cancer

    National Research Council Canada - National Science Library

    Bristow, Robert

    2003-01-01

    ... (given in vivo tumor cell populations). An in vivo program of prostate xenograft radioresponse and patient biopsy studies will determine the level of DNA repair in situ using immunohistochemistry and immunoflorescent markers...

  19. A novel fusidic acid resistance determinant, fusF, in Staphylococcus cohnii.

    Science.gov (United States)

    Chen, Hsiao-Jan; Hung, Wei-Chun; Lin, Yu-Tzu; Tsai, Jui-Chang; Chiu, Hao-Chieh; Hsueh, Po-Ren; Teng, Lee-Jene

    2015-02-01

    To determine MICs of fusidic acid for and identify genetic determinants of resistance in Staphylococcus cohnii isolates. Susceptibility to fusidic acid was determined by the standard agar dilution method in 24 S. cohnii subsp. urealyticus clinical isolates, 7 S. cohnii subsp. cohnii clinical isolates and 2 reference strains. Sequencing of a novel resistance determinant, fusF, and its flanking regions was performed by long and accurate PCR and inverse PCR. To evaluate the function of fusF, the MIC of fusidic acid was determined for recombinant Staphylococcus aureus carrying a plasmid expressing fusF. A total of 25 S. cohnii subsp. urealyticus (24 clinical isolates and 1 reference strain) and 2 S. cohnii subsp. cohnii displayed low-level resistance to fusidic acid (MICs 2-16 mg/L). Sequencing of a 4259 bp fragment from S. cohnii subsp. urealyticus ATCC 49330 revealed a novel resistance gene, designated fusF, which displayed 70.5% nucleotide and 67.3% amino acid identity to fusD. Expression of fusF in S. aureus confers resistance to fusidic acid. A novel FusB-family gene, fusF, was identified as a major resistance determinant in S. cohnii clinical isolates resistant to fusidic acid. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  20. Monitoring of drug resistance amplification and attenuation with the use of tetracycline-resistant bacteria during wastewater treatment

    Science.gov (United States)

    Harnisz, Monika; Korzeniewska, Ewa; Niestępski, Sebastian; Osińska, Adriana; Nalepa, Beata

    2017-11-01

    The objective of this study was to monitor changes (amplification or attenuation) in antibiotic resistance during wastewater treatment based on the ecology of tetracycline-resistant bacteria. The untreated and treated wastewater were collected in four seasons. Number of tetracycline-(TETR) and oxytetracycline-resistant (OTCR) bacteria, their qualitative composition, minimum inhibitory concentrations (MICs), sensitivity to other antibiotics, and the presence of tet (A, B, C, D, E) resistance genes were determined. TETR and OTCR counts in untreated wastewater were 100 to 1000 higher than in treated effluent. OTCR bacterial counts were higher than TETR populations in both untreated and treated wastewater. TETR isolates were not dominated by a single bacterial genus or species, whereas Aeromonas hydrophila and Aeromonas sobria were the most common in OTCR isolates. The treatment process attenuated the drug resistance of TETR bacteria and amplified the resistance of OTCR bacteria. In both microbial groups, the frequency of tet(A) gene increased in effluent in comparison with untreated wastewater. Our results also indicate that treated wastewater is a reservoir of multiple drug-resistant bacteria as well as resistance determinants which may pose a health hazard for humans and animals when released to the natural environment.

  1. Potentiometric studies on the complexes of tetracycline (TC) and oxytetracycline (OTC) with some metal ions

    International Nuclear Information System (INIS)

    Ghandour, M.A.; Azab, H.A.; Hassan, A.; Ali, A.M.

    1992-01-01

    The interaction of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Zn(II), Cd(II), Hg(II), Pb(II), Al(III), and UO 2 (II) ions with tetracycline (TC) were studied by potentiometric pH titrations. The formation constants of the different binary complexes formed in such systems have been determined at 25±0.1 deg C and μ=0.1 moll -1 (NaNO 3 ). Potentiometric pH equilibrium measurements have been made under the same conditions for the interaction of oxytetracycline (OTC) and Cu(II), Cd(II), Pb(II), and UO 2 (II). The formation of (1:1) binary complexes are inferred from the potentiometric pH titration curves. The protonation constants of TC and OTC were also determined under the same conditions and refined (ESAB2M computer program). The transition metal stability constants are consistent with the Irving-Williams series. (authors)

  2. Determination of resist parameters using the extended Nijboer-Zernike theory

    NARCIS (Netherlands)

    Dirksen, P.; Braat, J.; Janssen, A.J.E.M.; Leeuwestein, A.; Kwinten, H.; Van Steenwinckel, D.

    2004-01-01

    This study presents an experimental method to determine the resist parameters that are at the origin of a general blurring of the projected aerial image. The resist model includes the effects of diffusion in the horizontal plane and a second cause for image blur that originates from a stochastic

  3. On the difference between optically and electrically determined resistivity of ultra-thin titanium nitride films

    NARCIS (Netherlands)

    Van Hao, B.; Kovalgin, Alexeij Y.; Wolters, Robertus A.M.

    2013-01-01

    This work reports on the determination and comparison of the resistivity of ultra-thin atomic layer deposited titanium nitride films in the thickness range 0.65–20 nm using spectroscopic ellipsometry and electrical test structures. We found that for films thicker than 4 nm, the resistivity values

  4. Genotypes, Virulence Factors and Antimicrobial Resistance Genes of Staphylococcus aureus Isolated in Bovine Subclinical Mastitis from Eastern China

    Directory of Open Access Journals (Sweden)

    Javed Memon§, Yongchun Yang§, Jam Kashifa, Muhammad Yaqoob, Rehana Buriroa, Jamila Soomroa, Wang Liping and Fan Hongjie*

    2013-11-01

    Full Text Available This study was carried out to determine the genotypes, virulence factors and antimicrobial resistance traits of 34 Staphylococcus aureus isolated from subclinical mastitis in Eastern China. Minimal inhibitory concentration (MIC results showed resistance to erythromycin in all isolates. A high frequency of Methicillin resistant S. aureus (MRSA; 29% was observed and these isolates were also highly resistant to penicillin, oxacillin, oxytetracycline and chloramphenicol than methicillin sensitive S. aureus (MSSA isolates. Thirteen pathogenic factors and seven resistance genes including mecA and blaZ gene were checked through PCR. The spaX gene was found in all isolates, whereas cna, spaIg, nuc, clfA, fnbpB, hlA, hlB and seA were present in 35, 79, 85, 59, 35, 85, 71 and 38% isolates, respectively. Nine isolates carried a group of 8 different virulence genes. Moreover, macrolide resistance genes ermB and ermC were present in all isolates. High resistance rate against methicillin was found but no isolate was positive for mecA gene, whereas blaZ and tetK were detected in 82 and 56% isolates, respectively. Genes; fnbpA, seB, seC, seD, dfrK and tetM were not found in any isolate. The statistical association between phenotypic resistance and virulence genes showed, clfA, fnbpB, hlB and seA, were potentially associated with penicillin G, ciprofloxacin, methicillin, chloramphenicol, trimethoprim and oxytetracycline resistance (P≤0.05. REP-PCR based genotyping showed seven distinct genotypes (A-G prevalent in this region. This study reports the presence of multidrug resistant S. aureus in sub-clinical mastitis which were also highly virulent that could be a major obstacle in the treatment of mastitis in this region of China.

  5. Determination and Application of Comprehensive Specific Frictional Resistance in Heating Engineering

    Directory of Open Access Journals (Sweden)

    Yanan Tian

    2018-01-01

    Full Text Available In this study, we analyze the deficiencies of specific frictional resistance in heating engineering. Based on economic specific frictional resistance, we put forward the concept of comprehensive specific frictional resistance, which considers the multiple factors of technology, economy, regulation modes, pipe segment differences, and medium pressure. Then, we establish a mathematical model of a heating network across its lifespan in order to develop a method for determining the comprehensive specific frictional resistance. Relevant conclusions can be drawn from the results. As an application, we have planned the heating engineering for Yangyuan County in China, which demonstrates the feasibility and superiority of the method.

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

    DEFF Research Database (Denmark)

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

    2002-01-01

    Tetracyclines used in veterinary therapy invariably will find their way as parent compound and degradation products to the agricultural field. Major degradation products formed due to the limited stability of parent tetracyclines (tetracycline, chlortetracycline, and oxytetracycline) in aqueous...... at the same concentration level as tetracycline, chlortetracycline, and oxytetracycline on both the sludge and the tetracycline-sensitive soil bacteria. Further, both 5a,6-anhydrotetracychne and 5a,6-anhydrochlortetracycline had potency on tetracycline-resistant bacteria supporting a mode of action different...

  7. Complexação da tetraciclina, da oxitetraciclina e da clortetraciclina com o catião cobre (II. Estudo potenciométrico Tetracycline, oxytetracycline and chlortetracycline complexation with copper (II. Potentiometric study

    Directory of Open Access Journals (Sweden)

    Cristina M. C. M. Couto

    2000-08-01

    Full Text Available Stability constants of complexes formed by copper (II with three different tetracyclines (tetracycline, oxytetracycline and chlortetracycline have been determined potentiometrically with an automatic system in aqueous medium at 25,0 ± 0,2 ºC and I = 0,1 mol L-1 NaNO3. The protonation constants of the three tetracyclines were also determined under the same conditions. The distribution of the complexes was then simulated at therapeutic levels of the drugs.

  8. Genome-Wide Identification of Antimicrobial Intrinsic Resistance Determinants in Staphylococcus aureus

    DEFF Research Database (Denmark)

    Vestergaard, Martin; Leng, Bingfeng; Haaber, Jakob

    2016-01-01

    The emergence of antimicrobial resistance severely threatens our ability to treat bacterial infections. While acquired resistance has received considerable attention, relatively little is known of intrinsic resistance that allows bacteria to naturally withstand antimicrobials. Gene products...... that confer intrinsic resistance to antimicrobial agents may be explored for alternative antimicrobial therapies, by potentiating the efficacy of existing antimicrobials. In this study, we identified the intrinsic resistome to a broad spectrum of antimicrobials in the human pathogen, Staphylococcus aureus. We...... with the atpA mutant compared to wild type cells with gentamicin at a clinically relevant concentration. Our results demonstrate that many gene products contribute to the intrinsic antimicrobial resistance of S. aureus. Knowledge of these intrinsic resistance determinants provides alternative targets...

  9. A measurement method for determination of dc internal resistance of batteries and supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Shuhong; Wu, Feng [Department of Materials Science, Beijing Science and Technology University, Beijing 100081 (China); Yang, Liuxiang; Gao, Lijun [Department of Chemistry, NanChang University, JiangXi 330031 (China); Burke, Andrew F. [Institute of Transportation, University of California, Davis, CA 95616 (United States)

    2010-02-15

    Internal resistance is an importance parameter determining the power performance of a battery or supercapacitor. An 8.5 Ah Li-ion battery and a 350 F supercapacitor were tested as examples to validate the measurement method of dc internal resistance. Voltage data were taken at 10 ms, 2 s and 30 s after the current interruption or pulse. The ac resistances at 1 kHz of the battery and supercapacitor were also measured for comparison with the dc values. Based on these tests, it is proposed that the dc internal resistance of the battery and supercapacitor be obtained from {delta}V/{delta}I where the {delta}V is the voltage change after the current interruption, and {delta}I means current change from I to 0. When the voltage change at 10 ms or less is selected, the resistance corresponds to the Ohmic resistance of the device. (author)

  10. 76 FR 60448 - Syngenta Biotechnology, Inc.; Determination of Nonregulated Status for Lepidopteran-Resistant Cotton

    Science.gov (United States)

    2011-09-29

    ...] Syngenta Biotechnology, Inc.; Determination of Nonregulated Status for Lepidopteran-Resistant Cotton AGENCY... our determination that a cotton line developed by Syngenta Biotechnology, Inc., designated as event... submitted by Syngenta Biotechnology, Inc., in its petition for a determination of nonregulated status, our...

  11. Molecular Basis of Resistance to Selected Antimicrobial Agents in the Emerging Zoonotic Pathogen Streptococcus suis.

    Science.gov (United States)

    Gurung, Mamata; Tamang, Migma Dorji; Moon, Dong Chan; Kim, Su-Ran; Jeong, Jin-Ha; Jang, Geum-Chan; Jung, Suk-Chan; Park, Yong-Ho; Lim, Suk-Kyung

    2015-07-01

    Characterization of 227 Streptococcus suis strains isolated from pigs during 2010 to 2013 showed high levels of resistance to clindamycin (95.6%), tilmicosin (94.7%), tylosin (93.8%), oxytetracycline (89.4%), chlortetracycline (86.8%), tiamulin (72.7%), neomycin (70.0%), enrofloxacin (56.4%), penicillin (56.4%), ceftiofur (55.9%), and gentamicin (55.1%). Resistance to tetracyclines, macrolides, aminoglycosides, and fluoroquinolone was attributed to the tet gene, erm(B), erm(C), mph(C), and mef(A) and/or mef(E) genes, aph(3')-IIIa and aac(6')-Ie-aph(2″)-Ia genes, and single point mutations in the quinolone resistance-determining region of ParC and GyrA, respectively. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  12. Non-invasive determination of absolute lung resistivity in adults using electrical impedance tomography

    International Nuclear Information System (INIS)

    Zhang, Jie; Patterson, Robert

    2010-01-01

    Lung resistivity is a physiological parameter that describes the electrical characteristics of the lungs. Lung composition changes due to changes in the lung tissues, fluid and air volume. Various diseases that can cause a change in lung composition may be monitored by measuring lung resistivity. Currently, there is no accepted non-invasive method to measure lung resistivity. In this study, we presented a method and framework to non-invasively determine lung resistivity using electrical impedance tomography (EIT). By comparing actual measurements from subjects with data from a 3D human thorax model, an EIT image can be reconstructed to show a resistivity difference between the model and the subject. By adjusting the lung resistivity in the model, the resistivity difference in the lung regions can be reduced to near zero. This resistivity value then is the estimation of the lung resistivity of the subject. Using the proposed method, the lung resistivities of four normal adult males (43 ± 13 years, 78 ± 10 kg) in the supine position at air volumes starting at functional residual capacity (FRC—end expiration) and increasing in 0.5 l steps to 1.5 l were studied. The averaged lung resistivity changes 12.59%, from 1406 Ω cm to 1583 Ω cm, following the inspiration of 1.5 l air from FRC. The coefficients of variation (CV) of precision for the four subjects are less than 10%. The experiment was repeated five times at each air volume on a subject to test the reproducibility. The CVs are less than 3%. The results show that it is feasible to determine absolute lung resistivity using an EIT-based method

  13. Non-invasive determination of absolute lung resistivity in adults using electrical impedance tomography.

    Science.gov (United States)

    Zhang, Jie; Patterson, Robert

    2010-08-01

    Lung resistivity is a physiological parameter that describes the electrical characteristics of the lungs. Lung composition changes due to changes in the lung tissues, fluid and air volume. Various diseases that can cause a change in lung composition may be monitored by measuring lung resistivity. Currently, there is no accepted non-invasive method to measure lung resistivity. In this study, we presented a method and framework to non-invasively determine lung resistivity using electrical impedance tomography (EIT). By comparing actual measurements from subjects with data from a 3D human thorax model, an EIT image can be reconstructed to show a resistivity difference between the model and the subject. By adjusting the lung resistivity in the model, the resistivity difference in the lung regions can be reduced to near zero. This resistivity value then is the estimation of the lung resistivity of the subject. Using the proposed method, the lung resistivities of four normal adult males (43 +/- 13 years, 78 +/- 10 kg) in the supine position at air volumes starting at functional residual capacity (FRC--end expiration) and increasing in 0.5 l steps to 1.5 l were studied. The averaged lung resistivity changes 12.59%, from 1406 Omega cm to 1583 Omega cm, following the inspiration of 1.5 l air from FRC. The coefficients of variation (CV) of precision for the four subjects are less than 10%. The experiment was repeated five times at each air volume on a subject to test the reproducibility. The CVs are less than 3%. The results show that it is feasible to determine absolute lung resistivity using an EIT-based method.

  14. Fluoroquinolone Resistance Mechanisms in an Escherichia coli Isolate, HUE1, Without Quinolone Resistance-Determining Region Mutations

    Directory of Open Access Journals (Sweden)

    Toyotaka eSato

    2013-05-01

    Full Text Available Fluoroquinolone resistance can cause major clinical problems. Here, we investigated fluoroquinolone resistance mechanisms in a clinical Escherichia coli isolate, HUE1, which had no mutations quinolone resistance-determining regions (QRDRs of DNA gyrase and topoisomerase IV. HUE1 demonstrated MICs that exceeded the breakpoints for ciprofloxacin, levofloxacin, and norfloxacin. HUE1 harbored oqxAB and qnrS1 on distinct plasmids. In addition, it exhibited lower intracellular ciprofloxacin concentrations and higher mRNA expression levels of efflux pumps and their global activators than did reference strains. The genes encoding AcrR (local AcrAB repressor and MarR (MarA repressor were disrupted by insertion of the transposon IS3-IS629 and a frameshift mutation, respectively. A series of mutants derived from HUE1 were obtained by plasmid curing and gene knockout using homologous recombination. Compared to the MICs of the parent strain HUE1, the fluoroquinolone MICs of these mutants indicated that qnrS1, oqxAB, acrAB, acrF, acrD, mdtK, mdfA, and tolC contributed to the reduced susceptibility to fluoroquinolone in HUE1. Therefore, fluoroquinolone resistance in HUE1 is caused by concomitant acquisition of QnrS1 and OqxAB and overexpression of AcrAB−TolC and other chromosome-encoded efflux pumps. Thus, we have demonstrated that QRDR mutations are not absolutely necessary for acquiring fluoroquinolone resistance in E. coli.

  15. Mutations inside rifampicin-resistance determining region of rpoB gene associated with rifampicin-resistance in Mycobacterium tuberculosis.

    Science.gov (United States)

    Zaw, Myo T; Emran, Nor A; Lin, Zaw

    2018-04-26

    Rifampicin (RIF) plays a pivotal role in the treatment of tuberculosis due to its bactericidal effects. Because the action of RIF is on rpoB gene encoding RNA polymerase β subunit, 95% of RIF resistant mutations are present in rpoB gene. The majority of the mutations in rpoB gene are found within an 81bp RIF-resistance determining region (RRDR). Literatures on RIF resistant mutations published between 2010 and 2016 were thoroughly reviewed. The most commonly mutated codons in RRDR of rpoB gene are 531, 526 and 516. The possibilities of absence of mutation in RRDR of rpoB gene in MDR-TB isolates in few studies was due to existence of other rare rpoB mutations outside RRDR or different mechanism of rifampicin resistance. Molecular methods which can identify extensive mutations associated with multiple anti-tuberculous drugs are in urgent need so that the research on drug resistant mutations should be extended. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. Specific detection of oxytetracycline using DNA aptamer-immobilized interdigitated array electrode chip

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeon Seok; Niazi, Javed H [School of Life Sciences and Biotechnology, Korea University, Anam-dong, Seongbuk-gu, Seoul 136-701 (Korea, Republic of); Gu, Man Bock [School of Life Sciences and Biotechnology, Korea University, Anam-dong, Seongbuk-gu, Seoul 136-701 (Korea, Republic of)], E-mail: mbgu@korea.ac.kr

    2009-02-23

    An electrochemical sensing system for oxytetracycline (OTC) detection was developed using ssDNA aptamer immobilized on gold interdigitated array (IDA) electrode chip. A highly specific ssDNA aptamer that bind to OTC with high affinity was employed to discriminate other tetracyclines (TCs), such as doxycycline (DOX) and tetracycline (TET). The immobilized thiol-modified aptamer on gold electrode chip served as a biorecognition element for the target molecules and the electrochemical signals generated from interactions between the aptamers and the target molecules was evaluated by cyclic voltammetry (CV) and square wave voltammetry (SWV). The current decrease due to the interference of bound OTC, DOX or TET was analyzed with the electron flow produced by a redox reaction between ferro- and ferricyanide. The specificity of developed EC-biosensor for OTC was highly distinguishable from the structurally similar antibiotics (DOX and TET). The dynamic range was determined to be 1-100 nM of OTC concentration in semi-logarithmic coordinates.

  17. Specific detection of oxytetracycline using DNA aptamer-immobilized interdigitated array electrode chip

    International Nuclear Information System (INIS)

    Kim, Yeon Seok; Niazi, Javed H.; Gu, Man Bock

    2009-01-01

    An electrochemical sensing system for oxytetracycline (OTC) detection was developed using ssDNA aptamer immobilized on gold interdigitated array (IDA) electrode chip. A highly specific ssDNA aptamer that bind to OTC with high affinity was employed to discriminate other tetracyclines (TCs), such as doxycycline (DOX) and tetracycline (TET). The immobilized thiol-modified aptamer on gold electrode chip served as a biorecognition element for the target molecules and the electrochemical signals generated from interactions between the aptamers and the target molecules was evaluated by cyclic voltammetry (CV) and square wave voltammetry (SWV). The current decrease due to the interference of bound OTC, DOX or TET was analyzed with the electron flow produced by a redox reaction between ferro- and ferricyanide. The specificity of developed EC-biosensor for OTC was highly distinguishable from the structurally similar antibiotics (DOX and TET). The dynamic range was determined to be 1-100 nM of OTC concentration in semi-logarithmic coordinates

  18. The efficacy of mass-marking channel catfish fingerlings by immersion in oxytetracycline

    Science.gov (United States)

    Stewart, David R.

    2011-01-01

    Oxytetracycline (OTC) has been extensively used for marking a variety of fish species, but has never been successfully used to mark channel catfish Ictalurus punctatus. Channel catfish fingerlings (~ 25 mm TL) obtained from the Oklahoma Department of Wildlife Conservation at Byron Fish Hatchery were kept in Living Streams (791 to 1,018 L) equipped with recirculation units. Marking trials consisted of immersing channel catfish in one of three concentrations (250, 450, and 700 mg/L) OTC hydrochloride [HCl] for 6 hours. Samples of channel catfish were obtained from each group at 1-week and 4-week postimmersion. Lapilli otoliths and pectoral spines were removed to assess mark presence with an epi-fluorescent compound microscope. After one week, no marks were detected on pectoral spines for all treatments, mark detection on otoliths depended on concentration, but never exceeded 43% (700 mg/L). After four weeks, all otoliths and pectoral spines were determined marked for 700 mg/L OTC, 20% for fish immersed in 450 mg/L OTC, and 0% were marked after four weeks at the 250 mg/L OTC. Results show, channel catfish fingerlings can be successfully marked with immersion in OTC at 700 mg/L for at least 6 hours.

  19. Determination of the attrition resistance of granular charcoals

    International Nuclear Information System (INIS)

    Dietz, V.R.

    1979-01-01

    A laboratory procedure has been developed to evaluate the attrition of granular adsorbent charcoals on passing an air flow through the bed. Two factors observed in plant operations were selected as relevant: (1) the characteristic structural vibrations in plant scale equipment (motors, fans, etc.) that are transmitted to charcoal particles and cause the particles to move and rub each other, and (2) the rapid air flow that results in the movement of the attrited dust. In the test a container for charcoal [50 mm diameter and 50 mm high] was vibrated at a frequency of 60 Hz and at a constant energy input manually controlled using a vibration meter in the acceleration mode. Simultaneously, air was applied and exited through glass fiber filter paper. The quantity of dust trapped on the exit filter was then determined, either optically or gravimetrically. The dust formed per minute (attrition coefficient) was found to approach a constant value. The plateau-values from sequential determinations varied with the source of the charcoal; a 5-fold difference was found among a large variety of commercial products. The first testing of a sample released the excess dust accumulated in previous handling of the charcoal. The plateau values were then attained in the succeeding tests and these were characteristic of the material. The results were compared with those obtained for the same charcoals using older test methods such as the Ball and Pan Hardness Test described in RDTM16-1T

  20. Probing the In Vitro Cytotoxicity of the Veterinary Drug Oxytetracycline

    Science.gov (United States)

    Chi, Zhenxing; Liu, Rutao; You, Hong; Ma, Shanshan; Cui, Hao; Zhang, Qiang

    2014-01-01

    The study investigated the effect of oxytetracycline (OTC) on the anti-oxidative defense system, the structure (hemolysis rate and morphology) and function (ATP enzyme activity) of human red blood cells (hRBCs) to investigate the possible toxic mechanism of OTC to hRBCs. The experimental results indicate that OTC can cause a decline in the function of the antioxidant defense system of hRBCs, resulting in oxidative stress. OTC can bring about morphological changes to hRBCs, and further leads to hemolysis, when the concentration of OTC is over 8×10−5 M (about 164 µg/ml). At a low OTC concentration, below 4×10−5 M (82 µg/ml), OTC can enhance the activity of ATP enzyme of hRBCs, known as hormesis. However, at a high concentration, above 4×10−5 M (about 82 µg/ml), the ATP enzymatic activity was inhibited, affecting the function of hRBCs. The estalished mechanism of toxicity of OTC to hRBCs can facilitate a deeper understanding of the toxicity of OTC in vivo. PMID:25019386

  1. Adsorption Property and Mechanism of Oxytetracycline onto Willow Residues

    Directory of Open Access Journals (Sweden)

    Di Wang

    2017-12-01

    Full Text Available To elucidate the adsorption property and the mechanism of plant residues to reduce oxytetracycline (OTC, the adsorption of OTC onto raw willow roots (WR-R, stems (WS-R, leaves (WL-R, and adsorption onto desugared willow roots (WR-D, stems (WS-D, and leaves (WL-D were investigated. The structural characterization was analyzed by scanning electron microscopy, Fourier-transform infrared spectra, and an elemental analyzer. OTC adsorption onto the different tissues of willow residues was compared and correlated with their structures. The adsorption kinetics of OTC onto willow residues was found to follow the pseudo-first-order model. The isothermal adsorption process of OTC onto the different tissues of willow residues followed the Langmuir and Freundlich model and the process was also a spontaneous endothermic reaction, which was mainly physical adsorption. After the willow residues were desugared, the polarity decreased and the aromaticity increased, which explained why the adsorption amounts of the desugared willow residues were higher than those of the unmodified residues. These observations suggest that the raw and modified willow residues have great potential as adsorbents to remove organic pollutants.

  2. Otolith marking of juvenile shortnose gar by immersion in oxytetracycline

    Science.gov (United States)

    Snow, Richard A.; Long, James M.

    2017-01-01

    Oxytetracycline (OTC) has been used to mark a variety of fish species at multiple developmental stages; however, there is little information on batch-marking Lepisosteidae. Juvenile Shortnose Gar Lepisosteus platostomus (53 ± 3 mm TL) were seined from an Oklahoma State University research pond and transported to the Oklahoma Fishery Research Lab. Juvenile Shortnose Gar were exposed to a range of OTC concentrations—0, 500, 600, and 700 mg/L—for 4, 5, or 6 h. Lapillus and sagitta otoliths were examined 14 d postexposure for mark presence and evaluation using fluorescent microscopy. Overall, 93.3% of otoliths exposed to OTC exhibited a mark. Concentration of OTC affected the mean mark quality, whereas duration and otolith type examined did not. However, as concentration increased, so did mortality, suggesting a balance is needed to achieve marking goals. Based on our findings, batch marking of Shortnose Gar can be successful at OTC concentrations from 500 to 700 mg/L for 4–6 h, although mark quality may vary and mortality rates increase at the higher concentrations and longer durations.

  3. Probing the in vitro cytotoxicity of the veterinary drug oxytetracycline.

    Directory of Open Access Journals (Sweden)

    Zhenxing Chi

    Full Text Available The study investigated the effect of oxytetracycline (OTC on the anti-oxidative defense system, the structure (hemolysis rate and morphology and function (ATP enzyme activity of human red blood cells (hRBCs to investigate the possible toxic mechanism of OTC to hRBCs. The experimental results indicate that OTC can cause a decline in the function of the antioxidant defense system of hRBCs, resulting in oxidative stress. OTC can bring about morphological changes to hRBCs, and further leads to hemolysis, when the concentration of OTC is over 8×10(-5 M (about 164 µg/ml. At a low OTC concentration, below 4×10(-5 M (82 µg/ml, OTC can enhance the activity of ATP enzyme of hRBCs, known as hormesis. However, at a high concentration, above 4×10(-5 M (about 82 µg/ml, the ATP enzymatic activity was inhibited, affecting the function of hRBCs. The estalished mechanism of toxicity of OTC to hRBCs can facilitate a deeper understanding of the toxicity of OTC in vivo.

  4. Oxytetracycline analysis in honey using a specific portable analyzer

    Science.gov (United States)

    Chen, Guoying; Schwartz, Daniel; Braden, S.; Nunez, Alberto

    2007-09-01

    Oxytetracycline (OTC) residue in honey is detected using a portable analyzer designed to specifically target tetracycline (TC) drugs based on europium-sensitized luminescence (ESL). A 385 nm light emitting diode (LED) is used as the excitation source and a photomultiplier tube as the light detector. OTC is extracted from honey and cleaned up by solid phase extraction (SPE) using Strata X-WC weak cation exchange cartridges. To the eluate Eu(III) is added to form a Eu-TC chelate at pH 8.5. Efficient intrachelate energy transfer allows sensitive OTC detection at λ ex=385 nm and λ em=610 nm. After a 25-µs time delay, the ESL signal is integrated over a 25-1000 µs interval. The signal intensity reveals a linear relationship (R2=0.972) to OTC concentrations in the 10-200 ng/g range. The limit-of-detection is 6.7 ng/g with an average 5.8% relative standard deviation. The background signal corresponds to ~10 ppb. This instrumentation and method combination enables field analysis that is especially useful for beekeeping industry.

  5. Oxytetracycline and penicillin-G residues in cattle slaughtered in south-western Nigeria: implications for livestock disease management and public health.

    Science.gov (United States)

    Adesokan, Hezekiah K; Agada, Charity A; Adetunji, Victoria O; Akanbi, Ibikunle M

    2013-01-01

    After the discovery of indiscriminate antibiotic use in ready-for-slaughter cattle in south-western Nigeria, 90 tissue samples from randomly selected slaughtered cattle were evaluated for oxytetracycline and penicillin-G residues using high performance liquid chromatography and the data analysed by one-way Analysis of variance (ANOVA). The findings revealed residues of oxytetracycline (kidney: 9.47 µ/kg ± 3.24 µ/kg; liver: 12.73 µ/kg ± 4.39 µ/kg; muscle: 16.17 µ/kg ± 5.52 µ/kg) and penicillin-G (kidney: 6.27 µ/kg ± 2.46 µ/kg; liver: 8.5 µ/kg ± 2.80 µ/kg; muscle: 11.67 µ/kg ± 2.94 µ/kg) in all tissues screened. Significantly high levels (oxytetracycline: F = 16.77; penicillin-G: F = 29.38) were, however, found in muscles, followed by liver and then kidney – findings confirming recent antibiotic administration to the animals before slaughter. The dietary intakes through the tissues screened were 0.024% (oxytetracycline) and 0.017% (penicillin-G) of the acceptable daily intake (ADI). Although the concentrations in the tissues screened were below the maximum residue limits despite recent administration of these antibiotics before slaughter, the lower concentrations are suggestive of the probable low dosages often administered by those involved in indiscriminate use of antibiotics. This therefore raises serious concerns for the livestock industry as well as human health, given the resultant emergence and spread of resistant strains of bacterial pathogens that could ensue from prolonged use of low dosages of antibiotics. Additionally, the lower concentrations of the daily intakes notwithstanding, the plausible exposure to these antibiotics from other food sources is a cause for concern. Since antimicrobial misuse and its consequent effects are not just a problem limited to Nigeria but also a concern in sub-Saharan Africa, the need for national and international stakeholder intervention is emphasised.

  6. Oxytetracycline and penicillin-G residues in cattle slaughtered in south-western Nigeria: Implications for livestock disease management and public health

    Directory of Open Access Journals (Sweden)

    Hezekiah K. Adesokan

    2013-07-01

    Full Text Available After the discovery of indiscriminate antibiotic use in ready-for-slaughter cattle in south-western Nigeria, 90 tissue samples from randomly selected slaughtered cattle were evaluated for oxytetracycline and penicillin-G residues using high performance liquid chromatography and the data analysed by one-way Analysis of variance (ANOVA. The findings revealed residues of oxytetracycline (kidney: 9.47 µ/kg ± 3.24 µ/kg; liver: 12.73 µ/kg ± 4.39 µ/kg; muscle: 16.17 µ/kg ± 5.52 µ/kg and penicillin-G (kidney: 6.27 µ/kg ± 2.46 µ/kg; liver: 8.5 µ/kg ± 2.80 µ/kg; muscle: 11.67 µ/kg ± 2.94 µ/kg in all tissues screened. Significantly high levels (oxytetracycline: F = 16.77; penicillin-G: F = 29.38 were, however, found in muscles, followed by liver and then kidney – findings confirming recent antibiotic administration to the animals before slaughter. The dietary intakes through the tissues screened were 0.024% (oxytetracycline and 0.017% (penicillin-G of the acceptable daily intake (ADI. Although the concentrations in the tissues screened were below the maximum residue limits despite recent administration of these antibiotics before slaughter, the lower concentrations are suggestive of the probable low dosages often administered by those involved in indiscriminate use of antibiotics. This therefore raises serious concerns for the livestock industry as well as human health, given the resultant emergence and spread of resistant strains of bacterial pathogens that could ensue from prolonged use of low dosages of antibiotics. Additionally, the lower concentrations of the daily intakes notwithstanding, the plausible exposure to these antibiotics from other food sources is a cause for concern. Since antimicrobial misuse and its consequent effects are not just a problem limited to Nigeria but also a concern in sub-Saharan Africa, the need for national and international stakeholder intervention is emphasised.

  7. Kinetics and mechanism investigation on the destruction of oxytetracycline by UV-254 nm activation of persulfate

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yiqing [Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756 (China); Environmental Engineering and Science Program, University of Cincinnati, Cincinnati, OH 45221-0012 (United States); He, Xuexiang [Environmental Engineering and Science Program, University of Cincinnati, Cincinnati, OH 45221-0012 (United States); Fu, Yongsheng [Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756 (China); Dionysiou, Dionysios D., E-mail: dionysios.d.dionysiou@uc.edu [Environmental Engineering and Science Program, University of Cincinnati, Cincinnati, OH 45221-0012 (United States)

    2016-03-15

    Highlights: • The most effective destruction of OTC by UV/PS was achieved at near neutral pH. • Deprotonated HOTC{sup −} had the highest second-order rate constant with SO{sub 4}·{sup −}. • Presence of HCO{sub 3}{sup −} or Cu{sup 2+} enhanced the removal of OTC in UV/PS system. • Total organic carbon was degraded slowly during the mineralization of OTC. • Studies on the degradation mechanism revealed four different reaction pathways. - Abstract: Oxytetracycline (OTC), an important broad-spectrum antibiotic, has been detected extensively in various environmental systems, which may have a detrimental impact on ecosystem and human health through the development of drug resistant bacteria and pathogens. In this study, the degradation of OTC was evaluated by UV-254 nm activated persulfate (PS). The observed UV fluence based pseudo first-order rate constant (k{sub obs}) was found to be the highest at near neutral pH conditions (pH 5.5–8.5). Presence of various natural water constituents had different effects on OTC degradation, with a significant enhancement in the presence of bicarbonate or Cu{sup 2+}. Limited elimination of total organic carbon (TOC) and PS was observed during the mineralization of OTC. Transformation byproducts in the presence and absence of hydroxyl radical scavenging agent tert-butanol (t-BuOH) were identified using ultra-high definition accurate-mass quadrupole time-of-flight liquid chromatography/mass spectrometer (LC-QTOF/MS). Potential OTC degradation mechanism was subsequently proposed revealing four different reaction pathways by SO{sub 4}·{sup −} reaction including hydroxylation (+16 Da), demethylation (−14 Da), decarbonylation (−28 Da) and dehydration (−18 Da). This study suggests that UV-254 nm/PS is a promising treatment technology for the control of water pollution caused by emerging contaminants such as OTC.

  8. Kinetics and mechanism investigation on the destruction of oxytetracycline by UV-254 nm activation of persulfate

    International Nuclear Information System (INIS)

    Liu, Yiqing; He, Xuexiang; Fu, Yongsheng; Dionysiou, Dionysios D.

    2016-01-01

    Highlights: • The most effective destruction of OTC by UV/PS was achieved at near neutral pH. • Deprotonated HOTC"− had the highest second-order rate constant with SO_4·"−. • Presence of HCO_3"− or Cu"2"+ enhanced the removal of OTC in UV/PS system. • Total organic carbon was degraded slowly during the mineralization of OTC. • Studies on the degradation mechanism revealed four different reaction pathways. - Abstract: Oxytetracycline (OTC), an important broad-spectrum antibiotic, has been detected extensively in various environmental systems, which may have a detrimental impact on ecosystem and human health through the development of drug resistant bacteria and pathogens. In this study, the degradation of OTC was evaluated by UV-254 nm activated persulfate (PS). The observed UV fluence based pseudo first-order rate constant (k_o_b_s) was found to be the highest at near neutral pH conditions (pH 5.5–8.5). Presence of various natural water constituents had different effects on OTC degradation, with a significant enhancement in the presence of bicarbonate or Cu"2"+. Limited elimination of total organic carbon (TOC) and PS was observed during the mineralization of OTC. Transformation byproducts in the presence and absence of hydroxyl radical scavenging agent tert-butanol (t-BuOH) were identified using ultra-high definition accurate-mass quadrupole time-of-flight liquid chromatography/mass spectrometer (LC-QTOF/MS). Potential OTC degradation mechanism was subsequently proposed revealing four different reaction pathways by SO_4·"− reaction including hydroxylation (+16 Da), demethylation (−14 Da), decarbonylation (−28 Da) and dehydration (−18 Da). This study suggests that UV-254 nm/PS is a promising treatment technology for the control of water pollution caused by emerging contaminants such as OTC.

  9. Determinants of Intravascular Resistance in Indian Diabetic Nephropathy Patients: A Hospital-Based Study

    Directory of Open Access Journals (Sweden)

    Anubhav Thukral

    2011-01-01

    Full Text Available Aims and Objectives. Metabolic dysregulation has failed to explain clinical variability of patients with diabetic nephropathy and hence a renewed interest emerged in haemodynamic factors as determinant of progression and development of diabetic nephropathy. We therefore studied for various factors which can correlate with raised renal vascular resistance in diabetic nephropathy. Material and Methods. Renal vascular resistance was measured in patients with established and incipient diabetic nephropathy and compared with controls using noninvasive color Doppler examinations of intrarenal vasculature. Results. Renal vascular resistance correlated with age, duration of disease, GFR, serum creatinine, and stage of retinopathy. Renal vascular resistance was significantly reduced in patients on treatment with RAAS inhibitors and insulin, than those on OHA and antihypertensives other than RAAS inhibitors. Conclusion. The study implies that renal vascular resistance may help identify diabetics at high risk of developing nephropathy, and these set of patients could be candidates for RAAS inhibition and early insulin therapy even in patients without albuminuria.

  10. What is the true in vitro potency of oxytetracycline for the pig pneumonia pathogens Actinobacillus pleuropneumoniae and Pasteurella multocida?

    Science.gov (United States)

    Dorey, L; Hobson, S; Lees, P

    2017-10-01

    The pharmacodynamics of oxytetracycline was determined for pig respiratory tract pathogens, Actinobacillus pleuropneumoniae and Pasteurella multocida. Indices of potency were determined for the following: (i) two matrices, broth and pig serum; (ii) five overlapping sets of twofold dilutions; and (iii) a high strength starting culture. For A. pleuropneumoniae, minimum inhibitory concentration (MIC) was similar for the two matrices, but for P. multocida, differences were marked and significantly different. MIC and minimum bactericidal concentration (MBC) serum: broth ratios for A. pleuropneumoniae were 0.83:1 and 1.22:1, respectively, and corresponding values for P. multocida were 22.0:1 and 7.34:1. For mutant prevention concentration (MPC) serum: broth ratios were 0.79:1 (A. pleuropneumoniae) and 20.9:1 (P. multocida). These ratios were corrected for serum protein binding to yield fraction unbound (fu) serum: broth MIC ratios of 0.24:1 (A. pleuropneumoniae) and 6.30:1 (P. multocida). Corresponding fu serum: broth ratios for MPC were almost identical, 0.23:1 and 6.08:1. These corrections for protein binding did not account for potency differences between serum and broth for either species; based on fu serum MICs, potency in serum was approximately fourfold greater than predicted for A. pleuropneumoniae and sixfold smaller than predicted for P. multocida. For both broth and serum and both bacterial species, MICs were also dependent on initial inoculum strength. The killing action of oxytetracycline had the characteristics of codependency for both A. pleuropneumoniae and P. multocida in both growth media. The in vitro potency of oxytetracycline in pig serum is likely to be closer to the in vivo plasma/serum concentration required for efficacy than potency estimated in broths. © 2017 The Authors. Journal of Veterinary Pharmacology and Therapeutics Published by John Wiley & Sons Ltd.

  11. Using Resistivity Measurements to Determine Anisotropy in Soil and Weathered Rock

    Directory of Open Access Journals (Sweden)

    S. Soto-Caban

    2013-08-01

    Full Text Available This study uses electrical resistivity measurements of soils and weathered rock to perform a fast and reliable evaluation of field anisotropy. Two test sites at New Concord, Ohio were used for the study. These sites are characterized by different landform and slightly east dipping limestone and siltstone formations of Pennsylvanian age. The measured resistivity ranged from 19 Ω∙m to 100 ��∙m, and varied with depth, landform, and season. The anisotropy was determined by a comparison of resistance values along the directions of strike and the dip. Measurements showed that the orientation of electrical anisotropy in the shallow ground may vary due to fluid connection, which is determined by the pore geometry in soil and rock, as well as by the direction of fluid movement. Results from this study indicated that a portable electrical resistivity meter is sensitive and reliable enough to be used for shallow ground fluid monitoring.

  12. Antibiotic resistance determinants in a Pseudomonas putida strain isolated from a hospital.

    Directory of Open Access Journals (Sweden)

    Lázaro Molina

    Full Text Available Environmental microbes harbor an enormous pool of antibiotic and biocide resistance genes that can impact the resistance profiles of animal and human pathogens via horizontal gene transfer. Pseudomonas putida strains are ubiquitous in soil and water but have been seldom isolated from humans. We have established a collection of P. putida strains isolated from in-patients in different hospitals in France. One of the isolated strains (HB3267 kills insects and is resistant to the majority of the antibiotics used in laboratories and hospitals, including aminoglycosides, ß-lactams, cationic peptides, chromoprotein enediyne antibiotics, dihydrofolate reductase inhibitors, fluoroquinolones and quinolones, glycopeptide antibiotics, macrolides, polyketides and sulfonamides. Similar to other P. putida clinical isolates the strain was sensitive to amikacin. To shed light on the broad pattern of antibiotic resistance, which is rarely found in clinical isolates of this species, the genome of this strain was sequenced and analysed. The study revealed that the determinants of multiple resistance are both chromosomally-borne as well as located on the pPC9 plasmid. Further analysis indicated that pPC9 has recruited antibiotic and biocide resistance genes from environmental microorganisms as well as from opportunistic and true human pathogens. The pPC9 plasmid is not self-transmissible, but can be mobilized by other bacterial plasmids making it capable of spreading antibiotic resistant determinants to new hosts.

  13. Tests for determining impact resistance and strength of glass used for nuclear waste disposal

    International Nuclear Information System (INIS)

    Bunnell, L.R.

    1979-05-01

    Tests are described for determining the impact resistance (Section A) and static tensile strength (Section B) of glasses containing simulated or actual nuclear wastes. This report describes the development and use of these tests to rank different glasses, to assess effects of devitrification, and to examine the effect of impact energy on resulting surface area. For clarity this report is divided into two sections, Impact Resistance and Tensile Strength

  14. Genetically determined differences in the resistance to myocardial infarction in Wistar and August rats.

    Science.gov (United States)

    Belkina, L M; Saltykova, V A; Pshennikova, M G

    2001-06-01

    In intact August rats, the cardiac contractile function at rest was by 76% higher than in Wistar rats, while their hearts, both intact and after acute myocardial infarction, were more resistant to isometric load than the hearts of Wistar rats. Postinfarction mortality in August rats was 18% vs. 70% in Wistar rats. Adrenoreactivity of the myocardium in August rats was decreased compared to that in Wistar rats. These peculiarities can determine high resistance of August rats to myocardial infarction.

  15. Translocation of integron-associated resistance in a natural system: Acquisition of resistance determinants by Inc P and Inc W Plasmids from Salmonella enterica Typhimurium DT104

    DEFF Research Database (Denmark)

    Sandvang, Dorthe; Diggle, M.; Platt, D.J.

    2002-01-01

    to determinate the genetic content. Translocation to R751 and R388 was associated with the loss of the indigenous trimethoprim cassette to both plasmids and also acquisition of sulfonamide resistance by R751 and RP4::Tn7, which indicated movement of the 3' terminus of one or both of the DT104 integrons......Salmonella enterica Typhimurium DT104, 961368, a veterinary field isolate that encodes a chromosomal cluster of resistance genes as well as two integrons, was used to study the mobility of resistance cassettes (aadA2 and pse-1) and nonintegron-associated resistance determinants (chloramphenicol...... and tetracycline). A range of natural plasmids was used as targets for the translocation of resistance. Plasmids that acquired resistance from the DT104 chromosome were segregated by conjugation into Escherichia coli K12. Plasmids R751, R388, and RP4::Tn7 acquired several combinations of resistance determinant...

  16. Determining resistance to mastitis in a bovine subject comprises detecting the presence or absence of a genetic marker that is linked to a trait indicative of mastitis resistance

    DEFF Research Database (Denmark)

    2007-01-01

    The invention relates to a method for determining mastitis resistance in bovine subjects, wherein mastitis resistance comprise resistance to both sub-clinical and clinical mastitis. In particular, the method of the invention involves identification of genetic markers and/or Quantitative Trait Locus...... (QTL) for the determination of mastitis resistance in a bovine subject. The determination of mastitis resistance involves resolution of the specific microsatellite status. Furthermore, the invention relates to a diagnostic kit for detection of genetic marker(s) associated with mastitis resistance....... The method and kit of the present invention can be applied for selection of bovine subjects for breeding purposes. Thus, the invention provides a method of genetically selecting bovine subjects with mastitis resistance, thereby yielding cows less prone to mastitis...

  17. Effect of tetracycline dose and treatment-mode on selection of resistant coliform bacteria in nursery pigs

    DEFF Research Database (Denmark)

    Græsbøll, Kaare; Damborg, Peter; Mellerup, Anders

    2017-01-01

    This study describes results of a randomized clinical trial investigating the effect of oxytetracycline treatment dose and mode of administration on selection of antibiotic resistant coliform bacteria in fecal samples from nursery pigs. Nursery pigs (pigs of 4-7 weeks of age) were treated...... with oxytetracycline against Lawsonia intracellularis induced diarrhea in five pig herds. Each group was randomly allocated to one of five treatment groups: oral flock treatment with (i) high (20 mg/kg), (ii) medium (10 mg/kg) and (iii) low (5 mg/kg) dosage, (iv) oral-pen-wise (small group) treatment (10 mg...... significant changes in number or proportion of tetracycline resistant coliforms. Selection for tetracycline-resistant coliforms was significantly correlated to selection for ampicillin- and sulfonamide-resistant, but not to cefotaxime-resistant strains. In conclusion, difference in dose of oxytetracycline...

  18. Determination of Screw and Nail Withdrawal Resistance of Some Important Wood Species

    Directory of Open Access Journals (Sweden)

    Alper Aytekin

    2008-04-01

    Full Text Available In this study, screw and nail withdrawal resistance of fir (Abies nordmanniana, oak (Quercus robur L. black pine (Pinus nigra Arnold and Stone pine (Pinus pinea L. wood were determined and compared. The data represent the testing of withdrawal resistance of three types of screws as smart, serrated and conventional and common nails. The specimens were prepared according to TS 6094 standards. The dimensions of the specimens were 5x5x15cm and for all of the directions. Moreover, the specimens were conditioned at ambient room temperature and 65±2% relative humidity. The screws and nails were installed according to ASTM-D 1761 standards. Nail dimensions were 2.5mm diameter and 50 mm length, conventional screws were 4x50mm, serrated screws were 4x45mm and smart screws were 4x50mm. Results show that the maximum screw withdrawal resistance value was found in Stone pine for the serrated screw. There were no significant differences between Stone pine and oak regarding screw withdrawal resistance values. Conventional screw yielded the maximum screw withdrawal resistance value in oak, followed by Stone pine, black pine and fir. Oak wood showed the maximum screw withdrawal resistance value for the smart screw, followed by Stone pine, black pine, and fir. Oak wood showed higher nail withdrawal resistances than softwood species. It was also determined that oak shows the maximum nail withdrawal resistance in all types. The nail withdrawal resistances at the longitudinal direction are lower with respect to radial and tangential directions.

  19. Standardization of a broth microdilution susceptibility testing method to determine minimum inhibitory concentrations of aquatic bacteria

    DEFF Research Database (Denmark)

    Miller, R.A.; Walker, R.D.; Carson, J.

    2005-01-01

    (ampicillin, enrofloxacin, erythromycin, florfenicol, flumequine, gentamicin, ormetoprim/sulfadimethoxine, oxolinic acid, oxytetracycline and trimethoprim/sulfamethoxazole). Minimum inhibitory concentration (MIC) QC ranges were determined using dry- and frozen-form 96-well plates and cation-adjusted Mueller...

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

    Directory of Open Access Journals (Sweden)

    Magalhães V.D.

    1997-01-01

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

  1. Radiological examination of the spinal column in farmed rainbow trout Oncorhynchus mykiss (Walbaum): experiments with Flavobacterium psychrophilum and oxytetracycline

    DEFF Research Database (Denmark)

    Madsen, Lone; Arnbjerg, J.; Dalsgaard, Inger

    2001-01-01

    Flavobacterium psychrophilum and oxytetracycline have both been associated with spinal deformities in salmonids. Experiments were carried out to investigate whether infection with F, psychrophilum or medication with oxytetracycline (OTC) at the fry stage would result in an increased occurrence...... of infected fish. OTC treatments of up to 200 mg of OTC(kgfish)(-1) day(-1) for 10 days and repeated three times did not result in increased spinal deformities relative to untreated control groups; therefore, medication of rainbow trout with oxytetracycline did not cause deformities of the spinal column under...

  2. Comparison of Several Methods for Determining the Internal Resistance of Lithium Ion Cells

    Directory of Open Access Journals (Sweden)

    Hans-Georg Schweiger

    2010-06-01

    Full Text Available The internal resistance is the key parameter for determining power, energy efficiency and lost heat of a lithium ion cell. Precise knowledge of this value is vital for designing battery systems for automotive applications. Internal resistance of a cell was determined by current step methods, AC (alternating current methods, electrochemical impedance spectroscopy and thermal loss methods. The outcomes of these measurements have been compared with each other. If charge or discharge of the cell is limited, current step methods provide the same results as energy loss methods.

  3. Nickel-resistance determinants in Acidiphilium sp. PM identified by genome-wide functional screening.

    Directory of Open Access Journals (Sweden)

    Patxi San Martin-Uriz

    Full Text Available Acidiphilium spp. are conspicuous dwellers of acidic, metal-rich environments. Indeed, they are among the most metal-resistant organisms; yet little is known about the mechanisms behind the metal tolerance in this genus. Acidiphilium sp. PM is an environmental isolate from Rio Tinto, an acidic, metal-laden river located in southwestern Spain. The characterization of its metal resistance revealed a remarkable ability to tolerate high Ni concentrations. Here we report the screening of a genomic library of Acidiphilium sp. PM to identify genes involved in Ni resistance. This approach revealed seven different genes conferring Ni resistance to E. coli, two of which form an operon encoding the ATP-dependent protease HslVU (ClpQY. This protease was found to enhance resistance to both Ni and Co in E. coli, a function not previously reported. Other Ni-resistance determinants include genes involved in lipopolysaccharide biosynthesis and the synthesis of branched amino acids. The diversity of molecular functions of the genes recovered in the screening suggests that Ni resistance in Acidiphilium sp. PM probably relies on different molecular mechanisms.

  4. Reduced antimicrobial potencies of Oxytetracycline, tylosin, sulfadiazine, streptomycin, ciprofloxacin and olaquindox due to environmental processes

    DEFF Research Database (Denmark)

    Halling-Sørensen, Bent; Sengeløv, G.; Ingerslev, Flemming

    2003-01-01

    The stability of oxytetracycline (OTC), tylosin (TYL), sulfadiazin (SDZ), streptomycin (ST), ciprofloxacin (CF) and olaquindox (O) was examined in environmentally relevant matrices, such as soil interstitial water and sewage sludge water. Compounds were assessed in both aerobic (OTC, TYL, SDZ, ST...

  5. Withdrawal times of oxytetracycline and tylosin in eggs of laying hens after oral administration.

    Science.gov (United States)

    Muñoz, Rubén; Cornejo, Javiera; Maddaleno, Aldo; Araya-Jordán, Carolina; Iragüen, Daniela; Pizarro, Nicolás; San Martín, Betty

    2014-06-01

    Antimicrobials administered to laying hens may be distributed into egg white or yolk, indicating the importance of evaluating withdrawal times (WDTs) of the pharmaceutical formulations. In the present study, oxytetracycline and tylosin's WDTs were estimated. The concentration and depletion of these molecules in eggs were linked to their pharmacokinetic and physicochemical properties. Twenty-seven Leghorn hens were used: 12 treated with oxytetracycline, 12 treated with tylosin, and 3 remained as an untreated control group. After completion of therapies, eggs were collected daily and drug concentrations in egg white and yolk were assessed. The yolk was used as the target tissue to evaluate the WDT; the results were 9 and 3 days for oxytetracycline and tylosin, respectively. In particular, oxytetracycline has a good oral bioavailability, a moderate apparent volume of distribution, a molecular weight of 460 g/mol, and is lightly liposoluble. Tylosin, a hydrosoluble compound, with a molecular weight of 916 g/mol, has a low oral bioavailability and a low apparent volume of distribution, too. Present results suggest that the WDTs of the studied antimicrobials are strongly influenced by their oral bioavailability, the distribution, and the molecular weight and solubility, and that these properties also influence the distribution between the egg yolk and white.

  6. Simple colorimetric detection of doxycycline and oxytetracycline using unmodified gold nanoparticles

    Science.gov (United States)

    Li, Jie; Fan, Shumin; Li, Zhigang; Xie, Yuanzhe; Wang, Rui; Ge, Baoyu; Wu, Jing; Wang, Ruiyong

    2014-08-01

    The interaction between tetracycline antibiotics and gold nanoparticles was studied. With citrate-coated gold nanoparticles as colorimetric probe, a simple and rapid detection method for doxycycline and oxytetracycline has been developed. This method relies on the distance-dependent optical properties of gold nanoparticles. In weakly acidic buffer medium, doxycycline and oxytetracycline could rapidly induce the aggregation of gold nanoparticles, resulting in red-to-blue (or purple) colour change. The experimental parameters were optimized with regard to pH, the concentration of the gold nanoparticles and the reaction time. Under optimal experimental conditions, the linear range of the colorimetric sensor for doxycycline/oxytetracycline was 0.06-0.66 and 0.59-8.85 μg mL-1, respectively. The corresponding limit of detection for doxycycline and oxytetracycline was 0.0086 and 0.0838 μg mL-1, respectively. This assay was sensitive, selective, simple and readily used to detect tetracycline antibiotics in food products.

  7. Pharmacokinetics of oxytetracycline in broiler chickens following different routes of administration.

    Science.gov (United States)

    Ziółkowski, Hubert; Grabowski, Tomasz; Jasiecka, Agnieszka; Zuśka-Prot, Monika; Barski, Dariusz; Jaroszewski, Jerzy J

    2016-02-01

    The aim of this study was to determine the pharmacokinetics of oxytetracycline (OTC) in broiler chickens following intravenous (IV), intramuscular (IM), subcutaneous (SC) and oral (PO) administrations at a dose of 15 mg/kg bodyweight. Plasma concentrations of OTC were determined using liquid chromatography-tandem mass spectrometry and non-compartmental pharmacokinetic analysis was then conducted. The absorption half-life time was 1.23 ± 0.36 h, 1.19 ± 0.52 h, and 0.49 ± 0.38 h after IM, SC and PO administration, respectively. The elimination half-life time was 27.41 ± 6.06 h, 10.23 ± 4.20 h, 7.83 ± 0.56 h, and 14.86 ± 9.23 h, and the mean residence time was 9.67 ± 1.7 h, 11.45 ± 1.76 h, 11.38 ± 0.59 h, and 10.37 ± 3.91 h after IV, IM, SC and PO administration, respectively. Bioavailability was 76.88 ± 12.90%, 92.20 ± 10.53% and 12.13 ± 4.56% after IM, SC and PO administration, respectively, which indicated that OTC is poorly absorbed from the gastrointestinal tract in broiler chickens. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Prevalence of Genotypes That Determine Resistance of Staphylococci to Macrolides and Lincosamides in Serbia

    Directory of Open Access Journals (Sweden)

    Milena Mišić

    2017-08-01

    Full Text Available Macrolides, lincosamides, and streptogramins (MLS resistance genes are responsible for resistance to these antibiotics in Staphylococcus infections. The purpose of the study was to analyze the distribution of the MLS resistance genes in community- and hospital-acquired Staphylococcus isolates. The MLS resistance phenotypes [constitutive resistance to macrolide–lincosamide–streptogramin B (cMLSb, inducible resistance to macrolide–lincosamide–streptogramin B (iMLSb, resistance to macrolide/macrolide–streptogramin B (M/MSb, and resistance to lincosamide–streptogramin A/streptogramin B (LSa/b] were determined by double-disc diffusion method. The presence of the MLS resistance genes (ermA, ermB, ermC, msrA/B, lnuA, lnuB, and lsaA were determined by end-point polymerase chain reaction in 179 isolates of staphylococci collected during 1-year period at the Center for Microbiology of Public Health Institute in Vranje. The most frequent MLS phenotype among staphylococcal isolates, both community-acquired and hospital-acquired, was iMLSb (33.4%. The second most frequent was M/MSb (17.6% with statistically significantly higher number of hospital-acquired staphylococcal isolates (p < 0.05. MLS resistance was mostly determined by the presence of msrA/B (35.0% and ermC (20.8% genes. Examined phenotypes were mostly determined by the presence of one gene, especially by msrA/B (26.3% and ermC (14.5%, but 15.6% was determined by a combination of two or more genes. M/MSb phenotype was the most frequently encoded by msrA/B (95.6% gene, LSa/b phenotype by lnuA (56.3% gene, and iMLSb phenotype by ermC (29.4% and ermA (25.5% genes. Although cMLSb phenotype was mostly determined by the presence of ermC (28.9%, combinations of two or more genes have been present too. This pattern was particularly recorded in methicillin-resistant Staphylococcus aureus (MRSA (58.3% and methicillin-resistant coagulase-negative staphylococci (MRCNS (90.9% isolates with c

  9. Standard test method for determination of resistance to stable crack extension under low-constraint conditions

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 This standard covers the determination of the resistance to stable crack extension in metallic materials in terms of the critical crack-tip-opening angle (CTOAc), ψc and/or the crack-opening displacement (COD), δ5 resistance curve (1). This method applies specifically to fatigue pre-cracked specimens that exhibit low constraint (crack-length-to-thickness and un-cracked ligament-to-thickness ratios greater than or equal to 4) and that are tested under slowly increasing remote applied displacement. The recommended specimens are the compact-tension, C(T), and middle-crack-tension, M(T), specimens. The fracture resistance determined in accordance with this standard is measured as ψc (critical CTOA value) and/or δ5 (critical COD resistance curve) as a function of crack extension. Both fracture resistance parameters are characterized using either a single-specimen or multiple-specimen procedures. These fracture quantities are determined under the opening mode (Mode I) of loading. Influences of environment a...

  10. Socioeconomic Determinants of Ciprofloxacin-Resistant Shigella Infections in Bangladeshi Children

    Directory of Open Access Journals (Sweden)

    Randon J. Gruninger

    2017-03-01

    Full Text Available Background: Shigella species (spp. are a leading cause of moderate to severe diarrhea in children worldwide. The recent emergence of quinolone-resistant Shigella spp. gives cause for concern, and South Asia has been identified as a reservoir for global spread. The influence of socioeconomic status on antimicrobial resistance in developing countries, such as those in South Asia, remains unknown. Methods: We used data collected from 2009 to 2014 from a hospital specializing in the treatment of diarrhea in Dhaka, Bangladesh, to determine the relationship between ciprofloxacin-resistant Shigella spp. isolates and measures of socioeconomic status in Bangladeshi children less than 5 years of age. Results: We found 2.7% (230/8, 672 of children who presented with diarrhea had Shigella spp. isolated from their stool, and 50% (115/230 had resistance to ciprofloxacin. Using multivariable logistic regression analysis, we found that children from families where the father’s income was in the highest quintile had significantly higher odds of having ciprofloxacin-resistant Shigella spp. compared to children in the lowest quintile (OR = 6.1, CI 1.9-19. Factors protective against the development of resistance included access to improved sanitation (OR = 0.27, CI 0.11-0.7, and improved water sources (OR = 0.48, CI 0.25-0.92. We did not find a relationship between ciprofloxacin resistance and other proxies for socioeconomic status, including the presence of animals in the home, nutritional status, paternal education level, and the number of family members in the home. Conclusions: Although the associations between wealth and antimicrobial resistance are not fully understood, possible explanations include increased access and use of antibiotics, greater access to healthcare facilities and thus resistant pathogens, or greater consumption of commercially produced foods prepared with antibiotics.

  11. Determination Pattern of Antibiotic Resistance in Entropathogenic Escherichia coli Strains Isolated from Children with Diarrhea

    Directory of Open Access Journals (Sweden)

    P. Karami

    2012-04-01

    Full Text Available Introduction & Objective: Diarrheal diseases are considered a major health problem, especially in children. Enteropathogenic Escherichia coli (EPEC strains are the common cause of diarrhea in children especially in developing countries. Because of undesirable effects of diarrhea and its interference with children's growth, in some cases antibiotic treatment is recommended. In recent years, resistance toward common and effective antibiotics in the treatment of infectious diseases became one of the most important challenges in medical society, for this purpose, antibiotic sensitivity and resistance of strains in every geographical zone must be determined. So in this study, of antibiotic patterns of these bacteria were examined.Materials & Methods: This cross-sectional study was performed on 192 strains of Enteropathogen Escherichia coli isolated from children who were suffering from diarrhea in 1389-1390 in the microbiology laboratory of Hamadan University of medical sciences. To identify these strains, standard biochemical and serology tests were used. The antibiotic sensitivity test of these isolates was carried out with disc diffusion agar method according to the CLSI standards for 14 different antibiotics disc. Resistance toward 3 or more than 3 classes of antibiotics were defined as multidrug resistance.Results: The result of this study shows EPEC strains had the highest resistance to cefpodoxime (97%, trimethoprim (60.7%, tetracycline (58.4% and ampicillin (45.8%. Multidrug resistance was 68.7 percent. These strains also showed the highest sensitivity against imipenem, ceftriaxone, and ciprofloxacin antibiotics.Conclusion: EPEC strains that were studied with resistance to ampicillin, tetracycline and convenient sensitivity against fluoroquinolones are one of the major factors in children’s diarrhea. A result of this research suggests that antimicrobial resistance in Escherichia coli strains are high and prescribing and antibiotic is not

  12. Antimicrobial resistance patterns in Danish isolates of Flavobacterium psychrophilum

    DEFF Research Database (Denmark)

    Bruun, Morten Sichlau; Schmidt, A.S.; Madsen, Lone

    2000-01-01

    were tested and the resulting antibiograms were used to predict the theoretical therapeutic efficacy and to evaluate if resistance had changed as a course of time. Antimicrobial agents included in this investigation were oxolinic acid (OXA), amoxicillin (AMX), potentiated sulfadiazine, oxytetracycline...

  13. Determination of Soil Moisture Content using Laboratory Experimental and Field Electrical Resistivity Values

    Science.gov (United States)

    Hazreek, Z. A. M.; Rosli, S.; Fauziah, A.; Wijeyesekera, D. C.; Ashraf, M. I. M.; Faizal, T. B. M.; Kamarudin, A. F.; Rais, Y.; Dan, M. F. Md; Azhar, A. T. S.; Hafiz, Z. M.

    2018-04-01

    The efficiency of civil engineering structure require comprehensive geotechnical data obtained from site investigation. In the past, conventional site investigation was heavily related to drilling techniques thus suffer from several limitations such as time consuming, expensive and limited data collection. Consequently, this study presents determination of soil moisture content using laboratory experimental and field electrical resistivity values (ERV). Field and laboratory electrical resistivity (ER) test were performed using ABEM SAS4000 and Nilsson400 soil resistance meter. Soil sample used for resistivity test was tested for characterization test specifically on particle size distribution and moisture content test according to BS1377 (1990). Field ER data was processed using RES2DINV software while laboratory ER data was analyzed using SPSS and Excel software. Correlation of ERV and moisture content shows some medium relationship due to its r = 0.506. Moreover, coefficient of determination, R2 analyzed has demonstrate that the statistical correlation obtain was very good due to its R2 value of 0.9382. In order to determine soil moisture content based on statistical correlation (w = 110.68ρ-0.347), correction factor, C was established through laboratory and field ERV given as 19.27. Finally, this study has shown that soil basic geotechnical properties with particular reference to water content was applicably determined using integration of laboratory and field ERV data analysis thus able to compliment conventional approach due to its economic, fast and wider data coverage.

  14. Determination of resistance to salt crystallization on natural stone measured with ultrasonic wave

    DEFF Research Database (Denmark)

    Alm, D.; Brix, S.; Kjærgaard, H. Howe

    2008-01-01

    and after salt exposure. Four different stones are investigated: the limestone Bateig Azul, the sandstone Oberkirchener, the limestone Perlatino, and the limestone Travertine. The procedure for the salt crystallization test is EN 12370 standard “Natural stone test methods – Determination of resistance...

  15. Impact of integrated fish farming on antimicrobial resistance in a pond environment

    DEFF Research Database (Denmark)

    Petersen, Andreas; Andersen, Jens Strodl; Kaewmak, T.

    2002-01-01

    different antimicrobials was found for the indicator organism Acinetobacter spp. isolated from composite water-sediment samples. The initial resistance levels prior to the new production cycle were 1. to 5%. After 2 months the levels of resistance to oxytetracycline and sulfamethoxazole reached 100...

  16. Molecular and Cellular Effects Induced in Mytilus galloprovincialis Treated with Oxytetracycline at Different Temperatures.

    Directory of Open Access Journals (Sweden)

    Mohamed Banni

    Full Text Available The present study evaluated the interactive effects of temperature (16°C and 24°C and a 4-day treatment with the antibiotic oxytetracycline (OTC at 1 and 100 μg/L on cellular and molecular parameters in the mussel Mytilus galloprovincialis. Lysosomal membrane stability (LMS, a sensitive biomarker of impaired health status in this organism, was assessed in the digestive glands. In addition, oxidative stress markers and the expression of mRNAs encoding proteins involved in antioxidant defense (catalase (cat and glutathione-S-transferase (gst and the heat shock response (hsp90, hsp70, and hsp27 were evaluated in the gills, the target tissue of soluble chemicals. Finally, cAMP levels, which represent an important cell signaling pathway related to oxidative stress and the response to temperature challenges, were also determined in the gills. Exposure to heat stress as well as to OTC rendered a decrease in LMS and an increase in malonedialdehyde accumulation (MDA. CAT activity was not significantly modified, whereas GST activity decreased at 24°C. Cat and gst expression levels were reduced in animals kept at 24°C compared to 16°C in the presence or absence of OTC. At 16°C, treatment with OTC caused a significant increase in cat and gst transcript levels. Hsp27 mRNA was significantly up-regulated at all conditions compared to controls at 16°C. cAMP levels were increased at 24°C independent of the presence of OTC. PCA analysis showed that 37.21% and 25.89% of the total variance was explained by temperature and OTC treatment, respectively. Interestingly, a clear interaction was observed in animals exposed to both stressors increasing LMS and MDA accumulation and reducing hsp27 gene expression regulation. These interactions may suggest a risk for the organisms due to temperature increases in contaminated seawaters.

  17. Molecular and Cellular Effects Induced in Mytilus galloprovincialis Treated with Oxytetracycline at Different Temperatures

    Science.gov (United States)

    Banni, Mohamed; Sforzini, Susanna; Franzellitti, Silvia; Oliveri, Caterina; Viarengo, Aldo; Fabbri, Elena

    2015-01-01

    The present study evaluatedthe interactive effects of temperature (16°C and 24°C) and a 4-day treatment with the antibiotic oxytetracycline (OTC) at 1 and 100μg/L on cellular and molecular parameters in the mussel Mytilus galloprovincialis. Lysosomal membrane stability (LMS), a sensitive biomarker of impaired health status in this organism, was assessed in the digestive glands. In addition, oxidative stress markers and the expression of mRNAs encoding proteins involved in antioxidant defense (catalase (cat) and glutathione-S-transferase (gst)) and the heat shock response (hsp90, hsp70, and hsp27) were evaluated in the gills, the target tissue of soluble chemicals. Finally, cAMP levels, which represent an important cell signaling pathway related to oxidative stress and the response to temperature challenges, were also determined in the gills. Exposure to heat stress as well as to OTC rendered a decrease in LMS and an increase in malonedialdehyde accumulation (MDA). CAT activity was not significantly modified, whereas GST activity decreased at 24°C. Cat and gst expression levels were reduced in animals kept at 24°C compared to 16°C in the presence or absence of OTC. At 16°C, treatment with OTC caused a significant increase in cat and gst transcript levels. Hsp27 mRNA was significantly up-regulated at all conditions compared to controls at 16°C. cAMP levels were increased at 24°C independent of the presence of OTC. PCA analysis showed that 37.21% and 25.89% of the total variance was explained by temperature and OTC treatment, respectively. Interestingly, a clear interaction was observed in animals exposed to both stressors increasing LMS and MDA accumulation and reducing hsp27 gene expression regulation. These interactions may suggest a risk for the organisms due to temperature increases in contaminated seawaters. PMID:26067465

  18. Antibiotic Resistance Determinant-Focused Acinetobacter baumannii Vaccine Designed Using Reverse Vaccinology.

    Science.gov (United States)

    Ni, Zhaohui; Chen, Yan; Ong, Edison; He, Yongqun

    2017-02-21

    As one of the most influential and troublesome human pathogens, Acinetobacter baumannii ( A. baumannii ) has emerged with many multidrug-resistant strains. After collecting 33 complete A. baumannii genomes and 84 representative antibiotic resistance determinants, we used the Vaxign reverse vaccinology approach to predict classical type vaccine candidates against A. baumannii infections and new type vaccine candidates against antibiotic resistance. Our genome analysis identified 35 outer membrane or extracellular adhesins that are conserved among all 33 genomes, have no human protein homology, and have less than 2 transmembrane helices. These 35 antigens include 11 TonB dependent receptors, 8 porins, 7 efflux pump proteins, and 2 fimbrial proteins (FilF and CAM87009.1). CAM86003.1 was predicted to be an adhesin outer membrane protein absent from 3 antibiotic-sensitive strains and conserved in 21 antibiotic-resistant strains. Feasible anti-resistance vaccine candidates also include one extracellular protein (QnrA), 3 RND type outer membrane efflux pump proteins, and 3 CTX-M type β-lactamases. Among 39 β-lactamases, A. baumannii CTX-M-2, -5, and -43 enzymes are predicted as adhesins and better vaccine candidates than other β-lactamases to induce preventive immunity and enhance antibiotic treatments. This report represents the first reverse vaccinology study to systematically predict vaccine antigen candidates against antibiotic resistance for a microbial pathogen.

  19. Significance of Coexisting Mutations on Determination of the Degree of Isoniazid Resistance in Mycobacterium tuberculosis Strains.

    Science.gov (United States)

    Karunaratne, Galbokka Hewage Roshanthi Eranga; Wijesundera, Sandhya Sulochana; Vidanagama, Dhammika; Adikaram, Chamila Priyangani; Perera, Jennifer

    2018-04-23

    The emergence and spread of drug-resistant tuberculosis (TB) pose a threat to TB control in Sri Lanka. Isoniazid (INH) is a key element of the first-line anti-TB treatment regimen. Resistance to INH is mainly associated with point mutations in katG, inhA, and ahpC genes. The objective of this study was to determine mutations of these three genes in INH-resistant Mycobacterium tuberculosis (MTb) strains in Sri Lanka. Complete nucleotide sequence of the three genes was amplified by polymerase chain reaction and subjected to DNA sequencing. Point mutations in the katG gene were identified in 93% isolates, of which the majority (78.6%) were at codon 315. Mutations at codons 212 and 293 of the katG gene have not been reported previously. Novel mutations were recognized in the promoter region of the inhA gene (C deletion at -34), fabG1 gene (codon 27), and ahpC gene (codon 39). Single S315T mutation in the katG gene led to a high level of resistance, while a low level of resistance with high frequency (41%) was observed when katG codon 315 coexisted with the mutation at codon 463. Since most of the observed mutations of all three genes coexisted with the katG315 mutation, screening of katG315 mutations will be a useful marker for molecular detection of INH resistance of MTb in Sri Lanka.

  20. Acinetobacter baumannii Isolated from Lebanese Patients: Phenotypes and Genotypes of Resistance, Clonality, and Determinants of Pathogenicity.

    Science.gov (United States)

    Dahdouh, Elias; Hajjar, Micheline; Suarez, Monica; Daoud, Ziad

    2016-01-01

    Introduction: Acinetobacter baumannii is a nosocomial pathogen that usually affects critically ill patients. High mortality rates have been associated with MDR A. baumannii infections. Carbapenem resistance among these isolates is increasing worldwide and is associated with certain International Clones (ICs) and oxacillinases (OXAs). Moreover, this organism possesses a wide range of virulence factors, whose expression is not yet fully understood. In this study, clinical A. baumannii isolates are characterized in terms of antibiotic resistance, mechanisms of carbapenem resistance, clonality, and virulence. Materials and Methods: A. baumannii clinical isolates ( n = 90) where obtained from a tertiary care center in Beirut, Lebanon. API 20NE strips in addition to the amplification of bla OXA-51-like were used for identification. Antibiotic susceptibility testing by disk diffusion was then performed in addition to PCRs for the detection of the most commonly disseminated carbapenemases. Clonality was determined by tri-locus PCR typing and doubling times were determined for isolates with varying susceptibility profiles. Biofilm formation, hemolysis, siderophore production, proteolytic activity, and surface motility was then determined for all the isolates. Statistical analysis was then performed for the determination of associations. Results and Discussion: 81 (90%) of the isolates were resistant to carbapenems. These high rates are similar to other multi-center studies in the country suggesting the need of intervention on a national level. 74 (91.3%) of the carbapenem resistant isolates harbored bla OXA-23-like including two that also harbored bla OXA-24-like . 88.9% of the A. baumannii isolates pertained to ICII and three other international clones were detected, showing the wide dissemination of clones into geographically distinct locations. Virulence profiles were highly diverse and no specific pattern was observed. Nevertheless, an association between motility

  1. Insulin Sensitivity Determines Effects of Insulin and Meal Ingestion on Systemic Vascular Resistance in Healthy Subjects.

    Science.gov (United States)

    Woerdeman, Jorn; Meijer, Rick I; Eringa, Etto C; Hoekstra, Trynke; Smulders, Yvo M; Serné, Erik H

    2016-01-01

    In addition to insulin's metabolic actions, insulin can dilate arterioles which increase blood flow to metabolically active tissues. This effect is blunted in insulin-resistant subjects. Insulin's effect on SVR, determined by resistance arterioles, has, however, rarely been examined directly. We determined the effects of both hyperinsulinemia and a mixed meal on SVR and its relationship with insulin sensitivity. Thirty-seven lean and obese women underwent a hyperinsulinemic-euglycemic clamp, and 24 obese volunteers underwent a mixed-meal test. SVR was assessed using CPP before and during hyperinsulinemia as well as before and 60 and 120 minutes after a meal. SVR decreased significantly during hyperinsulinemia (-13%; p Insulin decreased SVR more strongly in insulin-sensitive individuals (standardized β: -0.44; p = 0.01). In addition, SVR at 60 minutes after meal ingestion was inversely related to the Matsuda index (β: -0.39; p = 0.04) and the change in postprandial SVR was directly related to postprandial glycemia (β: 0.53; p insulin resistance. This suggests that resistance to insulin-induced vasodilatation contributes to regulation of vascular resistance. © 2015 John Wiley & Sons Ltd.

  2. Exploration of genetically determined resistance against hepatitis C infection in high-risk injecting drug users.

    Science.gov (United States)

    Sugden, P B; Cameron, B; Luciani, F; Lloyd, A R

    2014-08-01

    Genetic resistance to specific infections is well recognized. In hepatitis C virus (HCV) infection, genetic polymorphisms in IL-28B and the killer cell immunoglobulin-like receptors (KIR) and their HLA class I ligands have been shown to affect clearance of the virus following infection. There are limited data regarding resistance to established HCV infection. Reliable quantification of repeated exposure in high-risk populations, such as injecting drug users (IDU), is a key limitation of previous studies of resistance. Behavioural data and DNA from IDU (n = 210) in the Hepatitis C Incidence and Transmission Study in prisons (HITS-p) cohort were genotyped for polymorphisms in: IL-28B, peptidyl-prolyl isomerase A (PPIA), HLA-C and KIR2. To quantify risk, a composite risk index based on factors predictive of incident HCV infection was derived. Logistic regression analysis revealed the risk index was strongly associated with incident HCV infection (P C1, or their combination. A framework for the investigation of genetic determinants of resistance to HCV infection has been developed. Several candidate gene associations were investigated and excluded. Further investigation of genetic determinants of resistance to HCV infection is warranted. © 2014 John Wiley & Sons Ltd.

  3. Use of the azimuthal resistivity technique for determination of regional azimuth of transmissivity

    Science.gov (United States)

    Carlson, D.

    2010-01-01

    Many bedrock units contain joint sets that commonly act as preferred paths for the movement of water, electrical charge, and possible contaminants associated with production or transit of crude oil or refined products. To facilitate the development of remediation programs, a need exists to reliably determine regional-scale properties of these joint sets: azimuth of transmissivity ellipse, dominant set, and trend(s). The surface azimuthal electrical resistivity survey method used for local in situ studies can be a noninvasive, reliable, efficient, and relatively cost-effective method for regional studies. The azimuthal resistivity survey method combines the use of standard resistivity equipment with a Wenner array rotated about a fixed center point, at selected degree intervals, which yields an apparent resistivity ellipse from which joint-set orientation can be determined. Regional application of the azimuthal survey method was tested at 17 sites in an approximately 500 km2 (193 mi2) area around Milwaukee, Wisconsin, with less than 15m (50 ft) overburden above the dolomite. Results of 26 azimuthal surveys were compared and determined to be consistent with the results of two other methods: direct observation of joint-set orientation and transmissivity ellipses from multiple-well-aquifer tests. The average of joint-set trend determined by azimuthal surveys is within 2.5?? of the average of joint-set trend determined by direct observation of major joint sets at 24 sites. The average of maximum of transmissivity trend determined by azimuthal surveys is within 5.7?? of the average of maximum of transmissivity trend determined for 14 multiple-well-aquifer tests. Copyright ?? 2010 The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

  4. DETERMINING THE THERMAL RESISTANCE OF A VENTILATED HINGED FACADE SYSTEM LAYER

    Directory of Open Access Journals (Sweden)

    Gagarin Vladimir Gennad'evich

    2015-03-01

    Full Text Available Enveloping structures with hinged façade systems are nowadays widely used for moisture control of enveloping structures, prevention of overheating of the structures by insolation, saving the constructions from atmospheric moisture and also for correspondence with the raised requirements to thermal protection of the enveloping structures, aimed also at reducing energy consumption. In the winter conditions the influence of air layer on the thermal insulation parameters is usually neglected. In the article the thermal resistance of an air gap and is considered and its effect in the calculation of the heat resistance of a building envelope with hinged facade system is analyzed in the conditions of cold weather. The thermal resistance of the air layer determines how the heat losses decrease.

  5. Measurement of oxytetracycline and emamectin benzoate in freshwater sediments downstream of land based aquaculture facilities in the Atlantic Region of Canada.

    Science.gov (United States)

    Lalonde, Benoit A; Ernst, William; Greenwood, Lyndsay

    2012-09-01

    This study investigated the occurrence of oxytetracycline (OTC) and emamectin benzoate (EB) in sediments located near the effluent outfall from four freshwater aquaculture facilities in Atlantic Canada. While two facilities had no detectable concentrations of EB or OTC, two facilities had detectable concentrations of one or both of these chemicals. Concentrations ranged from <0.05-18 mg/kg to <0.01-2.5 mg/kg for OTC and EB respectively. Although these values could not be compared with freshwater toxicant values, some of the concentrations of EB and OTC detected were higher than LC(50) values calculated for marine invertebrates. OTC concentrations measured in this study are also of a magnitude which has been known to produce resistant bacteria.

  6. Associations of antimicrobial use with antimicrobial resistance in Campylobacter coli from grow-finish pigs in Japan.

    Science.gov (United States)

    Ozawa, M; Makita, K; Tamura, Y; Asai, T

    2012-10-01

    To determine associations between antimicrobial use and antimicrobial resistance in Campylobacter coli, 155 isolates were obtained from the feces of apparently healthy grow-finish pigs in Japan. In addition, data on the use of antibiotics collected through the national antimicrobial resistance monitoring system in Japan were used for the analysis. Logistic regression was used to identify risk factors to antimicrobial resistance in C. coli in pigs for the following antimicrobials: ampicillin, dihydrostreptomycin, erythromycin, oxytetracycline, chloramphenicol, and enrofloxacin. The data suggested the involvement of several different mechanisms of resistance selection. The statistical relationships were suggestive of co-selection; use of macrolides was associated with enrofloxacin resistance (OR=2.94; CI(95%): 0.997, 8.68) and use of tetracyclines was associated with chloramphenicol resistance (OR=2.37; CI(95%): 1.08, 5.19). The statistical relationships were suggestive of cross-resistance: use of macrolides was associated with erythromycin resistance (OR=9.36; CI(95%): 2.96, 29.62) and the use of phenicols was associated with chloramphenicol resistance (OR=11.83; CI(95%): 1.41, 99.44). These data showed that the use of antimicrobials in pigs selects for resistance in C. coli within and between classes of antimicrobials. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Determination of a Wear Initiation Cycle by using a Contact Resistance Measurement in Nuclear Fuel Fretting

    International Nuclear Information System (INIS)

    Lee, Young Ho; Kim, Hyung Kyu

    2008-01-01

    In nuclear fuel fretting, the improving of the contact condition with a modified spring shape is a useful method for increasing the wear resistance of the nuclear fuel rod. This is because the fretting wear resistance between the fuel rod and grid spring is mainly affected by the grid spring shape rather than the environment, the contact modes, etc. In addition, the wear resistance is affected by the wear debris behavior between contact surfaces. So, it is expected that the wear initiation of each spring shape should be determined in order to evaluate a wear resistance. However, it is almost impossible to measure the wear behavior in contact surfaces on a real time basis because the contact surfaces are always hidden. Besides, the results of the worn surface observation after the fretting wear tests are restricted to archive the information on the wear debris behavior and the formation mechanism of the wear scar. In order to evaluate the wear behavior during the fretting wear tests, it is proposed that the contact resistance measurement is a useful method for examining the wear initiation cycle and modes. Generally, fretting wear damages are rapidly progressed by a localized plastic deformation between the contact surfaces, crack initiation and fracture of the deformed surface with a strain hardening difference between a surface and a subsurface and finally a detachment of wear debris. After this, wear debris is easily oxidized by frictional heat, test environment, etc. At this time, a small amount of electric current applied between the contact surfaces will be influenced by the wear debris, which could be an obstacle to an electric current flow. So, it is possible to archive the information on the wear behavior by measuring the contact resistance. In order to determine the wear initiation cycle during the fretting wear tests, in this study, fretting wear tests have been performed by applying a constant electric current in room temperature air

  8. Comparative Analysis of Three Methods for Determination of Imipenem Resistance in Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Tanaz Zabihi

    2016-02-01

    Full Text Available "> Background: These days, the antibiotic resistance of Pseudomonas aeruginosa isolates toimipenem has significantly increased. Therefore the study of resistance to imipenem in thisorganism to imipenem in determining the appropriate treatment is crucial and necessary. The goalof this study is to compare three phenotypic methods of E-test, disk diffusion and micro brothdilution in the study of resistance to imipenem in clinical isolates of P. aeruginosa.Methods: Within a 6-month interval, 120 clinical specimens were collected and evaluated. Allisolates were identified as P. aeruginosa by standard biochemical tests and amplification of 16SrRNA gene. Three phenotypic methods of E-test, disk diffusion, and micro broth dilution wereused to determine imipenem resistance in P. aeruginosa isolates.Results: Of the 96 P. aeruginosa isolates studied for their resistance to imipenem by the use ofE-test, disk diffusion and micro broth dilution methods, 38.5% of the strains in micro broth dilutionmethod and 33.3% in the two methods of E-test and disk diffusion were resistant to imipenem. Therate of sensitivity and specificity of disk diffusion and E-test methods were 100%, 90.1%, and theywere 100% and 83.1% for micro broth dilution, respectively.Conclusions: With regard to the results obtained from the comparison of the three methods100% agreement were observed among the antimicrobial susceptibility results obtained by the Etest and disk diffusion methods (P ≥ 0.05. Therefore, the use of disk diffusion method can bean appropriate replacement for E-test method with regard to its being easy and cost-effective.

  9. Multidrug resistance 1 gene polymorphisms may determine Crohn's disease behavior in patients from Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    Ana Teresa P. Carvalho

    2014-01-01

    Full Text Available OBJECTIVES: Conflicting data from studies on the potential role of multidrug resistance 1 gene polymorphisms in inflammatory bowel disease may result from the analysis of genetically and geographically distinct populations. Here, we investigated whether multidrug resistance 1 gene polymorphisms are associated with inflammatory bowel diseases in patients from Rio de Janeiro. METHODS: We analyzed 123 Crohn's disease patients and 83 ulcerative colitis patients to determine the presence of the multidrug resistance 1 gene polymorphisms C1236T, G2677T and C3435T. In particular, the genotype frequencies of Crohn's disease and ulcerative colitis patients were analyzed. Genotype-phenotype associations with major clinical characteristics were established, and estimated risks were calculated for the mutations. RESULTS: No significant difference was observed in the genotype frequencies of the multidrug resistance 1 G2677T/A and C3435T polymorphisms between Crohn's disease and ulcerative colitis patients. In contrast, the C1236T polymorphism was significantly more common in Crohn's disease than in ulcerative colitis (p = 0.047. A significant association was also found between the multidrug resistance 1 C3435T polymorphism and the stricturing form of Crohn's disease (OR: 4.13; p = 0.009, whereas no association was found with penetrating behavior (OR: 0.33; p = 0.094. In Crohn's disease, a positive association was also found between the C3435T polymorphism and corticosteroid resistance/refractoriness (OR: 4.14; p = 0.010. However, no significant association was found between multidrug resistance 1 gene polymorphisms and UC subphenotypic categories. CONCLUSION: The multidrug resistance 1 gene polymorphism C3435T is associated with the stricturing phenotype and an inappropriate response to therapy in Crohn's disease. This association with Crohn's disease may support additional pathogenic roles for the multidrug resistance 1 gene in regulating gut

  10. The costs of infection and resistance as determinants of West Nile virus susceptibility in Culex mosquitoes

    Directory of Open Access Journals (Sweden)

    Styer Linda M

    2011-10-01

    Full Text Available Abstract Background Understanding the phenotypic consequences of interactions between arthropod-borne viruses (arboviruses and their mosquito hosts has direct implications for predicting the evolution of these relationships and the potential for changes in epidemiological patterns. Although arboviruses are generally not highly pathogenic to mosquitoes, pathology has at times been noted. Here, in order to evaluate the potential costs of West Nile virus (WNV infection and resistance in a primary WNV vector, and to assess the extent to which virus-vector relationships are species-specific, we performed fitness studies with and without WNV exposure using a highly susceptible Culex pipiens mosquito colony. Specifically, we measured and compared survival, fecundity, and feeding rates in bloodfed mosquitoes that were (i infected following WNV exposure (susceptible, (ii uninfected following WNV exposure (resistant, or (iii unexposed. Results In contrast to our previous findings with a relatively resistant Cx. tarsalis colony, WNV infection did not alter fecundity or blood-feeding behaviour of Cx. pipiens, yet results do indicate that resistance to infection is associated with a fitness cost in terms of mosquito survival. Conclusions The identification of species-specific differences provides an evolutionary explanation for variability in vector susceptibility to arboviruses and suggests that understanding the costs of infection and resistance are important factors in determining the potential competence of vector populations for arboviruses.

  11. Identification and Determination of Drug Resistant of Candida species isolated from Hospital Acquired Infections

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    Kambiz Diba

    2015-01-01

    Full Text Available Background & aim: Currently, the use of antifungal azole group and yeasts resistant to these drugs is increasing. The aim of this study was to isolate and identify the yeasts obtained from candidiasis patients and furthermore determining thier antifungal resistance. Methods: In the present descriptive study, infections samples were collected from 256 patients with suspected nosocomial candidiasis, then direct exam and culture were performed. Yeast colonies were identified using phenotypic methods, polymerase chain reaction method and enzyme digestion. Data were analyzed using Descriptive statistical tests. Results: Of sixty isolated yeast, thirty-seven cases of Candida albicans (61.6%, seven cases of C. krusei and C. glabrata (11.6% each, five cases of C. dubliniensis (8.3% and four cases of C. tropicalis (6.6% were indicated. The study showed that the sensitivity of C. albicans and C. cruise species to amphotericin B was negligible in disk diffusion and very sensitve in microdilution. Conclusion: Inspite of the results of antifungal susceptibility test of strains studied did not show high resistance, but screening for drug-resistant Candida isolates in Candida infection by disk diffusion and microdilution methods for new cases of drug resistance is reasonable.

  12. Production and Statistical Optimization of Oxytetracycline from Streptomyces rimosus NCIM 2213 using a New Cellulosic Substrate, Prosopis juliflora

    Directory of Open Access Journals (Sweden)

    Surjith Ramasamy

    2014-10-01

    Full Text Available Prosopis juliflora is a drought-resistant evergreen spiny tree that grows in semi-arid and arid tracts of tropical and sub-tropical regions of the world. Dry pods of P. juliflora are a rich source of carbon (40% total sugar and nitrogen (15% of total nitrogen and so can be considered as a good substrate for the microbial growth. The present study was mainly focused on the utilization of these pods for the production and statistical optimization of oxytetracycline (OTC from Streptomyces rimosus NCIM 2213 under SSF. The spectral characterization and chemical color reactions of purified OTC by UV, FTIR, 1H NMR, 13C NMR, and HPLC revealed that the structure was homologous to a standard sample. A central composite design with 26 trails yielded the following critical values of supplements to be added to the dry pods: maltose (0.125 g/gds, Inoculum size (0.617 mL/gds, CaCO3 (0.0026 g/gds, and moisture content (74.87% with the maximum OTC yield 5.02 mg/gds.

  13. Molecular Insights into the pH-Dependent Adsorption and Removal of Ionizable Antibiotic Oxytetracycline by Adsorbent Cyclodextrin Polymers

    Science.gov (United States)

    Zhang, Yu; Cai, Xiyun; Xiong, Weina; Jiang, Hao; Zhao, Haitong; Yang, Xianhai; Li, Chao; Fu, Zhiqiang; Chen, Jingwen

    2014-01-01

    Effects of pH on adsorption and removal efficiency of ionizable organic compounds (IOCs) by environmental adsorbents are an area of debate, because of its dual mediation towards adsorbents and adsorbate. Here, we probe the pH-dependent adsorption of ionizable antibiotic oxytetracycline (comprising OTCH2 +, OTCH±, OTC−, and OTC2−) onto cyclodextrin polymers (CDPs) with the nature of molecular recognition and pH inertness. OTCH± commonly has high adsorption affinity, OTC− exhibits moderate affinity, and the other two species have negligible affinity. These species are evidenced to selectively interact with structural units (e.g., CD cavity, pore channel, and network) of the polymers and thus immobilized onto the adsorbents to different extents. The differences in adsorption affinity and mechanisms of the species account for the pH-dependent adsorption of OTC. The mathematical equations are derived from the multiple linear regression (MLR) analysis of quantitatively relating adsorption affinity of OTC at varying pH to adsorbent properties. A combination of the MLR analysis for OTC and molecular recognition of adsorption of the species illustrates the nature of the pH-dependent adsorption of OTC. Based on this finding, γ-HP-CDP is chosen to adsorb and remove OTC at pH 5.0 and 7.0, showing high removal efficiency and strong resistance to the interference of coexisting components. PMID:24465975

  14. Chronic impacts of oxytetracycline on mesophilic anaerobic digestion of excess sludge: Inhibition of hydrolytic acidification and enrichment of antibiotic resistome.

    Science.gov (United States)

    Tian, Zhe; Zhang, Yu; Yang, Min

    2018-07-01

    We evaluated the chronic impact of oxytetracycline (OTC) on performance and antibiotic resistance development during the mesophilic anaerobic digestion (AD) of antibiotic-containing biomass. Mesophilic AD was conducted in a completely stirred tank reactor by constantly feeding municipal excess sludge spiked with increasing concentrations of OTC (0-1000 mg L -1 ) under a solid retention time of 20 days over a period of 265 days. Results showed that methane generation of mesophilic AD was inhibited when the OTC concentration in digested sludge was increased to around 18,000 mg kg -1 (OTC dose, 1000 mg L -1 ), due to the inhibition of fermenting and acidogenic bacteria. Metagenomic sequencing and high-throughput quantitative PCR analysis demonstrated that tetracycline resistance genes were the most dominant type (38.47-43.76%) in the resistome, with tetG, tetX, tetM, tetR, tetQ, tetO, and tetL as the dominant resistant subtypes throughout the whole experimental period. The relative abundance of these tet genes increased from 2.10 × 10 -1 before spiking OTC (OTC concentration in digested sludge, 8.97 mg kg -1 ) to 2.83 × 10 -1 (p resistome variation were 29.35% and 21.51%, respectively. Thus, considering the inhibition of hydrolytic acidification and enrichment of antibiotic resistome, mesophilic AD is not suggested to directly treat the biomass containing OTC concentration higher than 200 mg L -1 . Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. System and method for determining stator winding resistance in an AC motor

    Science.gov (United States)

    Lu, Bin [Kenosha, WI; Habetler, Thomas G [Snellville, GA; Zhang, Pinjia [Atlanta, GA; Theisen, Peter J [West Bend, WI

    2011-05-31

    A system and method for determining stator winding resistance in an AC motor is disclosed. The system includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of an AC motor. The circuit includes at least one contactor and at least one switch to control current flow and terminal voltages in the AC motor. The system also includes a controller connected to the circuit and configured to modify a switching time of the at least one switch to create a DC component in an output of the system corresponding to an input to the AC motor and determine a stator winding resistance of the AC motor based on the injected DC component of the voltage and current.

  16. The determination of multiple resistance, inheritance and cytochrome P450 activity in bifenthrinresistant Tetranychus urticae Koch (Acari: Tetranychidae)

    OpenAIRE

    AY, Recep; YORULMAZ, Sibel

    2010-01-01

    In this study, multiple resistance, inheritance and cytochrome P450 enzyme activity were determined in Tetranychus urticae Koch (SAK) population after 20 selections for bifenthrin resistance. Selection study and LC50, 60 levels of SAK population of T. urticae were determined by dry film method. LC50 level of the SAK population selected twenty times with bifenthrin was increased from 984.49 to 11914.40 µl l-1 distiled water. Selected population showing 21.84 fold resistances was named ...

  17. Microcontroller based Stator Winding Resistance Determination of Induction Motor Drive on Temperature Variations

    OpenAIRE

    Siraj Ahmed T; Sukhdeo Sao; K.S.R Anjaneyulu

    2014-01-01

    In this paper an experiment has been conducted to determine the online stator winding resistance of an induction motor, in industries as well as domestic purpose induction motors is largely utilized, as it has both applications of variable and constant torque operation nature. The major requirement of an electric drive system is its independent control of torque and speed; this is achieved in DC motor Drive but has more disadvantages. With the help of fast acting switching devices it is possi...

  18. Efficiency determination of resistive plate chambers for fast quasi-monoenergetic neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Roeder, M.; Cowan, T.E.; Kempe, M.; Yakorev, D. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Technische Universitaet Dresden, Dresden (Germany); Elekes, Z. [MTA ATOMKI, Debrecen (Hungary); Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Aumann, T.; Caesar, C. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Technische Universitaet Darmstadt, Darmstadt (Germany); Bemmerer, D.; Sobiella, M.; Stach, D.; Wagner, A. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Boretzky, K.; Hehner, J.; Heil, M. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Maroussov, V. [Universitaet zu Koeln, Koeln (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Nusair, O. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Al-Balqa Applied University, Salt (Jordan); Prokofiev, A.V. [Uppsala University, The Svedberg Laboratory, Uppsala (Sweden); Reifarth, R. [Johann Wolfgang Goethe - Universitaet, Frankfurt am Main (Germany); Zilges, A. [Universitaet zu Koeln, Koeln (Germany); Zuber, K. [Technische Universitaet Dresden, Dresden (Germany); Collaboration: R3B Collaboration

    2014-07-15

    Composite detectors made of stainless-steel converters and multigap resistive plate chambers have been irradiated with quasi-monoenergetic neutrons with a peak energy of 175 MeV. The neutron detection efficiency has been determined using two different methods. The data are in agreement with the output of Monte Carlo simulations. The simulations are then extended to study the response of a hypothetical array made of these detectors to energetic neutrons from a radioactive ion beam experiment. (orig.)

  19. Determination of Antimicrobial Activity and Resistance to Oxidation of Moringa peregrina Seed Oil

    Directory of Open Access Journals (Sweden)

    Ioanna Chinou

    2012-02-01

    Full Text Available The antimicrobial activity of the oil extracted with n-hexane from the seeds of Moringa peregrina was tested against Staphylococcus aureus, S. epidermidis, Pseudomonas aeruginosa, Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, Candida albicans, C. tropicalis and C. glabrata. The oil proved effective against all of the tested microorganisms. Standard antibiotics (netilmycin, 5-flucytocine, intraconazole and 7-amino-4-methylcoumarin-3-acetic acid were used for comparison. The resistance to oxidation of the extracted seed oil was also determined.

  20. Antibiotic resistance determinants and genetic analysis of Salmonella enterica isolated from food in Morocco.

    Science.gov (United States)

    Murgia, Manuela; Bouchrif, Brahim; Timinouni, Mohammed; Al-Qahtani, Ahmed; Al-Ahdal, Mohammed N; Cappuccinelli, Pietro; Rubino, Salvatore; Paglietti, Bianca

    2015-12-23

    Antimicrobial-resistant non-typhoidal Salmonella (NTS) are an important cause of infection in Africa, but there is a lack of information on their molecular mechanisms of resistance and epidemiology. This study contributes to fill this gap through the characterization by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), plasmid profiling and analysis of antibiotic-resistance determinants of 94 Salmonella enterica strains isolated from food in Morocco. PFGE revealed considerable heterogeneity among the strains, showing 32 pulsotypes. MLST of strains representative of the different serovars evidenced 13 sequence types (STs), three of which were newly identified (ST1694, ST1768 and ST1818) and nine not previously reported in Morocco. Thirty-four strains harbored from one to four plasmids, of IncI1 group in S. Mbandaka, IncFIIA in S. Typhimurium, IncL/M in S. Hadar and S. Blockley. For the first time in Morocco an intact Salmonella Genomic Island 1 (SGI1) carrying the resistance genes aadA2, floR, tetG, blaPSE-1 and sul1 was detected in S. Typhimurium DT104. In serovar Hadar resistance to ampicillin, tetracycline and streptomycin was associated to blaTEM-1, tetA and strA genes respectively, whereas one mutation in gyrA (Asp87Asn) and one in parC (Thr54Ser) genes conferred resistance to nalidixic acid. These findings improve the information on foodborne Salmonella in Morocco, evidencing the presence of MDR strains potentially dangerous to humans, and provide useful data for future studies. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Isolation and Determination of Antibiotic Resistance Patterns in Nontyphoid Salmonella spp isolated from chicken

    Directory of Open Access Journals (Sweden)

    Seyyedeh Hoorieh Fallah

    2013-01-01

    Full Text Available Background: Salmonellosis is one of the most common food borne diseases in industrial and developing countries. In recent years, an increase in antimicrobial drug resistance, among non-typhoid Salmonella spp has been observed. Objectives: The aim of this study was to isolate and determine antibiotic resistance pattern in non-typhoid Salmonella spp. Materials and Methods: This descriptive study was done on 100 samples of chickens collected from 196 retail markets and was examined for the presence of Salmonella using standard bacteriological procedures and stereotyping kit. Antimicrobial susceptibility testing was performed by disk diffusion methods according to the National Committee for Clinical Laboratory Standards (CLSI. The data were analyzed by using the SPSS software version 18. Result: Forty- four percent of samples were contaminated with Salmonella infection and 56% didn’t have any contamination. The stereotyping results showed that 34 of 44 isolates of Salmonella belonged to Salmonella infantis (79.5 %, one strain (2.3% of group C and 8 strain (18.2% of group D. However, all these strains were sensitive to Cefotaxime and Ciprofloxacin, and 100% were resistant to Nalidixic acid, Tetracyclin and Sterptomycin. The most common resistance pattern (34.1% was towards six antibiotics, and 6.8% of strains were resistant to at least three antibiotics. Conclusion: High levels of resistance to antibiotics that are used commonly for human and poultry can be a warning for our community health and this information must be used to form important strategies for improvement of infection control.

  2. Genome-wide identification of antimicrobial intrinsic resistance determinants in Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Martin Vestergaard

    2016-12-01

    Full Text Available The emergence of antimicrobial resistance severely threatens our ability to treat bacterial infections. While acquired resistance has received considerable attention, relatively little is known of intrinsic resistance that allows bacteria to naturally withstand antimicrobials. Gene products that confer intrinsic resistance to antimicrobial agents may be explored for alternative antimicrobial therapies, by potentiating the efficacy of existing antimicrobials. In this study, we identified the intrinsic resistome to a broad spectrum of antimicrobials in the human pathogen, Staphylococcus aureus. We screened the Nebraska Transposon Mutant Library of 1920 single-gene inactivations in S. aureus strain JE2, for increased susceptibility to the anti-staphylococcal antimicrobials (ciprofloxacin, oxacillin, linezolid, fosfomycin, daptomycin, mupirocin, vancomycin and gentamicin. 68 mutants were confirmed by E-test to display at least two-fold increased susceptibility to one or more antimicrobial agents. The majority of the identified genes have not previously been associated with antimicrobial susceptibility in S. aureus. For example, inactivation of genes encoding for subunits of the ATP synthase, atpA, atpB, atpG and atpH, reduced the minimum inhibitory concentration (MIC of gentamicin 16-fold. To elucidate the potential of the screen, we examined treatment efficacy in the Galleria mellonella infection model. Gentamicin efficacy was significantly improved, when treating larvae infected with the atpA mutant compared to wild type cells with gentamicin at a clinically relevant concentration. Our results demonstrate that many gene products contribute to the intrinsic antimicrobial resistance of S. aureus. Knowledge of these intrinsic resistance determinants provides alternative targets for compounds that may potentiate the efficacy of existing antimicrobial agents against this important pathogen.

  3. Determination of Insulin Resistance and Beta Cell Function in Healthy Obese and Non-obese Individuals

    International Nuclear Information System (INIS)

    Kazmi, A.; Sattar, A.; Tariq, K. M.; Najamussahar; Hashim, R.; Almani, M. I.

    2013-01-01

    Objective: To determine insulin resistance and beta cell function in healthy obese and nonobese individuals of the local population. Study Design: Case control study. Place and Duration of Study: AFIP Rawalpindi in collaboration with department of medicine military hospital(MH) Rawalpindi, from Aug 2008 to Mar 2009. Methods: Eighty obese(n=40) and non-obese(n=40) subjects were selected by non-probability convenience sampling. Plasma insulin, glucose, and serum total cholestrol were estimated in fasting state. Insulin resistance was calculated by HOMA-IR and beta cell function by HOMA- equation. Results: Significant differences were observed between obese and non-obese individuals regarding insulin resistance, beta cell function, and BMI and serum total cholesterol. Mean insulin resistance in obese group was found to be 11.1 +- 5.1(range 7.0-16.2) and in non-obese group it was 0.9+-0.4 (range 0.5-1.3). This difference was highly significant (p=0.001). There was a highly significant difference between the two groups in term of beta cell function with mean rank 60.1 for obese group and 20.9 non obese groups (Asym sig. 2 tailed 0.000). Also the correlation (r = 0.064) between insulin resistance and beta cell function in obese group is highly significant (p = 0.000). Mean serum leptin levels were lower (6.3 ng/ml) in non-obese, and high (57.2 ng/ml) in the obese group. Conclusions: Insulin resistance is found higher in obese individuals. Beta cell function is significantly different between obese and non-obese groups. (author)

  4. The effect of polymorphism on powder compaction and dissolution properties of chemically equivalent oxytetracycline hydrochloride powders.

    Science.gov (United States)

    Liebenberg, W; de Villiers, M M; Wurster, D E; Swanepoel, E; Dekker, T G; Lötter, A P

    1999-09-01

    In South Africa, oxytetracycline is identified as an essential drug; many generic products are on the market, and many more are being developed. In this study, six oxytetracycline hydrochloride powders were obtained randomly from manufacturers, and suppliers were compared. It was found that compliance to a pharmacopoeial monograph was insufficient to ensure the optimum dissolution performance of a simple tablet formulation. Comparative physicochemical raw material analysis showed no major differences with regard to differential scanning calorimetry (DSC), infrared (IR) spectroscopy, powder dissolution, and particle size. However, the samples could be divided into two distinct types with respect to X-ray powder diffraction (XRD) and thus polymorphism. The two polymorphic forms had different dissolution properties in water or 0.1 N hydrochloride acid. This difference became substantial when the dissolution from tablets was compared. The powders containing form A were less soluble than that containing form B.

  5. Effects of oxytetracycline, tylosin, and amoxicillin antibiotics on specific methanogenic activity of anaerobic biomass

    OpenAIRE

    Mohammad Mehdi Amin; Hassan Hashemi; Afshin Ebrahimi; Asghar Ebrahimi

    2012-01-01

    Aims: The purpose of this study was to survey the antibiotics effects of oxytetracycline, tylosin, and amoxicillin on anerobic wastewater treatment process. Materials and Methods: To evaluate the inhibitory antibiotics amoxicillin, tetracycline, and tylosin on biomass activity, specific methanogenic activity (SMA) using anerobic biomass batch; into 120 ml vials: 30 ml biomass and 70 ml substrate including volatile fatty acids, mainly acetic acid and various concentrations of antibiotics we...

  6. Sclerotic effect of oxytetracycline on the submandibular gland: An experimental model.

    Science.gov (United States)

    Güçlü, Oğuz; Muratli, Asli; Arik, Deniz; Tekin, Kazım; Erdogan, Halil; Dereköy, Fevzi Sefa

    2016-12-01

    Oxytetracycline has been suggested as an alternate therapy for chronic recurrent sialadenitis and sialorrhea. We conducted an experimental study to investigate the sclerotic effect of this drug on the submandibular gland by histopathologic methods. Our subjects were 20 New Zealand white rabbits, which were divided into two groups of 10. The right submandibular gland of the rabbits in the active-treatment group was injected with 0.3 ml of oxytetracycline (100 mg/ml), and that of the controls was injected with saline. Four weeks after the injections, all the glands were removed. Histopathologic studies, including hematoxylin and eosin and Masson trichrome staining, were carried out. The glands were evaluated for tissue inflammation, congestion, fibrosis, edema, lipomatosis, and atrophy. To investigate apoptosis, terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick-end labeling (TUNEL) immunohistochemical staining was used. In the study group, inflammation (n = 9), congestion (n = 9), fibrosis (n = 6), edema (n = 6), and lipomatosis (n = 4) were observed; in the sham group, only lipomatosis was seen (n = 5). The TUNEL assay results for acinar cells were 4.51 ± 1.41% in the oxytetracycline group and 2.08 ± 1.76% in the control group (p = 0.006); the corresponding figures for the duct cells were 7.05 ± 0.87% and 3.10 ± 2.26% (p = 0.001). Based on our findings, we conclude that oxytetracycline might be a viable alternative for the treatment of chronic recurrent sialadenitis and sialorrhea. However, more research in this area is needed.

  7. Determination of response time of resistance thermometers by in situ measurements

    International Nuclear Information System (INIS)

    Goncalves, I.M.P.; Soares, A.J.

    1986-01-01

    The loop-current-step-response test provides a mean for determining the time constant of resistance thermometers. The test consists in heating the sensor a few degrees above ambient temperature by causing a step perurbation in the electric current that flows through the sensor leads. The developed mathematical transformation permits to use data collected during the internal heating transient to predict the sensor response to perturbations in fluid temperature. Experimental data obtained show that time constant determined by this method is within 15 percent of the true value. (Author) [pt

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

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  9. Potentiometric studies on the complexes of tetracycline (TC) and oxytetracycline (OTC) with some metal ions. Potentiometrische Untersuchungen der Komplexe von Tetracyclin (TC) und Oxytetracyclin (OTC) mit einigen Metall-Ionen

    Energy Technology Data Exchange (ETDEWEB)

    Ghandour, M A; Azab, H A; Hassan, A; Ali, A M [Assiut Univ. (Egypt)

    1992-01-01

    The interaction of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Zn(II), Cd(II), Hg(II), Pb(II), Al(III), and UO[sub 2](II) ions with tetracycline (TC) were studied by potentiometric pH titrations. The formation constants of the different binary complexes formed in such systems have been determined at 25[+-]0.1 deg C and [mu]=0.1 moll[sup -1] (NaNO[sub 3]). Potentiometric pH equilibrium measurements have been made under the same conditions for the interaction of oxytetracycline (OTC) and Cu(II), Cd(II), Pb(II), and UO[sub 2](II). The formation of (1:1) binary complexes are inferred from the potentiometric pH titration curves. The protonation constants of TC and OTC were also determined under the same conditions and refined (ESAB2M computer program). The transition metal stability constants are consistent with the Irving-Williams series. (authors).

  10. Buprofezin susceptibility survey, resistance selection and preliminary determination of the resistance mechanism in Nilaparvata lugens (Homoptera: Delphacidae).

    Science.gov (United States)

    Wang, Yanhua; Gao, Congfen; Xu, Zhiping; Zhu, Yu Cheng; Zhang, Jiushuang; Li, Wenhong; Dai, Dejiang; Lin, Youwei; Zhou, Weijun; Shen, Jinliang

    2008-10-01

    Buprofezin has been used for many years to control Nilaparvata lugens (Stål). Assessment of susceptibility change in the insect is essential for maintaining control efficiency and resistance management. Eleven-year surveys showed that most field populations were susceptible before 2004. However, substantially higher levels of resistance (up to 28-fold) were found in most of the rice fields in China after 2004. A field population was collected and periodically selected for buprofezin resistance in the laboratory. After 65 generations (56 were selected), the colony successfully obtained 3599-fold resistance to buprofezin. Synergism tests showed that O,O-diethyl-O-phenyl phosphorothioate (SV1), piperonyl butoxide (PBO) and diethyl maleate (DEM) increased buprofezin toxicity in the resistant strain by only 1.5-1.6 fold, suggesting that esterases, P450-monooxygenases and glutathione S-transferases had no substantial effect on buprofezin resistance development. The results from this study indicate that N. lugens has the potential to develop high resistance to buprofezin. A resistance management program with rotation of buprofezin and other pesticides may efficiently delay or slow down resistance development in the insect. Further investigation is also necessary to understand the resistance mechanisms in N. lugens.

  11. Allelic variation of bile salt hydrolase genes in Lactobacillus salivarius does not determine bile resistance levels.

    LENUS (Irish Health Repository)

    Fang, Fang

    2009-09-01

    Commensal lactobacilli frequently produce bile salt hydrolase (Bsh) enzymes whose roles in intestinal survival are unclear. Twenty-six Lactobacillus salivarius strains from different sources all harbored a bsh1 allele on their respective megaplasmids. This allele was related to the plasmid-borne bsh1 gene of the probiotic strain UCC118. A second locus (bsh2) was found in the chromosomes of two strains that had higher bile resistance levels. Four Bsh1-encoding allele groups were identified, defined by truncations or deletions involving a conserved residue. In vitro analyses showed that this allelic variation was correlated with widely varying bile deconjugation phenotypes. Despite very low activity of the UCC118 Bsh1 enzyme, a mutant lacking this protein had significantly lower bile resistance, both in vitro and during intestinal transit in mice. However, the overall bile resistance phenotype of this and other strains was independent of the bsh1 allele type. Analysis of the L. salivarius transcriptome upon exposure to bile and cholate identified a multiplicity of stress response proteins and putative efflux proteins that appear to broadly compensate for, or mask, the effects of allelic variation of bsh genes. Bsh enzymes with different bile-degrading kinetics, though apparently not the primary determinants of bile resistance in L. salivarius, may have additional biological importance because of varying effects upon bile as a signaling molecule in the host.

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

    Science.gov (United States)

    Fernández-Calviño, David; Bermúdez-Couso, Alipio; Arias-Estévez, Manuel; Nóvoa-Muñoz, Juan Carlos; Fernández-Sanjurjo, Maria J; Álvarez-Rodríguez, Esperanza; Núñez-Delgado, Avelino

    2015-01-01

    The purpose of this work was to quantify retention/release of tetracycline, oxytetracycline, and chlortetracycline on two soils, paying attention to sorption kinetics and to implications of the adsorption/desorption processes on transfer of these pollutants to the various environmental compartments. We used the stirred flow chamber (SFC) procedure to achieve this goal. All three antibiotics showed high affinity for both soils, with greater adsorption intensity for soil 1, the one with the highest organic matter and Al and Fe oxides contents. Desorption was always  oxytetracycline > chlortetracycline in soil 1, with similar values for the three antibiotics and the sequence tetracycline > chlortetracycline > oxytetracycline in soil 2. The desorption sequences were oxytetracycline > tetracycline > chlortetracycline in soil 1 and oxytetracycline > chlortetracycline > tetracycline in soil 2. In conclusion, the SFC technique has yielded new kinetic data regarding tetracycline, oxytetracycline, and chlortetracycline adsorption/desorption on soils, indicating that it can be used to shed further light on the retention and transport processes affecting antibiotics on soils and other media, thus increasing knowledge on the behavior and evolution of these pharmaceutical residues in the environment.

  13. The veterinary antibiotic oxytetracycline and Cu influence functional diversity of the soil microbial community

    Energy Technology Data Exchange (ETDEWEB)

    Kong, W -D [Research Center for Eco-Environmental Sciences, Soil Environment of Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Zhu, Y -G [Research Center for Eco-Environmental Sciences, Soil Environment of Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Fu, B -J [Research Center for Eco-Environmental Sciences, Soil Environment of Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Marschner, P [Soil and Land Systems, School of Earth and Environmental Sciences, University of Adelaide, DP 636, 5005 (Australia); He, J -Z [Research Center for Eco-Environmental Sciences, Soil Environment of Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China)

    2006-09-15

    There are increasing concerns over the effects of veterinary antibiotics and heavy metals in agricultural soils. The widely used veterinary antibiotic oxytetracycline (OTC), Cu and their combination on soil microbial community function were assessed with the Biolog method. The microbial community was extracted from the soil and exposed to a 0.85% sodium chloride solution containing OTC (0, 1, 5, 11, 43, 109 and 217 {mu}M), or Cu (0, 10, 20, 100 and 300 {mu}M), or combination of the two pollutants (OTC 0, 5, 11 {mu}M and Cu 0, 20 {mu}M). Functional diversity, evenness, average well color development (AWCD) and substrate utilization decreased significantly with increasing concentrations of OTC or Cu (p < 0.005). The critical concentrations were 11 {mu}M for OTC and 20 {mu}M for Cu. The combination of OTC and Cu significantly decreased Shannon's diversity, evenness and utilization of carbohydrates and carboxylic acids compared to individual one of the contaminants. The antibiotic OTC and Cu had significant negative effects on soil microbial community function, particularly when both pollutants were present. - Oxytetracycline reduces the functional diversity of soil microbial community, and the combination of Cu and oxytetracycline leads to a further reduction.

  14. Tumor induction in rats by feeding aminopyrine or oxytetracycline with nitrite

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, H W; Luinsky, W

    1975-01-01

    Sprague-Dawley rats were given combinations of aminopyrine or oxytetracycline and sodium nitrite in drinking water. Of 30 animals receiving 0.1 percent (1,000 ppm) of aminopyrine and sodium nitrite for 30 weeks, 29 died with hemangioendothelial sarcomas of the liver. The same tumor caused death in 26 of 30 animals that received 0.025 percent (250 ppm) of both aminopyrine and sodium nitrite for 50 weeks. No animals in a control group of the same size that received 0.1 percent aminopyrine for 30 weeks developed this tumor, although one-half of them were still alive 2 years after the experiment was begun. After feeding a comparable dose (0.1 percent) of oxytetracycline and sodium nitrite for 60 weeks, liver tumors were present in 4 of 30 rats (3 hepatocellular tumors and 1 cholangioma). Since aminopyrine has been widely used for medicinal purposes in the human population, it is possible that many people have been exposed to a potent carcinogen (dimethylnitrosamine) by its formation in vivo. It is not certain whether the result of feeding oxytetracycline and sodium nitrite indicates significant carcinogenicity of this combination. (auth)

  15. Acute and subacute toxicities effect of oxytetracycline pharmaceutical wastewater on Zebrafish

    Science.gov (United States)

    Wu, Pengpeng; Shen, Hong-Yan

    2018-02-01

    Oxytetracycline wastewater is a major category of pharmaceutical wastewater, and its toxic effects on aquatic organisms have aroused people’s attention. In this study, Zebrafish were separately exposed to four Oxytetracycline wastewater treatments (20%, 40%, 60%, 80%) and a control group were sampled on days 3, 6, 9, 12, and 15. Superoxide dismutase (SOD) activities showed significant inhibition, but the highest SOD activity was found in 20% and 40% the treatment groups (195.12U/mgprot, 187.43U/mgprot, respectively) on the 12th day. MDA contents increased significantly compared with control group. MDA contents showed that the higher the volume concentration, the higher the contents of MDA with the increase of exposure time. The highest MDA content shown in 60% exposure group (5.49nmol/mgprot) on the 12th day. And SOD activities and MDA contents showed a trend of “Λ” type. In conclusion, Oxytetracycline wastewater induced oxidative stress and toxicity in Zebrafish muscle tissue.

  16. The veterinary antibiotic oxytetracycline and Cu influence functional diversity of the soil microbial community

    International Nuclear Information System (INIS)

    Kong, W.-D.; Zhu, Y.-G.; Fu, B.-J.; Marschner, P.; He, J.-Z.

    2006-01-01

    There are increasing concerns over the effects of veterinary antibiotics and heavy metals in agricultural soils. The widely used veterinary antibiotic oxytetracycline (OTC), Cu and their combination on soil microbial community function were assessed with the Biolog method. The microbial community was extracted from the soil and exposed to a 0.85% sodium chloride solution containing OTC (0, 1, 5, 11, 43, 109 and 217 μM), or Cu (0, 10, 20, 100 and 300 μM), or combination of the two pollutants (OTC 0, 5, 11 μM and Cu 0, 20 μM). Functional diversity, evenness, average well color development (AWCD) and substrate utilization decreased significantly with increasing concentrations of OTC or Cu (p < 0.005). The critical concentrations were 11 μM for OTC and 20 μM for Cu. The combination of OTC and Cu significantly decreased Shannon's diversity, evenness and utilization of carbohydrates and carboxylic acids compared to individual one of the contaminants. The antibiotic OTC and Cu had significant negative effects on soil microbial community function, particularly when both pollutants were present. - Oxytetracycline reduces the functional diversity of soil microbial community, and the combination of Cu and oxytetracycline leads to a further reduction

  17. Metagenomic profiling of microbial composition and antibiotic resistance determinants in Puget Sound.

    Science.gov (United States)

    Port, Jesse A; Wallace, James C; Griffith, William C; Faustman, Elaine M

    2012-01-01

    Human-health relevant impacts on marine ecosystems are increasing on both spatial and temporal scales. Traditional indicators for environmental health monitoring and microbial risk assessment have relied primarily on single species analyses and have provided only limited spatial and temporal information. More high-throughput, broad-scale approaches to evaluate these impacts are therefore needed to provide a platform for informing public health. This study uses shotgun metagenomics to survey the taxonomic composition and antibiotic resistance determinant content of surface water bacterial communities in the Puget Sound estuary. Metagenomic DNA was collected at six sites in Puget Sound in addition to one wastewater treatment plant (WWTP) that discharges into the Sound and pyrosequenced. A total of ~550 Mbp (1.4 million reads) were obtained, 22 Mbp of which could be assembled into contigs. While the taxonomic and resistance determinant profiles across the open Sound samples were similar, unique signatures were identified when comparing these profiles across the open Sound, a nearshore marina and WWTP effluent. The open Sound was dominated by α-Proteobacteria (in particular Rhodobacterales sp.), γ-Proteobacteria and Bacteroidetes while the marina and effluent had increased abundances of Actinobacteria, β-Proteobacteria and Firmicutes. There was a significant increase in the antibiotic resistance gene signal from the open Sound to marina to WWTP effluent, suggestive of a potential link to human impacts. Mobile genetic elements associated with environmental and pathogenic bacteria were also differentially abundant across the samples. This study is the first comparative metagenomic survey of Puget Sound and provides baseline data for further assessments of community composition and antibiotic resistance determinants in the environment using next generation sequencing technologies. In addition, these genomic signals of potential human impact can be used to guide initial

  18. Metagenomic profiling of microbial composition and antibiotic resistance determinants in Puget Sound.

    Directory of Open Access Journals (Sweden)

    Jesse A Port

    Full Text Available Human-health relevant impacts on marine ecosystems are increasing on both spatial and temporal scales. Traditional indicators for environmental health monitoring and microbial risk assessment have relied primarily on single species analyses and have provided only limited spatial and temporal information. More high-throughput, broad-scale approaches to evaluate these impacts are therefore needed to provide a platform for informing public health. This study uses shotgun metagenomics to survey the taxonomic composition and antibiotic resistance determinant content of surface water bacterial communities in the Puget Sound estuary. Metagenomic DNA was collected at six sites in Puget Sound in addition to one wastewater treatment plant (WWTP that discharges into the Sound and pyrosequenced. A total of ~550 Mbp (1.4 million reads were obtained, 22 Mbp of which could be assembled into contigs. While the taxonomic and resistance determinant profiles across the open Sound samples were similar, unique signatures were identified when comparing these profiles across the open Sound, a nearshore marina and WWTP effluent. The open Sound was dominated by α-Proteobacteria (in particular Rhodobacterales sp., γ-Proteobacteria and Bacteroidetes while the marina and effluent had increased abundances of Actinobacteria, β-Proteobacteria and Firmicutes. There was a significant increase in the antibiotic resistance gene signal from the open Sound to marina to WWTP effluent, suggestive of a potential link to human impacts. Mobile genetic elements associated with environmental and pathogenic bacteria were also differentially abundant across the samples. This study is the first comparative metagenomic survey of Puget Sound and provides baseline data for further assessments of community composition and antibiotic resistance determinants in the environment using next generation sequencing technologies. In addition, these genomic signals of potential human impact can be used

  19. Effect of Oxytetracycline on In vitro Mineralization and Demineralization Reactions in the Absence and Presence of Collagen

    Directory of Open Access Journals (Sweden)

    Monica Kakkar

    2017-11-01

    Full Text Available Introduction: Oxytetracycline and its derivatives are routinely used to treat various ailments have also been shown to inhibit embryonic bone formation, mineralization in pregnant female rats and parathyroid hormone induced demineralization of bones. Oxytetracycline has also been routinely used as bone fluorochrome to study bone metabolism. However, despite the above observations, its mechanism of action is not clearly understood. Some studies tend to suggest that it acts by inhibiting collagen biosynthesis while others indicate that it acts without influencing collagen metabolism. Aim: To study the mechanism by which oxytetracycline influences the mineralization and demineralization reactions. Materials and Methods: Homogeneous and heterogeneous systems of in vitro mineralization under physiological conditions of temperature, pH and ionic strength were used to investigate the effect of oxytetracycline not only on initial mineral phase formation but also on its subsequent growth or demineralization. In the Homogenous system, supersaturated conditions with respect to calcium and phosphate ions were employed to study their precipitation as mineral phase resembling hydroxyapatite in nature. However, in the heterogeneous system, collagen isolated from sheep tendons was used to induce identical mineral phases under saturated conditions with respect to calcium and phosphate ions prevailing in the body fluids. Results: The study demonstrated that in the homogeneous reaction system (mineralization in the absence of collagen oxytetracycline inhibited both the initial mineral phase formation and its subsequent growth without influencing its demineralization. However, in the heterogeneous system, oxytetracycline was found to inhibit not only the initial mineralization but also its subsequent growth or demineralization. Conclusion: Oxytetracycline acted like crystal poisons to inhibit the mineralization and demineralization reactions by tightly associating

  20. Metal ion-oxytetracycline pharmacokinetic interactions after oral co-administration in broiler chickens.

    Science.gov (United States)

    Ziółkowski, H; Jasiecka, A; Zuśka-Prot, M; Przybysz, J; Grabowski, T; Jaroszewski, J J

    2016-08-01

    The influence of the composition of calcium (Ca(2+)), magnesium (Mg(2+)), and iron (Fe(3+)) ions in two concentration levels (low-500 mg/L of CaCl2, 125 mg/L of MgCl2, and 10 mg/L of FeCl3 and high-2,500 mg/L of CaCl2, 625 mg/L of MgCl2, and 50 mg/L of FeCl3) contained in water on the pharmacokinetics (PK) of oxytetracycline (OTC) was determined. OTC hydrochloride was administered at a dose of 25 mg/kg of body weight to broiler chickens divided into four groups of nine birds each, including 3 oral groups (in deionized water -control, in water with low ion concentration, and in water with high ion concentration) and 1 intravenous group. OTC concentrations in plasma were determined using liquid chromatography-tandem mass spectrometry, after which non-compartmental pharmacokinetic analysis was conducted.The absolute bioavailability of OTC in the group of birds exposed to higher ions concentration was reduced (8.68% ± 2.56) as compared to the control (13.71% ± 2.60). Additionally, in this group, decrease in PK parameters such as: area under the concentration-time curve from 0 to infinity (15.36 μg × h/mL ± 4.36), from 0 to t (14.78 μg × h/mL ± 4.37), area under the first moment of curve from 0 to t (107.54 μg × h/mL ± 36.48), and maximum plasma concentration (2.13 μg/mL ± 0.32) were also observed. It is noteworthy, all mentioned parameters demonstrated a downward trend with high correlation coefficient (P = 0.004, P = 0.002, P = 0.005, P = 0.004, P = 0.011, respectively), reflecting the influence of increasing concentrations of Ca(2+), Mg(2+), and Fe(3+) ions on the decreasing absorption rate of OTC.Based on the current research results, it can be assumed that high concentrations of several ions applied concomitantly are able to decrease the absorption of OTC from gastrointestinal tract in broiler chickens. This occurrence might impair the drug's clinical efficacy toward some pathogenic microorganisms. It implies that using OTC on a farm may require

  1. Antibiotic resistance of Clostridium perfringens isolates from broiler chickens in Egypt.

    Science.gov (United States)

    Osman, K M; Elhariri, M

    2013-12-01

    The use of antibiotic feed additives in broiler chickens results in a high prevalence of resistance among their enteric bacteria, with a consequent emergence of antibiotic resistance in zoonotic enteropathogens. Despite growing concerns about the emergence of antibiotic-resistant strains, which show varying prevalences in different geographic regions, little work has been done to investigate this issue in the Middle East. This study provides insight into one of the world's most common and financially crippling poultry diseases, necrotic enteritis caused by Clostridium perfringens. The study was designed to determine the prevalence of antibiotic resistance in C. perfringens isolates from clinical cases of necrotic enteritis in broiler chickens in Egypt. A total of 125 isolates were obtained from broiler flocks in 35 chicken coops on 17 farms and were tested using the disc diffusion method. All 125 isolates were resistant to gentamicin, streptomycin, oxolinic acid, lincomycin, erythromycin and spiramycin. The prevalence of resistance to other antibiotics was also high: rifampicin (34%), chloramphenicol (46%), spectinomycin (50%), tylosin-fosfomycin (52%), ciprofloxacin (58%), norfloxacin (67%), oxytetracycline (71%), flumequine (78%), enrofloxacin (82%), neomycin (93%), colistin (94%), pefloxacin (94%), doxycycline (98%) and trimethoprim-sulfamethoxazole (98%). It is recommended that C. perfringens infections in Egypt should be treated with antibiotics for which resistant isolates are rare at present; namely, amoxicillin, ampicillin, cephradine, fosfomycin and florfenicol.

  2. Antibiotic Resistance of Salmonella spp. Isolated from Shrimp Farming Freshwater Environment in Northeast Region of Brazil

    Directory of Open Access Journals (Sweden)

    Fátima C. T. Carvalho

    2013-01-01

    Full Text Available This study investigated the presence and antibiotic resistance of Salmonella spp. in a shrimp farming environment in Northeast Region of Brazil. Samples of water and sediments from two farms rearing freshwater-acclimated Litopenaeus vannamei were examined for the presence of Salmonella. Afterwards, Salmonella isolates were serotyped, the antimicrobial resistance was determined by a disk diffusion method, and the plasmid curing was performed for resistant isolates. A total of 30 (16.12% of the 186 isolates were confirmed to be Salmonella spp., belonging to five serovars: S. serovar Saintpaul, S. serovar Infantis, S. serovar Panama, S. serovar Madelia, and S. serovar Braenderup, along with 2 subspecies: S. enterica serovar houtenae and S. enterica serovar enterica. About twenty-three percent of the isolates were resistant to at least one antibiotic, and twenty percent were resistant to at least two antibiotics. Three strains isolated from water samples (pond and inlet canal exhibited multiresistance to ampicillin, tetracycline, oxytetracycline, and nitrofurantoin. One of them had a plasmid with genes conferring resistance to nitrofurantoin and ampicillin. The incidence of bacteria pathogenic to humans in a shrimp farming environment, as well as their drug-resistance pattern revealed in this study, emphasizes the need for a more rigorous attention to this area.

  3. Antimicrobial resistance determinants in Staphylococcus spp. recovered from birds of prey in Portugal.

    Science.gov (United States)

    Sousa, Margarida; Silva, Nuno; Igrejas, Gilberto; Silva, Filipe; Sargo, Roberto; Alegria, Nuno; Benito, Daniel; Gómez, Paula; Lozano, Carmen; Gómez-Sanz, Elena; Torres, Carmen; Caniça, Manuela; Poeta, Patrícia

    2014-07-16

    Antibiotic resistance among wild animals represent an emerging public health concern. The objective of this study was to analyze the staphylococcal nasal microbiota in birds of prey and their content in antimicrobial resistance determinants. Nasal samples from 16 birds of prey were collected, swabs were dipped and incubated into BHI broth [6.5% NaCl] and later seeded on manitol salt agar and oxacillin-resistance screening agar base media. Staphylococcal colonies were isolated from both media and were identified by biochemical and molecular methods. Susceptibility testing to 18 antimicrobial agents was performed by disk-diffusion method. Six of the 16 tested animals carried staphylococci (37.5%) and 7 isolates of the following species were recovered: Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus saprophyticus, Staphylococcus sciuri rodentium, Staphylococcus cohnii urealitycum, and Staphylococcus gallinarum. The S. aureus isolate was penicillin-resistant (with blaZ gene) but methicillin-susceptible and was ascribed to spa-type t012, sequence-type ST30 and agr-type III. The S. epidermidis isolate carried blaZ, mecA, mrs(A/B), mphC, tet(K), drfA, and fusC genes, ica operon, and was typed as ST35. The genes ant6'-Ia, tet(K), tet(L), dfrG, cat221, cat194, and cat223 were detected in S. saprophyticus or S. gallinarum isolates. Birds of prey seem to be a natural reservoir of S. aureus and coagulase-negative staphylococci resistant to multiple antibiotics. Due to the convergence between habitats, the contact between wildlife, other animals and humans is now more common and this involves an increased possibility of interchange of these microorganisms in the different ecosystems. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Factors determining sensitivity or resistance of tumor cell lines towards artesunate.

    Science.gov (United States)

    Sertel, Serkan; Eichhorn, Tolga; Sieber, Sebastian; Sauer, Alexandra; Weiss, Johanna; Plinkert, Peter K; Efferth, Thomas

    2010-04-15

    Clinical oncology is still challenged by the development of drug resistance of tumors that result in poor prognosis for patients. There is an urgent necessity to understand the molecular mechanisms of resistance and to develop novel therapy strategies. Artesunate (ART) is an anti-malarial drug, which also exerts profound cytotoxic activity towards cancer cells. We first applied a gene-hunting approach using cluster and COMPARE analyses of microarray-based transcriptome-wide mRNA expression profiles. Among the genes identified by this approach were genes from diverse functional groups such as structural constituents of ribosomes (RPL6, RPL7, RPS12, RPS15A), kinases (CABC1, CCT2, RPL41), transcriptional and translational regulators (SFRS2, TUFM, ZBTB4), signal transducers (FLNA), control of cell growth and proliferation (RPS6), angiogenesis promoting factors (ITGB1), and others (SLC25A19, NCKAP1, BST1, DBH, FZD7, NACA, MTHFD2). Furthermore, we applied a candidate gene approach and tested the role of resistance mechanisms towards established anti-cancer drugs for ART resistance. By using transfected or knockout cell models we found that the tumor suppressor p16(INK4A) and the anti-oxidant protein, catalase, conferred resistance towards ART, while the oncogene HPV-E6 conferred sensitivity towards ART. The tumor suppressor p53 and its downstream protein, p21, as well as the anti-oxidant manganese-dependent superoxide dismutase did not affect cellular response to ART. In conclusion, our pharmacogenomic approach revealed that response of tumor cells towards ART is multi-factorial and is determined by gene expression associated with either ART sensitivity or resistance. At least some of the functional groups of genes (e.g. angiogenesis promoting factors, cell growth and proliferation-associated genes signal transducers and kinases) are also implicated in clinical responsiveness of tumors towards chemotherapy. It merits further investigation, whether ART is responsive in

  5. Establishment of a nested-ASP-PCR method to determine the clarithromycin resistance of Helicobacter pylori.

    Science.gov (United States)

    Luo, Xiao-Feng; Jiao, Jian-Hua; Zhang, Wen-Yue; Pu, Han-Ming; Qu, Bao-Jin; Yang, Bing-Ya; Hou, Min; Ji, Min-Jun

    2016-07-07

    To investigate clarithromycin resistance positions 2142, 2143 and 2144 of the 23SrRNA gene in Helicobacter pylori (H. pylori) by nested-allele specific primer-polymerase chain reaction (nested-ASP-PCR). The gastric tissue and saliva samples from 99 patients with positive results of the rapid urease test (RUT) were collected. The nested-ASP-PCR method was carried out with the external primers and inner allele-specific primers corresponding to the reference strain and clinical strains. Thirty gastric tissue and saliva samples were tested to determine the sensitivity of nested-ASP-PCR and ASP-PCR methods. Then, clarithromycin resistance was detected for 99 clinical samples by using different methods, including nested-ASP-PCR, bacterial culture and disk diffusion. The nested-ASP-PCR method was successfully established to test the resistance mutation points 2142, 2143 and 2144 of the 23SrRNA gene of H. pylori. Among 30 samples of gastric tissue and saliva, the H. pylori detection rate of nested-ASP-PCR was 90% and 83.33%, while the detection rate of ASP-PCR was just 63% and 56.67%. Especially in the saliva samples, nested-ASP-PCR showed much higher sensitivity in H. pylori detection and resistance mutation rates than ASP-PCR. In the 99 RUT-positive gastric tissue and saliva samples, the H. pylori-positive detection rate by nested-ASP-PCR was 87 (87.88%) and 67 (67.68%), in which there were 30 wild-type and 57 mutated strains in gastric tissue and 22 wild-type and 45 mutated strains in saliva. Genotype analysis showed that three-points mixed mutations were quite common, but different resistant strains were present in gastric mucosa and saliva. Compared to the high sensitivity shown by nested-ASP-PCR, the positive detection of bacterial culture with gastric tissue samples was 50 cases, in which only 26 drug-resistant strains were found through analyzing minimum inhibitory zone of clarithromycin. The nested-ASP-PCR assay showed higher detection sensitivity than ASP-PCR and

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

    DEFF Research Database (Denmark)

    Agersø, Yvonne; Wulff, Gitte; Vaclavik, Elvira

    2006-01-01

    and oxytetracycline were almost stable through out the experimental period, but the tetracycline concentrations had no effect on prevalence of tetracycline-resistant bacteria. The presented microcosm approach simulated natural farmland conditions well and supported results from previous field studies. (c) 2006...

  7. Exploration of a new method in determining the glass transition temperature of BMGs by electrical resistivity

    Science.gov (United States)

    Guo, Jing; Zu, Fangqiu; Chen, Zhihao; Zheng, Shubin; Yuan, Yuan

    2005-07-01

    Based on a brief retrospect of the method in establishing Tg of the bulk metallic glasses (BMGs), some perplexities concerning this are pointed out. With the experimental results of Zr-Al-Ni-Cu-X (Nb,Ti) BMGs, a electrical resistivity method is proposed to determine the glass transition temperature of BMGs. With the method, we define two kinds of characteristic temperature related to the glass transition, Tg-dep and Tg-int, respectively. By comparing Tg-dep and Tg-int with Tg determined by the DSC method, we have found that, for the same alloy at the same heating rate, Tg-dep is very close to Tg-onset while Tg-int is approximate to Tg-mid. As a method to determine the glass transition temperature, the electrical resistivity method has proved to be more convenient and practical in comparison with the DSC method, especially when the DSC curve cannot show the glass transition character of BMGs. In addition, we would emphasize that when we refer to Tg, it is necessary to expatiate on the way of denoting the glass transition temperature, such as Tg-dep or Tg-int ( Tg-onset or Tg-mid), and on the heating rate, in order to avoid ambiguity.

  8. Some Remarks on the Accuracy of Wave Resistance Determination From Wave Measurements along a Parallel Cut

    OpenAIRE

    Moriconi, Alessandro; Lalli, Francesco; Di Felice, Fabio; Esposito, Pier Giorgio; Piscopia, Rodolfo

    1998-01-01

    In the present work some of the main error sources in the wave pattern resistance determination were investigated. The experimental data obtained at the Italian Ship Model Basin (longitudinal wave profiles generated by the steady motion of the Series 60 model and a hard chine Catamaran) were analyzed. It was found that, within the range of Froude numbers tested (.225 ≤ Fr ≤ .345 for the Series 60 and .5 ≤ Fr ≤ 1 for the Catamaran) two sources of uncertainty play a sign...

  9. Determining the fracture resistance of advanced SiC fiber reinforced SiC matrix composites

    International Nuclear Information System (INIS)

    Nozawa, T.; Katoh, Y.; Kishimoto, H.

    2007-01-01

    Full text of publication follows: One of the perceived advantages for highly-crystalline and stoichiometric silicon carbide (SiC) and SiC composites, e.g., advanced SiC fiber reinforced chemically-vapor-infiltrated (CVI) SiC matrix composites, is the retention of fast fracture properties after neutron irradiation at high-temperatures (∼1000 deg. C) to intermediate-doses (∼15 dpa). Accordingly, it has been clarified that the maximum allowable stress (or strain) limit seems unaffected in certain irradiation conditions. Meanwhile, understanding the mechanism of crack propagation from flaws, as potential weakest link to cause composite failure, is somehow lacking, despite that determining the strength criterion based on the fracture mechanics will eventually become important considering the nature of composites' fracture. This study aims to evaluate crack propagation behaviors of advanced SiC/SiC and to provide fundamentals on fracture resistance of the composites to define the strength limit for the practical component design. For those purposes, the effects of irreversible energies related to interfacial de-bonding, fiber bridging, and microcrack forming on the fracture resistance were evaluated. Two-dimensional SiC/SiC composites were fabricated by CVI or nano-infiltration and transient-eutectic-phase (NITE ) methods. Hi-Nicalon TM Type-S or Tyranno TM -SA fibers were used as reinforcements. In-plane mode-I fracture resistance was evaluated by the single edge notched bend technique. The key finding is the continuous Load increase with the crack growth for any types of advanced composites, while many studies specified the gradual load decrease for the conventional composites once the crack initiates. This high quasi-ductility appeared due primarily to high friction (>100 MPa) at the fiber/matrix interface using rough SiC fibers. The preliminary analysis based on the linear elastic fracture mechanics, which does not consider the effects of irreversible energy

  10. Comparative pharmacokinetics of oxytetracycline in blunt-snout bream (Megalobrama amblycephala) with single and multiple-dose oral administration.

    Science.gov (United States)

    Li, Ru-Qin; Ren, Yu-Wei; Li, Jing; Huang, Can; Shao, Jun-Hui; Chen, Xiao-Xuan; Wu, Zhi-Xin

    2015-06-01

    Research into the pharmacokinetics and residue elimination of oxytetracycline (OTC) is important both to determine the optimal dosage regimens and to establish a safe withdrawal time in fish. A depletion study is presented here for OTC in Megalobrama amblycephala with a single-dose (100 mg/kg) and multiple-dose (100 mg/kg for five consecutive days) oral administration. The study was conducted at 25 °C. As a result, a one-compartment model was developed. For the single dose, the absorption half-life was 5.79, 9.40, 6.96, and 8.06 h in the plasma, liver, kidney, and muscle, respectively. However, the absorption half-life was 3.62, 7.33, 4.59, and 6.02 h with multiple-dose oral administration. The elimination half-time in the plasma, liver, kidney, and muscle was 58.63, 126.43, 65.1, and 58.85 h when M. amblycephala was treated with a single dose. However, the elimination half-time changed to 91.75, 214.87, 126.22, and 135.84 h with multiple-dose oral administration.

  11. Effects of oxytetracycline on the abundance and community structure of nitrogen-fixing bacteria during cattle manure composting.

    Science.gov (United States)

    Sun, Jiajun; Qian, Xun; Gu, Jie; Wang, Xiaojuan; Gao, Hua

    2016-09-01

    The effects of oxytetracycline (OTC) on nitrogen-fixing bacterial communities were investigated during cattle manure composting. The abundance and community structure of nitrogen-fixing bacteria were determined by qPCR and denaturing gradient gel electrophoresis (DGGE), respectively. The matrix was spiked with OTC at four levels: no OTC, 10mg/kg dry weight (DW) OTC (L), 60mg/kg DW OTC (M), and 200mg/kg DW OTC (H). The high temperature period of composting was shorter with M and H, and the decline in temperature during the cooling stage was accelerated by OTC. OTC had a concentration-dependent inhibitory effect on the nitrogenase activity during early composting, and the nifH gene abundance declined significantly during the later composting stage. The DGGE profile and statistical analysis showed that OTC changed the nitrogen-fixing bacterial community succession and reduced the community richness and dominance. The nitrogen-fixing bacterial community structure was affected greatly by the high level of OTC. Copyright © 2016. Published by Elsevier Ltd.

  12. Distribution of resistance genetic determinants among Vibrio cholerae isolates of 2012 and 2013 outbreaks in IR Iran.

    Science.gov (United States)

    Rezaie, Niloofar; Bakhshi, Bita; Najar-Peerayeh, Shahin

    2017-03-01

    The objective of this study was to characterize antimicrobial resistance determinants in relation to antimicrobial susceptibility and genotyping profile in 20 clinical isolates of Vibrio cholerae. All of the isolates were resistant to streptomycin. The second most prevalent resistance was observed to trimethoprim (75%), co-trimoxazole (60%), tetracycline (50%), and minocycline (45%). About 50% of the isolates fulfilled the criteria of Multi Drug Resistance (MDR) phenotype. None of the isolates carried tet A, B, C, and, D determinants. This finding shows that tetracycline resistance determinants recognized so far, does not satisfactorily describe the 50% tetracycline resistance phenotype in this study, suggesting the possible contribution of other not yet characterized resistance mechanisms involved. Class 1 integron, widely distributed among enteric bacteria, was not detected among V. cholerae strains under study. Conversely, 100% of the isolates harbored SXT constin (int) , among which 70% were positive for dfrA1, strA, and strB genes. The sul1gene was present in 60% of the isolates while none of them contained floR gene. All the isolates uniformly appeared to be identical in fingerprinting profiles expected from outbreak strains. In conclusion, SXT element with its mosaic structure was the exclusive antimicrobial resistance determinant of clonal V. cholerae isolates taken from outbreaks of 2012 and 2013 in Iran. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Draft Genome Sequence of Neisseria gonorrhoeae Strain NG_869 with Penicillin, Tetracycline and Ciprofloxacin Resistance Determinants Isolated from Malaysia

    OpenAIRE

    Ang, Geik Yong; Yu, Choo Yee; Yong, Delicia Ann; Cheong, Yuet Meng; Yin, Wai-Fong; Chan, Kok-Gan

    2016-01-01

    Gonorrhea is a sexually transmitted infection caused by Neisseria gonorrhoeae and the increasing reports of multidrug-resistant gonococcal isolates are a global public health care concern. Herein, we report the genome sequence of N. gonorrhoeae strain NG_869 isolated from Malaysia which may provide insights into the drug resistance determinants in gonococcal bacteria.

  14. Crystal Structure of the Substrate-Binding Domain from Listeria monocytogenes Bile-Resistance Determinant BilE

    NARCIS (Netherlands)

    Ruiz, Stephanie J.; Schuurman-Wolters, Gea K.; Poolman, Bert

    2016-01-01

    BilE has been reported as a bile resistance determinant that plays an important role in colonization of the gastrointestinal tract by Listeria monocytogenes, the causative agent of listeriosis. The mechanism(s) by which BilE mediates bile resistance are unknown. BilE shares significant sequence

  15. A Laboratory Exercise in Physics: Determining the Resistance of Single Resistors and Series and Parallel Combinations of Resistance.

    Science.gov (United States)

    Schlenker, Richard M.

    Presented is a secondary level physics unit which introduces students to electrical resistance in series and parallel combinations, use of the voltmeter and ammeter, wiring simple circuits, and writing scientific reports. (SL)

  16. Molecular mechanisms of plasmid-determined mercury and cadmium resistances in bacteria

    International Nuclear Information System (INIS)

    Nucifora, G.

    1989-01-01

    The structural basis for induction of the broad spectrum mercurial resistance operon of pDU1358 with inorganic mercury and with phenylmercury acetate was addressed by DNA sequencing analysis (that showed that a major difference occurred in the 3' 29 base pairs of the ital merR gene compared to the merR genes of Tn501 and R100) and by lac-fusion transcription experiments regulated by merR in trans. The lac-fusion results were compared with those from a narrow spectrum operon, and the pDU1358 merR deleted at the 3' end. A hybrid mer operon containing the merR gene from pDU1358 and lacking the merB gene was inducible by both phenylmercury and inorganic Hg 2+ , showing that organomercurial lyase is not needed for induction by organomercurials. A mutant form of pDU1358 merR missing the C-terminal 17 amino acids responded to inorganic Hg 2+ but not to phenylmercury, indicating that the C-terminal region of the MerR protein of the pDU1358 mer operon is required for the recognition of phenylmercury acetate. The down regulation of the mer operon by the merD gene was also measured in trans with complementing mer operons of pDU1358 or R100 or merD - mutants. In the presence of the merD gene, beta-galactosidase activity was lowered by 2 to 4 fold. The merD gene gene product was visualized by autoradiography. The Cd 2+ resistance determinant cadA of S. aureus was investigated. The nucleotide sequence of the DNA fragment containing the cadA determinant revealed two open reading frames the larger one of which is essential for expression of cadmium resistance

  17. Determinants of carriage of resistant Staphylococcus aureus among S. aureus carriers in the Indonesian population inside and outside hospitals

    NARCIS (Netherlands)

    E.S. Lestari (Endang Sri); D.O. Duerink (Offra); U. Hadi (Usman); J.A. Severin (Juliëtte); N.J.D. Nagelkerke (Nico); K. Kuntaman (Kuntaman); H. Wahjono (Hendro); W. Gardjito (Widjoseno); A. Soejoenoes (Ariawan); P. van den Broek (Peterhans); M. Keuter (Monique); I.C. Gyssens (Inge); H.A. Verbrugh (Henri)

    2010-01-01

    textabstractOBJECTIVES: To identify determinants of carriage of resistant Staphylococcus aureus in both hospitalized patients and individuals from the community in two urban centres in Indonesia. METHODS: Staphylococcus aureus cultures and data on recent antibiotic use, demographic, socioeconomic,

  18. DETERMINATION OF THE ISSUE CONCERNING THE LIFT RESISTANCE FACTOR OF LIGHTWEIGHT CAR

    Directory of Open Access Journals (Sweden)

    A. O. Shvets

    2015-10-01

    Full Text Available Purpose. The analytical study of the connection between the longitudinal force, acting on the light-weight car, lateral and vertical forces of interaction in the contact zone «wheel – rail» with the lift resistance factor value is to provide a simple relationships between them. Methodology. Research was conducted by the method of mathematical modeling of loading the freight car when driving at different speeds on straight and curved sections of a track. Findings. Even in the absence of «lift» accordingly the classical train stability theory, as the hinge-rod system, the presence of the longitudinal compressive forces may become a factor provoking cars derailment. The main reason of wheel climbing on rails is the combination of processes of dynamic interaction between the hunting vehicle and the track with simultaneous action of longitudinal compressive forces, and not the destabilization of train as a hingedrod system. To assess the impact of the longitudinal forces value on the lift resistance factor there are presented the calculation results for the empty gondola car motion, model No. 12-532, on 250 m radius curve with 150 mm rise and cross starting of car underframe relating to the track axis in 50 mm guiding section. The calculations were made in such a curve excluding the inertial forces from outstanding acceleration and taking into account the unbalanced acceleration with the permissible speed of 65 km/h. Originality. This study provides the technique of determining the lift resistance factor by longitudinal forces, which is somewhat different from the standard one, as well as evaluates impact of rolling stock speed on this factor. Practical value. The authors clarify the current method of determining the lift resistance factor by longitudinal forces and assess the impact of rolling stock speed on the value of this factor. From these studies one can conclude that because of cars hunting their lift is possible even when the train as

  19. DETERMINATION THE PERMISSIBLE FORCES IN ASSESSING THE LIFT RESISTANT FACTOR OF FREIGHT CARS IN TRAINS

    Directory of Open Access Journals (Sweden)

    A. O. Shvets

    2016-02-01

    Full Text Available Purpose. In the analytical research are considered: 1 relationships between the longitudinal force acting on the car in the train; 2 lateral and vertical forces of interaction in the contact zone «wheel – rail»; 3 dynamic indicators of cars with the magnitude of the car lift resistance factor; 4 obtaining of the dependencies between them. Methodology. The study was conducted by an analytical method assessing the sustainability of the freight car when driving at different speeds on the straight and curved track sections. Findings. In the process of studying the motion of the train, in the investigation of transport events, as well as during the training on the simulator operator, to assess the actions of the driver, the values of the longitudinal forces in the inter car connections are used. To calculate the longitudinal compressive forces, acting on the car, in which car lift resistance factor will be equal to the allowable value (critical force. To assess the impact on the value of the longitudinal force speed, coefficients of the vertical and horizontal dynamics, as well as the wind load on the side surface of the car body are the results of calculations of motion of the empty gondola car, model № 12-532 curve radius of 250 m with a rise of 150 mm and a transverse run of body of car frame relative to the track axis of the guide section 50 mm. Originality. In this study, the technique of determining the longitudinal compressive force was shown, that is somewhat different from the standard. So, as well as assessing the impact on it the speed of rolling coefficients of vertical and horizontal dynamics and wind load on the side surface of the car body. Practical value. The authors developed proposals on the enhancement of existing methods for determining the value of the longitudinal compressive forces acting on the car in which the safety value of the car lift resistance factor will be equal to the allowable value. It will evaluate the

  20. Efficiency of oxytetracycline treatment in rainbow trout experimentally infected with Flavobacterium psychrophilum strains having different in vitro antibiotic susceptibilities

    DEFF Research Database (Denmark)

    Bruun, Morten Sichlau; Madsen, Lone; Dalsgaard, Inger

    2003-01-01

    The medication effect of oxytetracycline on groups of rainbow trout fry experimentally infected with three strains of Flavobacterium psychrophilum was investigated. The infection model was based on intraperitoneal injection of the pathogen and treatment was done using medicated feed resulting...... in 100 mg oxytetracycline/kg fish for 10 days. The three F. psychrophilum strains had different antimicrobial susceptibilities and successful treatment was only obtained in the trial using a strain with a MICOTC of 0.25 mug/ml. No effect of treatment was seen in the group infected with a strain having...

  1. Antibiotic Resistance of Gram Negatives isolates from loggerhead sea turtles (Caretta caretta) in the central Mediterranean Sea.

    Science.gov (United States)

    Foti, M; Giacopello, C; Bottari, Teresa; Fisichella, V; Rinaldo, D; Mammina, C

    2009-09-01

    Previous studies on fish and marine mammals support the hypothesis that marine species harbor antibiotic resistance and therefore may serve as reservoirs for antibiotic-resistance genetic determinants. The aim of this study was to assess the resistance to antimicrobial agents of Gram negative strains isolated from loggerhead sea turtles (Carettacaretta). Oral and cloacal swabs from 19 live-stranded loggerhead sea turtles, with hooks fixed into the gut, were analyzed. The antimicrobial resistance of the isolates to 31 antibiotics was assessed using the disk-diffusion method. Conventional biochemical tests identified Citrobacter spp., Proteus spp., Enterobacter spp., Escherichia spp., Providencia spp., Morganella spp., Pantoea spp., Pseudomonas spp. and Shewanella spp. Highest prevalences of resistance was detected to carbenicillin (100%), cephalothin (92.6%), oxytetracycline (81.3%) and amoxicillin (77.8%). The isolates showing resistance to the widest range of antibiotics were identified as Citrobacterfreundii, Proteusvulgaris, Providenciarettgeri and Pseudomonasaeruginosa. In this study, antibiotic resistant bacteria reflect marine contamination by polluted effluents and C.caretta is considered a bioindicator which can be used as a monitor for pollution.

  2. Systematic errors of EIT systems determined by easily-scalable resistive phantoms.

    Science.gov (United States)

    Hahn, G; Just, A; Dittmar, J; Hellige, G

    2008-06-01

    We present a simple method to determine systematic errors that will occur in the measurements by EIT systems. The approach is based on very simple scalable resistive phantoms for EIT systems using a 16 electrode adjacent drive pattern. The output voltage of the phantoms is constant for all combinations of current injection and voltage measurements and the trans-impedance of each phantom is determined by only one component. It can be chosen independently from the input and output impedance, which can be set in order to simulate measurements on the human thorax. Additional serial adapters allow investigation of the influence of the contact impedance at the electrodes on resulting errors. Since real errors depend on the dynamic properties of an EIT system, the following parameters are accessible: crosstalk, the absolute error of each driving/sensing channel and the signal to noise ratio in each channel. Measurements were performed on a Goe-MF II EIT system under four different simulated operational conditions. We found that systematic measurement errors always exceeded the error level of stochastic noise since the Goe-MF II system had been optimized for a sufficient signal to noise ratio but not for accuracy. In time difference imaging and functional EIT (f-EIT) systematic errors are reduced to a minimum by dividing the raw data by reference data. This is not the case in absolute EIT (a-EIT) where the resistivity of the examined object is determined on an absolute scale. We conclude that a reduction of systematic errors has to be one major goal in future system design.

  3. Systematic errors of EIT systems determined by easily-scalable resistive phantoms

    International Nuclear Information System (INIS)

    Hahn, G; Just, A; Dittmar, J; Hellige, G

    2008-01-01

    We present a simple method to determine systematic errors that will occur in the measurements by EIT systems. The approach is based on very simple scalable resistive phantoms for EIT systems using a 16 electrode adjacent drive pattern. The output voltage of the phantoms is constant for all combinations of current injection and voltage measurements and the trans-impedance of each phantom is determined by only one component. It can be chosen independently from the input and output impedance, which can be set in order to simulate measurements on the human thorax. Additional serial adapters allow investigation of the influence of the contact impedance at the electrodes on resulting errors. Since real errors depend on the dynamic properties of an EIT system, the following parameters are accessible: crosstalk, the absolute error of each driving/sensing channel and the signal to noise ratio in each channel. Measurements were performed on a Goe-MF II EIT system under four different simulated operational conditions. We found that systematic measurement errors always exceeded the error level of stochastic noise since the Goe-MF II system had been optimized for a sufficient signal to noise ratio but not for accuracy. In time difference imaging and functional EIT (f-EIT) systematic errors are reduced to a minimum by dividing the raw data by reference data. This is not the case in absolute EIT (a-EIT) where the resistivity of the examined object is determined on an absolute scale. We conclude that a reduction of systematic errors has to be one major goal in future system design

  4. Lysosomes and unfolded protein response, determinants of differential resistance of melanoma cells to vinca alkaloids.

    Science.gov (United States)

    Vincent, Laure-Anais; Attaoua, Chaker; Bellis, Michel; Rozkydalova, Lucie; Hadj-Kaddour, Kamel; Vian, Laurence; Cuq, Pierre

    2015-04-01

    On account of its strong ability to become chemoresistant after a primary response to drugs, malignant melanoma (MM) remains a therapeutic challenge. This study focuses on acquired resistance to vinca alkaloids (VAs) using VA-resistant MM cell lines (CAL1R-VCR, CAL1R-VDS, and CAL1R-VRB), established by long-term continuous exposure of parental CAL1-wt cells to vincristine (VCR), vindesine (VDS), or vinorelbine (VRB), respectively. Transcriptomic profiling using rma and rdam methods led to distinguish two cell groups: CAL1R-VCR and CAL1R-VDS, CAL1R-VRB, and CAL1-wt. mgsa of the specifically altered genes in the first group evidenced the GO terms 'lysosomal lumen' and 'vacuolar lumen' linked to underexpressed genes, and 'endoplasmic reticulum (ER) stress response' associated with overexpressed genes. A specific reduction of lysosomal enzymes, independent of acidic vacuole organelle (AVO) turnover, was observed (LTG probe) in CAL1R-VCR and CAL1R-VDS cells. It was associated with the specific lowering of cathepsin B and L, known to be involved in the lysosomal pathway of apoptosis. Confirming gene profiling, the same groups (CAL1R-VCR and CAL1R-VDS, CAL1-wt and CAL1R-VRB) could be distinguished regarding the VA-mediated changes on mean size areas and on acidic compartment volumes. These two parameters were reduced in CAL1R-VCR and CAL1R-VDS cells, suggesting a smaller AVO accumulation and thus a reduced sensitivity to lysosomal membrane permeabilization-mediated apoptosis. In addition, 'ER stress response' inhibition by tauroursodeoxycholic acid induced a higher VA sensitization of the first cell group. In conclusion, lysosomes and unfolded protein response could be key determinants of the differential resistance of MM to VAs. © 2015 Société Française de Pharmacologie et de Thérapeutique.

  5. Salmon Aquaculture and Antimicrobial Resistance in the Marine Environment

    Science.gov (United States)

    Buschmann, Alejandro H.; Tomova, Alexandra; López, Alejandra; Maldonado, Miguel A.; Henríquez, Luis A.; Ivanova, Larisa; Moy, Fred; Godfrey, Henry P.; Cabello, Felipe C.

    2012-01-01

    Antimicrobials used in salmon aquaculture pass into the marine environment. This could have negative impacts on marine environmental biodiversity, and on terrestrial animal and human health as a result of selection for bacteria containing antimicrobial resistance genes. We therefore measured the numbers of culturable bacteria and antimicrobial-resistant bacteria in marine sediments in the Calbuco Archipelago, Chile, over 12-month period at a salmon aquaculture site approximately 20 m from a salmon farm and at a control site 8 km distant without observable aquaculture activities. Three antimicrobials extensively used in Chilean salmon aquaculture (oxytetracycline, oxolinic acid, and florfenicol) were studied. Although none of these antimicrobials was detected in sediments from either site, traces of flumequine, a fluoroquinolone antimicrobial also widely used in Chile, were present in sediments from both sites during this period. There were significant increases in bacterial numbers and antimicrobial-resistant fractions to oxytetracycline, oxolinic acid, and florfenicol in sediments from the aquaculture site compared to those from the control site. Interestingly, there were similar numbers of presumably plasmid-mediated resistance genes for oxytetracycline, oxolinic acid and florfenicol in unselected marine bacteria isolated from both aquaculture and control sites. These preliminary findings in one location may suggest that the current use of large amounts of antimicrobials in Chilean aquaculture has the potential to select for antimicrobial-resistant bacteria in marine sediments. PMID:22905164

  6. Salmon aquaculture and antimicrobial resistance in the marine environment.

    Directory of Open Access Journals (Sweden)

    Alejandro H Buschmann

    Full Text Available Antimicrobials used in salmon aquaculture pass into the marine environment. This could have negative impacts on marine environmental biodiversity, and on terrestrial animal and human health as a result of selection for bacteria containing antimicrobial resistance genes. We therefore measured the numbers of culturable bacteria and antimicrobial-resistant bacteria in marine sediments in the Calbuco Archipelago, Chile, over 12-month period at a salmon aquaculture site approximately 20 m from a salmon farm and at a control site 8 km distant without observable aquaculture activities. Three antimicrobials extensively used in Chilean salmon aquaculture (oxytetracycline, oxolinic acid, and florfenicol were studied. Although none of these antimicrobials was detected in sediments from either site, traces of flumequine, a fluoroquinolone antimicrobial also widely used in Chile, were present in sediments from both sites during this period. There were significant increases in bacterial numbers and antimicrobial-resistant fractions to oxytetracycline, oxolinic acid, and florfenicol in sediments from the aquaculture site compared to those from the control site. Interestingly, there were similar numbers of presumably plasmid-mediated resistance genes for oxytetracycline, oxolinic acid and florfenicol in unselected marine bacteria isolated from both aquaculture and control sites. These preliminary findings in one location may suggest that the current use of large amounts of antimicrobials in Chilean aquaculture has the potential to select for antimicrobial-resistant bacteria in marine sediments.

  7. Rejection of Tetracycline and Oxytetracycline in Water by a Nanofiltration Membrane

    Science.gov (United States)

    Li, Weiying; Sun, Xiuli; Wang, Qing; Xu, Jingjing; Lu, Junyu

    2010-11-01

    The removal of tetracycline (TC) and oxytetracycline (OTC) by a nanofiltration (NF) membrane was studied using synthetic solutions. The effects of operation parameters (recovery and flux), feed concentration and salinity on the rejection of tetracyclines and their adsorption on membranes were investigated. TC was observed to show a high adsorptive affinity for the membrane. Almost 80% of TC and 70% of OTC were adsorbed on the membrane surface after stirring for 2000 min and over 50% of them had been adsorbed just 120 min after stir. High removal efficiencies (>90%) were observed for TC and OTC with NF membrane. Rejection ratio of OTC by NF was slightly higher than that of TC.

  8. Development of spinal deformities in Atlantic salmon and Arctic charr fed diets supplemented with oxytetracycline

    International Nuclear Information System (INIS)

    Toften, H.; Jobling, M.

    1996-01-01

    Some individuals within populations of Atlantic salmon Salmo salar and Arctic charr Salvelinus alpinus fed diets supplemented with oxytetracycline (OTC) developed spinal deformations. Possible differences in feed intake and growth of spinally deformed fish relative to fish without any deformities were investigated. Amongst Atlantic salmon, 17% of the fish fed OTC-supplemented feed developed spinal fractures, whereas none of the fish receiving the basic feed did so. Despite deformation of the spinal column, the injured fish continued to feed and grow, but at lower rates than unaffected individuals. In contrast to Atlantic salmon, Arctic charr showed no signs of spinal fractures at any time during the 65-day experiment

  9. Development of spinal deformities in Atlantic salmon and Arctic charr fed diets supplemented with oxytetracycline

    Energy Technology Data Exchange (ETDEWEB)

    Toften, H.; Jobling, M. [Norwegian Institute of Fisheries and Aquaculture, N-9005 Tromsoe (Norway)

    1996-07-01

    Some individuals within populations of Atlantic salmon Salmo salar and Arctic charr Salvelinus alpinus fed diets supplemented with oxytetracycline (OTC) developed spinal deformations. Possible differences in feed intake and growth of spinally deformed fish relative to fish without any deformities were investigated. Amongst Atlantic salmon, 17% of the fish fed OTC-supplemented feed developed spinal fractures, whereas none of the fish receiving the basic feed did so. Despite deformation of the spinal column, the injured fish continued to feed and grow, but at lower rates than unaffected individuals. In contrast to Atlantic salmon, Arctic charr showed no signs of spinal fractures at any time during the 65-day experiment.

  10. Forced degradation of metronidazole, oxytetracycline and furazolidone studies using High Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Violeta Tauber (Giugiu,

    2014-06-01

    Full Text Available The study describes the development of a HPLC -DAD method for the estimation of oxytetracycline and furazolidone in Enteroguard M - powder. The proposed method utilizes a Betasil C 18 column, (4.6 x 250 mm, 5 µm, at 300 C, optimum mobile phase consisted of 40 mM phosphate buffer (pH=7.5: methanol in gradient elution. The flow rate was optimized to 1mL/min and the detection was carried at 254 nm. The drug substance was exposed to temperature, light, oxidants, acid and basic hydrolysis, and the resultant samples were analyzed by the proposed method.

  11. Widespread distribution of a tet W determinant among tetracycline-resistant isolates of the animal pathogen Arcanobacterium pyogenes.

    Science.gov (United States)

    Billington, Stephen J; Songer, J Glenn; Jost, B Helen

    2002-05-01

    Tetracycline resistance is common among isolates of the animal commensal and opportunistic pathogen Arcanobacterium pyogenes. The tetracycline resistance determinant cloned from two bovine isolates of A. pyogenes was highly similar at the DNA level (92% identity) to the tet(W) gene, encoding a ribosomal protection tetracycline resistance protein, from the rumen bacterium Butyrivibrio fibrisolvens. The tet(W) gene was found in all 20 tetracycline-resistant isolates tested, indicating that it is a widely distributed determinant of tetracycline resistance in this organism. In 25% of tetracycline-resistant isolates, the tet(W) gene was associated with a mob gene, encoding a functional mobilization protein, and an origin of transfer, suggesting that the determinant may be transferable to other bacteria. In fact, low-frequency transfer of tet(W) was detected from mob+ A. pyogenes isolates to a tetracycline-sensitive A. pyogenes recipient. The mobile nature of this determinant and the presence of A. pyogenes in the gastrointestinal tract of cattle and pigs suggest that A. pyogenes may have inherited this determinant within the gastrointestinal tracts of these animals.

  12. Automated systems in the identification and determination of methicillin resistance among coagulase negative staphylococci

    Directory of Open Access Journals (Sweden)

    Juliana Caierão

    2006-05-01

    Full Text Available Coagulase-negative staphylococci (CoNS are an important cause of nosocomial bacteremia, specially in patients with indwelling devices or those submitted to invasive medical procedures. The identification of species and the accurate and rapid detection of methicillin resistance are directly dependent on the quality of the identification and susceptibility tests used, either manual or automated. The objective of this study was to evaluate the accuracy of two automated systems MicroScan and Vitek - in the identification of CoNS species and determination of susceptibility to methicillin, considering as gold standard the biochemical tests and the characterization of the mecA gene by polymerase chain reaction, respectively. MicroScan presented better results in the identification of CoNS species (accuracy of 96.8 vs 78.8%, respectively; isolates from the following species had no precise identification: Staphylococcus haemolyticus, S. simulans, and S. capitis. Both systems were similar in the characterization of methicillin resistance. The higher discrepancies for gene mec detection were observed among species other than S. epidermidis (S. hominis, S. saprophyticus, S. sciuri, S. haemolyticus, S. warneri, S. cohnii, and those with borderline MICs.

  13. A proposed analytic framework for determining the impact of an antimicrobial resistance intervention.

    Science.gov (United States)

    Grohn, Yrjo T; Carson, Carolee; Lanzas, Cristina; Pullum, Laura; Stanhope, Michael; Volkova, Victoriya

    2017-06-01

    Antimicrobial use (AMU) is increasingly threatened by antimicrobial resistance (AMR). The FDA is implementing risk mitigation measures promoting prudent AMU in food animals. Their evaluation is crucial: the AMU/AMR relationship is complex; a suitable framework to analyze interventions is unavailable. Systems science analysis, depicting variables and their associations, would help integrate mathematics/epidemiology to evaluate the relationship. This would identify informative data and models to evaluate interventions. This National Institute for Mathematical and Biological Synthesis AMR Working Group's report proposes a system framework to address the methodological gap linking livestock AMU and AMR in foodborne bacteria. It could evaluate how AMU (and interventions) impact AMR. We will evaluate pharmacokinetic/dynamic modeling techniques for projecting AMR selection pressure on enteric bacteria. We study two methods to model phenotypic AMR changes in bacteria in the food supply and evolutionary genotypic analyses determining molecular changes in phenotypic AMR. Systems science analysis integrates the methods, showing how resistance in the food supply is explained by AMU and concurrent factors influencing the whole system. This process is updated with data and techniques to improve prediction and inform improvements for AMU/AMR surveillance. Our proposed framework reflects both the AMR system's complexity, and desire for simple, reliable conclusions.

  14. Diversity of Antimicrobial Resistance and Virulence Determinants in Pseudomonas aeruginosa Associated with Fresh Vegetables

    Directory of Open Access Journals (Sweden)

    Kashina Allydice-Francis

    2012-01-01

    Full Text Available With the increased focus on healthy eating and consuming raw vegetables, this study assessed the extent of contamination of fresh vegetables by Pseudomonas aeruginosa in Jamaica and examined the antibiotic susceptibility profiles and the presence of various virulence associated determinants of P. aeruginosa. Analyses indicated that vegetables from retail markets and supermarkets were widely contaminated by P. aeruginosa; produce from markets were more frequently contaminated, but the difference was not significant. Lettuce and carrots were the most frequently contaminated vegetables, while tomatoes were the least. Pigment production (Pyoverdine, pyocyanin, pyomelanin and pyorubin, fluorescein and alginate were common in these isolates. Imipenem, gentamicin and ciprofloxacin were the most inhibitory antimicrobial agents. However, isolates were resistant or showed reduced susceptibility to ampicillin, chloramphenicol, sulphamethoxazole/trimethoprim and aztreonam, and up to 35% of the isolates were resistant to four antimicrobial agents. As many as 30% of the isolates were positive for the fpv1 gene, and 13% had multiple genes. Sixty-four percent of the isolates harboured an exoenzyme gene (exoS, exoT, exoU or exoY, and multiple exo genes were common. We conclude that P. aeruginosa is a major contaminant of fresh vegetables, which might be a source of infection for susceptible persons within the community.

  15. Molecular Characterization of Copper and Cadmium Resistance Determinants in the Biomining Thermoacidophilic Archaeon Sulfolobus metallicus

    Directory of Open Access Journals (Sweden)

    Alvaro Orell

    2013-01-01

    Full Text Available Sulfolobus metallicus is a thermoacidophilic crenarchaeon used in high-temperature bioleaching processes that is able to grow under stressing conditions such as high concentrations of heavy metals. Nevertheless, the genetic and biochemical mechanisms responsible for heavy metal resistance in S. metallicus remain uncharacterized. Proteomic analysis of S. metallicus cells exposed to 100 mM Cu revealed that 18 out of 30 upregulated proteins are related to the production and conversion of energy, amino acids biosynthesis, and stress responses. Ten of these last proteins were also up-regulated in S. metallicus treated in the presence of 1 mM Cd suggesting that at least in part, a common general response to these two heavy metals. The S. metallicus genome contained two complete cop gene clusters, each encoding a metallochaperone (CopM, a Cu-exporting ATPase (CopA, and a transcriptional regulator (CopT. Transcriptional expression analysis revealed that copM and copA from each cop gene cluster were cotranscribed and their transcript levels increased when S. metallicus was grown either in the presence of Cu or using chalcopyrite (CuFeS2 as oxidizable substrate. This study shows for the first time the presence of a duplicated version of the cop gene cluster in Archaea and characterizes some of the Cu and Cd resistance determinants in a thermophilic archaeon employed for industrial biomining.

  16. NOVEL ANTIBIOTIC RESISTANCE DETERMINANTS FROM AGRICULTURAL SOIL EXPOSED TO ANTIBIOTICS WIDELY USED IN HUMAN MEDICINE AND ANIMAL FARMING.

    Science.gov (United States)

    Lau, Calvin Ho-Fung; van Engelen, Kalene; Gordon, Stephen; Renaud, Justin; Topp, Edward

    2017-06-16

    Antibiotic resistance has emerged globally as one of the biggest threats to human and animal health. Although the excessive use of antibiotics is recognized for accelerating the selection for resistance, there is a growing body of evidence suggesting that natural environments are "hotspots" for the development of both ancient and contemporary resistance mechanisms. Given that pharmaceuticals can be entrained onto agricultural land through anthropogenic activities, this could be a potential driver for the emergence and dissemination of resistance in soil bacteria. Using functional metagenomics, we interrogated the "resistome" of bacterial communities found in a collection of Canadian agricultural soil, some of which had been receiving antibiotics widely used in human medicine (macrolides) or food animal production (sulfamethazine, chlortetracycline and tylosin) for up to 16 years. Of the 34 new antibiotic resistance genes (ARGs) recovered, the majority were predicted to encode for (multi)drug efflux systems, while a few share little to no homology with established resistance determinants. We characterized several novel gene products, including putative enzymes that can confer high-level resistance against aminoglycosides, sulfonamides, and broad range of beta-lactams, with respect to their resistance mechanisms and clinical significance. By coupling high-resolution proteomics analysis with functional metagenomics, we discovered an unusual peptide, PPP AZI 4 , encoded within an alternative open-reading frame not predicted by bioinformatics tools. Expression of the proline-rich PPP AZI 4 can promote resistance against different macrolides but not other ribosomal-targeting antibiotics, implicating a new macrolide-specific resistance mechanism that could be fundamentally linked to the evolutionary design of this peptide. IMPORTANCE Antibiotic resistance is a clinical phenomenon with an evolutionary link to the microbial pangenome. Genes and protogenes encoding for

  17. Improved annotation of antibiotic resistance determinants reveals microbial resistomes cluster by ecology.

    Science.gov (United States)

    Gibson, Molly K; Forsberg, Kevin J; Dantas, Gautam

    2015-01-01

    Antibiotic resistance is a dire clinical problem with important ecological dimensions. While antibiotic resistance in human pathogens continues to rise at alarming rates, the impact of environmental resistance on human health is still unclear. To investigate the relationship between human-associated and environmental resistomes, we analyzed functional metagenomic selections for resistance against 18 clinically relevant antibiotics from soil and human gut microbiota as well as a set of multidrug-resistant cultured soil isolates. These analyses were enabled by Resfams, a new curated database of protein families and associated highly precise and accurate profile hidden Markov models, confirmed for antibiotic resistance function and organized by ontology. We demonstrate that the antibiotic resistance functions that give rise to the resistance profiles observed in environmental and human-associated microbial communities significantly differ between ecologies. Antibiotic resistance functions that most discriminate between ecologies provide resistance to β-lactams and tetracyclines, two of the most widely used classes of antibiotics in the clinic and agriculture. We also analyzed the antibiotic resistance gene composition of over 6000 sequenced microbial genomes, revealing significant enrichment of resistance functions by both ecology and phylogeny. Together, our results indicate that environmental and human-associated microbial communities harbor distinct resistance genes, suggesting that antibiotic resistance functions are largely constrained by ecology.

  18. Performance Assessment and Translation of Physiologically Based Pharmacokinetic Models From acslX to Berkeley Madonna, MATLAB, and R Language: Oxytetracycline and Gold Nanoparticles As Case Examples.

    Science.gov (United States)

    Lin, Zhoumeng; Jaberi-Douraki, Majid; He, Chunla; Jin, Shiqiang; Yang, Raymond S H; Fisher, Jeffrey W; Riviere, Jim E

    2017-07-01

    Many physiologically based pharmacokinetic (PBPK) models for environmental chemicals, drugs, and nanomaterials have been developed to aid risk and safety assessments using acslX. However, acslX has been rendered sunset since November 2015. Alternative modeling tools and tutorials are needed for future PBPK applications. This forum article aimed to: (1) demonstrate the performance of 4 PBPK modeling software packages (acslX, Berkeley Madonna, MATLAB, and R language) tested using 2 existing models (oxytetracycline and gold nanoparticles); (2) provide a tutorial of PBPK model code conversion from acslX to Berkeley Madonna, MATLAB, and R language; (3) discuss the advantages and disadvantages of each software package in the implementation of PBPK models in toxicology, and (4) share our perspective about future direction in this field. Simulation results of plasma/tissue concentrations/amounts of oxytetracycline and gold from different models were compared visually and statistically with linear regression analyses. Simulation results from the original models were correlated well with results from the recoded models, with time-concentration/amount curves nearly superimposable and determination coefficients of 0.86-1.00. Step-by-step explanations of the recoding of the models in different software programs are provided in the Supplementary Data. In summary, this article presents a tutorial of PBPK model code conversion for a small molecule and a nanoparticle among 4 software packages, and a performance comparison of these software packages in PBPK model implementation. This tutorial helps beginners learn PBPK modeling, provides suggestions for selecting a suitable tool for future projects, and may lead to the transition from acslX to alternative modeling tools. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  19. Unión de los antibióticos tilosina, tilmicosina y oxitetraciclina a proteínas presentes en abejas, larvas y productos de la colmena de Apis mellifera L Binding of tylosin, tilmicosin and oxytetracycline to proteins from honeybees, larvae and beehive products

    Directory of Open Access Journals (Sweden)

    F. J. Reynaldi

    2010-12-01

    misuse may lead to antibiotic resistance of bacterial strains and honey contamination. The objective of the present work was to determine, through a biological method, the protein binding of tylosin, tilmicosin and oxytetracycline to worker jelly; honey; pollen; adult bees and larvae in order to propose their kinetic routes. The sensitivity limit of the technique used was 0.05 μg/ml for tylosin and tilmicosin and 0.01 μg/ml for oxytetracycline, respectively. The method had intra and inter-assay correlation coefficients over 0.90, respectively and a coefficient variation of intra-and inter-assay for all antibiotics and processed samples under 5%. Tylosin and oxytetracycline presented lower percentages of protein binding in tissues and hive products (average 15% in relation to those observed for tilmicosin (29%. In conclusion, tylosin is useful for AFB control in honey bee colonies due to its chemical characteristics, antimicrobial activity and levels of protein binding in bees, larvae, and beehive products.

  20. Glucocorticoid and cytokine crosstalk: Feedback, feedforward, and co-regulatory interactions determine repression or resistance.

    Science.gov (United States)

    Newton, Robert; Shah, Suharsh; Altonsy, Mohammed O; Gerber, Antony N

    2017-04-28

    Inflammatory signals induce feedback and feedforward systems that provide temporal control. Although glucocorticoids can repress inflammatory gene expression, glucocorticoid receptor recruitment increases expression of negative feedback and feedforward regulators, including the phosphatase, DUSP1, the ubiquitin-modifying enzyme, TNFAIP3, or the mRNA-destabilizing protein, ZFP36. Moreover, glucocorticoid receptor cooperativity with factors, including nuclear factor-κB (NF-κB), may enhance regulator expression to promote repression. Conversely, MAPKs, which are inhibited by glucocorticoids, provide feedforward control to limit expression of the transcription factor IRF1, and the chemokine, CXCL10. We propose that modulation of feedback and feedforward control can determine repression or resistance of inflammatory gene expression toglucocorticoid. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  1. Therapeutic response of West African Dwarf goats infected with Peste des Petits Ruminants whose oral lesions were treated with oxytetracycline long acting and gentian violet topical spray

    Directory of Open Access Journals (Sweden)

    Iniobong Chukwuebuka Ikenna Ugochukwu

    2017-11-01

    Full Text Available Objective: To assess the therapeutic response of West African Dwarf (WAD goats infected with Peste des Petits Ruminants (PPR virus treated with Amantidine hydrochloride. Methods: Apart from the presence of the characteristic clinical signs, complement ELISA and haemagglutination inhibition (HI tests were used to confirm PPR infection in the WAD goats. The oral lesions in one group were cleaned with 70% alcohol and treated with oxytetracycline long acting (LA intramuscularly (IM and topically treated with gentian violet spray which also contained oxytetracycline, and in another group WAD goats infected with PPR virus were only treated with oxytetracycline LA intramuscularly. Results: The oral lesions in the group cleaned with 70% alcohol, treated with oxyteteracycline LA intramuscularly and gentian violet spray which also contained oxytetracycline topically healed appreciably within 3 weeks before the termination of the experiment, while the group that was treated with oxyteteracycline LA intramuscularly only healed poorly. The mortality of the WAD goats with PPR whose oral lesions were not treated with gentian violet topical spray was 100%, while the mortality of WAD goats treated with oxytetracycline LA intramuscularly and gentian violet topical spray was 71.42%. Conclusions: The results of this present study suggest that in addition to antiviral therapy, cleaning with 70% alcohol, combination of oxytetracycline LA and topical spraying of the oral lesions with gentian violet spray which also contains oxytetracycline reduced the morbidity and mortality considerably.

  2. Determination of the resistance to tensile fracture of refractory mixtures of gunite

    International Nuclear Information System (INIS)

    Gomez Sanchez, A; Tomba Martinez, A.G

    2004-01-01

    The determination of the mechanical properties of cooled refractory mixtures is useful since it allows the materials to be compared for the purposes of selection and reports on their degree of internal cohesion, green or calcination, so that their structural ability can be estimated, especially during installation. Given the testing difficulties originating in the fragility of the ceramic materials, the tension test is not generally used in refractories. However, ASTM C-307 94 determines the tensile strength of cured chemical-resistant materials, for which this work considered the possibility of testing cement-based monolithic refractories in this non conventional condition. The tensile resistance to the fracture of three different refractory mixtures (A, B 1 and B 2 ), used in heat repairing by gunite in coking ovens, that were characterized by chemical, granulometric, and mineralogical analysis pycnometric density measurements. The pieces for the tests ('bone' type: length = 75 mm, maximum width = 40 mm, minimum width = 25 mm, thickness = 10 - 25 mm) were prepared by ramming of mixtures of material/water in a metallic mold; they were sinterized (1200 o C, 1h) and characterized by measures of bulk density, porosity and observation of the surface texture, in green and calcinated. The tensile tests, based on ASTM C-307 94, were performed in an Instron model 4467 machine in open air, at room temperature and position control (0.5 mm/min). The following values were obtained, in kPa: AW347±308; B 1 W738±130; B 2 W604±64. These values were lower than those for the tensile fracture module (MOR), although they displayed an equivalent order: A≤B 2 ≤B 1 . This was related to the characteristics of each refractory mixture and at the end of the pieces tested (CW)

  3. Residue depletion of oxytetracycline (OTC) and 4-epi-oxytetracycline (4-epi-OTC) in broiler chicken's claws by liquid chromatography-tandem mass spectrometry (LC-MS/MS).

    Science.gov (United States)

    Cornejo, J; Pokrant, E; Araya, D; Briceño, C; Hidalgo, H; Maddaleno, A; Araya-Jordán, C; San Martin, B

    2017-04-01

    Antibiotics are widely used in poultry production for the treatment of bacterial diseases. However, residues may remain in products and by-products destined for human consumption or animal feeding. The claws of chickens, which are a by-product of the poultry industry, can directly or indirectly enter the food chain as meals destined to feed other productive animals. Thus, it becomes necessary to determine and quantify antimicrobial residues present in this matrix. The objective of the study was to assess the depletion of oxytetracycline (OTC) and its metabolite 4-epi-OTC in broiler chicken's claws. Claws of 32 broilers treated with a therapeutic dosage of 10% OTC during 7 days were analysed. Samples were taken at days 3, 9, 15 and 19 post-treatment. As for the control group, eight broiler chickens were raised under the same conditions. Extraction was carried out through EDTA-McIlvaine buffer, and clean-up employed a SPE C-18 Sep-Pak®. Instrumental analysis was performed through LC-MS/MS. The concentrations of both analytes were determined in claw samples until day 19 post-treatment. Average concentrations were within the LOD (20 μg kg - 1 ) and LOQ (22 µg kg - 1 ) for OTC and 84 μg kg - 1 for 4-epi-OTC. Withdrawal times (WDTs) of 39 days for OTC and 54 days for 4-epi-OTC were established in claws based on 95% confidence. These findings demonstrate that claws can be a source of antimicrobial residue entry into the food chain, since the results showed that OTC and its metabolite can be found in chicken's claws for long periods, even exceeding the average lifespan of a broiler chicken.

  4. Distribution of extended-spectrum cephalosporin resistance determinants in Salmonella enterica and Escherichia coli isolated from broilers in southern Japan.

    Science.gov (United States)

    Shahada, F; Chuma, T; Kosugi, G; Kusumoto, M; Iwata, T; Akiba, M

    2013-06-01

    This study was conducted to investigate the distribution and diversity of extended-spectrum cephalosporin (ESC) resistance determinants in Salmonella enterica and Escherichia coli obtained from the same cecal samples and to provide evidence of transmission of the resistance determinants among these bacteria in broiler farms in southern Japan. Salmonella enterica and E. coli were characterized by serotyping and multilocus sequence typing, respectively. An antimicrobial susceptibility test, plasmid analysis, and identification and localization of resistance genes were performed to determine the relatedness of ESC resistance determinants among the isolates. Of 48 flocks examined, 14 had S. enterica. In total, 57 S. enterica isolates were obtained, 45 of which showed ESC resistance. Extended-spectrum cephalosporin-resistant E. coli were also obtained from all of these ESC-resistant Salmonella-positive samples. β-Lactamase genes, blaTEM-52 (38 isolates), blaCTX-M-14 (1 isolate), and blaCMY-2 (6 isolates), were carried by conjugative untypable or IncP plasmids detected in the S. enterica serovars Infantis and Manhattan. The β-lactamase genes blaCTX-M-14 (3 isolates), blaCTX-M-15 (3 isolates), blaSHV-2 (1 isolate), blaSHV-12 (2 isolates), and blaCMY-2 (32 isolates) associated with IncI1-Iγ, IncFIB, IncFIC, IncK, IncB/O, and IncY plasmids were detected in E. coli co-isolates. Restriction mapping revealed similar plasmids in Salmonella Infantis and Salmonella Manhattan and in different sequence types of E. coli. Intraspecies transmission of plasmids was suggested within S. enterica and E. coli populations, whereas interspecies transmission was not observed. This study highlights the importance of plasmids as carriers of ESC resistance determinants.

  5. Cloning and DNA sequence of the mercuric- and organomercurial-resistance determinants of plasmid pDU1358

    International Nuclear Information System (INIS)

    Griffin, H.G.; Foster, T.J.; Silver, S.; Misra, T.K.

    1987-01-01

    The broad-spectrum mercurial-resistance plasmid pDU1358 was analyzed by cloning the resistance determinants and preparing a physical and genetic map of a 45-kilobase (kb) region of the plasmid that contains two separate mercurial-resistance operons that mapped about 20 kb apart. One encoded narrow-spectrum mercurial resistance to Hg 2+ and a few organomercurials; the other specified broad-spectrum resistance to phenylmercury and additional organomercurials. Each determinant governed mercurial transport functions. Southern DNA x DNA hybridization experiments using gene-specific probes from the plasmid R100 mer operon indicated close homology with the R100 deteminant. The 2153 base pairs of the promoter-distal part of the broad-spectrum Hg 2+ -resistance operon of pDU1358 were sequenced. This region included the 3'-terminal part of the merA gene, merD, unidentified reading frame URF1, and a part of URF2 homologous to previously sequenced determinants of plasmid R100. Between the merA and merD genes, an open reading frame encoding a 212 amino acid polypeptide was identified as the merB gene that determines the enzyme organomercurial lyase that cleaves the C-Hg bond of phenylmercury

  6. Multidrug resistance in Clostridium perfringens isolated from diarrheal neonatal piglets in Thailand.

    Science.gov (United States)

    Ngamwongsatit, Bhinyada; Tanomsridachchai, Wimonrat; Suthienkul, Orasa; Urairong, Supanee; Navasakuljinda, Wichian; Janvilisri, Tavan

    2016-04-01

    Clostridium perfringens causes diarrhea in neonatal piglets, thereby affecting commercial swine farming. The objective of this study was to determine the prevalence and characterize antimicrobial resistance in C. perfringens isolated from diarrheal neonatal piglets in Thailand. A total of 260 rectal swab samples were collected from 13 farms and were subjected to C. perfringens isolation. A total of 148 samples were PCR-positive for C. perfringens toxin genes, from which 122 were recovered. All isolates were cpb2-encoding C. perfringens type A and enterotoxin gene negative. Most of the isolates were susceptible to ampicillin, bacitracin, chlorotetracycline, doxycycline, and oxytetracycline with MIC50 values ranging from 0.32 to 8 μg/ml. The high resistance rates were observed for ceftiofur, enrofloxacin, erythromycin, lincomycin, and tylosin. Among resistant isolates, 82% were resistant to more than one type of antibiotics. The distinct pattern of multiple drug resistance in C. perfringens was observed in different regions, potentially reflecting the farm specific usage of these agents. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Improved annotation of antibiotic resistance determinants reveals microbial resistomes cluster by ecology

    OpenAIRE

    Gibson, Molly K; Forsberg, Kevin J; Dantas, Gautam

    2014-01-01

    Antibiotic resistance is a dire clinical problem with important ecological dimensions. While antibiotic resistance in human pathogens continues to rise at alarming rates, the impact of environmental resistance on human health is still unclear. To investigate the relationship between human-associated and environmental resistomes, we analyzed functional metagenomic selections for resistance against 18 clinically relevant antibiotics from soil and human gut microbiota as well as a set of multidr...

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

    DEFF Research Database (Denmark)

    Agersø, Yvonne; Guardabassi, L.

    2005-01-01

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

  9. Prevalence and determinants of fecal colonization with vancomycin-resistant Enterococcus in hospitalized patients in The Netherlands

    NARCIS (Netherlands)

    van den Braak, N.; Ott, A.; van Belkum, A.; Kluytmans, J. A.; Koeleman, J. G.; Spanjaard, L.; Voss, A.; Weersink, A. J.; Vandenbroucke-Grauls, C. M.; Buiting, A. G.; Verbrugh, H. A.; Endtz, H. P.

    2000-01-01

    To determine the prevalence and determinants of fecal carriage of vancomycin-resistant enterococci (VRE) in intensive care unit (ICU), hematology-oncology, and hemodialysis patients in The Netherlands. Descriptive, multicenter study, with yearly 1-week point-prevalence assessments between 1995 and

  10. Adsorption and oxidation of SO₂in a fixed-bed reactor using activated carbon produced from oxytetracycline bacterial residue and impregnated with copper.

    Science.gov (United States)

    Zhou, Baohua; Yu, Lei; Song, Hanning; Li, Yaqi; Zhang, Peng; Guo, Bin; Duan, Erhong

    2015-02-01

    The SO₂removal ability (including adsorption and oxidation ability) of activated carbon produced from oxytetracycline bacterial residue and impregnated with copper was investigated. The activated carbon produced from oxytetracycline bacterial residue and modified with copper was characterized by x-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy. The effects of the catalysts, SO₂concentration, weight hourly space velocity, and temperature on the SO₂adsorption and oxidation activity were evaluated. Activated carbon produced from oxytetracycline bacterial residue and used as catalyst supports for copper oxide catalysts provided high catalytic activity for the adsorbing and oxidizing of SO₂from flue gases.

  11. Contact-free sheet resistance determination of large area graphene layers by an open dielectric loaded microwave cavity

    International Nuclear Information System (INIS)

    Shaforost, O.; Wang, K.; Adabi, M.; Guo, Z.; Hanham, S.; Klein, N.; Goniszewski, S.; Gallop, J.; Hao, L.

    2015-01-01

    A method for contact-free determination of the sheet resistance of large-area and arbitrary shaped wafers or sheets coated with graphene and other (semi) conducting ultrathin layers is described, which is based on an open dielectric loaded microwave cavity. The sample under test is exposed to the evanescent resonant field outside the cavity. A comparison with a closed cavity configuration revealed that radiation losses have no significant influence of the experimental results. Moreover, the microwave sheet resistance results show good agreement with the dc conductivity determined by four-probe van der Pauw measurements on a set of CVD samples transferred on quartz. As an example of a practical application, correlations between the sheet resistance and deposition conditions for CVD graphene transferred on quartz wafers are described. Our method has a high potential as measurement standard for contact-free sheet resistance measurement and mapping of large area graphene samples

  12. Genetically Determined Insulin Resistance is Characterized by Down-Regulation of Mitochondrial Oxidative Metabolism in Human Skeletal Muscle

    DEFF Research Database (Denmark)

    Kristensen, Jonas M; Skov, Vibe; Wojtaszewski, Jørgen

    2010-01-01

    Transcriptional profiling of skeletal muscle from patients with type 2 diabetes and high-risk individuals have demonstrated a co-ordinated down-regulation of oxidative phosphorylation (OxPhos) genes, suggesting a link between insulin resistance and mitochondrial dysfunction. However, whether...... mitochondrial dysfunction is a cause or consequence of insulin resistance remains to be clarified. In the present study, we tested the hypothesis that mitochondrial oxidative metabolism was down-regulated in skeletal muscle of patients with genetically determined insulin resistance. Skeletal muscle biopsies.......02), and complex V (ATP5B; p=0.005). Our data demonstrate that genetically determined insulin resistance is associated with a co-ordinated down-regulation of OxPhos components both at the transcriptional and translational level. These findings suggest that an impaired biological response to insulin in skeletal...

  13. Uptake of oxytetracycline and its phytotoxicity to alfalfa (Medicago sativa L.)

    Energy Technology Data Exchange (ETDEWEB)

    Kong, W D [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Zhu, Y G [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Liang, Y C [Ministry of Agriculture Key Laboratory of Plant Nutrition and Nutrient Cycling, Institute of Soils and Fertilizers, Chinese Academy of Agricultural Sciences, Beijing 100081 (China); Zhang, J [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Smith, F A [Soil and Land Systems, School of Earth and Environmental Sciences, University of Adelaide, DP 636, Adelaide, SA 5005 (Australia); Yang, M [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)

    2007-05-15

    A series of experiments were conducted in a hydroponic system to investigate the uptake of oxytetracycline (OTC) and its toxicity to alfalfa (Medicago sativa L.). OTC inhibited alfalfa shoot and root growth by up to 61% and 85%, respectively. The kinetics of OTC uptake could be well described by Michaelis-Menten equation with V {sub max} of 2.25 {mu}mol g{sup -1} fresh weight h{sup -1}, and K {sub m} of 0.036 mM. The uptake of OTC by alfalfa was strongly inhibited by the metabolic inhibitor, 2,4-DNP (2,4-dinitrophenol), at pH 3.5 and 6.0, but not by the aquaporin competitors, glycerol and Ag{sup +}. OTC uptake, however, was significantly inhibited by Hg{sup 2+}, suggesting that the inhibition of influx was due to general cellular stress rather than the specific action of Hg{sup 2+} on aquaporins. Results from the present study suggested that OTC uptake into alfalfa is an energy-dependent process. - Plant uptake of antibiotic oxytetracycline is energy-dependent.

  14. Impact of 4-epi-oxytetracycline on the gut microbiota and blood metabolomics of Wistar rats.

    Science.gov (United States)

    Han, Hongxing; Xiao, Hailong; Zhang, Kai; Lu, Zhenmei

    2016-03-15

    The impact of 4-epi-oxytetracycline (4-EOTC), one of the main oxytetracycline (OTC) metabolites, on the gut microbiota and physiological metabolism of Wistar rats was analyzed to explore the dynamic alterations apparent after repeated oral exposure (0.5, 5.0 or 50.0 mg/kg bw) for 15 days as shown by 16S rRNA pyrosequencing and UPLC-Q-TOF/MS analysis. Both principal component analysis and cluster analysis showed consistently altered patterns with distinct differences in the treated groups versus the control groups. 4-EOTC treatment at 5.0 or 50.0 mg/kg increased the relative abundance of the Actinobacteria, specifically Bifidobacteriaceae, and improved the synthesis of lysophosphatidylcholine (LysoPC), as shown by the lipid biomarkers LysoPC(16:0), LysoPC(18:3), LysoPC(20:3), and LysoPC(20:4). The metabolomic analysis of urine samples also identified four other decreased metabolites: diacylglycerol, sphingomyelin, triacylglycerol, and phosphatidylglycerol. Notably, the significant changes observed in these biomarkers demonstrated the ongoing disorder induced by 4-EOTC. Blood and urine analysis revealed that residual 4-EOTC accumulated in the rats, even two weeks after oral 4-EOTC administration, ceased. Thus, through thorough analysis, it can be concluded that the alteration of the gut microbiota and disorders in blood metabolomics are correlated with 4-EOTC treatment.

  15. Uptake of oxytetracycline and its phytotoxicity to alfalfa (Medicago sativa L.)

    International Nuclear Information System (INIS)

    Kong, W.D.; Zhu, Y.G.; Liang, Y.C.; Zhang, J.; Smith, F.A.; Yang, M.

    2007-01-01

    A series of experiments were conducted in a hydroponic system to investigate the uptake of oxytetracycline (OTC) and its toxicity to alfalfa (Medicago sativa L.). OTC inhibited alfalfa shoot and root growth by up to 61% and 85%, respectively. The kinetics of OTC uptake could be well described by Michaelis-Menten equation with V max of 2.25 μmol g -1 fresh weight h -1 , and K m of 0.036 mM. The uptake of OTC by alfalfa was strongly inhibited by the metabolic inhibitor, 2,4-DNP (2,4-dinitrophenol), at pH 3.5 and 6.0, but not by the aquaporin competitors, glycerol and Ag + . OTC uptake, however, was significantly inhibited by Hg 2+ , suggesting that the inhibition of influx was due to general cellular stress rather than the specific action of Hg 2+ on aquaporins. Results from the present study suggested that OTC uptake into alfalfa is an energy-dependent process. - Plant uptake of antibiotic oxytetracycline is energy-dependent

  16. Transport of oxytetracycline, chlortetracycline, and ivermectin in surface runoff from irrigated pasture.

    Science.gov (United States)

    Bair, Daniel A; Popova, Ina E; Tate, Kenneth W; Parikh, Sanjai J

    2017-09-02

    The transport of oxytetracycline, chlortetracycline, and ivermectin from manure was assessed via surface runoff on irrigated pasture. Surface runoff plots in the Sierra Foothills of Northern California were used to evaluate the effects of irrigation water application rates, pharmaceutical application conditions, vegetative cover, and vegetative filter strip length on the pharmaceutical discharge in surface runoff. Experiments were designed to permit the maximum potential transport of pharmaceuticals to surface runoff water, which included pre-irrigation to saturate soil, trimming grass where manure was applied, and laying a continuous manure strip perpendicular to the flow of water. However, due to high sorption of the pharmaceuticals to manure and soil, less than 0.1% of applied pharmaceuticals were detected in runoff water. Results demonstrated an increase of pharmaceutical transport in surface runoff with increased pharmaceutical concentration in manure, the concentration of pharmaceuticals in runoff water remained constant with increased irrigation flow rate, and no appreciable decrease in pharmaceutical runoff was produced with the vegetative filter strip length increased from 30.5 to 91.5 cm. Most of the applied pharmaceuticals were retained in the manure or within the upper 5 cm of soil directly beneath the manure application sites. As this study evaluated conditions for high transport potential, the data suggest that the risk for significant chlortetracycline, oxytetracycline, and ivermectin transport to surface water from cattle manure on irrigated pasture is low.

  17. Degradation of oxytetracycline and its impacts on biogas-producing microbial community structure.

    Science.gov (United States)

    Coban, Halil; Ertekin, Emine; Ince, Orhan; Turker, Gokhan; Akyol, Çağrı; Ince, Bahar

    2016-07-01

    The effect of veterinary antibiotics in anaerobic digesters is a concern where methane production efficiency is highly dependent on microbial community structure. In this study, both anaerobic degradation of a common veterinary antibiotic, oxytetracycline (OTC), and its effects on an anaerobic digester microbial community were investigated. Qualitative and quantitative molecular tools were used to monitor changes in microbial community structure during a 60-day batch incubation period of cow manure with the addition of different concentrations of the antibiotic. Molecular data were interpreted by a further redundancy analysis as a multivariate statistics approach. At the end of the experiment, approximately 48, 33, and 17 % of the initially added 50, 100, and 200 mg l(-1) of OTC was still present in the serum bottles which reduced the biogas production via accumulation of some of the volatile fatty acids (VFAs). Biogas production was highly correlated with Methanobacteriales and Methanosarcinales gene copy numbers, and those parameters were negatively affected with oxytetracycline and VFA concentrations.

  18. Genome Sequences of the Oxytetracycline Production Strain Streptomyces rimosus R6-500 and Two Mutants with Chromosomal Rearrangements

    KAUST Repository

    Baranasic, Damir

    2014-07-17

    The genome sequence of Streptomyces rimosus R6-500, an industrially improved strain which produces high titers of the important antibiotic oxytetracycline, is reported, as well as the genome sequences of two derivatives arising due to the genetic instability of the strain.

  19. Genome Sequences of the Oxytetracycline Production Strain Streptomyces rimosus R6-500 and Two Mutants with Chromosomal Rearrangements

    KAUST Repository

    Baranasic, Damir; Zucko, Jurica; Nair, Mridul; Pain, Arnab; Long, Paul F.; Hranueli, Daslav; Cullum, John; Starcevic, Antonio

    2014-01-01

    The genome sequence of Streptomyces rimosus R6-500, an industrially improved strain which produces high titers of the important antibiotic oxytetracycline, is reported, as well as the genome sequences of two derivatives arising due to the genetic instability of the strain.

  20. Development of an efficient extraction method for oxytetracycline in animal manure for high performance liquid chromatography analysis

    Science.gov (United States)

    Oxytetracycline (2-(amino-hydroxy-methylidene)-4-dimethylamino-5,6,10,11,12a-pentahydroxy-6-methyl-4,4a,5,5a-tetrahydrotetracene- 1,3,12-trione) is a majormember of the tetracycline antibiotics family ofwhich are widely administered to animals in concentrated animal feeding operations for purposes o...

  1. Rapid screening of oxytetracycline residue in catfish muscle by dispersive liquid-liquid microextraction and europium-sensitized luminescence

    Science.gov (United States)

    Oxytetracycline (OTC) residue in catfish muscle was screened by dispersive liquid-liquid microextraction (DLLME) and europium-sensitized luminescence (ESL). After extraction in EDTA, HCl, and acetonitrile, cleanup was carried out by DLLME, and ESL was measured at microgram = 385 nm and wavelength = ...

  2. Multivariable Analysis of the Association Between Antimicrobial Use and Antimicrobial Resistance in Escherichia coli Isolated from Apparently Healthy Pigs in Japan.

    Science.gov (United States)

    Makita, Kohei; Goto, Masaki; Ozawa, Manao; Kawanishi, Michiko; Koike, Ryoji; Asai, Tetsuo; Tamura, Yutaka

    2016-01-01

    The objective of this study was to investigate the association between antimicrobial agent use and antimicrobial resistance in Escherichia coli isolated from healthy pigs using data from 2004 to 2007 in the Japanese Veterinary Antimicrobial Resistance Monitoring System (JVARM). Fecal E. coli isolates from 250 pigs (one isolate each from a pig per farm) were examined for antimicrobial resistance. Information on the use of antimicrobials within preceding 6 months and types of farms recorded in JVARM was collected and statistically analyzed against the resistance patterns. In the univariate analysis, associations between both therapeutic and feed additive use of antimicrobials, and resistance to dihydrostreptomycin, gentamicin, kanamycin, ampicillin, cefazolin, ceftiofur, oxytetracycline, chloramphenicol, trimethoprim, nalidixic acid, enrofloxacin, colistin, and bicozamycin, and husbandry factors were investigated. In multivariable analysis, generalized estimating equations were used to control geographical intraclass correlation. Confounding for structurally unrelated associations was tested using generalized linear models. The results suggested direct and cross selections in the associations between use of aminoglycosides in reproduction farms and resistance to kanamycin, use of tetracyclines in larger farms and resistance to oxytetracycline, use of beta-lactams and resistance to ampicillin, use of phenicols and resistance to chloramphenicol, and use of fluoroquinolones and resistance to nalidixic acid and enrofloxacin. Coselection was suggested in the use of tetracyclines and chloramphenicol resistance. The associations between use of beta-lactams and dihydrostreptomycin resistance, use of macrolides and ampicillin and oxytetracycline resistance, and use of colistin and kanamycin resistance were significant, but were confounded by the simultaneous use of homologous antimicrobials.

  3. Crystal Structure of the Substrate-Binding Domain from Listeria monocytogenes Bile-Resistance Determinant BilE

    OpenAIRE

    Stephanie J. Ruiz; Gea K. Schuurman-Wolters; Bert Poolman

    2016-01-01

    BilE has been reported as a bile resistance determinant that plays an important role in colonization of the gastrointestinal tract by Listeria monocytogenes, the causative agent of listeriosis. The mechanism(s) by which BilE mediates bile resistance are unknown. BilE shares significant sequence similarity with ATP-binding cassette (ABC) importers that contribute to virulence and stress responses by importing quaternary ammonium compounds that act as compatible solutes. Assays using related co...

  4. Adiponectin expression in visceral adiposity is an important determinant of insulin resistance in morbid obesity.

    Science.gov (United States)

    Sirbu, Anca Elena; Buburuzan, Laura; Kevorkian, Steliana; Martin, Sorina; Barbu, Carmen; Copaescu, Catalin; Smeu, Bogdan; Fica, Simona

    2018-04-12

    Visceral adiposity is associated with decreased serum adiponectin levels, peripheral resistance to insulin and an increased risk of cardio-metabolic complications. However, the link between adiponectin expression in visceral adipose tissue (VAT), its serum levels and metabolic protection is controversial. The aim of this study was to investigate the relationship between the adiponectin gene expression in VAT and clinical and metabolic parameters in patients with severe obesity. This is a cross-sectional study that included 51 severely obese patients (age 43.24±11.29 years, BMI 45.13±8.67 kg/m2), extensively evaluated clinically and biologically (metabolic tests, serum adiponectin measurements, HOMA-IR) before bariatric surgery. Omental adipose tissue was sampled during the intervention and the relative quantification of adiponectin gene expression was performed by real-time PCR, using beta-actin as reference gene. Adiponectin mRNA in VAT was significantly higher in obese insulin-sensitive patients than in the rest of obese patients (p<0.05) and negatively correlated with HOMA-IR (r =-0.354, p=0.016) and uric acid (r =-0.304, p=0.045). After adjustment for gender, TG/HDL ratio and uric acid, adiponectin expresion (β= -0.439, p=0.001), waist circumference (β=0.467, p=0.001) and serum adiponectin (β =-0.339, p=0.011) remained significantly associated with HOMA-IR, together explaining more than 50% of its variation. In severely obese patients, adiponectin gene expression in VAT is negatively correlated with serum levels of uric acid and is an independent determinant, together with anthropometric parameters of visceral obesity and serum adiponectin levels, of insulin resistance.

  5. Solid oxide fuel cell cathode infiltrate particle size control and oxygen surface exchange resistance determination

    Science.gov (United States)

    Burye, Theodore E.

    Over the past decade, nano-sized Mixed Ionic Electronic Conducting (MIEC) -- micro-sized Ionic Conducting (IC) composite cathodes produced by the infiltration method have received much attention in the literature due to their low polarization resistance (RP) at intermediate (500-700°C) operating temperatures. Small infiltrated MIEC oxide nano-particle size and low intrinsic MIEC oxygen surface exchange resistance (Rs) have been two critical factors allowing these Nano-Micro-Composite Cathodes (NMCCs) to achieve high performance and/or low temperature operation. Unfortunately, previous studies have not found a reliable method to control or reduce infiltrated nano-particle size. In addition, controversy exists on the best MIEC infiltrate composition because: 1) Rs measurements on infiltrated MIEC particles are presently unavailable in the literature, and 2) bulk and thin film Rs measurements on nominally identical MIEC compositions often vary by up to 3 orders of magnitude. Here, two processing techniques, precursor nitrate solution desiccation and ceria oxide pre-infiltration, were developed to systematically produce a reduction in the average La0.6Sr0.4Co0.8Fe 0.2O3-delta (LSCF) infiltrated nano-particle size from 50 nm to 22 nm. This particle size reduction reduced the SOFC operating temperature, (defined as the temperature where RP=0.1 Ocm 2) from 650°C to 540°C. In addition, Rs values for infiltrated MIEC particles were determined for the first time through finite element modeling calculations on 3D Focused Ion Beam-Scanning Electron Microscope (FIB-SEM) reconstructions of electrochemically characterized infiltrated electrodes.

  6. Determination of antibiotic resistance of lactic acid bacteria isolated from traditional Turkish fermented dairy products.

    Science.gov (United States)

    Erginkaya, Z; Turhan, E U; Tatlı, D

    2018-01-01

    In this study, the antibiotic resistance (AR) of lactic acid bacteria (LAB) isolated from traditional Turkish fermented dairy products was investigated. Yogurt, white cheese, tulum cheese, cokelek, camız cream and kefir as dairy products were collected from various supermarkets. Lactic acid bacteria such as Lactobacillus spp., Streptococcus spp., Bifidobacterium spp., and Enterecoccus spp. were isolated from these dairy products. Lactobacillus spp. were resistant to vancomycin (58%), erythromycin (10.8%), tetracycline (4.3%), gentamicin (28%), and ciprofloxacin (26%). Streptococcus spp. were resistant to vancomycin (40%), erythromycin (10%), chloramphenicol (10%), gentamicin (20%), and ciprofloxacin (30%). Bifidobacterium spp. were resistant to vancomycin (60%), E 15 (6.6%), gentamicin (20%), and ciprofloxacin (33%). Enterococcus spp. were resistant to vancomycin (100%), erythromycin (100%), rifampin (100%), and ciprofloxacin (100%). As a result, LAB islated from dairy products in this study showed mostly resistance to vancomycin.

  7. Photoproducts of tetracycline and oxytetracycline involving self-sensitized oxidation in aqueous solutions: Effects of Ca2+ and Mg2+

    Institute of Scientific and Technical Information of China (English)

    Yong Chen; Hua Li; Zongping Wang; Tao Tao; Chun Hu

    2011-01-01

    Tetracyclines constitute one of the most important antibiotic families and represent a classic example of phototoxicity.The photoproducts of tetracyclines and their parent compounds have potentially adverse effects on natural ecosystem.In this study,the self-sensitized oxidation products of tetracycline (TC) and oxytetracycline (OTC) were determined and the effects of Ca2+ and Mg2+on self-sensitized degradation were investigated.The Ca2+ and Mg2+ in the natural water sample accounted for enhancement (pH 7.3)and inhibition (pH 9.0) of photodegradation of TC and OTC due to the formation of metal-ions complexes.The formation of Mg2+ complexes was unfavorable for the photodegradation of the tetracyclines at both pH values.In contrast,the Ca2+ complexes facilitated the attack of singlet oxygen (1O2) arising from self-sensitization at pH 7.3 and enhanced TC photodegradation.For the first time,selfsensitized oxidation products of TC and OTC were verified by quenching experiments and detected by LC/ESI-DAD-MS.The products had a nominal mass 14 Da higher than the parent drugs (designated M+14),which resulted from the 1O2 attack of the dimethylamino group on the C-4 atom of the tetracyclines.The presence of Ca2+ and Mg2+ also affected the generation of M+14 due to the formation of metal-ions complexes with TC and OTC.The findings suggest that the metal-ion complexation has significant impact on the selfsensitized oxidation processes and the photoproducts of tetracyclines.

  8. Pharmacokinetic/pharmacodynamic integration and modelling of oxytetracycline for the porcine pneumonia pathogens Actinobacillus pleuropneumoniae and Pasteurella multocida.

    Science.gov (United States)

    Dorey, L; Pelligand, L; Cheng, Z; Lees, P

    2017-10-01

    Pharmacokinetic-pharmacodynamic (PK/PD) integration and modelling were used to predict dosage schedules of oxytetracycline for two pig pneumonia pathogens, Actinobacillus pleuropneumoniae and Pasteurella multocida. Minimum inhibitory concentration (MIC) and mutant prevention concentration (MPC) were determined in broth and porcine serum. PK/PD integration established ratios of average concentration over 48 h (C av0-48 h )/MIC of 5.87 and 0.27 μg/mL (P. multocida) and 0.70 and 0.85 μg/mL (A. pleuropneumoniae) for broth and serum MICs, respectively. PK/PD modelling of in vitro time-kill curves established broth and serum breakpoint values for area under curve (AUC 0-24 h )/MIC for three levels of inhibition of growth, bacteriostasis and 3 and 4 log 10 reductions in bacterial count. Doses were then predicted for each pathogen, based on Monte Carlo simulations, for: (i) bacteriostatic and bactericidal levels of kill; (ii) 50% and 90% target attainment rates (TAR); and (iii) single dosing and daily dosing at steady-state. For 90% TAR, predicted daily doses at steady-state for bactericidal actions were 1123 mg/kg (P. multocida) and 43 mg/kg (A. pleuropneumoniae) based on serum MICs. Lower TARs were predicted from broth MIC data; corresponding dose estimates were 95 mg/kg (P. multocida) and 34 mg/kg (A. pleuropneumoniae). © 2017 The Authors. Journal of Veterinary Pharmacology and Therapeutics Published by John Wiley & Sons Ltd.

  9. Development and validation of a method for the simultaneous extraction and separate measurement of oxytetracycline, florfenicol, oxolinic acid and flumequine from marine sediments.

    Science.gov (United States)

    Norambuena, Luis; Gras, Nuri; Contreras, Sergio

    2013-08-15

    A simple and rapid method for the detection and extraction of oxolinic acid, flumequine, florfenicol and oxytetracycline from marine sediments was developed and validated. The analytes were extracted from the marine sediment using a solution of oxalic acid diluted in methanol with sonication before detection by HPLC using a diode-array detector (florfenicol and oxytetracycline) and fluorescence (oxolinic acid and flumequine). The quantification limits (QL) were 100 ng/g for oxytetracycline and florfenicol and 5 ng/g for oxolinic acid and flumequine. The coefficients of variation of the repeatability and intermediate precision were less than 10% in all of the analytes. The calibration curves were linear between 50 and 500 ng/ml for oxytetracycline and florfenicol and 1 and 20 ng/ml for oxolinic acid and flumequine. The recuperation rate for the analytes was above 86%. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Determination of the specific resistance of individual freestanding ZnO nanowires with the low energy electron point source microscope

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Dirk Henning; Beyer, Andre; Voelkel, Berthold; Goelzhaeuser, Armin [Physik Supramolekularer Systeme, Universitaet Bielefeld (Germany); Schlenker, Eva; Bakin, Andrey; Waag, Andreas [Institut fuer Halbleitertechnik, Technische Universitaet Braunschweig (Germany)

    2008-07-01

    A low energy electron point source (LEEPS) microscope is used to determine the electrical conductivity of individual freestanding ZnO nanowires in UHV. The nanowires were contacted with a manipulation tip and I-V curves were taken at different wire lengths. From those, the specific resistance was calculated and separated from the contact resistance. By comparing the specific resistances of ZnO nanowires with diameters between 1100 and 48 nm, a large surface contribution for the thin nanowires was found. A geometric model for separation between surface and bulk contributions is given. The results of electrical transport measurements on vapor phase grown ZnO nanowires are discussed, as well as the size dependence of the wire resistance.

  11. In situ determination of the static inductance and resistance of a plasma focus capacitor bank

    Energy Technology Data Exchange (ETDEWEB)

    Saw, S. H. [INTI University College, Nilai 71800 (Malaysia); Institute for Plasma Focus Studies, 32 Oakpark Drive, Chadstone, Victoria 3148 (Australia); Lee, S. [INTI University College, Nilai 71800 (Malaysia); Institute for Plasma Focus Studies, 32 Oakpark Drive, Chadstone, Victoria 3148 (Australia); National Institute of Education, Nanyang Technological University, Singapore 637616 (Singapore); Roy, F.; Chong, P. L.; Vengadeswaran, V.; Sidik, A. S. M.; Leong, Y. W.; Singh, A. [INTI University College, Nilai 71800 (Malaysia)

    2010-05-15

    The static (unloaded) electrical parameters of a capacitor bank are of utmost importance for the purpose of modeling the system as a whole when the capacitor bank is discharged into its dynamic electromagnetic load. Using a physical short circuit across the electromagnetic load is usually technically difficult and is unnecessary. The discharge can be operated at the highest pressure permissible in order to minimize current sheet motion, thus simulating zero dynamic load, to enable bank parameters, static inductance L{sub 0}, and resistance r{sub 0} to be obtained using lightly damped sinusoid equations given the bank capacitance C{sub 0}. However, for a plasma focus, even at the highest permissible pressure it is found that there is significant residual motion, so that the assumption of a zero dynamic load introduces unacceptable errors into the determination of the circuit parameters. To overcome this problem, the Lee model code is used to fit the computed current trace to the measured current waveform. Hence the dynamics is incorporated into the solution and the capacitor bank parameters are computed using the Lee model code, and more accurate static bank parameters are obtained.

  12. Detection of Genes that Determine Maize Grain Quality Characteristics and Resistance to Stress Factors

    Directory of Open Access Journals (Sweden)

    Markovskyi, O.V.

    2014-01-01

    Full Text Available 200 experimental maize samples (Maize Company were examined for the presence of genes that determine the quality characteristics of grain (wx and fl-2 genes, herbicide (bar (pat, epsps genes and insect (cry-genes resistance. The total DNA was extracted from maize living plant tissue. Primers to detect wx, fl-2, bar (pat, mepsps, CP4 epsps, cry1A(b, cry1F, cry1A.105, mcry3A, cry2Ab2, cry3Bb1, cry34Ab1, cry35Ab1 genes were designed and selected. Multiplex and Touchdown PCR were worked out. PCR amplification of certain sequences was carried out. No transgenes (bar (pat, mepsps, CP4 epsps, cry1A(b, cry1F, cry1A.105, mcry3A, cry2Ab2, cry3Bb1, cry34Ab1, cry35Ab1 were found among 200 analyzed experimental maize samples. At the same time, fl-2 gene was found in 41 samples, wx gene was found in 192 analyzed samples.

  13. In situ determination of the static inductance and resistance of a plasma focus capacitor bank

    International Nuclear Information System (INIS)

    Saw, S. H.; Lee, S.; Roy, F.; Chong, P. L.; Vengadeswaran, V.; Sidik, A. S. M.; Leong, Y. W.; Singh, A.

    2010-01-01

    The static (unloaded) electrical parameters of a capacitor bank are of utmost importance for the purpose of modeling the system as a whole when the capacitor bank is discharged into its dynamic electromagnetic load. Using a physical short circuit across the electromagnetic load is usually technically difficult and is unnecessary. The discharge can be operated at the highest pressure permissible in order to minimize current sheet motion, thus simulating zero dynamic load, to enable bank parameters, static inductance L 0 , and resistance r 0 to be obtained using lightly damped sinusoid equations given the bank capacitance C 0 . However, for a plasma focus, even at the highest permissible pressure it is found that there is significant residual motion, so that the assumption of a zero dynamic load introduces unacceptable errors into the determination of the circuit parameters. To overcome this problem, the Lee model code is used to fit the computed current trace to the measured current waveform. Hence the dynamics is incorporated into the solution and the capacitor bank parameters are computed using the Lee model code, and more accurate static bank parameters are obtained.

  14. Skid resistance determination for pavement management and wet-weather road safety

    Directory of Open Access Journals (Sweden)

    T.F. Fwa

    2017-09-01

    Full Text Available Road accidents during wet weather have been a topic of major concern of road engineers in regions of wet-tropical climate and in other parts of the world during the wet season of the year. Road safety studies indicate that approximately 20% of all road accidents occurred during wet weather, and that the skid resistance of wet pavements have a major influence on the occurrences of wet-weather accidents. Monitoring of wet pavement skid resistance has been an integral part of a typical pavement management system. However, because of the lack of prediction capability of pavement skid resistance under various rainfall intensities, the minimum skid resistance threshold for safe wet-weather driving has been specified by highway agencies based on either engineering judgement or past experience. It is shown in this paper that the single-point minimum skid resistance threshold is inadequate to offer a complete description of the skid resistance performance of the pavement sections in question for effective management of a road network. It is unable to assess the risk involved in an actual wet-weather condition where the pavement surface water-film thickness and vehicle speed are different from standard test conditions. This limitation of the current system of specifying a minimum skid resistance threshold can be overcome by adopting a theoretically sound approach to represent pavement skid resistance under different conditions of water-film thickness and vehicle speed. This paper describes the theoretical basis of the approach and the development of a mechanistically derived three-dimensional finite-element skid resistance simulation model to predict skid resistance. The application of the proposed approach and the skid resistance prediction procedure in pavement management system and wet-weather driving safety assessment is presented.

  15. Determination of nonlinear resistance voltage-current relationships by measuring harmonics

    Science.gov (United States)

    Stafford, J. M.

    1971-01-01

    Test configuration measures harmonic signal amplitudes generated in nonlinear resistance. Vacuum-type voltmeter measures low frequency sinusoidal input signal amplitude and wave-analyzer measures amplitude of harmonic signals generated in junction. Input signal harmonics amplitude must not exceed that of harmonics generated in nonlinear resistance.

  16. Mechanisms of Linezolid Resistance among Coagulase-Negative Staphylococci Determined by Whole-Genome Sequencing

    Science.gov (United States)

    Tewhey, Ryan; Gu, Bing; Kelesidis, Theodoros; Charlton, Carmen; Bobenchik, April; Hindler, Janet; Schork, Nicholas J.

    2014-01-01

    ABSTRACT Linezolid resistance is uncommon among staphylococci, but approximately 2% of clinical isolates of coagulase-negative staphylococci (CoNS) may exhibit resistance to linezolid (MIC, ≥8 µg/ml). We performed whole-genome sequencing (WGS) to characterize the resistance mechanisms and genetic backgrounds of 28 linezolid-resistant CoNS (21 Staphylococcus epidermidis isolates and 7 Staphylococcus haemolyticus isolates) obtained from blood cultures at a large teaching health system in California between 2007 and 2012. The following well-characterized mutations associated with linezolid resistance were identified in the 23S rRNA: G2576U, G2447U, and U2504A, along with the mutation C2534U. Mutations in the L3 and L4 riboproteins, at sites previously associated with linezolid resistance, were also identified in 20 isolates. The majority of isolates harbored more than one mutation in the 23S rRNA and L3 and L4 genes. In addition, the cfr methylase gene was found in almost half (48%) of S. epidermidis isolates. cfr had been only rarely identified in staphylococci in the United States prior to this study. Isolates of the same sequence type were identified with unique mutations associated with linezolid resistance, suggesting independent acquisition of linezolid resistance in each isolate. PMID:24915435

  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. GenoType HelicoDR test in the determination of antimicrobial resistance of Helicobacter pylori in Korea.

    Science.gov (United States)

    Lee, Jung Won; Kim, Nayoung; Nam, Ryoung Hee; Park, Ji Hyun; Choi, Yoon Jin; Kim, Jung Mogg; Kim, Joo Sung; Jung, Hyun Chae

    2014-09-01

    Antimicrobial resistance of Helicobacter pylori is most important factor in eradication success. GenoType HelicoDR test has been developed for rapid detection of antimicrobial resistance. The present study evaluated the clinical usefulness of GenoType HelicoDR test in Korea. To detect 23S rRNA for clarithromycin resistance and gyrA mutations for fluoroquinolone resistance, both DNA sequencing after minimal inhibitory test (MIC) and GenoType HelicoDR test were performed in H. pylori isolates from the gastric mucosa of 101 patients. The eradication results of clarithromycin and moxifloxacin-containing triple therapy were evaluated by the 23S rRNA and gyrA mutations. For 42 isolates with A2143G mutation by GenoType HelicoDR, 83.3% (35/42) of concordance rate was estimated with DNA sequencing method and 85.7% (36/42) for MIC test. For 43 isolates with N87K mutation by GenoType HelicoDR, 71.1% (31/43) of concordance rate was estimated with DNA sequencing and 88.4% (38/43) for MIC test. The sensitivity and specificity of GenoType HelicoDR test in determination of 23S rRNA mutation were 94.9% and 87.1%, and those of gyrA 98.2% and 80.0%. The sensitivity and specificity of GenoType HelicoDR test in determination of clarithromycin resistance based on MIC test were 55.0% and 80.0%, for fluoroquinolone 74.4% and 70.0%. GenoType HelicoDR test is useful to determine mutations responsible for clarithromycin or fluoroquinolone-containing eradication failure but has a limitation for the clinical applicability in determination of resistance.

  19. Determinants of between-country differences in ambulatory antibiotic use and antibiotic resistance in Europe: a longitudinal observational study.

    Science.gov (United States)

    Blommaert, A; Marais, C; Hens, N; Coenen, S; Muller, A; Goossens, H; Beutels, P

    2014-02-01

    To identify key determinants explaining country-year variations in antibiotic use and resistance. Ambulatory antibiotic use data [in defined daily doses per 1000 inhabitants per day (DIDs)] for 19 European countries from 1999 to 2007 were collected, along with 181 variables describing countries in terms of their agriculture, culture, demography, disease burden, education, healthcare organization and socioeconomics. After assessing data availability, overlap and relevance, multiple imputation generalized estimating equations were applied with a stepwise selection procedure to select significant determinants of global antibiotic use (expressed in DIDs), relative use of subgroups (amoxicillin and co-amoxiclav) and resistance of Escherichia coli and Streptococcus pneumoniae. Relative humidity, healthcare expenditure proportional to gross domestic product, feelings of distrust, proportion of population aged >65 years and availability of treatment guidelines were associated with higher total antibiotic use expressed in DIDs. Restrictions on marketing activities towards prescribers, population density, number of antibiotics, educational attainment and degree of atheism were associated with a lower number of total DIDs used. Relative prescribing of amoxicillin and co-amoxiclav was mainly determined by healthcare system choices [e.g. general practitioner (GP) registration and restricted marketing]. Specific antibiotic use was found to be a significant determinant of resistance for some but not all drug/organism combinations. Incentives to stimulate GP gatekeeping were associated with lower levels of resistance, and life expectancy at age 65+ and atheism were associated with more resistance. Myriad factors influence antibiotic use and resistance at the country level and an important part of these can be modified by policy choices.

  20. Prevalence of sulfonamide resistance genes in bacterial isolates from manured agricultural soils and pig slurry in the United Kingdom.

    Science.gov (United States)

    Byrne-Bailey, K G; Gaze, W H; Kay, P; Boxall, A B A; Hawkey, P M; Wellington, E M H

    2009-02-01

    The prevalences of three sulfonamide resistance genes, sul1, sul2, and sul3 and sulfachloropyridazine (SCP) resistance were determined in bacteria isolated from manured agricultural clay soils and slurry samples in the United Kingdom over a 2-year period. Slurry from tylosin-fed pigs amended with SCP and oxytetracycline was used for manuring. Isolates positive for sul genes were further screened for the presence of class 1 and 2 integrons. Phenotypic resistance to SCP was significantly higher in isolates from pig slurry and postapplication soil than in those from preapplication soil. Of 531 isolates, 23% carried sul1, 18% sul2, and 9% sul3 only. Two percent of isolates contained all three sul genes. Class 1 and class 2 integrons were identified in 5% and 11.7%, respectively, of sul-positive isolates. In previous reports, sul1 was linked to class 1 integrons, but in this study only 8% of sul1-positive isolates carried the intI1 gene. Sulfonamide-resistant pathogens, including Shigella flexneri, Aerococcus spp., and Acinetobacter baumannii, were identified in slurry-amended soil and soil leachate, suggesting a potential environmental reservoir. Sulfonamide resistance in Psychrobacter, Enterococcus, and Bacillus spp. is reported for the first time, and this study also provides the first description of the genotypes sul1, sul2, and sul3 outside the Enterobacteriaceae and in the soil environment.

  1. Prevalence of Sulfonamide Resistance Genes in Bacterial Isolates from Manured Agricultural Soils and Pig Slurry in the United Kingdom▿

    Science.gov (United States)

    Byrne-Bailey, K. G.; Gaze, W. H.; Kay, P.; Boxall, A. B. A.; Hawkey, P. M.; Wellington, E. M. H.

    2009-01-01

    The prevalences of three sulfonamide resistance genes, sul1, sul2, and sul3 and sulfachloropyridazine (SCP) resistance were determined in bacteria isolated from manured agricultural clay soils and slurry samples in the United Kingdom over a 2-year period. Slurry from tylosin-fed pigs amended with SCP and oxytetracycline was used for manuring. Isolates positive for sul genes were further screened for the presence of class 1 and 2 integrons. Phenotypic resistance to SCP was significantly higher in isolates from pig slurry and postapplication soil than in those from preapplication soil. Of 531 isolates, 23% carried sul1, 18% sul2, and 9% sul3 only. Two percent of isolates contained all three sul genes. Class 1 and class 2 integrons were identified in 5% and 11.7%, respectively, of sul-positive isolates. In previous reports, sul1 was linked to class 1 integrons, but in this study only 8% of sul1-positive isolates carried the intI1 gene. Sulfonamide-resistant pathogens, including Shigella flexneri, Aerococcus spp., and Acinetobacter baumannii, were identified in slurry-amended soil and soil leachate, suggesting a potential environmental reservoir. Sulfonamide resistance in Psychrobacter, Enterococcus, and Bacillus spp. is reported for the first time, and this study also provides the first description of the genotypes sul1, sul2, and sul3 outside the Enterobacteriaceae and in the soil environment. PMID:19064898

  2. Determinants of Antimicrobial Resistance in Escherichia coli Strains Isolated from Faeces and Urine of Women with Recurrent Urinary Tract Infections

    NARCIS (Netherlands)

    den Heijer, Casper D. J.; Beerepoot, Mariëlle A. J.; Prins, Jan M.; Geerlings, Suzanne E.; Stobberingh, Ellen E.

    2012-01-01

    For women with recurrent urinary tract infections (rUTI), the contribution of antibiotic use versus patient-related factors in determining the presence of antimicrobial resistance in faecal and urinary Escherichia coli, obtained from the same patient population, has not been assessed yet. Within the

  3. Method of determination of temperature and heat resistance of the points on the integrated circuit crystal surface

    Directory of Open Access Journals (Sweden)

    Popov V. M.

    2011-12-01

    Full Text Available Method for visualization of integrated circuit (IC surface temperature by means of the liquid crystal film deposited from solution on its surface is proposed. The boundaries of local regions represent isotherms with corresponding phase transitions. On the base of isotherms positions and consumed by IC power thermal resistances between crystal and environment are determined.

  4. Determination of withdrawal resistance of staple joints constructed with various members of upholstered furniture

    Directory of Open Access Journals (Sweden)

    saeid Kazemi Najafi

    2017-05-01

    Full Text Available The goal of this study was to investigate the effects of joints members type (oriented strand lumber, plywood and poplar wood (Populusdeltoides, penetration deeps of staple (12 and 17mm and adhesives (with and without adhesive on face and edge withdrawal resistance of joints fabricated with staple. Experimental specimens under withdrawal load test of face and edge consisted of two principal structural members, main member and a secondary member which were joined together by one staple. The results showed that joint member, penetration deeps and adhesive significantly influence on the withdrawal resistance. Staple withdrawal resistance in the face was higher than that in the edge. Staple holding resistance increased with the increase of penetration deep and the withdrawal resistance of joints fabricated by adhesive was higher than those without adhesive. The joints made by oriented strand lumber exhibited better performance than other two members and joints made with poplar wood had higher resistance than plywood joints. The highest face (2326N and edge (1265N withdrawal resistances were obtained from joints prepared from oriented strand lumber with adhesive and17mm penetration deeps.

  5. Pathogenicity determinants and antibiotic resistance profiles of enterococci from foods of animal origin in Turkey.

    Science.gov (United States)

    Elal Mus, Tulay; Cetinkaya, Figen; Cibik, Recep; Soyutemiz, Gul Ece; Simsek, Husniye; Coplu, Nilay

    2017-12-01

    In this study, the presence of genes responsible for the pathogenicity and antibiotic resistance profile of enterococci isolated from various foodstuffs of animal origin was investigated. The percentage prevalence of enterococci was 54.1% (203/375) and the average count was found to be 3.81 log cfu/ml-g. Species-specific primers revealed Enterococcus faecalis as the predominant species carrying one or more virulence-associated traits of efa, gelE, ace, esp and agg genetic markers. Only one E. faecium isolate (from milk) was positive for the esp gene. Regarding antibiotic resistance, the highest frequency of resistance was observed for tetracycline (21.7%), followed by quinupristin/dalfopristin (13.3%), ciprofloxacin (2.0%), penicillin (2.0%), linezolid (1.0%), ampicillin (1.0%), streptomycin (1.0%), and gentamicin (0.5%). Enterococcus faecalis showed a higher prevalence of antibiotic resistance than other enterococci. The percentage of multidrug resistance among the isolates was 3.4%. Twenty-nine E. faecalis isolates (26.6%) carrying one of the virulence-associated traits were at the same time resistant to at least one antibiotic. Our results show that foods of animal origin, including ready-to-eat products, may be reservoirs of antibiotic-resistant and potentially virulent enterococci.

  6. The Application of 2-D Resistivity and Self Potential (SP) Methods in Determining the Water Flow

    Science.gov (United States)

    Nordiana, M. M.; Tajudeen Olugbenga, Adeeko; Afiq Saharudin, Muhamad; nabila, S.; El Hidayah Ismail, Noer

    2018-04-01

    Existence of water flow at urban area will decrease the shear strength and increase hydraulic conductivity of soil which finally caused subsurface problems at this area. To avoid landslide, slope instability and disturbance of the ecosystem, good and detailed planning must be done when developing hilly area. The understanding about geological condition has to be considering before construction activities be done. Six 2-D resistivity survey lines with minimum 5 m electrode spacing were executed using Pole-dipole array. The field investigation such as borehole was carried out at multiple locations in the area where the 2-D resistivity method have been conducted. The directions and intensities of the water were evaluated with self-potential (SP) method. Subsequently, the results from borehole were used to verify the results of electrical resistivity method. Interpretation of 2-D resistivity data showed a low resistivity value (ohm-m), which appears to be a zone that is fully saturated with sandy silt and this could be an influence factor the increasing water level because sandy silt is highly permeable in nature. The borehole, support the results of 2-D resistivity method relating a saturated zone in the survey area. There is a good correlation between the 2-D resistivity investigations and the results of borehole records.

  7. Effects of oxytetracycline, tylosin, and amoxicillin antibiotics on specific methanogenic activity of anaerobic biomass

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Amin

    2012-01-01

    Materials and Methods: To evaluate the inhibitory antibiotics amoxicillin, tetracycline, and tylosin on biomass activity, specific methanogenic activity (SMA using anerobic biomass batch; into 120 ml vials: 30 ml biomass and 70 ml substrate including volatile fatty acids, mainly acetic acid and various concentrations of antibiotics were added. Methane gas production replacement through solution of KOH (2 N as an absorber of CO 2 and bromine thymol blue as indicator was measured. Each batch was tested for 10 days. Results: Based on the findings, inhibitory concentration of oxytetracycline, amoxicillin, and tylosin were 8000, 9000, and 9000 mg/L, respectively. Conclusions: This study showed that with increasing concentrations of antibiotics, the produced biogas volume from biomass per unit weight is decreased. COD removal was 42-82 % due to long retention time and adsorption to flocks.

  8. Fluorescent assay for oxytetracycline based on a long-chain aptamer assembled onto reduced graphene oxide

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Huimin; Gao, Sheng; Liu, Meng; Chang, Yangyang; Fan, Xinfei; Quan, Xie [Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024 (China)

    2013-07-15

    We report on a fluorescent assay for oxytetracycline (OTC) using a fluorescein-labeled long-chain aptamer assembled onto reduced graphene oxide (rGO). The π-π stacking interaction between aptamer and rGO causes the fluorescence of the label to be almost completely quenched via energy transfer so that the system has very low background fluorescence. The addition of OTC leads to the formation of G-quadruplex OTC complexes and prevents the adsorption of labeled aptamer on the surface of rGO. As a result, fluorescence is restored, and this effect allows for a quantitative assay of OTC over the 0.1–2 μM concentration range and with a detection limit of 10 nM. This method is simple, rapid, selective and sensitive. It may be applied to other small molecule analytes by applying appropriate aptamers. (author)

  9. Fluorescent assay for oxytetracycline based on a long-chain aptamer assembled onto reduced graphene oxide

    International Nuclear Information System (INIS)

    Zhao, Huimin; Gao, Sheng; Liu, Meng; Chang, Yangyang; Fan, Xinfei; Quan, Xie

    2013-01-01

    We report on a fluorescent assay for oxytetracycline (OTC) using a fluorescein-labeled long-chain aptamer assembled onto reduced graphene oxide (rGO). The π-π stacking interaction between aptamer and rGO causes the fluorescence of the label to be almost completely quenched via energy transfer so that the system has very low background fluorescence. The addition of OTC leads to the formation of G-quadruplex OTC complexes and prevents the adsorption of labeled aptamer on the surface of rGO. As a result, fluorescence is restored, and this effect allows for a quantitative assay of OTC over the 0.1–2 μM concentration range and with a detection limit of 10 nM. This method is simple, rapid, selective and sensitive. It may be applied to other small molecule analytes by applying appropriate aptamers. (author)

  10. New test procedure to determine fuel's knock resistance; Neues Kraftstoffpruefverfahren zur Bestimmung der Klopffestigkeit

    Energy Technology Data Exchange (ETDEWEB)

    Huber, Karl [Hochschule Ingolstadt (Germany). Thermodynamik und Verbrennungsmotoren; Hauber, Johann; Raba, Andreas [Hochschule Ingolstadt (Germany). Inst. fuer Angewandte Forschung; Nell, Robert [Rofa Laboratory and Process Analyzers, Kritzendorf (Austria). Bereich Produktentwicklung

    2013-07-15

    Knock resistance is one of the most important quality features of gasoline that is determined by standardised motor test procedures. These procedures were developed more than 80 years ago and have been used nearly unchanged since then. During a four-year research project at Ingolstadt University of Applied Sciences, the procedures for determination of octane numbers were analysed in order to develop a new engine-based test method. (orig.)

  11. Genetic Determinants of Cisplatin Resistance in Patients With Advanced Germ Cell Tumors.

    Science.gov (United States)

    Bagrodia, Aditya; Lee, Byron H; Lee, William; Cha, Eugene K; Sfakianos, John P; Iyer, Gopa; Pietzak, Eugene J; Gao, Sizhi Paul; Zabor, Emily C; Ostrovnaya, Irina; Kaffenberger, Samuel D; Syed, Aijazuddin; Arcila, Maria E; Chaganti, Raju S; Kundra, Ritika; Eng, Jana; Hreiki, Joseph; Vacic, Vladimir; Arora, Kanika; Oschwald, Dayna M; Berger, Michael F; Bajorin, Dean F; Bains, Manjit S; Schultz, Nikolaus; Reuter, Victor E; Sheinfeld, Joel; Bosl, George J; Al-Ahmadie, Hikmat A; Solit, David B; Feldman, Darren R

    2016-11-20

    Purpose Owing to its exquisite chemotherapy sensitivity, most patients with metastatic germ cell tumors (GCTs) are cured with cisplatin-based chemotherapy. However, up to 30% of patients with advanced GCT exhibit cisplatin resistance, which requires intensive salvage treatment, and have a 50% risk of cancer-related death. To identify a genetic basis for cisplatin resistance, we performed whole-exome and targeted sequencing of cisplatin-sensitive and cisplatin-resistant GCTs. Methods Men with GCT who received a cisplatin-containing chemotherapy regimen and had available tumor tissue were eligible to participate in this study. Whole-exome sequencing or targeted exon-capture-based sequencing was performed on 180 tumors. Patients were categorized as cisplatin sensitive or cisplatin resistant by using a combination of postchemotherapy parameters, including serum tumor marker levels, radiology, and pathology at surgical resection of residual disease. Results TP53 alterations were present exclusively in cisplatin-resistant tumors and were particularly prevalent among primary mediastinal nonseminomas (72%). TP53 pathway alterations including MDM2 amplifications were more common among patients with adverse clinical features, categorized as poor risk according to the International Germ Cell Cancer Collaborative Group (IGCCCG) model. Despite this association, TP53 and MDM2 alterations predicted adverse prognosis independent of the IGCCCG model. Actionable alterations, including novel RAC1 mutations, were detected in 55% of cisplatin-resistant GCTs. Conclusion In GCT, TP53 and MDM2 alterations were associated with cisplatin resistance and inferior outcomes, independent of the IGCCCG model. The finding of frequent TP53 alterations among mediastinal primary nonseminomas may explain the more frequent chemoresistance observed with this tumor subtype. A substantial portion of cisplatin-resistant GCTs harbor actionable alterations, which might respond to targeted therapies. Genomic

  12. An NS5A single optimized method to determine genotype, subtype and resistance profiles of Hepatitis C strains.

    Directory of Open Access Journals (Sweden)

    Elisabeth Andre-Garnier

    Full Text Available The objective was to develop a method of HCV genome sequencing that allowed simultaneous genotyping and NS5A inhibitor resistance profiling. In order to validate the use of a unique RT-PCR for genotypes 1-5, 142 plasma samples from patients infected with HCV were analysed. The NS4B-NS5A partial region was successfully amplified and sequenced in all samples. In parallel, partial NS3 sequences were analyzed obtained for genotyping. Phylogenetic analysis showed concordance of genotypes and subtypes with a bootstrap >95% for each type cluster. NS5A resistance mutations were analyzed using the Geno2pheno [hcv] v0.92 tool and compared to the list of known Resistant Associated Substitutions recently published. In conclusion, this tool allows determination of HCV genotypes, subtypes and identification of NS5A resistance mutations. This single method can be used to detect pre-existing resistance mutations in NS5A before treatment and to check the emergence of resistant viruses while undergoing treatment in major HCV genotypes (G1-5 in the EU and the US.

  13. Heterologous expression of oxytetracycline biosynthetic gene cluster in Streptomyces venezuelae WVR2006 to improve production level and to alter fermentation process.

    Science.gov (United States)

    Yin, Shouliang; Li, Zilong; Wang, Xuefeng; Wang, Huizhuan; Jia, Xiaole; Ai, Guomin; Bai, Zishang; Shi, Mingxin; Yuan, Fang; Liu, Tiejun; Wang, Weishan; Yang, Keqian

    2016-12-01

    Heterologous expression is an important strategy to activate biosynthetic gene clusters of secondary metabolites. Here, it is employed to activate and manipulate the oxytetracycline (OTC) gene cluster and to alter OTC fermentation process. To achieve these goals, a fast-growing heterologous host Streptomyces venezuelae WVR2006 was rationally selected among several potential hosts. It shows rapid and dispersed growth and intrinsic high resistance to OTC. By manipulating the expression of two cluster-situated regulators (CSR) OtcR and OtrR and precursor supply, the OTC production level was significantly increased in this heterologous host from 75 to 431 mg/l only in 48 h, a level comparable to the native producer Streptomyces rimosus M4018 in 8 days. This work shows that S. venezuelae WVR2006 is a promising chassis for the production of secondary metabolites, and the engineered heterologous OTC producer has the potential to completely alter the fermentation process of OTC production.

  14. A multicopy suppressor screening approach as a means to identify antibiotic resistance determinant candidates in Yersinia pestis

    Directory of Open Access Journals (Sweden)

    Moy Richard L

    2008-07-01

    Full Text Available Abstract Background Yersinia pestis is the causative agent of plague and a potential agent of bioterrorism and biowarfare. The plague biothreat and the emergence of multidrug-resistant plague underscore the need to increase our understanding of the intrinsic potential of Y. pestis for developing antimicrobial resistance and to anticipate the mechanisms of resistance that may emerge in Y. pestis. Identification of Y. pestis genes that, when overexpressed, are capable of reducing antibiotic susceptibility is a useful strategy to expose genes that this pathogen may rely upon to evolve antibiotic resistance via a vertical modality. In this study, we explored the use of a multicopy suppressor, Escherichia coli host-based screening approach as a means to expose antibiotic resistance determinant candidates in Y. pestis. Results We constructed a multicopy plasmid-based, Y. pestis genome-wide expression library of nearly 16,000 clones in E. coli and screened the library for suppressors of the antimicrobial activity of ofloxacin, a fluoroquinolone antibiotic. The screen permitted the identification of a transcriptional regulator-encoding gene (robAYp that increased the MIC99 of ofloxacin by 23-fold when overexpressed from a multicopy plasmid in Y. pestis. Additionally, we found that robAYp overexpression in Y. pestis conferred low-level resistance to many other antibiotics and increased organic solvent tolerance. Overexpression of robAYp also upregulated the expression of several efflux pumps in Y. pestis. Conclusion Our study provides proof of principle for the use of multicopy suppressor screening based on the tractable and easy-to-manipulate E. coli host as a means to identify antibiotic resistance determinant candidates of Y. pestis.

  15. Informed herbivore movement and interplant communication determine the effects of induced resistance in an individual-based model.

    Science.gov (United States)

    Rubin, Ilan N; Ellner, Stephen P; Kessler, André; Morrell, Kimberly A

    2015-09-01

    1. Plant induced resistance to herbivory affects the spatial distribution of herbivores, as well as their performance. In recent years, theories regarding the benefit to plants of induced resistance have shifted from ideas of optimal resource allocation towards a more eclectic set of theories that consider spatial and temporal plant variability and the spatial distribution of herbivores among plants. However, consensus is lacking on whether induced resistance causes increased herbivore aggregation or increased evenness, as both trends have been experimentally documented. 2. We created a spatial individual-based model that can describe many plant-herbivore systems with induced resistance, in order to analyse how different aspects of induced resistance might affect herbivore distribution, and the total damage to a plant population, during a growing season. 3. We analyse the specific effects on herbivore aggregation of informed herbivore movement (preferential movement to less-damaged plants) and of information transfer between plants about herbivore attacks, in order to identify mechanisms driving both aggregation and evenness. We also investigate how the resulting herbivore distributions affect the total damage to plants and aggregation of damage. 4. Even, random and aggregated herbivore distributions can all occur in our model with induced resistance. Highest levels of aggregation occurred in the models with informed herbivore movement, and the most even distributions occurred when the average number of herbivores per plant was low. With constitutive resistance, only random distributions occur. Damage to plants was spatially correlated, unless plants recover very quickly from damage; herbivore spatial autocorrelation was always weak. 5. Our model and results provide a simple explanation for the apparent conflict between experimental results, indicating that both increased aggregation and increased evenness of herbivores can result from induced resistance. We

  16. In vitro antimicrobial susceptibility and genetic resistance determinants of Streptococcus agalactiae isolated from mastitic cows in Brazilian dairy herds

    Directory of Open Access Journals (Sweden)

    Juliana Rosa da Silva

    2017-08-01

    Full Text Available Streptococcus agalactiae is one of the main causative agents of bovine mastitis and is associated with several economic losses for producers. Few studies have evaluated antimicrobial susceptibility and the prevalence of genetic resistance determinants among isolates of this bacterium from Brazilian dairy cattle. This work aimed to evaluate the frequency of the antimicrobial resistance genes ermA, ermB, mefA, tetO, tetM, aphA3, and aad-6, and in vitro susceptibility to the antimicrobials amikacin, erythromycin, clindamycin, tetracycline, gentamicin, penicillin, ceftiofur, and cefalotin, and the associations between resistance genotypes and phenotypes among 118 S. agalactiae isolates obtained from mastitic cows in Brazilian dairy herds. Of the resistance genes examined, ermB was found in 19 isolates (16.1%, tetO in 23 (19.5%, and tetM in 24 (20.3%. The genes ermA, mefA, aphA3, and aad-6 were not identified. There was an association between the presence of genes ermB, tetM, and tetO and phenotypic resistance to erythromycin, clindamycin, and tetracycline. Rates of resistance to the tested antibiotics varied, as follows: erythromycin (19.5%, tetracycline (35.6%, gentamicin (9.3%, clindamycin (20.3%, penicillin (3.4%, and amikacin (38.1%; conversely, all isolates were susceptible to ceftiofur and cefalotin. Antimicrobial resistance testing facilitates the treatment decision process, allowing the most judicious choice of antibiotics. Moreover, it enables regional and temporal monitoring of the resistance dynamics of this pathogen of high importance to human and animal health.

  17. Enhanced resistance to fluoroquinolones in laboratory-grown mutants & clinical isolates of Shigella due to synergism between efflux pump expression & mutations in quinolone resistance determining region

    Directory of Open Access Journals (Sweden)

    Neelam Taneja

    2015-01-01

    Full Text Available Background & objectives: There is a worldwide emergence of fluoroquinolone resistance in Shigella species. To understand the molecular mechanisms associated with fluoroquinolone resistance, naturally occurring fluoroquinolone-resistant strains and laboratory-induced spontaneous mutants of Shigella spp. were used and the relative contributions of acrAB-tolC efflux pumps, gyrase and topoisomerase target gene mutations towards fluoroquinolone resistance were determined. Methods: Eight Shigella flexneri and six S. dysenteriae clinical isolates were studied. Three consecutive mutants resistant to ciprofloxacin for S. flexneri SFM1 (≥0.25 µg/ml, SFM2 (≥4 µg/ml and SFM3 (≥32 µg/ml were selected in 15 steps from susceptible isolates by serial exposure to increasing concentrations of nalidixic acid and ciprofloxacin. Similarly, two mutants for S. dysenteriae SDM1 (≥0.25 µg/ml and SDM2 (≥4 µg/ml were selected in eight steps. After PCR amplification sequence analyses of gyrase and topoisomerase target genes were performed. Expression of efflux genes acrA, acrB, acrR and tolC was measured using real-time PCR. Results: Mutations were observed in gyrA Ser [83]→Leu, Asp [87]→Asn/Gly, Val [196]→Ala and in parC Phe [93]→Val, Ser [80]→Ile, Asp [101]→Glu and Asp [110]→Glu. Overall, acrA and acrB overexpression was associated with fluoroquinolone resistance ( p0 <0.05; while tolC and acrR expression levels did not. Interpretation & conclusions: Fluoroquinolone resistance in Shigella spp. is the end product of either a single or a combination of mutations in QRDRs and/ or efflux activity. Novel polymorphisms were observed at Val [196]→Ala in gyrA in clinical isolates and Phe [93]→Val, Asp [101]→Glu, Asp [110]→Glu and in parC in majority of laboratory-grown mutants.

  18. Automated ribotyping and antibiotic resistance determining of Bacillus spp from conjunctiva of diabetic patients

    Directory of Open Access Journals (Sweden)

    Sertaç Argun Kıvanç

    2014-02-01

    Conclusion: Diabetic patients seem to be more prone to B. cereus infections than healthy individuals. It would be greatly beneficial to understand and recognize the prevalence of microorganisms and their resistance patterns for better outcome in ocular surgeries.

  19. Genetic Determinants of Drug Resistance in Mycobacterium tuberculosis and Their Diagnostic Value

    NARCIS (Netherlands)

    Farhat, M.R.; Sultana, R.; Iartchouk, O.; Bozeman, S.; Galagan, J.; Sisk, P.; Stolte, C.; Nebenzahl-Guimaraes, H.; Jacobson, K.; Sloutsky, A.; Kaur, D.; Posey, J.; Kreiswirth, B.N.; Kurepina, N.; Rigouts, L.; Streicher, E.M.; Victor, T.C.; Warren, R.M.; Soolingen, D. van; Murray, M.

    2016-01-01

    RATIONALE: The development of molecular diagnostics that detect both the presence of Mycobacterium tuberculosis in clinical samples and drug resistance-conferring mutations promises to revolutionize patient care and interrupt transmission by ensuring early diagnosis. However, these tools require the

  20. Phylogenetic relatedness determined between antibiotic resistance and 16S rRNA genes in actinobacteria

    Czech Academy of Sciences Publication Activity Database

    Ságová-Marečková, M.; Ulanová, Dana; Šanderová, P.; Omelka, M.; Kameník, Zdeněk; Olšovská, J.; Kopecký, J.

    2015-01-01

    Roč. 15, APR 2015 (2015) ISSN 1471-2180 Institutional support: RVO:61388971 Keywords : Actinobacteria * 16S rRNA diversity * Resistance genes Subject RIV: EH - Ecology, Behaviour Impact factor: 2.581, year: 2015

  1. Rapid determination of anti-tuberculosis drug resistance from whole-genome sequences

    KAUST Repository

    Coll, Francesc; McNerney, Ruth; Preston, Mark D; Guerra-Assunç ã o, José Afonso; Warry, Andrew; Hill-Cawthorne, Grant A.; Mallard, Kim; Nair, Mridul; Miranda, Anabela; Alves, Adriana; Perdigã o, Joã o; Viveiros, Miguel; Portugal, Isabel; Hasan, Zahra; Hasan, Rumina; Glynn, Judith R; Martin, Nigel; Pain, Arnab; Clark, Taane G

    2015-01-01

    Mycobacterium tuberculosis drug resistance (DR) challenges effective tuberculosis disease control. Current molecular tests examine limited numbers of mutations, and although whole genome sequencing approaches could fully characterise DR, data

  2. Identifying Chloris Species from Cuban Citrus Orchards and Determining Their Glyphosate-Resistance Status

    Directory of Open Access Journals (Sweden)

    Enzo R. Bracamonte

    2017-11-01

    Full Text Available The Chloris genus is a C4 photosynthetic species mainly distributed in tropical and subtropical regions. Populations of three Chloris species occurring in citrus orchards from central Cuba, under long history glyphosate-based weed management, were studied for glyphosate-resistant status by characterizing their herbicide resistance/tolerance mechanisms. Morphological and molecular analyses allowed these species to be identified as C. ciliata Sw., Chloris elata Desv., and Chloris barbata Sw. Based on the glyphosate rate that causes 50% mortality of the treated plants, glyphosate resistance (R was confirmed only in C. elata, The R population was 6.1-fold more resistant compared to the susceptible (S population. In addition, R plants of C. elata accumulated 4.6-fold less shikimate after glyphosate application than S plants. Meanwhile, populations of C. barbata and C. ciliata with or without glyphosate application histories showed similar LD50 values and shikimic acid accumulation rates, demonstrating that resistance to glyphosate have not evolved in these species. Plants of R and S populations of C. elata differed in 14C-glyphosate absorption and translocation. The R population exhibited 27.3-fold greater 5-enolpyruvyl shikimate-3-phosphate synthase (EPSPS activity than the S population due to a target site mutation corresponding to a Pro-106-Ser substitution found in the EPSPS gene. These reports show the innate tolerance to glyphosate of C. barbata and C. ciliata, and confirm the resistance of C. elata to this herbicide, showing that both non-target site and target-site mechanisms are involved in its resistance to glyphosate. This is the first case of herbicide resistance in Cuba.

  3. Epistatic determinism of durum wheat resistance to the wheat spindle streak mosaic virus.

    Science.gov (United States)

    Holtz, Yan; Bonnefoy, Michel; Viader, Véronique; Ardisson, Morgane; Rode, Nicolas O; Poux, Gérard; Roumet, Pierre; Marie-Jeanne, Véronique; Ranwez, Vincent; Santoni, Sylvain; Gouache, David; David, Jacques L

    2017-07-01

    The resistance of durum wheat to the Wheat spindle streak mosaic virus (WSSMV) is controlled by two main QTLs on chromosomes 7A and 7B, with a huge epistatic effect. Wheat spindle streak mosaic virus (WSSMV) is a major disease of durum wheat in Europe and North America. Breeding WSSMV-resistant cultivars is currently the only way to control the virus since no treatment is available. This paper reports studies of the inheritance of WSSMV resistance using two related durum wheat populations obtained by crossing two elite cultivars with a WSSMV-resistant emmer cultivar. In 2012 and 2015, 354 recombinant inbred lines (RIL) were phenotyped using visual notations, ELISA and qPCR and genotyped using locus targeted capture and sequencing. This allowed us to build a consensus genetic map of 8568 markers and identify three chromosomal regions involved in WSSMV resistance. Two major regions (located on chromosomes 7A and 7B) jointly explain, on the basis of epistatic interactions, up to 43% of the phenotypic variation. Flanking sequences of our genetic markers are provided to facilitate future marker-assisted selection of WSSMV-resistant cultivars.

  4. Resistance to infection with Eimeria vermiformis in mouse radiation chimeras is determined by donor bone-marrow cells

    International Nuclear Information System (INIS)

    Joysey, H.S.; Wakelin, D.; Rose, M.E.

    1988-01-01

    The course of infection with Eimeria vermiformis was determined in BALB/b, BALB/c, and C57BL/10ScSn (B10) mice and in radiation chimeras prepared from the H-2-compatible BALB/b and B10 mice. The BALB strains, irrespective of H-2 haplotype, were resistant, the B10 mice were susceptible, and in the chimeras infection was characterized by the genotype of the donated bone-marrow cells and not by the phenotype of the recipient. Thus, the genetic control of relative resistance or susceptibility to infection with this parasite is expressed through bone-marrow-derived cells

  5. Validation of the method for determination of the thermal resistance of fouling in shell and tube heat exchangers

    International Nuclear Information System (INIS)

    Markowski, Mariusz; Trafczynski, Marian; Urbaniec, Krzysztof

    2013-01-01

    Highlights: • Heat recovery in a heat exchanger network (HEN). • A novel method for on-line determination of the thermal resistance of fouling is presented. • Details are developed for shell and tube heat exchangers. • The method was validated and sensibility analysis was carried out. • Developed approach allows long-term monitoring of changes in the HEN efficiency. - Abstract: A novel method for on-line determination of the thermal resistance of fouling in shell and tube heat exchangers is presented. It can be applied under the condition that the data on pressure, temperature, mass flowrate and thermophysical properties of both heat-exchanging media are continuously available. The calculation algorithm for use in the novel method is robust and ensures reliable determination of the thermal resistance of fouling even if the operating parameters fluctuate. The method was validated using measurement data retrieved from the operation records of a heat exchanger network connected with a crude distillation unit rated 800 t/h. Sensibility analysis of the method was carried out and the calculated values of the thermal resistance of fouling were critically reviewed considering the results of qualitative evaluation of fouling layers in the exchangers inspected during plant overhaul

  6. Evaluation of the Presence and Levels of Enrofloxacin, Ciprofloxacin, Sulfaquinoxaline and Oxytetracycline in Broiler Chickens after Drug Administration

    Science.gov (United States)

    da Silva, Guilherme Resende; Lanza, Isabela Pereira; Ribeiro, Ana Cláudia dos Santos Rossi; Lana, Ângela Maria Quintão; Lara, Leonardo José Camargos

    2016-01-01

    The depletion times of enrofloxacin and its metabolite ciprofloxacin as well as sulfaquinoxaline and oxytetracycline were evaluated in broiler chickens that had been subjected to pharmacological treatment. The presence and residue levels of these drugs in muscle tissue were evaluated using an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method that was validated in this work. The results showed the presence of all antimicrobial residues; however, the presence of residues at concentrations higher than the drugs’ maximum residue limit (MRL) of 100 μg kg-1 was found only during the treatment period for oxytetracycline and until two days after discontinuation of the medication for enrofloxacin, ciprofloxacin and sulfaquinoxaline. It was concluded that the residues of all antimicrobials were rapidly metabolized from the broiler muscles; after four days of withdrawal, the levels were lower than the limit of quantification (LOQ) of the method for the studied analytes. PMID:27846314

  7. Evaluation of the Presence and Levels of Enrofloxacin, Ciprofloxacin, Sulfaquinoxaline and Oxytetracycline in Broiler Chickens after Drug Administration.

    Science.gov (United States)

    de Assis, Débora Cristina Sampaio; da Silva, Guilherme Resende; Lanza, Isabela Pereira; Ribeiro, Ana Cláudia Dos Santos Rossi; Lana, Ângela Maria Quintão; Lara, Leonardo José Camargos; de Figueiredo, Tadeu Chaves; Cançado, Silvana de Vasconcelos

    2016-01-01

    The depletion times of enrofloxacin and its metabolite ciprofloxacin as well as sulfaquinoxaline and oxytetracycline were evaluated in broiler chickens that had been subjected to pharmacological treatment. The presence and residue levels of these drugs in muscle tissue were evaluated using an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method that was validated in this work. The results showed the presence of all antimicrobial residues; however, the presence of residues at concentrations higher than the drugs' maximum residue limit (MRL) of 100 μg kg-1 was found only during the treatment period for oxytetracycline and until two days after discontinuation of the medication for enrofloxacin, ciprofloxacin and sulfaquinoxaline. It was concluded that the residues of all antimicrobials were rapidly metabolized from the broiler muscles; after four days of withdrawal, the levels were lower than the limit of quantification (LOQ) of the method for the studied analytes.

  8. Unique Determinants of Neuraminidase Inhibitor Resistance among N3, N7, and N9 Avian Influenza Viruses.

    Science.gov (United States)

    Song, Min-Suk; Marathe, Bindumadhav M; Kumar, Gyanendra; Wong, Sook-San; Rubrum, Adam; Zanin, Mark; Choi, Young-Ki; Webster, Robert G; Govorkova, Elena A; Webby, Richard J

    2015-11-01

    Human infections with avian influenza viruses are a serious public health concern. The neuraminidase (NA) inhibitors (NAIs) are the frontline anti-influenza drugs and are the major option for treatment of newly emerging influenza. Therefore, it is essential to identify the molecular markers of NAI resistance among specific NA subtypes of avian influenza viruses to help guide clinical management. NAI-resistant substitutions in NA subtypes other than N1 and N2 have been poorly studied. Here, we identified NA amino acid substitutions associated with NAI resistance among influenza viruses of N3, N7, and N9 subtypes which have been associated with zoonotic transmission. We applied random mutagenesis and generated recombinant influenza viruses carrying single or double NA substitution(s) with seven internal genes from A/Puerto Rico/8/1934 (H1N1) virus. In a fluorescence-based NA inhibition assay, we identified three categories of NA substitutions associated with reduced inhibition by NAIs (oseltamivir, zanamivir, and peramivir): (i) novel subtype-specific substitutions in or near the enzyme catalytic site (R152W, A246T, and D293N, N2 numbering), (ii) subtype-independent substitutions (E119G/V and/or D and R292K), and (iii) substitutions previously reported in other subtypes (Q136K, I222M, and E276D). Our data show that although some markers of resistance are present across NA subtypes, other subtype-specific markers can only be determined empirically. The number of humans infected with avian influenza viruses is increasing, raising concerns of the emergence of avian influenza viruses resistant to neuraminidase (NA) inhibitors (NAIs). Since most studies have focused on NAI-resistance in human influenza viruses, we investigated the molecular changes in NA that could confer NAI resistance in avian viruses grown in immortalized monolayer cells, especially those of the N3, N7, and N9 subtypes, which have caused human infections. We identified not only numerous NAI-resistant

  9. Handling technique of spore-forming bacteria in radiation sterilization. 2. Determination of numbers and radiation resistance of spores

    International Nuclear Information System (INIS)

    Koshikawa, Tomihiko

    1994-01-01

    Stepwise ten-fold dilution of bacterial solution is required in the determination of bacterial spores. For this, the selection of diluted solution is important according to the purpose of experiment. First, the preparation of suspension of bacterial spores and selection of diluted solution are presented. Then, a method for determining the number of bacterial spores in materials is outlined in terms of dilution methods of bacterial solution (shaking and homogenization) and application method of diluted solution to the plating medium. Finally, a method for determining radiation resistance of spore-forming bacteria is explained according to the measurement conditions (suspension of bacterial spores and filters applied with bacterial spores). (N.K.)

  10. Handling technique of spore-forming bacteria in radiation sterilization. 2. Determination of numbers and radiation resistance of spores

    Energy Technology Data Exchange (ETDEWEB)

    Koshikawa, Tomihiko [Japan Radioisotope Association, Shiga (Japan). Koka Laboratory

    1994-12-01

    Stepwise ten-fold dilution of bacterial solution is required in the determination of bacterial spores. For this, the selection of diluted solution is important according to the purpose of experiment. First, the preparation of suspension of bacterial spores and selection of diluted solution are presented. Then, a method for determining the number of bacterial spores in materials is outlined in terms of dilution methods of bacterial solution (shaking and homogenization) and application method of diluted solution to the plating medium. Finally, a method for determining radiation resistance of spore-forming bacteria is explained according to the measurement conditions (suspension of bacterial spores and filters applied with bacterial spores). (N.K.).

  11. Phenotypic Plasticity Determines Cancer Stem Cell Therapeutic Resistance in Oral Squamous Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Adrian Biddle

    2016-02-01

    Full Text Available Cancer stem cells (CSCs drive tumour spread and therapeutic resistance, and can undergo epithelial-to-mesenchymal transition (EMT and mesenchymal-to-epithelial transition (MET to switch between epithelial and post-EMT sub-populations. Examining oral squamous cell carcinoma (OSCC, we now show that increased phenotypic plasticity, the ability to undergo EMT/MET, underlies increased CSC therapeutic resistance within both the epithelial and post-EMT sub-populations. The post-EMT CSCs that possess plasticity exhibit particularly enhanced therapeutic resistance and are defined by a CD44highEpCAMlow/−CD24+ cell surface marker profile. Treatment with TGFβ and retinoic acid (RA enabled enrichment of this sub-population for therapeutic testing, through which the endoplasmic reticulum (ER stressor and autophagy inhibitor Thapsigargin was shown to selectively target these cells. Demonstration of the link between phenotypic plasticity and therapeutic resistance, and development of an in vitro method for enrichment of a highly resistant CSC sub-population, provides an opportunity for the development of improved chemotherapeutic agents that can eliminate CSCs.

  12. Phenotypic Plasticity Determines Cancer Stem Cell Therapeutic Resistance in Oral Squamous Cell Carcinoma.

    Science.gov (United States)

    Biddle, Adrian; Gammon, Luke; Liang, Xiao; Costea, Daniela Elena; Mackenzie, Ian C

    2016-02-01

    Cancer stem cells (CSCs) drive tumour spread and therapeutic resistance, and can undergo epithelial-to-mesenchymal transition (EMT) and mesenchymal-to-epithelial transition (MET) to switch between epithelial and post-EMT sub-populations. Examining oral squamous cell carcinoma (OSCC), we now show that increased phenotypic plasticity, the ability to undergo EMT/MET, underlies increased CSC therapeutic resistance within both the epithelial and post-EMT sub-populations. The post-EMT CSCs that possess plasticity exhibit particularly enhanced therapeutic resistance and are defined by a CD44(high)EpCAM(low/-) CD24(+) cell surface marker profile. Treatment with TGFβ and retinoic acid (RA) enabled enrichment of this sub-population for therapeutic testing, through which the endoplasmic reticulum (ER) stressor and autophagy inhibitor Thapsigargin was shown to selectively target these cells. Demonstration of the link between phenotypic plasticity and therapeutic resistance, and development of an in vitro method for enrichment of a highly resistant CSC sub-population, provides an opportunity for the development of improved chemotherapeutic agents that can eliminate CSCs.

  13. Analytical profiling of mutations in quinolone resistance determining region of gyrA gene among UPEC.

    Directory of Open Access Journals (Sweden)

    Lesley R Varughese

    Full Text Available Mutations in gyrA are the primary cause of quinolone resistance encountered in gram-negative clinical isolates. The prospect of this work was to analyze the role of gyrA mutations in eliciting high quinolone resistance in uropathogenic E.coli (UPEC through molecular docking studies. Quinolone susceptibility testing of 18 E.coli strains isolated from UTI patients revealed unusually high resistance level to all the quinolones used; especially norfloxacin and ciprofloxacin. The QRDR of gyrA was amplified and sequenced. Mutations identified in gyrA of E.coli included Ser83Leu, Asp87Asn and Ala93Gly/Glu. Contrasting previous reports, we found Ser83Leu substitution in sensitive strains. Strains with S83L, D87N and A93E (A15 and A26 demonstrated norfloxacin MICs ≥1024mg/L which could be proof that Asp87Asn is necessary for resistance phenotype. Resistance to levofloxacin was comparatively lower in all the isolates. Docking of 4 quinolones (ciprofloxacin, ofloxacin, levofloxacin and norfloxacin to normal and mutated E.coli gyrase A protein demonstrated lower binding energies for the latter, with significant displacement of norfloxacin in the mutated GyrA complex and least displacement in case of levofloxacin.

  14. Effectiveness of oxytetracycline in reducing the bacterial load in rohu fish (Labeo rohita, Hamilton) under laboratory culture condition

    OpenAIRE

    Syed Ariful Haque; Md. Shaheed Reza; Md. Rajib Sharker; Md. Mokhlasur Rahman; Md. Ariful Islam

    2014-01-01

    Objective: To observe the effectiveness of most widely used antibiotic, oxytetracycline (OTC) in reducing the bacterial load in rohu fish under artificial culture condition in the laboratory. Methods: The experiment was conducted in the Faculty Fisheries, Bangladesh Agricultural University, Mymensingh-2202. The fish were reared in 8 aquaria where fish in 5 aquaria were used for replication of the treatment (experimental group) and fish in remaining 3 aquaria were considered...

  15. Enterococcus spp. Resistant to Multiple Antimicrobial Drugs and Determination of Fecal Contamination Levels in Mangrove Oysters (Crassostrea rhizophorae

    Directory of Open Access Journals (Sweden)

    Cynthia Annes Rubião

    2017-08-01

    Full Text Available ABSTRACT The aim of this study was to determine and compare the Most Probable Number (MPN of Total Coliforms (TC, Escherichia coli and Enterococcus spp. and to characterize the antimicrobial resistance profiles of Enterococcus spp. isolated from oysters collected in the Barra de Guaratiba Mangrove, Rio de Janeiro, Brazil. The enumeration of E. coli has been used to indicate fecal contamination and hygienic-sanitary conditions of bivalve molluscs. Enterococci are capable to transfer several antimicrobial resistance genes to pathogenic bacteria, including those from Gram-negative group. The oysters were bought from local fishermen and a total of 123 individuals were analyzed. The TC, E. coli and Enterococcus spp. MPN mean were 26,300/100 g, 3,260/100 g and 2,820/100 g, respectively. The only correlation found was between TC and E. coli. Two strains of Enterococcus spp. were resistant to three different antimicrobial categories, including a high level resistance to streptomycin. One strain presented intermediate resistance to vancomycin. The E. coli levels exceeded the limits established by international legislation. This microbiological contamination in oysters reflects the water pollution and indicates a probable contamination of other seafood species from this mangrove, which can represent a risk for consumers and a threat to the environment and public health.

  16. A technique for the determination of center of gravity and rolling resistance for tilt-seat wheelchairs.

    Science.gov (United States)

    Lemaire, E D; Lamontagne, M; Barclay, H W; John, T; Martel, G

    1991-01-01

    A balance platform setup was defined for use in the determination of the center of gravity in the sagittal plane for a wheelchair and patient. Using the center of gravity information, measurements from the wheelchair and patient (weight, tire coefficients of friction), and various assumptions (constant speed, level-concrete surface, patient-wheelchair system is a rigid body), a method for estimating the rolling resistance for a wheelchair was outlined. The center of gravity and rolling resistance techniques were validated against criterion values (center of gravity error = 1 percent, rolling resistance root mean square error = 0.33 N, rolling resistance Pearson correlation coefficient = 0.995). Consistent results were also obtained from a test dummy and five subjects. Once the center of gravity is known, it is possible to evaluate the stability of a wheelchair (in terms of tipping over) and the interaction between the level of stability and rolling resistance. These quantitative measures are expected to be of use in the setup of wheelchairs with a variable seat angle and variable wheelbase length or when making comparisons between different wheelchairs.

  17. Comparison of Vibrio harveyi strains isolated from shrimp farms and from culture collection in terms of toxicity and antibiotic resistance.

    Science.gov (United States)

    Nakayama, Tatsuya; Ito, Emi; Nomura, Nakao; Nomura, Nobuhiko; Matsumura, Masatoshi

    2006-05-01

    Vibrio harveyi strains isolated from shrimp farms (wild strains) were compared with those from culture collections in terms of minimum inhibitory concentration (MIC) and toxicity. Wild strains had higher MIC values for four antibiotics (kanamycin, carbenicillin, oxytetracycline and ampicillin) and also showed higher toxicity compared with culture collection strains. Vibrio harveyi with the lowest antibacterial resistance was chosen to test if a gradual increase in antibiotic concentration and frequent subculture would enhance its antibiotic resistance. Results showed that V. harveyi was able to develop resistance to oxytetracycline. The MIC value was 250 times higher compared with the MIC before subculturing. Moreover, the V. harveyi strain developed slightly higher toxicity. Therefore, it is possible that there is a relationship between antibiotic resistance and toxicity in V. harveyi.

  18. Determine the Impact of Novel BRCA1 Translation Start Sites on Therapy Resistance in Ovarian Cancer

    Science.gov (United States)

    2017-09-01

    Award Number: W81XWH-15-1-0197 TITLE: PRINCIPAL INVESTIGATOR: Neil Johnson, Ph.D. CONTRACTING ORGANIZATION: Institute for Cancer Research...Therapy Resistance in Ovarian Cancer The views, opinions and/or findings contained in this report are those of the author(s) and should not be...Start Sites on Therapy 5b. GRANT NUMBER Resistance in Ovarian Cancer W81XWH-15-1-0197 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Neil

  19. Multiplex PCR To Identify Macrolide Resistance Determinants in Mannheimia haemolytica and Pasteurella multocida

    DEFF Research Database (Denmark)

    Rose, Simon; Desmolaize, Benoit; Jaju, Puneet

    2012-01-01

    The bacterial pathogens Mannheimia haemolytica and Pasteurella multocida are major etiological agents in respiratory tract infections of cattle. Although these infections can generally be successfully treated with veterinary macrolide antibiotics, a few recent isolates have shown resistance...... to these drugs. Macrolide resistance in members of the family Pasteurellaceae is conferred by combinations of at least three genes: erm(42), which encodes a monomethyltransferase and confers a type I MLS(B) (macrolide, lincosamide, and streptogramin B) phenotype; msr(E), which encodes a macrolide efflux pump...

  20. Determination of charge transfer resistance and capacitance of microbial fuel cell through a transient response analysis of cell voltage.

    Science.gov (United States)

    Ha, Phuc Thi; Moon, Hyunsoo; Kim, Byung Hong; Ng, How Yong; Chang, In Seop

    2010-03-15

    An alternative method for determining the charge transfer resistance and double-layer capacitance of microbial fuel cells (MFCs), easily implemented without a potentiostat, was developed. A dynamic model with two parameters, the charge transfer resistance and double-layer capacitance of electrodes, was derived from a linear differential equation to depict the current generation with respect to activation overvoltage. This model was then used to fit the transient cell voltage response to the current step change during the continuous operation of a flat-plate type MFC fed with acetate. Variations of the charge transfer resistance and the capacitance value with respect to the MFC design conditions (biocatalyst existence and electrode area) and operating parameters (acetate concentration and buffer strength in the catholyte) were then determined to elucidate the validity of the proposed method. This model was able to describe the dynamic behavior of the MFC during current change in the activation loss region; having an R(2) value of over 0.99 in most tests. Variations of the charge transfer resistance value (thousands of Omega) according to the change of the design factors and operational factors were well-correlated with the corresponding MFC performances. However, though the capacitance values (approximately 0.02 F) reflected the expected trend according to the electrode area change and catalyst property, they did not show significant variation with changes in either the acetate concentration or buffer strength. (c) 2009 Elsevier B.V. All rights reserved.

  1. Distribution of virulence determinants among antimicrobial-resistant and antimicrobial-susceptible Escherichia coli implicated in urinary tract infections.

    Science.gov (United States)

    Stephenson, Sam; Brown, P D

    2016-01-01

    Uropathogenic Escherichia coli (UPEC) rely on the correlation of virulence expression with antimicrobial resistance to persist and cause severe urinary tract infections (UTIs). We assessed the virulence pattern and prevalence among UPEC strains susceptible and resistant to multiple antimicrobial classes. A total of 174 non-duplicate UPEC strains from patients with clinically significant UTIs were analysed for susceptibility to aminoglycoside, antifolate, cephalosporin, nitrofuran and quinolone antibiotics for the production of extended-spectrum β-lactamases and for the presence of six virulence determinants encoding adhesins (afimbrial, Type 1 fimbriae, P and S-fimbriae) and toxins (cytotoxic necrotising factor and haemolysin). Relatively high resistance rates to nalidixic acid, ciprofloxacin, cephalothin and trimethoprim-sulfamethoxazole (82%, 78%, 62% and 59%, respectively) were observed. Fourteen distinct patterns were identified for the virulence determinants such as afaBC, cnfI, fimH, hylA, papEF and sfaDE. The toxin gene, cnfI (75.3%), was the second most prevalent marker to the adhesin, fimH (97.1%). The significant association of sfaDE/hylA (P < 0.01) among antimicrobial resistant and susceptible strains was also observed notwithstanding an overall greater occurrence of virulence factors among the latter. This study provides a snapshot of UPEC complexity in Jamaica and highlights the significant clonal heterogeneity among strains. Such outcomes emphasise the need for evidence-based strategies in the effective management and control of UTIs.

  2. Determining resistance to mastitis in a bovine subject involves detecting presence or absence of genetic marker associated with trait indicative of mastitis resistance of the bovine subject and/or off-spring from it

    DEFF Research Database (Denmark)

    2010-01-01

    NOVELTY - Determining (m1) resistance to mastitis in a bovine subject, involves detecting in a sample from the bovine subject the presence or absence of at least one genetic marker that is associated with at least one trait indicative of mastitis resistance of the bovine subject and/or off......-spring from it, where the genetic marker is located on the bovine chromosome BTA11 in the region flanked by and including the zeta-chain associated protein 70kD (ZAP70) and CD8B genes, where the presence or absence of the genetic marker is indicative of mastitis resistance. USE - For determining resistance...... to mastitis in a bovine subject for determining mastitis resistance in a bovine subject; for detecting the presence or absence in a bovine subject of at least one genetic marker associated with resistance to mastitis; and for estimating breeding value in respect of susceptibility to mastitis in a bovine...

  3. Prevalence and antimicrobial resistance of Listeria monocytogenes isolated in chicken slaughterhouses in Northern Greece.

    Science.gov (United States)

    Sakaridis, I; Soultos, N; Iossifidou, E; Papa, A; Ambrosiadis, I; Koidis, P

    2011-06-01

    This study was conducted to determine the prevalence and antimicrobial resistance of Listeria monocytogenes recovered from chicken carcasses in slaughterhouses in Northern Greece. A total of 100 poultry samples (300 carcasses) were examined for Listeria spp. The samples were neck skin taken from four different slaughterhouses in Northern Greece. Forty samples were also taken from the environment of the slaughterhouses. Identification of L. monocytogenes was carried out by PCR and fingerprinting of the isolates by random amplified polymorphic DNA. L. monocytogenes strains isolated from chicken carcasses and from the environment of the slaughterhouses were also examined for antibiotic resistance. Fifty-five isolates of L. monocytogenes were tested for susceptibility to 20 antibiotics using the disk diffusion method. Listeria spp. were present in 99 of the poultry samples tested (99%), and 38 yielded L monocytogenes (38%). L. monocytogenes was also isolated in 80% of samples from the environment of a certain slaughterhouse, while the other slaughterhouses were found to be contaminated only with Listeria spp. All isolates were resistant to nalidixic acid and oxolinic acid, the majority of them to clindamycin, and only a few to tetracycline and oxytetracycline, whereas they were found to be susceptible to all other antimicrobials. The results of this study demonstrate a high prevalence of L. monocytogenes contamination in chicken carcasses, and all isolates were found to be sensitive to the antimicrobials most commonly used to treat human listeriosis.

  4. Electrical resistance determination of actual contact area of cold welded metal joints

    Science.gov (United States)

    Hordon, M. J.

    1970-01-01

    Method measures the area of the bonded zone of a compression weld by observing the electrical resistance of the weld zone while the load changes from full compression until the joint ruptures under tension. The ratio of bonding force to maximum tensile load varies considerably.

  5. Resistance of Gram-positive bacteria to nisin is not determined by Lipid II levels

    NARCIS (Netherlands)

    Kramer, NE; Smid, EJ; Kok, J; de Kruijff, B; Kuipers, OP; Breukink, E; Kramer, Naomi E.; Smid, Eddy J.

    2004-01-01

    Lipid II is essential for nisin-mediated pore formation at nano-molar concentrations. We tested whether nisin resistance could result from different Lipid II levels, by comparing the maximal Lipid II pool in Micrococcus flavus (sensitive) and Listeria monocytogenes (relatively insensitive) and their

  6. Pea weevil damage and chemical characteristics of pea cultivars determining their resistance to Bruchus pisorum L.

    Science.gov (United States)

    Nikolova, I

    2016-04-01

    Bruchus pisorum (L.) is one of the most intractable pest problems of cultivated pea in Europe. Development of resistant cultivars is very important to environmental protection and would solve this problem to a great extent. Therefore, the resistance of five spring pea cultivars was studied to B. pisorum: Glyans, Modus; Kamerton and Svit and Pleven 4 based on the weevil damage and chemical composition of seeds. The seeds were classified as three types: healthy seeds (type one), damaged seeds with parasitoid emergence holes (type two) and damaged seeds with bruchid emergence holes (type three). From visibly damaged pea seeds by pea weevil B. pisorum was isolated the parasitoid Triaspis thoracica Curtis (Hymenoptera, Braconidae). Modus, followed by Glyans was outlined as resistant cultivars against the pea weevil. They had the lowest total damaged seed degree, loss in weight of damaged seeds (type two and type three) and values of susceptibility coefficients. A strong negative relationship (r = -0.838) between the weight of type one seeds and the proportion of type three seeds was found. Cultivars with lower protein and phosphorus (P) content had a lower level of damage. The crude protein, crude fiber and P content in damaged seeds significantly or no significantly were increased as compared with the healthy seeds due to weevil damage. The P content had the highest significant influence on pea weevil infestation. Use of chemical markers for resistance to the creation of new pea cultivars can be effective method for defense and control against B. pisorum.

  7. An in vitro study to determine fracture resistance of tooth roots after different instrumentation techniques

    Directory of Open Access Journals (Sweden)

    Marri Shilpa Reddy

    2016-01-01

    Conclusion: Preparation of canals with a conventional hand instrumentation technique using 0.02 taper K-files showed highest fracture resistance with least amount of dentin removed at all levels followed by Endowave, ProTaper Hand, and Rotary files.

  8. Resistance gene expression determines the in vitro chemosensitivity of non-small cell lung cancer (NSCLC)

    International Nuclear Information System (INIS)

    Glaysher, Sharon; Modi, Paul; Rahamim, Joe; Smith, Mark E; Amer, Khalid; Addis, Bruce; Poole, Matthew; Narayanan, Ajit; Gulliford, Tim J; Andreotti, Peter E; Cree, Ian A; Yiannakis, Dennis; Gabriel, Francis G; Johnson, Penny; Polak, Marta E; Knight, Louise A; Goldthorpe, Zoe; Peregrin, Katharine; Gyi, Mya

    2009-01-01

    NSCLC exhibits considerable heterogeneity in its sensitivity to chemotherapy and similar heterogeneity is noted in vitro in a variety of model systems. This study has tested the hypothesis that the molecular basis of the observed in vitro chemosensitivity of NSCLC lies within the known resistance mechanisms inherent to these patients' tumors. The chemosensitivity of a series of 49 NSCLC tumors was assessed using the ATP-based tumor chemosensitivity assay (ATP-TCA) and compared with quantitative expression of resistance genes measured by RT-PCR in a Taqman Array™ following extraction of RNA from formalin-fixed paraffin-embedded (FFPE) tissue. There was considerable heterogeneity between tumors within the ATP-TCA, and while this showed no direct correlation with individual gene expression, there was strong correlation of multi-gene signatures for many of the single agents and combinations tested. For instance, docetaxel activity showed some dependence on the expression of drug pumps, while cisplatin activity showed some dependence on DNA repair enzyme expression. Activity of both drugs was influenced more strongly still by the expression of anti- and pro-apoptotic genes by the tumor for both docetaxel and cisplatin. The doublet combinations of cisplatin with gemcitabine and cisplatin with docetaxel showed gene expression signatures incorporating resistance mechanisms for both agents. Genes predicted to be involved in known mechanisms drug sensitivity and resistance correlate well with in vitro chemosensitivity and may allow the definition of predictive signatures to guide individualized chemotherapy in lung cancer

  9. Resistance gene expression determines the in vitro chemosensitivity of non-small cell lung cancer (NSCLC

    Directory of Open Access Journals (Sweden)

    Amer Khalid

    2009-08-01

    Full Text Available Abstract Background NSCLC exhibits considerable heterogeneity in its sensitivity to chemotherapy and similar heterogeneity is noted in vitro in a variety of model systems. This study has tested the hypothesis that the molecular basis of the observed in vitro chemosensitivity of NSCLC lies within the known resistance mechanisms inherent to these patients' tumors. Methods The chemosensitivity of a series of 49 NSCLC tumors was assessed using the ATP-based tumor chemosensitivity assay (ATP-TCA and compared with quantitative expression of resistance genes measured by RT-PCR in a Taqman Array™ following extraction of RNA from formalin-fixed paraffin-embedded (FFPE tissue. Results There was considerable heterogeneity between tumors within the ATP-TCA, and while this showed no direct correlation with individual gene expression, there was strong correlation of multi-gene signatures for many of the single agents and combinations tested. For instance, docetaxel activity showed some dependence on the expression of drug pumps, while cisplatin activity showed some dependence on DNA repair enzyme expression. Activity of both drugs was influenced more strongly still by the expression of anti- and pro-apoptotic genes by the tumor for both docetaxel and cisplatin. The doublet combinations of cisplatin with gemcitabine and cisplatin with docetaxel showed gene expression signatures incorporating resistance mechanisms for both agents. Conclusion Genes predicted to be involved in known mechanisms drug sensitivity and resistance correlate well with in vitro chemosensitivity and may allow the definition of predictive signatures to guide individualized chemotherapy in lung cancer.

  10. Phylogenetic relatedness determined between antibiotic resistance and 16S rRNA genes in actinobacteria.

    Science.gov (United States)

    Sagova-Mareckova, Marketa; Ulanova, Dana; Sanderova, Petra; Omelka, Marek; Kamenik, Zdenek; Olsovska, Jana; Kopecky, Jan

    2015-04-01

    Distribution and evolutionary history of resistance genes in environmental actinobacteria provide information on intensity of antibiosis and evolution of specific secondary metabolic pathways at a given site. To this day, actinobacteria producing biologically active compounds were isolated mostly from soil but only a limited range of soil environments were commonly sampled. Consequently, soil remains an unexplored environment in search for novel producers and related evolutionary questions. Ninety actinobacteria strains isolated at contrasting soil sites were characterized phylogenetically by 16S rRNA gene, for presence of erm and ABC transporter resistance genes and antibiotic production. An analogous analysis was performed in silico with 246 and 31 strains from Integrated Microbial Genomes (JGI_IMG) database selected by the presence of ABC transporter genes and erm genes, respectively. In the isolates, distances of erm gene sequences were significantly correlated to phylogenetic distances based on 16S rRNA genes, while ABC transporter gene distances were not. The phylogenetic distance of isolates was significantly correlated to soil pH and organic matter content of isolation sites. In the analysis of JGI_IMG datasets the correlation between phylogeny of resistance genes and the strain phylogeny based on 16S rRNA genes or five housekeeping genes was observed for both the erm genes and ABC transporter genes in both actinobacteria and streptomycetes. However, in the analysis of sequences from genomes where both resistance genes occurred together the correlation was observed for both ABC transporter and erm genes in actinobacteria but in streptomycetes only in the erm gene. The type of erm resistance gene sequences was influenced by linkage to 16S rRNA gene sequences and site characteristics. The phylogeny of ABC transporter gene was correlated to 16S rRNA genes mainly above the genus level. The results support the concept of new specific secondary metabolite

  11. Enterococcus spp. Resistant to Multiple Antimicrobial Drugs and Determination of Fecal Contamination Levels in Mangrove Oysters (Crassostrea rhizophorae)

    OpenAIRE

    Rubião, Cynthia Annes; Franco, Robson Maia; Mesquita, Eliana de Fátima Marques de; Miguel, Marco Antonio Lemos; Cabral, Claudius Couto; Fonseca, Ana Beatriz Monteiro

    2017-01-01

    ABSTRACT The aim of this study was to determine and compare the Most Probable Number (MPN) of Total Coliforms (TC), Escherichia coli and Enterococcus spp. and to characterize the antimicrobial resistance profiles of Enterococcus spp. isolated from oysters collected in the Barra de Guaratiba Mangrove, Rio de Janeiro, Brazil. The enumeration of E. coli has been used to indicate fecal contamination and hygienic-sanitary conditions of bivalve molluscs. Enterococci are capable to transfer several ...

  12. Impact determination of strength and resistance training on Glycoside hemoglobin and blood sugar on patients with type II diabetes”

    OpenAIRE

    Bahman Hasanvand; Kobra Karami; Abdollah Khodadi; Mehdi Valipour

    2011-01-01

    Background : This study determined the impact of strength and resistance training on hemoglobin Glycoside and glucose in type II diabetic patients in Khorramabad in 2009. Materials and Methods: This quasi-experimental study was carried out on 30 men with type 2 diabetes referred to laboratories in Khorramabad, selected by screening and interview and purposeful sampling . After the subjects completed questionnaires of medical records and written consent, they were randomly divided into th...

  13. Resistivity method contribution in determining of fault zone and hydro-geophysical characteristics of carbonate aquifer, eastern desert, Egypt

    Science.gov (United States)

    Ammar, A. I.; Kamal, K. A.

    2018-03-01

    Determination of fault zone and hydro-geophysical characteristics of the fractured aquifers are complicated, because their fractures are controlled by different factors. Therefore, 60 VESs were carried out as well as 17 productive wells for determining the locations of the fault zones and the characteristics of the carbonate aquifer at the eastern desert, Egypt. The general curve type of the recorded rock units was QKH. These curves were used in delineating the zones of faults according to the application of the new assumptions. The main aquifer was included at end of the K-curve type and front of the H-curve type. The subsurface layers classified into seven different geoelectric layers. The fractured shaly limestone and fractured limestone layers were the main aquifer and their resistivity changed from low to medium (11-93 Ω m). The hydro-geophysical properties of this aquifer such as the areas of very high, high, and intermediate fracture densities of high groundwater accumulations, salinity, shale content, porosity distribution, and recharging and flowing of groundwater were determined. The statistical analysis appeared that depending of aquifer resistivity on the water salinities (T.D.S.) and water resistivities add to the fracture density and shale content. The T.D.S. increasing were controlled by Na+, Cl-, Ca2+, Mg2+, and then (SO4)2-, respectively. The porosity was calculated and its average value was 19%. The hydrochemical analysis of groundwater appeared that its type was brackish and the arrangements of cation concentrations were Na+ > Ca2+ > Mg2+ > K+ and anion concentrations were Cl- > (SO4)2- > HCO3 - > CO3 -. The groundwater was characterized by sodium-bicarbonate and sodium-sulfate genetic water types and meteoric in origin. Hence, it can use the DC-resistivity method in delineating the fault zone and determining the hydro-geophysical characteristics of the fractured aquifer with taking into account the quality of measurements and interpretation.

  14. Determination of antimicrobial and heavy metal resistance profiles of some bacteria isolated from aquatic amphibian and reptile species.

    Science.gov (United States)

    Hacioglu, Nurcihan; Tosunoglu, Murat

    2014-01-01

    The aim of the present study was to determine the level of antibiotic resistance patterns and distribution of heavy metal resistance of bacterial isolates from aquatic animals (Lissotriton vulgaris, Pelophylax ridibundus, Emys orbicularis, Mauremys rivulata, and Natrix natrix) in Turkey (Kavak Delta). A total of 153 bacteria have been successfully isolated from cloaca and oral samples of the aquatic amphibians and reptilians which were found, namely, Aeromonas sp. (n = 29), Plesiomonas sp. (n = 7), Vibrio sp. (n = 12), Citrobacter sp. (n = 12), Enterobacter sp. (n = 11), Escherichia sp. (n = 22), Klebsiella sp. (n = 22), Edwardsiella sp. (n = 6), Hafnia sp. (n = 1), Proteus sp. (n = 19), Providencia sp. (n = 8), and Pseudomonas sp. (n = 4). In terms of antibiotic and heavy metal susceptibility testing, each isolate was tested against 12 antibiotics and 4 metals. There was a high incidence of resistance to cefoxitin (46.40 %), ampicillin (44.44 %), erythromycin (35.29 %), and a low incidence of resistance to gentamicin (6.53 %), kanamycin (8.49 %), chloramphenicol (9.15 %), and cefotaxime (10.45 %). The multiple antibiotic resistance index of each bacterial species indicated that bacteria from raised amphibians and reptiles have been exposed to tested antibiotics, with results ranging from 0 to 0.58. Most isolates showed tolerance to different concentrations of heavy metals, and minimal inhibition concentrations ranged from100 to >3,200 μg/mL. According to these results, a significant occurrence of bacteria in the internal organs of reptiles and amphibians, with a high incidence of resistance against antibiotics and heavy metals, may risk aquatic animals and the public health. These data appoint the importance of epidemiological surveillance and microbiological monitoring and reinforce the need to implement environment protection programs for amphibian and reptile species.

  15. Prevalence of virulence determinants and antimicrobial resistance among commensal Escherichia coli derived from dairy and beef cattle.

    Science.gov (United States)

    Bok, Ewa; Mazurek, Justyna; Stosik, Michał; Wojciech, Magdalena; Baldy-Chudzik, Katarzyna

    2015-01-19

    Cattle is a reservoir of potentially pathogenic E. coli, bacteria that can represent a significant threat to public health, hence it is crucial to monitor the prevalence of the genetic determinants of virulence and antimicrobial resistance among the E. coli population. The aim of this study was the analysis of the phylogenetic structure, distribution of virulence factors (VFs) and prevalence of antimicrobial resistance among E. coli isolated from two groups of healthy cattle: 50 cows housed in the conventional barn (147 isolates) and 42 cows living on the ecological pasture (118 isolates). The phylogenetic analysis, identification of VFs and antimicrobial resistance genes were based on either multiplex or simplex PCR. The antimicrobial susceptibilities of E. coli were examined using the broth microdilution method. Two statistical approaches were used to analyse the results obtained for two groups of cattle. The relations between the dependent (VFs profiles, antibiotics) and the independent variables were described using the two models. The mixed logit model was used to characterise the prevalence of the analysed factors in the sets of isolates. The univariate logistic regression model was used to characterise the prevalence of these factors in particular animals. Given each model, the odds ratio (OR) and the 95% confidence interval for the population were estimated. The phylogroup B1 was predominant among isolates from beef cattle, while the phylogroups A, B1 and D occurred with equal frequency among isolates from dairy cattle. The frequency of VFs-positive isolates was significantly higher among isolates from beef cattle. E. coli from dairy cattle revealed significantly higher resistance to antibiotics. Some of the tested resistance genes were present among isolates from dairy cattle. Our study showed that the habitat and diet may affect the genetic diversity of commensal E. coli in the cattle. The results suggest that the ecological pasture habitat is related to

  16. Typing of Staphylococcus aureus in order to determine the spread of drug resistant strains inside and outside hospital environment.

    Science.gov (United States)

    Pobiega, Monika; Wójkowska-Mach, Jadwiga; Heczko, Piotr B

    2013-01-01

    Staphylococcus aureus is one of the most important etiological factors of both nosocomial and community-acquired infections. Multidrug-resistant S. aureus is frequently isolated nowadays. Antibiotics used on the hospital ward exert a selective pressure on the strains and favor resistant strains. Multidrug-resistant and highly virulent strains can spread not only within the hospital but also between hospitals. Numerous studies show a predominance of one clone on a specific territory. The spread of such dangerous clones to neighboring countries and the entire continent is possible. Typing methods are very useful in infection control and prevention. Modern methods which are based on sequencing are necessary in rationalizing of infection control programs. Typing of Staphylococcus aureus includes methods that allow to determine the spread of drug-resistant pathogens. 'Gold standard' is pulsed-field gel electrophoresis (PFGE), which relies on separating the DNA fragments after restriction cutting. MLST (Multi Locus Sequence Typing) is based on a comparison of"housekeeping" gene sequences controlling the basic cell functions. With the MLST method, it is possible to demonstrate a broad, international spread of the specific clones. However, for epidemiological investigations, MLST seems to be too time-consuming and expensive to be used as a basic typing tool. The complementary method is spa typing, based on the sequencing of short repetitive sequences of the polymorphic X region from the gene encoding protein A. This method can be used for studying molecular evolution of S. aureus, as well as for testing for hospital outbreaks. It is faster and cheaper than MLST. It is also necessary to subtype the elements responsible for methycillin resistance (SCCmec), which allows to distinguish MRSA (Methicillin-resistant Staphylococcus aureus) clones with a common ancestor, but different epidemiological origin. All of those methods have their specific advantages and disadvantages and

  17. A method to determine the kink resistance of stents and stent delivery systems according to international standards

    Directory of Open Access Journals (Sweden)

    Brandt-Wunderlich Christoph

    2016-09-01

    Full Text Available The kink behavior of vascular stents is of particular interest for clinicians, stent manufacturers and regulatory as a kinked stent generates a lumen loss in the stented vessel and can lead to in-stent restenosis. In this study methods to determine the kink resistance of stents and stent delivery systems according to the ISO 25539-2 and FDA guidance no. 1545 were presented. The methods are applicable for balloon expandable stents as well as for self-expanding stents and determine the lumen loss and residual diameter change dependent on the specific bending radius.

  18. Determination of Heritage SSME Pogo Suppressor Resistance and Inertance from Waterflow Pulse Testing

    Science.gov (United States)

    McDougal, Chris; Eberhart, Chad; Lee, Erik

    2016-01-01

    Waterflow tests of a heritage Space Shuttle Main Engine pogo suppressor were performed to experimentally quantify the resistance and inertance provided by the suppressor. Measurements of dynamic pressure and flow rate in response to pulsing flow were made throughout the test loop. A unique system identification methodology combined all sensor measurements with a one-dimensional perturbational flow model of the complete water flow loop to spatially translate physical measurements to the device under test. Multiple techniques were then employed to extract the effective resistance and inertance for the pogo suppressor. Parameters such as steady flow rate, perturbational flow rate magnitude, and pulse frequency were investigated to assess their influence on the behavior of the pogo suppressor dynamic response. These results support validation of the RS-25 pogo suppressor performance for use on the Space Launch System Core Stage.

  19. Use of P-32 for determining varietal resistance of rice to brown planthopper (Nilaparvata lugens stal)

    Energy Technology Data Exchange (ETDEWEB)

    Kuswadi, A.N. (National Atomic Energy Agency, Jakarta (Indonesia). Pasar Djumat Research Centre)

    1981-07-01

    The resistance was assessed based on the feeding activities of the insect on 15-day old seedling of six test varieties namely TN 1, Asahan, Brantas, Citarum, Serayu and Mudgo. A level of 175 ..mu..Ci per seedling appeared to give sufficiently high absorption of radiophosphorus by the brown planthoppers. The level of radioactivity in the brown planthopper fed for 24 hours on labelled rice plants appeared to be correlated with the susceptibility of the rice plant to brown planthopper. The radioactivity in the honeydew of those hoppers was less correlated with the rice susceptibility. The promising resistance screening method using P-32 tracer is thus more reliable when the radioactivity is detected in the insect rather than in the honeydew.

  20. The importance of lag time extension in determining bacterial resistance to\\ud antibiotics

    OpenAIRE

    Li, Bing; Qiu, Yong; Shi, Hanchang; Yin, Huabing

    2016-01-01

    It is widely appreciated that widespread antibiotic resistance has significantly reduced the utility of today’s antibiotics. Many antibiotics now fail to cure infectious diseases, although they are classified as effective bactericidal agents based on antibiotic susceptibility tests. Here, via kinetic growth assays, we evaluated the effects of 12 commonly used antibiotics on the lag phase of a range of pure environmental isolates and sludge bacterial communities of high diversity. We show that...

  1. Experimental Determination of Frost Resistance of Autoclaved Aerated Concrete at Different Levels of Moisture Saturation

    Science.gov (United States)

    Kočí, Václav; Maděra, Jiří; Jerman, Miloš; Černý, Robert

    2018-06-01

    The ability of porous building materials to stand up to moisture phase changes induced by alternating environment is described mostly by means of their frost resistance. However, the test conditions defined by relevant standards might not capture the real situation on building site in various locations. In particular, the prescribed full water saturation of analyzed specimens during the whole time of a freeze/thaw experiment presents an ultimate case only but certainly not an everyday reality. Even the materials of surface layers are mostly exposed to such severe conditions just for a limited period of time. In this paper, the experimental analysis of frost resistance of three different types of autoclaved aerated concrete (AAC) is performed in an extended way, including not only the standard testing but also the investigation of dry- and partially saturated samples. A complementary computational analysis of an AAC building envelope in Central European climate is presented as well, in order to illustrate the likely hygric conditions in the wall. Experimental results show that according to the standard test the loss of compressive strength, as well as the loss of mass after 25 cycles, is acceptable for all studied samples but after 50 cycles only the material with the compressive strength of 4 MPa performs satisfactorily. On the other hand, the tests with initially dried or partially saturated samples indicate a good frost resistance of all studied materials for both 25 and 50 cycles.

  2. Environmental determinants of type 1 diabetes: a role for overweight and insulin resistance.

    Science.gov (United States)

    Islam, Sadia T; Srinivasan, Shubha; Craig, Maria E

    2014-11-01

    Rates of type 1 diabetes are rising globally, with a decreasing proportion of high-risk genotypes and twin concordance rates below 50%. Therefore, environmental factors such as viruses, nutrition and overweight have been examined as putative aetiological agents. The accelerator hypothesis proposes that overweight and insulin resistance are central to both type 1 and type 2 diabetes and may explain, in part, the rise in type 1 diabetes incidence. The temporal rise in body mass index at type 1 diabetes onset and the observation that pre-diabetic children are heavier and more insulin resistant than their peers suggests convergence of type 1 and type 2 diabetes phenotypes. The influence of insulin resistance may begin in utero, although the aetiological role of birthweight in type 1 diabetes remains unclear. Further research to elucidate the role of these modifiable risk factors in today's obesogenic environment may provide future potential for diabetes prevention. © 2014 The Authors. Journal of Paediatrics and Child Health © 2014 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

  3. Allelic Variation of Bile Salt Hydrolase Genes in Lactobacillus salivarius Does Not Determine Bile Resistance Levels▿ †

    Science.gov (United States)

    Fang, Fang; Li, Yin; Bumann, Mario; Raftis, Emma J.; Casey, Pat G.; Cooney, Jakki C.; Walsh, Martin A.; O'Toole, Paul W.

    2009-01-01

    Commensal lactobacilli frequently produce bile salt hydrolase (Bsh) enzymes whose roles in intestinal survival are unclear. Twenty-six Lactobacillus salivarius strains from different sources all harbored a bsh1 allele on their respective megaplasmids. This allele was related to the plasmid-borne bsh1 gene of the probiotic strain UCC118. A second locus (bsh2) was found in the chromosomes of two strains that had higher bile resistance levels. Four Bsh1-encoding allele groups were identified, defined by truncations or deletions involving a conserved residue. In vitro analyses showed that this allelic variation was correlated with widely varying bile deconjugation phenotypes. Despite very low activity of the UCC118 Bsh1 enzyme, a mutant lacking this protein had significantly lower bile resistance, both in vitro and during intestinal transit in mice. However, the overall bile resistance phenotype of this and other strains was independent of the bsh1 allele type. Analysis of the L. salivarius transcriptome upon exposure to bile and cholate identified a multiplicity of stress response proteins and putative efflux proteins that appear to broadly compensate for, or mask, the effects of allelic variation of bsh genes. Bsh enzymes with different bile-degrading kinetics, though apparently not the primary determinants of bile resistance in L. salivarius, may have additional biological importance because of varying effects upon bile as a signaling molecule in the host. PMID:19592587

  4. Study on contamination of sheep meat in Shahrekord area with Listeria ivanovii and determination its antibiotic resistance pattern

    Directory of Open Access Journals (Sweden)

    Farid Khalili Borujeni

    2013-06-01

    Full Text Available Background and objectives: Listeria monocytogenes and Listeria ivanovii are two pathogenic species of Listeria. The role of Listeria ivanovii is important in abortion, stillbirth, septicemia in animals and this bacterium sometimes is pathogenic in humans. Contamination of ovine carcasses during the slaughter and processing can cause foodborne infections in humans. In this study we examined the contamination of sheep meat in slaughter house of Shahrekord city to Listeria ivanovii and determined its antibiotic resistance pattern.Material and Methods: A total 200 samples of sheep meat were collected from abattoir and processed by use of two enrichment method. After doing specific biochemical tests and PCR, Listeria spp was identified and antibiotic resistance of isolated Listeria were tested by the agar disc diffusion method. Results: The contamination of sheep carcasses with listeria was 2.5% (5 out of 200 samples. All five isolates (2.5% were recognized as Listeria ivanovii and were resistant to four antibiotics, sensitive to six antibiotics and intermediate to other antibiotics.  Conclusion: According to the contamination rate in sheep carcasses with Listeria ivanovii and the relatively high antibiotic resistance specified in this bacteria, the role of red meat in transmission of Listeria spp. and appropriate use of antibiotics against this bacteria should be considered.

  5. The survey of shigellosis frequency and determination of antibiotic resistance profile of isolated strains from infected children in Tehran

    Directory of Open Access Journals (Sweden)

    Shahla Abbaspour

    2014-04-01

    Full Text Available Background: Shigellosis is endemic throughout the world and it is among the most common causes of bacterial diarrheal diseases. Antibiotic resistance of Shigella is becoming a progressive problem in world. The aim of this study was the survey of shigellosis frequency and determination of antibiotic resistance profile of isolated strains from infected children in Tehran. Material and Methods: This study conducted on 9131 patients with acute diarrheal disease. For isolation of Shigella spp. from stool samples, culture performed on different selective and differential media. After confirmation of bacteria by biochemical tests, susceptibility testing was done by disc diffusion method according to clinical and laboratory standards (CLSI recomendations. Results: Among 9131 stool samples, Shigella spp. was isolated from 90 cases. Shigella sonnei was the most common isolated species. 92/2 % of isolates were resistant to cotrimoxazole. In contrast, most of the Shigella spp. was founded to be sensitive to ciprofloxacin, imipenem and third-generation cephalosporins. Conclusion: Surveillance programs on antimicrobial resistance not only identify pathogenic bacterial species, by reporting data like serotyping, microorganisms incidence rates, and susceptibility to the antimicrobial agents currently used for treatment, but also contribute to monitoring the intervention strategies including removing organism from reservoirs.

  6. [Determination of drug resistance mutations of NS3 inhibitors in chronic hepatitis C patients infected with genotype 1].

    Science.gov (United States)

    Şanlıdağ, Tamer; Sayan, Murat; Akçalı, Sinem; Kasap, Elmas; Buran, Tahir; Arıkan, Ayşe

    2017-04-01

    Direct-acting antiviral agents (DAA) such as NS3 protease inhibitors is the first class of drugs used for chronic hepatitis C (CHC) treatment. NS3 inhibitors (PI) with low genetic barrier have been approved to be used in the CHC genotype 1 infections, and in the treatment of compensated liver disease including cirrhosis together with pegile interferon and ribavirin. Consequently, the development of drug resistance during DAA treatment of CHC is a major problem. NS3 resistant variants can be detected before treatment as they can occurnaturally. The aim of this study was to investigate new and old generation NS3 inhibitors resistance mutations before DAA treatment in hepatitis C virus (HCV) that were isolated from CHC. The present study was conducted in 2015 and included 97 naive DAA patients infected with HCV genotype 1, who were diagnosed in Manisa and Kocaeli cities of Turkey. Magnetic particle based HCV RNA extraction and than RNA detection and quantification were performed using commercial real-time PCR assay QIASypmhony + Rotorgene Q/ArtusHCV QS-RGQ and COBAS Ampliprep/COBAS TaqMan HCV Tests. HCV NS3 viral protease genome region was amplified with PCR and mutation analysis was performed by Sanger dideoxy sequencing technique of NS3 protease codons (codon 32-185). HCV NS3 protease inhibitors; asunaprevir, boceprevir, faldaprevir, grazoprevir, pariteprevir, simeprevir and telaprevir were analysed for resistant mutations by Geno2pheno-HCV resistance tool. HCV was genotyped in all patients and 88 patients (n= 88/97, 91%) had genotype 1. Eight (n= 8/97, 8.2%) and 80 (n= 80/97, 82.4%) HCC patients were subgenotyped as 1a and 1b, respectively. Many aminoacid substitutions and resistance mutations were determined in 39/88 (44%) patients in the study group. Q80L, S122C/N, S138W were defined as potential substitutions (6/88 patients; 7%); R109K, R117C, S122G, I132V, I170V, N174S were described as potential resistance (34/88 patients; 39%); V36L, T54S, V55A, Q80H were

  7. Analysis of β-Lactamase Resistance Determinants in Enterobacteriaceae from Chicago Children: a Multicenter Survey

    Science.gov (United States)

    Hujer, Andrea M.; Marshall, Steven H.; Domitrovic, T. Nicholas; Rudin, Susan D.; Zheng, Xiaotian; Qureshi, Nadia K.; Hayden, Mary K.; Scaggs, Felicia A.; Karadkhele, Anand; Bonomo, Robert A.

    2016-01-01

    Multidrug-resistant (MDR) Enterobacteriaceae infections are increasing in U.S. children; however, there is a paucity of multicentered analyses of antibiotic resistance genes responsible for MDR phenotypes among pediatric Enterobacteriaceae isolates. In this study, 225 isolates phenotypically identified as extended-spectrum β-lactamase (ESBL) or carbapenemase producers, recovered from children ages 0 to 18 years hospitalized between January 2011 and April 2015 at three Chicago area hospitals, were analyzed. We used DNA microarray platforms to detect ESBL, plasmid-mediated AmpC (pAmpC), and carbapenemase type β-lactamase (bla) genes. Repetitive-sequence-based PCR and multilocus sequence typing (MLST) were performed to assess isolate similarity. Plasmid replicon typing was conducted to classify plasmids. The median patient age was 4.2 years, 56% were female, and 44% presented in the outpatient setting. The majority (60.9%) of isolates were Escherichia coli and from urinary sources (69.8%). Of 225 isolates exhibiting ESBL- or carbapenemase-producing phenotypes, 90.7% contained a bla gene. The most common genotype was the blaCTX-M-1 group (49.8%); 1.8% were carbapenem-resistant Enterobacteriaceae (three blaKPC and one blaIMP). Overall, pAmpC (blaACT/MIR and blaCMY) were present in 14.2%. The predominant E. coli phylogenetic group was the virulent B2 group (67.6%) associated with ST43/ST131 (Pasteur/Achtman MLST scheme) containing the blaCTX-M-1 group (84%), and plasmid replicon types FIA, FII, and FIB. K. pneumoniae harboring blaKPC were non-ST258 with replicon types I1 and A/C. Enterobacter spp. carrying blaACT/MIR contained plasmid replicon FIIA. We found that β-lactam resistance in children is diverse and that certain resistance mechanisms differ from known circulating genotypes in adults in an endemic area. The potential impact of complex molecular types and the silent dissemination of MDR Enterobacteriaceae in a vulnerable population needs to be studied further

  8. Determination of the influence of dispersion pattern of pesticide-resistant individuals on the reliability of resistance estimates using different sampling plans.

    Science.gov (United States)

    Shah, R; Worner, S P; Chapman, R B

    2012-10-01

    Pesticide resistance monitoring includes resistance detection and subsequent documentation/ measurement. Resistance detection would require at least one (≥1) resistant individual(s) to be present in a sample to initiate management strategies. Resistance documentation, on the other hand, would attempt to get an estimate of the entire population (≥90%) of the resistant individuals. A computer simulation model was used to compare the efficiency of simple random and systematic sampling plans to detect resistant individuals and to document their frequencies when the resistant individuals were randomly or patchily distributed. A patchy dispersion pattern of resistant individuals influenced the sampling efficiency of systematic sampling plans while the efficiency of random sampling was independent of such patchiness. When resistant individuals were randomly distributed, sample sizes required to detect at least one resistant individual (resistance detection) with a probability of 0.95 were 300 (1%) and 50 (10% and 20%); whereas, when resistant individuals were patchily distributed, using systematic sampling, sample sizes required for such detection were 6000 (1%), 600 (10%) and 300 (20%). Sample sizes of 900 and 400 would be required to detect ≥90% of resistant individuals (resistance documentation) with a probability of 0.95 when resistant individuals were randomly dispersed and present at a frequency of 10% and 20%, respectively; whereas, when resistant individuals were patchily distributed, using systematic sampling, a sample size of 3000 and 1500, respectively, was necessary. Small sample sizes either underestimated or overestimated the resistance frequency. A simple random sampling plan is, therefore, recommended for insecticide resistance detection and subsequent documentation.

  9. Determination of tungsten in high-alloy steels and heat resisting alloys by isotope dilution-spark source mass spectrometry

    International Nuclear Information System (INIS)

    Saito, Morimasa; Yamada, Kei; Okochi, Haruno; Hirose, Fumio

    1983-01-01

    Tungsten in high-alloy steels and heat-resisting alloys was determined by isotope dilution method combined with spark source mass spectrometry by using 183 W enriched tungsten. The spike solution was prepared by fusing tungsten trioxide in sodium carbonate. A high-alloy steel sample was dissolved in the mixture of sulfuric acid and phosphoric acid together with the spike solution; a sample of heat resisting alloy was similarly dissolved in the mixture of hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid. The solution was evaporated to give dense white fumes. Tungsten was separated from the residue by a conventional cinchonine salt-precipitation method. The salt was ignited, and the residue was mixed with graphite powder and pressed into electrodes. The isotope 183 W and 184 W were measured. The method was applied to the determination of tungsten in JSS and NBS standard high-alloy steels and JAERI standard nickel- and NBS standard cobalt-base heat resisting alloys containing more than 0.05% tungsten. The results were obtained with satisfactory precision and accuracy. However, the results obtained for JSS standard high- speed steels containing molybdenum tended to be significantly lower than the certified values. (author)

  10. Biofilm is a Major Virulence Determinant in Bacterial Colonization of Chronic Skin Ulcers Independently from the Multidrug Resistant Phenotype

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    Enea Gino Di Domenico

    2017-05-01

    Full Text Available Bacterial biofilm is a major factor in delayed wound healing and high levels of biofilm production have been repeatedly described in multidrug resistant organisms (MDROs. Nevertheless, a quantitative correlation between biofilm production and the profile of antimicrobial drug resistance in delayed wound healing remains to be determined. Microbial identification, antibiotic susceptibility and biofilm production were assessed in 135 clinical isolates from 87 patients. Gram-negative bacteria were the most represented microorganisms (60.8% with MDROs accounting for 31.8% of the total isolates. Assessment of biofilm production revealed that 80% of the strains were able to form biofilm. A comparable level of biofilm production was found with both MDRO and not-MDRO with no significant differences between groups. All the methicillin-resistant Staphylococcus aureus (MRSA and 80% of Pseudomonas aeruginosa MDR strains were found as moderate/high biofilm producers. Conversely, less than 17% of Klebsiella pneumoniae extended-spectrum beta-lactamase (ESBL, Escherichia coli-ESBL and Acinetobacter baumannii were moderate/high biofilm producers. Notably, those strains classified as non-biofilm producers, were always associated with biofilm producer bacteria in polymicrobial colonization. This study shows that biofilm producers were present in all chronic skin ulcers, suggesting that biofilm represents a key virulence determinant in promoting bacterial persistence and chronicity of ulcerative lesions independently from the MDRO phenotype.

  11. A Simple and Sensitive Plant-Based Western Corn Rootworm Bioassay Method for Resistance Determination and Event Selection.

    Science.gov (United States)

    Wen, Zhimou; Chen, Jeng Shong

    2018-05-26

    We report here a simple and sensitive plant-based western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), bioassay method that allows for examination of multiple parameters for both plants and insects in a single experimental setup within a short duration. For plants, injury to roots can be visually examined, fresh root weight can be measured, and expression of trait protein in plant roots can be analyzed. For insects, in addition to survival, larval growth and development can be evaluated in several aspects including body weight gain, body length, and head capsule width. We demonstrated using the method that eCry3.1Ab-expressing 5307 corn was very effective against western corn rootworm by eliciting high mortality and significantly inhibiting larval growth and development. We also validated that the method allowed determination of resistance in an eCry3.1Ab-resistant western corn rootworm strain. While data presented in this paper demonstrate the usefulness of the method for selection of events of protein traits and for determination of resistance in laboratory populations, we envision that the method can be applied in much broader applications.

  12. Graphene/TiO2/ZSM-5 composites synthesized by mixture design were used for photocatalytic degradation of oxytetracycline under visible light: Mechanism and biotoxicity

    Science.gov (United States)

    Hu, Xin-Yan; Zhou, Kefu; Chen, Bor-Yann; Chang, Chang-Tang

    2016-01-01

    This first-attempt study revealed mixture design of experiments to obtain the most promising composites of TiO2 loaded on zeolite and graphene for maximal photocatalytic degradation of oxytetracycline (OTC). The optimal weight ratio of graphene, titanium dioxide (TiO2), and zeolite was 1:8:1 determined via experimental design of simplex lattice mixture. The composite material was characterized by XRD, UV-vis, TEM and EDS analysis. The findings showed the composite material had a higher stability and a stronger absorption of the visible light. In addition, it was uniformly dispersed with promising adsorption characteristics. OTC was used as model toxicant to evaluate the photodegradation efficiency of the GTZ (1:8:1). At optimal operating conditions (i.e., pH 7 and 25 °C), complete degradation (ca. 100%) was achieved in 180 min. The biotoxicity of the degraded intermediates of OTC on cell growth of Escherichia coli DH5α were also assayed. After 180 min photocatalytic treatment, OTC solution treated by GTZ (1:8:1) showed insignificant biotoxicity to receptor DH5α cells. Furthermore, EDTA (hole scavengers) and t-BuOH (radical scavengers) were used to detect the main active oxidative species in the system. The results showed that the holes are the main oxidation species in the photocatalytic process.

  13. Adsorption in a Fixed-Bed Column and Stability of the Antibiotic Oxytetracycline Supported on Zn(II)-[2-Methylimidazolate] Frameworks in Aqueous Media

    Science.gov (United States)

    Anceski Bataglion, Giovana; Nogueira Eberlin, Marcos; Machado Ronconi, Célia

    2015-01-01

    A metal-organic framework, Zn-[2-methylimidazolate] frameworks (ZIF-8), was used as adsorbent material to remove different concentrations of oxytetracycline (OTC) antibiotic in a fixed-bed column. The OTC was studied at concentrations of 10, 25 and 40 mg L-1. At 40 mg L-1, the breakthrough point was reached after approximately 10 minutes, while at 10 and 25 mg L-1 this point was reached in about 30 minutes. The highest removal rate of 60% for the 10 mg L-1 concentration was reached after 200 minutes. The highest adsorption capacity (28.3 mg g-1) was attained for 25 mg L-1 of OTC. After the adsorption process, a band shift was observed in the UV-Vis spectrum of the eluate. Additional studies were carried out to determine the cause of this band shift, involving a mass spectrometry (MS) analysis of the supernatant liquid during the process. This investigation revealed that the main route of adsorption consisted of the coordination of OTC with the metallic zinc centers of ZIF-8. The materials were characterized by thermal analysis (TA), scanning electron microscopy (SEM), powder X-ray diffraction (XRD), and infrared spectroscopy (IR) before and after adsorption, confirming the presence of OTC in the ZIF-8 and the latter’s structural stability after the adsorption process. PMID:26057121

  14. A novel sandwich-type electrochemical aptasensor based on GR-3D Au and aptamer-AuNPs-HRP for sensitive detection of oxytetracycline.

    Science.gov (United States)

    Liu, Su; Wang, Yu; Xu, Wei; Leng, Xueqi; Wang, Hongzhi; Guo, Yuna; Huang, Jiadong

    2017-02-15

    In this paper, a novel sandwich-type electrochemical aptasensor has been fabricated and applied for sensitive and selective detection of antibiotic oxytetracycline (OTC). This sensor was based on graphene-three dimensional nanostructure gold nanocomposite (GR-3D Au) and aptamer-AuNPs-horseradish peroxidase (aptamer-AuNPs-HRP) nanoprobes as signal amplification. Firstly, GR-3D Au film was modified on glassy carbon electrode only by one-step electrochemical coreduction with graphite oxide (GO) and HAuCl 4 at cathodic potentials, which enhanced the electron transfer and loading capacity of biomolecules. Then the aptamer and HRP modified Au nanoparticles provide high affinity and ultrasensitive electrochemical probe with excellent specificity for OTC. Under the optimized conditions, the peak current was linearly proportional to the concentration of OTC in the range of 5×10 -10 -2×10 -3 gL -1 , with a detection limit of 4.98×10 -10 gL -1 . Additionally, this aptasensor had the advantages in high sensitivity, superb specificity and showed good recovery in synthetic samples. Hence, the developed sandwich-type electrochemical aptasensor might provide a useful and practical tool for OTC determination and related food safety analysis and clinical diagnosis. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Adsorption in a Fixed-Bed Column and Stability of the Antibiotic Oxytetracycline Supported on Zn(II-[2-Methylimidazolate] Frameworks in Aqueous Media.

    Directory of Open Access Journals (Sweden)

    Janine dos Santos Ferreira da Silva

    Full Text Available A metal-organic framework, Zn-[2-methylimidazolate] frameworks (ZIF-8, was used as adsorbent material to remove different concentrations of oxytetracycline (OTC antibiotic in a fixed-bed column. The OTC was studied at concentrations of 10, 25 and 40 mg L(-1. At 40 mg L(-1, the breakthrough point was reached after approximately 10 minutes, while at 10 and 25 mg L(-1 this point was reached in about 30 minutes. The highest removal rate of 60% for the 10 mg L(-1 concentration was reached after 200 minutes. The highest adsorption capacity (28.3 mg g(-1 was attained for 25 mg L(-1 of OTC. After the adsorption process, a band shift was observed in the UV-Vis spectrum of the eluate. Additional studies were carried out to determine the cause of this band shift, involving a mass spectrometry (MS analysis of the supernatant liquid during the process. This investigation revealed that the main route of adsorption consisted of the coordination of OTC with the metallic zinc centers of ZIF-8. The materials were characterized by thermal analysis (TA, scanning electron microscopy (SEM, powder X-ray diffraction (XRD, and infrared spectroscopy (IR before and after adsorption, confirming the presence of OTC in the ZIF-8 and the latter's structural stability after the adsorption process.

  16. Characterization of antibiotic resistance in Salmonella enterica isolates determined from ready-to-eat (RTE) salad vegetables.

    Science.gov (United States)

    Taban, Birce Mercanoglu; Aytac, Sait Aykut; Akkoc, Nefise; Akcelik, Mustafa

    2013-01-01

    In the last decade, ready-to-eat (RTE) salad vegetables are gaining increasing importance in human diet. However, since they are consumed fresh, inadequate washing during processing can bring on some foodborne illnesses, like salmonellosis, since these food items have natural contamination from soil and water. During 2009-2010, a total of 81 samples were purchased arbitrarily from local markets in Ankara, and were examined for Salmonella contamination. Salmonella screening was performed by using anti-Salmonella magnetic beads system and polymerase chain reaction (PCR) identification of the suspected colonies. Then, the antibiotic resistance profiles of four Salmonella strains identified (strains RTE-1, RTE-2, RTE-3, and RTE-4) were also investigated, since the mechanism by which Salmonella spp. have accumulated antibiotic resistance genes is of interest. All strains showed resistance against sulfonamides (MIC > 128 mg/L). Further results suggested that associated sulfonamide resistance genes were encoded by the 55.0 kb plasmid of strain RTE-1 that involves no integrons. As a result of using two primers (P1254 and P1283) in randomly amplified polymorphic DNA-PCR (RAPD-PCR) analysis, two common amplicons (364 bp and 1065 bp) were determined. The findings of this study provide support to the adoption of guidelines for the prudent use of antibiotics in order to reduce the number of pathogens present on vegetable and fruit farms. Besides, since it is shown that these bacteria started to gain resistance to antibiotics, it is necessary to further investigate the prevalence of them in foods.

  17. Characterization of antibiotic resistance in Salmonella enterica isolates determined from ready-to-eat (RTE salad vegetables

    Directory of Open Access Journals (Sweden)

    Birce Mercanoglu Taban

    2013-01-01

    Full Text Available In the last decade, ready-to-eat (RTE salad vegetables are gaining increasing importance in human diet. However, since they are consumed fresh, inadequate washing during processing can bring on some foodborne illnesses, like salmonellosis, since these food items have natural contamination from soil and water. During 2009-2010, a total of 81 samples were purchased arbitrarily from local markets in Ankara, and were examined for Salmonella contamination. Salmonella screening was performed by using anti-Salmonella magnetic beads system and polymerase chain reaction (PCR identification of the suspected colonies. Then, the antibiotic resistance profiles of four Salmonella strains identified (strains RTE-1, RTE-2, RTE-3, and RTE-4 were also investigated, since the mechanism by which Salmonella spp. have accumulated antibiotic resistance genes is of interest. All strains showed resistance against sulfonamides (MIC > 128 mg/L. Further results suggested that associated sulfonamide resistance genes were encoded by the 55.0 kb plasmid of strain RTE-1 that involves no integrons. As a result of using two primers (P1254 and P1283 in randomly amplified polymorphic DNA-PCR (RAPD-PCR analysis, two common amplicons (364 bp and 1065 bp were determined. The findings of this study provide support to the adoption of guidelines for the prudent use of antibiotics in order to reduce the number of pathogens present on vegetable and fruit farms. Besides, since it is shown that these bacteria started to gain resistance to antibiotics, it is necessary to further investigate the prevalence of them in foods.

  18. Determination of physiological, taxonomic, and molecular characteristics of a cultivable arsenic-resistant bacterial community.

    Science.gov (United States)

    Cordi, A; Pagnout, C; Devin, S; Poirel, J; Billard, P; Dollard, M A; Bauda, P

    2015-09-01

    A collection of 219 bacterial arsenic-resistant isolates was constituted from neutral arsenic mine drainage sediments. Isolates were grown aerobically or anaerobically during 21 days on solid DR2A medium using agar or gelan gum as gelling agent, with 7 mM As(III) or 20 mM As(V) as selective pressure. Interestingly, the sum of the different incubation conditions used (arsenic form, gelling agent, oxygen pressure) results in an overall increase of the isolate diversity. Isolated strains mainly belonged to Proteobacteria (63%), Actinobacteria (25%), and Bacteroidetes (10%). The most representative genera were Pseudomonas (20%), Acinetobacter (8%), and Serratia (15%) among the Proteobacteria; Rhodococcus (13%) and Microbacterium (5%) among Actinobacteria; and Flavobacterium (13%) among the Bacteroidetes. Isolates were screened for the presence of arsenic-related genes (arsB, ACR3(1), ACR3(2), aioA, arsM, and arrA). In this way, 106 ACR3(1)-, 74 arsB-, 22 aioA-, 14 ACR3(2)-, and one arsM-positive PCR products were obtained and sequenced. Analysis of isolate sensitivity toward metalloids (arsenite, arsenate, and antimonite) revealed correlations between taxonomy, sensitivity, and genotype. Antimonite sensitivity correlated with the presence of ACR3(1) mainly present in Bacteroidetes and Actinobacteria, and arsenite or antimonite resistance correlated with arsB gene presence. The presence of either aioA gene or several different arsenite carrier genes did not ensure a high level of arsenic resistance in the tested conditions.

  19. Milk contamination and resistance to processing conditions determine the fate of Lactococcus lactis bacteriophages in dairies.

    Science.gov (United States)

    Madera, Carmen; Monjardín, Cristina; Suárez, Juan E

    2004-12-01

    Milk contamination by phages, the susceptibility of the phages to pasteurization, and the high levels of resistance to phage infection of starter strains condition the evolution dynamics of phage populations in dairy environments. Approximately 10% (83 of 900) of raw milk samples contained phages of the quasi-species c2 (72%), 936 (24%), and P335 (4%). However, 936 phages were isolated from 20 of 24 (85%) whey samples, while c2 was detected in only one (4%) of these samples. This switch may have been due to the higher susceptibility of c2 to pasteurization (936-like phages were found to be approximately 35 times more resistant than c2 strains to treatment of contaminated milk in a plate heat exchanger at 72 degrees C for 15 s). The restriction patterns of 936-like phages isolated from milk and whey were different, indicating that survival to pasteurization does not result in direct contamination of the dairy environment. The main alternative source of phages (commercial bacterial starters) does not appear to significantly contribute to phage contamination. Twenty-four strains isolated from nine starter formulations were generally resistant to phage infection, and very small progeny were generated upon induction of the lytic cycle of resident prophages. Thus, we postulate that a continuous supply of contaminated milk, followed by pasteurization, creates a factory environment rich in diverse 936 phage strains. This equilibrium would be broken if a particular starter strain turned out to be susceptible to infection by one of these 936-like phages, which, as a consequence, became prevalent.

  20. Porosity determination from 2-D resistivity method in studying the slope failures

    Science.gov (United States)

    Maslinda, Umi; Nordiana, M. M.; Bery, A. A.

    2017-07-01

    Slope failures have become the main focus for infrastructures development on hilly areas in Malaysia especially the development of tourism and residential. Lack of understanding and information of the subsoil conditions and geotechnical issues are the main cause of the slope failures. The failures happened are due to a combination of few factors such as topography, climate, geology and land use. 2-D resistivity method was conducted at the collapsed area in Selangor. The 2-D resistivity was done to study the instability of the area. The collapsed occurred because of the subsurface materials was unstable. Pole-dipole array was used with 5 m minimum electrode spacing for the 2-D resistivity method. The data was processed using Res2Dinv software and the porosity was calculated using Archie's law equation. The results show that the saturated zone (1-100 Ωm), alluvium or highly weathered rock (100-1000 Ωm), boulders (1600-7000 Ωm) and granitic bedrock (>7000 Ωm). Generally, the slope failures or landslides occur during the wet season or after rainfall. It is because of the water infiltrate to the slope and cause the saturation of the slope which can lead to landslides. Then, the porosity of saturated zone is usually high because of the water content. The area of alluvium or highly weathered rock and saturated zone have high porosity (>20%) and the high porosity also dominated at almost all the collapsed area which means that the materials with porosity >20% is potential to be saturated, unstable and might trigger slope failures.

  1. Determination of the resistance types to Spodoptera cosmioides (Walker (Lepidoptera: Noctuidae in soybean genotypes

    Directory of Open Access Journals (Sweden)

    Arlindo Leal Boiça Júnior

    2015-04-01

    Full Text Available The aim of this work was to evaluate the resistance types in soybean genotypes to Spodoptera cosmioides (Walker in laboratory. Soybean genotypes assessed were as follows: ‘IAC 100’ (resistance standard, ‘BR16’ (susceptible standard, ‘Dowling’, PI 227687, PI 274454, ‘IGRA RA 626 RR’, PI 227682, ‘BRSGO 8360’, ‘IGRA RA 516 RR’ and ‘P 98Y11 RR’. Free-choice and no-choice feeding non-preference tests were done using two newly-hatched larvae per genotype or one third-instar larva per genotype in both tests. Larvae attractiveness was evaluated in different times, and at the end of the experiments the leaf area consumed was quantified. In the antibiosis test, newly-hatched larvae were individualized into Petri dishes, where leaflets of the genotypes were offered over the larval stage, and the following biological parameters were assessed: period and viability of larvae, pupae and overall (larvae + pupae, weight of larvae and pupae, sex ratio and adults longevity. Overall, in the feeding preference tests, significant differences were not found in leaf consumption among the genotypes. In the antibiosis assay, genotypes PI 227687, PI 227682 and ‘IAC 100’ caused 100% larval mortality and the lowest weight of larvae, ranging between 37.65 and 85.56 mg. All soybean genotypes evaluated do not exhibit feeding non-preference type resistance to S. cosmioides, and PI 227687, PI 227682 and ‘IAC 100’ highlighted for possessing antibiosis.

  2. Is heart rate variability a feasible method to determine anaerobic threshold in progressive resistance exercise in coronary artery disease?

    Science.gov (United States)

    Sperling, Milena P R; Simões, Rodrigo P; Caruso, Flávia C R; Mendes, Renata G; Arena, Ross; Borghi-Silva, Audrey

    2016-01-01

    Recent studies have shown that the magnitude of the metabolic and autonomic responses during progressive resistance exercise (PRE) is associated with the determination of the anaerobic threshold (AT). AT is an important parameter to determine intensity in dynamic exercise. To investigate the metabolic and cardiac autonomic responses during dynamic resistance exercise in patients with Coronary Artery Disease (CAD). Twenty men (age = 63±7 years) with CAD [Left Ventricular Ejection Fraction (LVEF) = 60±10%] underwent a PRE protocol on a leg press until maximal exertion. The protocol began at 10% of One Repetition Maximum Test (1-RM), with subsequent increases of 10% until maximal exhaustion. Heart Rate Variability (HRV) indices from Poincaré plots (SD1, SD2, SD1/SD2) and time domain (rMSSD and RMSM), and blood lactate were determined at rest and during PRE. Significant alterations in HRV and blood lactate were observed starting at 30% of 1-RM (p<0.05). Bland-Altman plots revealed a consistent agreement between blood lactate threshold (LT) and rMSSD threshold (rMSSDT) and between LT and SD1 threshold (SD1T). Relative values of 1-RM in all LT, rMSSDT and SD1T did not differ (29%±5 vs 28%±5 vs 29%±5 Kg, respectively). HRV during PRE could be a feasible noninvasive method of determining AT in CAD patients to plan intensities during cardiac rehabilitation.

  3. Recommendations to address the difficulties encountered when determining linezolid resistance from whole genome sequencing data.

    Science.gov (United States)

    Beukers, Alicia G; Hasman, Henrik; Hegstad, Kristin; van Hal, Sebastiaan J

    2018-05-29

    Mutations associated with linezolid resistance within the V domain of 23S rRNA are annotated using an Escherichia coli numbering system. The 23S rRNA gene varies in length, nucleotide sequence and copy number between bacterial species. Consequently, this numbering system is not intuitive and can lead to confusion when locating mutation sites using whole genome sequencing data. Using the mutation G2576T as an example, we demonstrate the difficulties associated with using the E. coli numbering system. © Crown copyright 2018.

  4. Determination of the resistance of fabric printed with triclosan microcapsules to the action of soil micro-flora

    Science.gov (United States)

    Golja, B.; Forte Tavčer, P.

    2017-10-01

    Microcapsules with a pressure-sensitive melamine-formaldehyde wall and triclosan core were printed to 100% cotton fabric with screen printing technique. Previous research showed excellent antibacterial activity (estimated for E. Coli and S. Aureus) of such fabric, so our aim in this research was to determine its resistance to the action of microorganisms present in the soil. The soil burial test was conducted. The breaking strength of the buried samples was measured and also the scanning electron microscope analysis was done. The results showed that none of the samples are resistant to decay. It is evident from SEM micrographs that on all of the buried samples greater morphological changes occur due to the functions of the soil microflora. It can be concluded that the samples printed with triclosan microcapsules are biodegradable which is environmentally preferable.

  5. Insulin resistance determined by Homeostasis Model Assessment (HOMA) and associations with metabolic syndrome among Chinese children and teenagers.

    Science.gov (United States)

    Yin, Jinhua; Li, Ming; Xu, Lu; Wang, Ying; Cheng, Hong; Zhao, Xiaoyuan; Mi, Jie

    2013-11-15

    The aim of this study is to assess the association between the degree of insulin resistance and the different components of the metabolic syndrome among Chinese children and adolescents. Moreover, to determine the cut-off values for homeostasis model assessment of insulin resistance (HOMA-IR) at MS risk. 3203 Chinese children aged 6 to 18 years were recruited. Anthropometric and biochemical parameters were measured. Metabolic syndrome (MS) was identified by a modified Adult Treatment Panel III (ATP III) definition. HOMA-IR index was calculated and the normal reference ranges were defined from the healthy participants. Receiver operating characteristic (ROC) analysis was used to find the optimal cutoff of HOMA-IR for diagnosis of MS. With the increase of insulin resistance (quintile of HOMA-IR value), the ORs of suffering MS or its related components were significantly increased. Participants in the highest quintile of HOMA-IR were about 60 times more likely to be classified with metabolic syndrome than those in the lowest quintile group. Similarly, the mean values of insulin and HOMA-IR increased with the number of MS components. The present HOMA-IR cutoff point corresponding to the 95th percentile of our healthy reference children was 3.0 for whole participants, 2.6 for children in prepubertal stage and 3.2 in pubertal period, respectively. The optimal point for diagnosis of MS was 2.3 in total participants, 1.7 in prepubertal children and 2.6 in pubertal adolescents, respectively, by ROC curve, which yielded high sensitivity and moderate specificity for a screening test. According to HOMA-IR > 3.0, the prevalence of insulin resistance in obese or MS children were 44.3% and 61.6% respectively. Our data indicates insulin resistance is common among Chinese obese children and adolescents, and is strongly related to MS risk, therefore requiring consideration early in life. As a reliable measure of insulin resistance and assessment of MS risk, the optimal HOMA-IR cut

  6. Application of the surface azimuthal electrical resistivity survey method to determine patterns of regional joint orientation in glacial tills

    Science.gov (United States)

    Carlson, D.

    2010-01-01

    Joints within unconsolidated material such as glacial till can be primary avenues for the flow of electrical charge, water, and contaminants. To facilitate the siting and design of remediation programs, a need exists to map anisotropic distribution of such pathways within glacial tills by determining the azimuth of the dominant joint set. The azimuthal survey method uses standard resistivity equipment with a Wenner array rotated about a fixed center point at selected degree intervals that yields an apparent resistivity ellipse. From this ellipse, joint set orientation can be determined. Azimuthal surveys were conducted at 21 sites in a 500-km2 (193 mi2) area around Milwaukee, Wisconsin, and more specifically, at sites having more than 30 m (98 ft) of glacial till (to minimize the influence of underlying bedrock joints). The 26 azimuthal surveys revealed a systematic pattern to the trend of the dominant joint set within the tills, which is approximately parallel to ice flow direction during till deposition. The average orientation of the joint set parallel with the ice flow direction is N77??E and N37??E for the Oak Creek and Ozaukee tills, respectively. The mean difference between average direct observation of joint set orientations and average azimuthal resistivity results is 8??, which is one fifth of the difference of ice flow direction between the Ozaukee and Oak Creek tills. The results of this study suggest that the surface azimuthal electrical resistivity survey method used for local in situ studies can be a useful noninvasive method for delineating joint sets within shallow geologic material for regional studies. Copyright ?? 2010 The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

  7. Interactions of oxytetracycline with a smectite clay: a spectroscopic study with molecular simulations.

    Science.gov (United States)

    Aristilde, Ludmilla; Marichal, Claire; Miéhé-Brendlé, Jocelyne; Lanson, Bruno; Charlet, Laurent

    2010-10-15

    Binding of antibiotics to clay minerals can decrease both their physical and biological availability in soils. To elucidate the binding mechanisms of tetracycline antibiotics on smectite clays as a function of pH, we probed the interactions of oxytetracycline (OTC) with Na-montmorillonite (MONT) using X-ray diffraction (XRD), infrared (IR), and solid-state nuclear magnetic resonance (NMR) spectroscopies, and Monte Carlo molecular simulations. The XRD patterns demonstrate the presence of OTC in the MONT interlayer space at acidic pH whereas complexation of OTC by external basal and edge sites seems to prevail at pH 8. At both pH, the (1)H-(13)C NMR profile indicates restricted mobility of the adsorbed OTC species; and, -CH(3) deformation and C-N stretching IR vibration bands confirm a binding mechanism involving the protonated dimethylamino group of OTC. Changes in the (23)Na NMR environments are consistent with cation-exchange and cation complexation reactions at the different sites of adsorption. Molecular simulations indicate that MONT interlayer spacing and structural charge localization dictate favorable binding conformations of the intercalated OTC, facilitating multiple interactions in agreement with the spectroscopic data. Our results present complementary insights into the mechanisms of adsorption of TETs on smectites important for their retention in natural and engineered soil environments.

  8. Bioremediation of oxytetracycline in seawater by living and dead biomass of the microalga Phaeodactylum tricornutum.

    Science.gov (United States)

    Santaeufemia, Sergio; Torres, Enrique; Mera, Roi; Abalde, Julio

    2016-12-15

    Due to its use, a large amount of Oxytetracycline (OTC) is released into water, which has a detrimental impact on aquatic ecosystems and human health. Although there are different physicochemical methods (mainly photodegradation) to remove OTC, there is increasing interest in the use of bioremediation. The sorption characteristics of OTC using living and dead biomass of the microalga Phaeodactylum tricornutum have been investigated in this study. Kinetics, isotherms and maximum elimination capacity were tested and discussed. Kinetic studies showed that the OTC removal by living biomass followed a sigmoidal model. However, the dead biomass followed a pseudo-first order model. The living biomass showed higher efficiency than the dead biomass with maximum sorption capacities of 29.18mgg -1 and 4.54mgg -1 , respectively. Combination of living biomass and photodegradation under the culture conditions eliminated 13.2mgL -1 of OTC during 11h of culture and with an initial OTC concentration of 15mgL -1 . With an initial OTC concentration of 2.5mgL -1 , 97% of OTC was removed. This removal was mainly caused by bioremediation than by photodegradation. The results proved the potential practical application of the living P. tricornutum biomass for a low-cost and efficient removal of OTC from seawater. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Comparison of oxytetracycline degradation behavior in pig manure with different antibiotic addition methods.

    Science.gov (United States)

    Wang, Yan; Chen, Guixiu; Liang, Juanboo; Zou, Yongde; Wen, Xin; Liao, Xindi; Wu, Yinbao

    2015-12-01

    Using manure collected from swine fed with diet containing antibiotics and antibiotic-free swine manure spiked with antibiotics are the two common methods of studying the degradation behavior of veterinary antibiotic in manure in the environment. However, few studies had been conducted to co-compare these two different antibiotic addition methods. This study used oxytetracycline (OTC) as a model antibiotic to study antibiotic degradation behavior in manure under the above two OTC addition methods. In addition, the role of microorganisms present in the manure on degradation behavior was also examined. The results showed that degradation half-life of OTC in manure from swine fed OTC (9.04 days) was significantly shorter than that of the manure directly treated with OTC (9.65 days). Concentration of 4-epi-OTC in manure from swine fed OTC peaked earlier than that in manure spiked with OTC, and the degradation rates of 4-epi-OTC and α-apo-OTC in the manure from swine fed OTC were faster, but the peak concentrations were lower, than those in manure spiked with OTC. Bacterial diversity and relative abundance of Bacillus cereus data demonstrated that sterilization of the manure before experiment significantly decreased OTC degradation rate in both of the addition methods. Results of the present study demonstrated that the presence of the metabolites (especially 4-epi-OTC) and microorganisms had significant influence on OTC degradation.

  10. Quantitative models for predicting adsorption of oxytetracycline, ciprofloxacin and sulfamerazine to swine manures with contrasting properties.

    Science.gov (United States)

    Cheng, Dengmiao; Feng, Yao; Liu, Yuanwang; Li, Jinpeng; Xue, Jianming; Li, Zhaojun

    2018-09-01

    Understanding antibiotic adsorption in livestock manures is crucial to assess the fate and risk of antibiotics in the environment. In this study, three quantitative models developed with swine manure-water distribution coefficients (LgK d ) for oxytetracycline (OTC), ciprofloxacin (CIP) and sulfamerazine (SM1) in swine manures. Physicochemical parameters (n=12) of the swine manure were used as independent variables using partial least-squares (PLSs) analysis. The cumulative cross-validated regression coefficients (Q 2 cum ) values, standard deviations (SDs) and external validation coefficient (Q 2 ext ) ranged from 0.761 to 0.868, 0.027 to 0.064, and 0.743 to 0.827 for the three models; as such, internal and external predictability of the models were strong. The pH, soluble organic carbon (SOC) and nitrogen (SON), and Ca were important explanatory variables for the OTC-Model, pH, SOC, and SON for the CIP-model, and pH, total organic nitrogen (TON), and SOC for the SM1-model. The high VIPs (variable importance in the projections) of pH (1.178-1.396), SOC (0.968-1.034), and SON (0.822 and 0.865) established these physicochemical parameters as likely being dominant (associatively) in affecting transport of antibiotics in swine manures. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Toxicological Implications and Inflammatory Response in Human Lymphocytes Challenged with Oxytetracycline.

    Science.gov (United States)

    Di Cerbo, A; Palatucci, A T; Rubino, V; Centenaro, S; Giovazzino, A; Fraccaroli, E; Cortese, L; Ruggiero, G; Guidetti, G; Canello, S; Terrazzano, G

    2016-04-01

    Antibiotics are widely used in zoo technical and veterinary practices as feed supplementation to ensure wellness of farmed animals and livestock. Several evidences have been suggesting both the toxic role for tetracyclines, particularly for oxytetracycline (OTC). This potential toxicity appears of great relevance for human nutrition and for domestic animals. This study aimed to extend the evaluation of such toxicity. The biologic impact of the drug was assessed by evaluating the proinflammatory effect of OTC and their bone residues on cytokine secretion by in vitro human peripheral blood lymphocytes. Our results showed that both OTC and OTC-bone residues significantly induced the T lymphocyte and non-T cell secretion of interferon (IFN)-γ, as cytokine involved in inflammatory responses in humans as well as in animals. These results may suggest a possible implication for new potential human and animal health risks depending on the entry of tetracyclines in the food-processing chain. © 2015 The Authors Journal of Biochemical and Molecular Toxicology Published Wiley Periodicals, Inc.

  12. Extraction of Oxytetracycline Hydrochloride in Aqueous Two-phase System of Acetone and Ammonium Sulfate

    International Nuclear Information System (INIS)

    Han, J.

    2013-01-01

    Summary: Aqueous two-phase system (ATPS) is an efficient implement for separation of various substrates, and extracted by an aqueous two-phase system has been successful ly applied in the downstream processing of various biological compounds. In this research, the extraction of oxytetracycline hydrochloride (OTC-HCl) was carried out in an aqueous two-phase system containing acetone and ammonium sulfate solution, which partitioned the antibiotic to the upper phase. The effects of some parameters on the extraction efficiency of OTC-HCl were studied in detail, including temperature, the volume of acetone, the pH value of ammonium sulfate solution, the concentrations of (NH/sub 4/)/sub 2/ SO/sub 4/ and OTC-HCl. The results showed that the volume of acetone, the pH value of ammonium sulfate solution and the concentration of OTC-HCl in feed had significant effects on the extraction efficiency of OTC-HCl, but the effects of temperature on the extraction of OTC-HCl was not obvious. (author)

  13. Antibacterial activity of the soil-bound antimicrobials oxytetracycline and ofloxacin.

    Science.gov (United States)

    Peng, Feng-Jiao; Zhou, Li-Jun; Ying, Guang-Guo; Liu, You-Sheng; Zhao, Jian-Liang

    2014-04-01

    Soil contamination of antimicrobials has become an increasing concern because of the potential risks to the soil microbial ecosystem and human health. The present study investigated sorption and desorption behaviors of oxytetracycline (OTC) and ofloxacin (OFL) in 3 typical soils (A, B, and C), and evaluated the antibacterial activity of soil-adsorbed compounds to a pure sensitive strain Escherichia coli ATCC 25922. The results showed different sorption and desorption behaviors of OTC and OFL in the 3 soils, behaviors that were mainly influenced by soil organic matter content and cation exchange capacity (CEC) as well as pH value. In addition, complexation and cation-exchange reactions were shown to be the main sorption mechanisms. Strong adsorption was found in soil B (with a high organic matter content) and in soil C (with high CEC), whereas enhanced desorption was observed in soil A (with low organic matter content). The results also demonstrated that soil-bound antimicrobials retained antibacterial activity toward E. coli. Opposite patterns of antibacterial activity were found for the 2 antimicrobials in the 3 soils: A>B>C for OFL; and C>B>A for OTC. This finding suggests that soil-bound antimicrobials could still exert selective pressure on soil bacteria although less effectively in comparison with the dissolved forms. © 2014 SETAC.

  14. Extraction of Oxytetracycline Hydrochloride in Aqueous Two-phase System of Acetone and Ammonium Sulfate

    Energy Technology Data Exchange (ETDEWEB)

    Han, J. [Jiangsu Univ., Zhenjiang (China). Dept. of Food and Biological Engineering

    2013-02-15

    Summary: Aqueous two-phase system (ATPS) is an efficient implement for separation of various substrates, and extracted by an aqueous two-phase system has been successful ly applied in the downstream processing of various biological compounds. In this research, the extraction of oxytetracycline hydrochloride (OTC-HCl) was carried out in an aqueous two-phase system containing acetone and ammonium sulfate solution, which partitioned the antibiotic to the upper phase. The effects of some parameters on the extraction efficiency of OTC-HCl were studied in detail, including temperature, the volume of acetone, the pH value of ammonium sulfate solution, the concentrations of (NH/sub 4/)/sub 2/ SO/sub 4/ and OTC-HCl. The results showed that the volume of acetone, the pH value of ammonium sulfate solution and the concentration of OTC-HCl in feed had significant effects on the extraction efficiency of OTC-HCl, but the effects of temperature on the extraction of OTC-HCl was not obvious. (author)

  15. The Effect of Water Hardness on Mortality of Zebrafish (Danio rerio) During Exposure to Oxytetracycline.

    Science.gov (United States)

    Hundt, Matthias; Schreiber, Benjamin; Eckmann, Reiner; Lunestad, Bjørn Tore; Wünneman, Hannah; Schulz, Ralf

    2016-02-01

    Marking of fish otoliths with oxytetracycline and tetracycline is a widely used method to evaluate the effectiveness of stocking operations. Available protocols for the labeling of fish specify a number of factors influencing mark quality and potential risk for fish during marking. This study investigates the influence of water hardness on mortality of freshwater fish during marking with OTC. In order to pursue this question complexation of OTC with Mg(2+) and Ca(2+) cations was measured spectrophotometrically. Furthermore, zebrafish (Danio rerio) were immersed in OTC solutions (1200 mg/L; 48 h immersion) combined with varying levels of water hardness (5.5, 15.5, 25.5, 32.5°dH). The amount of OTC-Mg-Ca-complexes was positively correlated to water hardness. Moreover, it could be demonstrated that mortality of zebrafish during marking varied as a factor of water hardness. Highest mortalities occurred at the lowest (5.5°dH) and the highest (32.5°dH) tested levels during marking with OTC.

  16. Upconversion luminescence resonance energy transfer-based aptasensor for the sensitive detection of oxytetracycline.

    Science.gov (United States)

    Zhang, Hui; Fang, Congcong; Wu, Shijia; Duan, Nuo; Wang, Zhouping

    2015-11-15

    In this work, a biosensor based on luminescence resonance energy transfer (LRET) from NaYF4:Yb,Tm upconversion nanoparticles (UCNPs) to SYBR Green I has been developed. The aptamers are covalently linked to UCNPs and hybridized with their complementary strands. The subsequent addition of SYBR Green allows SYBR Green I to insert into the formed double-stranded DNA (dsDNA) duplex and brings the energy donor and acceptor into close proximity, leading to the fluorescence of UCNPs transferred to SYBR Green I. When excited at 980 nm, the UCNPs emit luminescence at 477 nm, and this energy is transferred to SYBR Green I, which emits luminescence at 530 nm. In the presence of oxytetracycline (OTC), the aptamers prefer to bind to its corresponding analyte and dehybridize with the complementary DNA. This dehybridization leads to the liberation of SYBR Green I, which distances SYBR Green I from the UCNPs and recovers the UCNPs' luminescence. Under optimal conditions, a linear calibration is obtained between the ratio of I530 to I477 nm (I530/I477) and the OTC concentration, which ranges from 0.1 to 10 ng/ml with a limit of detection (LOD) of 0.054 ng/ml. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Oxytetracycline induces DNA damage and epigenetic changes: a possible risk for human and animal health?

    Science.gov (United States)

    Gallo, Adriana; Landi, Rosaria; Rubino, Valentina; Di Cerbo, Alessandro; Giovazzino, Angela; Palatucci, Anna Teresa; Centenaro, Sara; Guidetti, Gianandrea; Canello, Sergio; Cortese, Laura; Ruggiero, Giuseppina; Alessandrini, Andrea; Terrazzano, Giuseppe

    2017-01-01

    Oxytetracycline (OTC), which is largely employed in zootechnical and veterinary practices to ensure wellness of farmed animals, is partially absorbed within the gastrointestinal tract depositing in several tissues. Therefore, the potential OTC toxicity is relevant when considering the putative risk derived by the entry and accumulation of such drug in human and pet food chain supply. Despite scientific literature highlights several OTC-dependent toxic effects on human and animal health, the molecular mechanisms of such toxicity are still poorly understood. Here, we evaluated DNA damages and epigenetic alterations by quantitative reverse transcription polymerase chain reaction, quantitative polymerase chain reaction, chromatin immuno-precipitation and Western blot analysis. We observed that human peripheral blood mononuclear cells (PBMCs) expressed DNA damage features (activation of ATM and p53, phosphorylation of H2AX and modifications of histone H3 methylation of lysine K4 in the chromatin) after the in vitro exposure to OTC. These changes are linked to a robust inflammatory response indicated by an increased expression of Interferon (IFN)- γ and type 1 superoxide dismutase (SOD1). Our data reveal an unexpected biological in vitro activity of OTC able to modify DNA and chromatin in cultured human PBMC. In this regard, OTC presence in foods of animal origin could represent a potential risk for both the human and animal health.

  18. Sorption of norfloxacin, sulfamerazine and oxytetracycline by KOH-modified biochar under single and ternary systems.

    Science.gov (United States)

    Luo, Jiwei; Li, Xue; Ge, Chengjun; Müller, Karin; Yu, Huamei; Huang, Peng; Li, Jiatong; Tsang, Daniel C W; Bolan, Nanthi S; Rinklebe, Jörg; Wang, Hailong

    2018-05-08

    Pollution of water by single antibiotics has been investigated in depth. However, in reality, a wide range of different contaminants is often mixed in the aquatic environment (contaminant cocktail). Here, single and competitive sorption dynamics of ionizable norfloxacin (NOR), sulfamerazine (SMR) and oxytetracycline (OTC) by both pristine and modified biochars were investigated. Sorption kinetics of the three antibiotics was faster in ternary-solute than single-solute system. Sorption efficiency was enhanced in the competitive system for NOR by the pristine biochar, and for OTC by both the pristine biochar and the modified biochar, while SMR sorption by the pristine biochar and the KOH-modified biochar was inhibited. Sorption was governed by electrostatic interactions, π-π EDA and H-bonds for antibiotics sorption by biochar. SMR and OTC sorption by biochar was influenced by cation bridging and surface complexation, respectively. This research finding will guide the development of treatment procedures for water polluted by multiple antibiotics. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Hairy roots of Helianthus annuus: a model system to study phytoremediation of tetracycline and oxytetracycline.

    Science.gov (United States)

    Gujarathi, Ninad P; Haney, Bryan J; Park, Heidi J; Wickramasinghe, S Ranil; Linden, James C

    2005-01-01

    The release of antibiotics to the environment has to be controlled because of serious threats to human health. Hairy root cultures of Helianthus annuus (sunflower), along with their inherent rhizospheric activity, provide a fast growing, microbe-free environment for understanding plant-pollutant interactions. The root system catalyzes rapid disappearance of tetracycline (TC) and oxytetracycline (OTC) from aqueous media, which suggests roots have potential for phytoremediation of the two antibiotics in vivo. In addition, in vitro modifications of the two antibiotics by filtered, cell- and microbe-free root exudates suggest involvement of root-secreted compounds. The modification is confirmed from changes observed in UV spectra of exudate-treated OTC. Modification appears to be more dominant at the BCD chromophore of the antibiotic molecule. Kinetic analyses dismiss direct enzyme catalysis; the modification rates decrease with increasing OTC concentrations. The rates increase with increasing age of cultures from which root exudates are prepared. The decrease in modification rates upon addition of the antioxidant ascorbic acid (AA) suggests involvement of reactive oxygen species (ROS) in the antibiotic modification process.

  20. The Escherichia coli BtuE protein functions as a resistance determinant against reactive oxygen species.

    Directory of Open Access Journals (Sweden)

    Felipe A Arenas

    2011-01-01

    Full Text Available This work shows that the recently described Escherichia coli BtuE peroxidase protects the bacterium against oxidative stress that is generated by tellurite and by other reactive oxygen species elicitors (ROS. Cells lacking btuE (ΔbtuE displayed higher sensitivity to K(2TeO(3 and other oxidative stress-generating agents than did the isogenic, parental, wild-type strain. They also exhibited increased levels of cytoplasmic reactive oxygen species, oxidized proteins, thiobarbituric acid reactive substances, and lipoperoxides. E. coli ΔbtuE that was exposed to tellurite or H(2O(2 did not show growth changes relative to wild type cells either in aerobic or anaerobic conditions. Nevertheless, the elimination of btuE from cells deficient in catalases/peroxidases (Hpx(- resulted in impaired growth and resistance to these toxicants only in aerobic conditions, suggesting that BtuE is involved in the defense against oxidative damage. Genetic complementation of E. coli ΔbtuE restored toxicant resistance to levels exhibited by the wild type strain. As expected, btuE overexpression resulted in decreased amounts of oxidative damage products as well as in lower transcriptional levels of the oxidative stress-induced genes ibpA, soxS and katG.

  1. Determination of Soft Lithology Causes The Land Subsidence in Coastal Semarang City by Resistivity Methods

    Science.gov (United States)

    Widada, Sugeng; Saputra, Sidhi; Hariadi

    2018-02-01

    Semarang City is located in the northern coastal plain of Java which is geologically composed of alluvial deposits. The process of the sediment diagenesis has caused a land subsidence. On the other hand, the development of the industrial, service, education and housing sectors has increased the number of building significantly. The number of building makes the pressure of land surface increased, and finally, this also increased the rate of land subsidence. The drilling data indicates that not all layers of lithology are soft layers supporting the land subsidence. However, vertical distribution of the soft layer is still unclear. This study used Resistivity method to map out the soft zone layers of lithology. Schlumberger electrode configuration with sounding system method was selected to find a good vertical resolution and maximum depth. The results showed that the lithology layer with resistivity less than 3 ohm is a layer of clay and sandy clay that has the low bearing capacity so easily compressed by pressure load. A high land subsidence is happening in the thick soft layer. The thickness of that layer is smaller toward the direction of avoiding the beach. The improvement of the bearing capacity of this layer is expected to be a solution to the problem of land subsidence.

  2. Determination of work function of graphene under a metal electrode and its role in contact resistance.

    Science.gov (United States)

    Song, Seung Min; Park, Jong Kyung; Sul, One Jae; Cho, Byung Jin

    2012-08-08

    Although the work function of graphene under a given metal electrode is critical information for the realization of high-performance graphene-based electronic devices, relatively little relevant research has been carried out to date. In this work, the work function values of graphene under various metals are accurately measured for the first time through a detailed analysis of the capacitance-voltage (C-V) characteristics of a metal-graphene-oxide-semiconductor (MGOS) capacitor structure. In contrast to the high work function of exposed graphene of 4.89-5.16 eV, the work function of graphene under a metal electrode varies depending on the metal species. With a Cr/Au or Ni contact, the work function of graphene is pinned to that of the contacted metal, whereas with a Pd or Au contact the work function assumes a value of ∼4.62 eV regardless of the work function of the contact metal. A study of the gate voltage dependence on the contact resistance shows that the latter case provides lower contact resistance.

  3. Estimation of hydraulic conductivity on clay content in soil determined from resistivity data

    Energy Technology Data Exchange (ETDEWEB)

    Shevnin, Vladimir; Delgado-Rodriguez, Omar; Mousatov, Aleksandr [Mexican Petroleum Institute, Mexico, D.F. (Mexico); Ryjov, Albert [Moscow State Geological Prospecting Academy, Geophysical Faculty, Moscow (Russian Federation)

    2006-07-15

    The influence of clay content in sandy and clayey soils on hydraulic conductivity (filtration coefficient) is considered. A review of published experimental data on the relationship of hydraulic conductivity with soil lithology and grain size, as dependent on clay content is presented. Theoretical calculations include clay content. Experimental and calculated data agree, and several approximation formulas for filtration coefficient vs clay content are presented. Clay content in soil is estimated from electric resistivity data obtained from 2D VES interpretation. A two-step method is proposed, the first step including clay content calculating from soil resistivity and groundwater salinity, and the second step including filtration coefficient estimating from clay content. Two applications are presented. [Spanish] El contenido de arcilla en suelos areno-arcillosos influye sobre la permeabilidad hidraulica (coeficiente de filtracion). Se presenta una revision de datos experimentales publicados que relacionan el coeficiente de filtracion con el tipo litologico del suelo y el tamano de las particulas. A partir de calculos teoricos, se modifican las conocidas formulas que relacionan el coeficiente de filtracion con el contenido de arcilla. Se estima el contenido de arcilla a partir de los datos interpretados por el metodo SEV, y se propone un procedimiento para la estimacion del coeficiente de filtracion: (a) calculo del contenido de arcilla a partir de la resistividad del suelo y de la salinidad del agua subterranea, (b) estimacion del coeficiente de filtracion a partir del contenido de arcilla. Se presentan algunos ejemplos de la aplicacion de esta metodologia.

  4. The effect of oxytetracycline on the amount of calcium and phosphorus of blood and density of bone tissue in broiler chickens

    Directory of Open Access Journals (Sweden)

    aziz Norouzi

    2016-01-01

    Full Text Available This study was designed to investigate the effects of oxytetracycline on the amount of calcium and phosphorus of blood and bone tissue density in broiler chickens. For this purpose, 72 day-old Ross chicks of, 308 strain in a completely randomized design in two groups: the control group (without dietary antibiotic and the treatment group (with a diet containing oxytetracycline 50%, 3 gr per kg of diet with 6 replicates in the same environmental conditions and management were studied for 42 days. In this experiment, the diameter of femoral shaft and ratio of various tissues of the femur and skull were studied. Blood parameters included calcium and phosphorus. In the group treated with oxytetracycline, femur shaft diameter was significantly decreased with the addition of drug to diet (p

  5. Applicability of the lattice Boltzmann method to determine the ohmic resistance in equivalent resistor connections

    Science.gov (United States)

    Espinoza-Andaluz, Mayken; Barzola, Julio; Guarochico-Moreira, Víctor H.; Andersson, Martin

    2017-12-01

    Knowing the ohmic resistance in the materials allow to know in advance its electrical behavior when a potential difference is applied, and therefore the prediction of the electrical performance can be achieved in a most certain manner. Although the Lattice Boltzmann method (LBM) has been applied to solve several physical phenomena in complex geometries, it has only been used to describe the fluid phase, but applicability studies of LBM on the solid-electric-conducting material have not been carried out yet. The purpose of this paper is to demonstrate the accuracy of calculating the equivalent resistor connections using LBM. Several series and parallel resistor connections are effected. All the computations are carried out with 3D models, and the domain materials are designed by the authors.

  6. Rapid determination of anti-tuberculosis drug resistance from whole-genome sequences

    KAUST Repository

    Coll, Francesc

    2015-05-27

    Mycobacterium tuberculosis drug resistance (DR) challenges effective tuberculosis disease control. Current molecular tests examine limited numbers of mutations, and although whole genome sequencing approaches could fully characterise DR, data complexity has restricted their clinical application. A library (1,325 mutations) predictive of DR for 15 anti-tuberculosis drugs was compiled and validated for 11 of them using genomic-phenotypic data from 792 strains. A rapid online ‘TB-Profiler’ tool was developed to report DR and strain-type profiles directly from raw sequences. Using our DR mutation library, in silico diagnostic accuracy was superior to some commercial diagnostics and alternative databases. The library will facilitate sequence-based drug-susceptibility testing.

  7. Nutrition, insulin resistance and dysfunctional adipose tissue determine the different components of metabolic syndrome

    Science.gov (United States)

    Paniagua, Juan Antonio

    2016-01-01

    Obesity is an excessive accumulation of body fat that may be harmful to health. Today, obesity is a major public health problem, affecting in greater or lesser proportion all demographic groups. Obesity is estimated by body mass index (BMI) in a clinical setting, but BMI reports neither body composition nor the location of excess body fat. Deaths from cardiovascular diseases, cancer and diabetes accounted for approximately 65% of all deaths, and adiposity and mainly abdominal adiposity are associated with all these disorders. Adipose tissue could expand to inflexibility levels. Then, adiposity is associated with a state of low-grade chronic inflammation, with increased tumor necrosis factor-α and interleukin-6 release, which interfere with adipose cell differentiation, and the action pattern of adiponectin and leptin until the adipose tissue begins to be dysfunctional. In this state the subject presents insulin resistance and hyperinsulinemia, probably the first step of a dysfunctional metabolic system. Subsequent to central obesity, insulin resistance, hyperglycemia, hypertriglyceridemia, hypoalphalipoproteinemia, hypertension and fatty liver are grouped in the so-called metabolic syndrome (MetS). In subjects with MetS an energy balance is critical to maintain a healthy body weight, mainly limiting the intake of high energy density foods (fat). However, high-carbohydrate rich (CHO) diets increase postprandial peaks of insulin and glucose. Triglyceride-rich lipoproteins are also increased, which interferes with reverse cholesterol transport lowering high-density lipoprotein cholesterol. In addition, CHO-rich diets could move fat from peripheral to central deposits and reduce adiponectin activity in peripheral adipose tissue. All these are improved with monounsaturated fatty acid-rich diets. Lastly, increased portions of ω-3 and ω-6 fatty acids also decrease triglyceride levels, and complement the healthy diet that is recommended in patients with MetS. PMID

  8. Nutrition, insulin resistance and dysfunctional adipose tissue determine the different components of metabolic syndrome

    Institute of Scientific and Technical Information of China (English)

    Juan; Antonio; Paniagua[1,2

    2016-01-01

    Obesity is an excessive accumulation of body fat that may be harmful to health. Today, obesity is a major public health problem, affecting in greater or lesser proportion all demographic groups. Obesity is estimated by body mass index (BMI) in a clinical setting, but BMI reports neither body composition nor the location of excess body fat.Deaths from cardiovascular diseases, cancer and diabetes accounted for approximately 65% of all deaths, and adiposity and mainly abdominal adiposity are associated with all these disorders. Adipose tissue could expand to inflexibility levels. Then, adiposity is associated with a state of low-grade chronic inflammation, with increased tumor necrosis factor-α and interleukin-6 release, which interfere with adipose cell differentiation, and the action pattern of adiponectin and leptin until the adipose tissue begins to be dysfunctional. In this state the subject presents insulin resistance and hyperinsulinemia, probably the first step of a dysfunctional metabolic system. Subsequent to central obesity, insulin resistance, hyperglycemia,hypertriglyceridemia, hypoalphalipoproteinemia, hypertension and fatty liver are grouped in the so-called metabolic syndrome (MetS). In subjects with MetS an energy balance is critical to maintain a healthy body weight, mainly limiting the intake of high energy density foods (fat). However, high-carbohydrate rich (CHO) diets increase postprandial peaks of insulin and glucose.Triglyceride-rich lipoproteins are also increased, which interferes with reverse cholesterol transport lowering highdensity lipoprotein cholesterol. In addition, CHO-rich diets could move fat from peripheral to central deposits and reduce adiponectin activity in peripheral adipose tissue. All these are improved with monounsaturated fatty acid-rich diets. Lastly, increased portions of ω-3 and ω-6 fatty acids also decrease triglyceride levels, and complement the healthy diet that is recommended in patients with MetS.

  9. Occurrence and characterization of livestock-associated methicillin-resistant Staphylococcus aureus in pig industries of northern Thailand.

    Science.gov (United States)

    Patchanee, Prapas; Tadee, Pakpoom; Arjkumpa, Orapun; Love, David; Chanachai, Karoon; Alter, Thomas; Hinjoy, Soawapak; Tharavichitkul, Prasit

    2014-12-01

    This study was conducted to determine the prevalence of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in pigs, farm workers, and the environment in northern Thailand, and to assess LA-MRSA isolate phenotypic characteristics. One hundred and four pig farms were randomly selected from the 21,152 in Chiang Mai and Lamphun provinces in 2012. Nasal and skin swab samples were collected from pigs and farm workers. Environmental swabs (pig stable floor, faucet, and feeder) were also collected. MRSA was identified by conventional bacterial culture technique, with results confirmed by multiplex PCR and multi locus sequence typing (MLST). Herd prevalence of MRSA was 9.61% (10 of 104 farms). Among pigs, workers, and farm environments, prevalence was 0.68% (two of 292 samples), 2.53% (seven of 276 samples), and 1.28% (four of 312 samples), respectively. Thirteen MRSA isolates (seven from workers, four from environmental samples, and two from pigs) were identified as Staphylococcal chromosomal cassette mec IV sequences type 9. Antimicrobial sensitivity tests found 100% of the MRSA isolates resistant to clindamycin, oxytetracycline, and tetracycline, while 100% were susceptible to cloxacillin and vancomycin. All possessed a multidrug-resistant phenotype. This is the first evidence of an LA-MRSA interrelationship among pigs, workers, and the farm environment in Thailand.

  10. Determination of antibiotic resistance profile in Klebsiella pneumonia strains isolated from urinary tract infections of patients hospitalized in Peyambaran hospital (Tehran-Iran

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    Marzieh Tavakol

    2017-04-01

    Full Text Available Background: Urinary tract infection (UTI is the second prevalent infection in human mostly caused by Escherichia coli and Klebsiella pneumonia. The aim of this study was to determine the antibiotic resistance profile and detect the prevalence of antibiotic resistance encoding genes in K .pneumoniae isolated from UTI. Materials and Methods: Fifty K. pneumonia strains isolated from 122 UTI samples of hospitalized patients in Payambaran Hospital (Tehran, Iran which were subjected to this study (2014 were confirmed by standard biochemical tests. Isolates were tested for susceptibility to 10 antimicrobial drugs by using disk diffusion method. Antibiotic resistance encoding genes frequently include the aadA1, aac(3-IV, sul1, blaSHV, Cat1, cmlA, tetA, tetB, dfrA1, CITM, qnr in isolates were determined by PCR. Results: The highest antibiotic resistance in K. pneumoniae isolates were for Tetracycline and the lowest resistance (2% for Gentamicin and Imipenem. To determine the frequency of antibiotic resistant genes, 64% and 4% of isolates had tetA and Gentamicin-(aac(3-IV resistant genes, respectively. Conclusion: Frequency of antibiotic resistance encoding genes may have important and basic role in the occurrence and transfer of antibiotic resistance which can be due to the indiscriminate use of antibiotics.

  11. Maternal malnutrition and offspring sex determine juvenile obesity and metabolic disorders in a swine model of leptin resistance.

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    Alicia Barbero

    Full Text Available The present study aimed to determine, in a swine model of leptin resistance, the effects of type and timing of maternal malnutrition on growth patterns, adiposity and metabolic features of the progeny when exposed to an obesogenic diet during their juvenile development and possible concomitant effects of the offspring sex. Thus, four groups were considered. A CONTROL group involved pigs born from sows fed with a diet fulfilling their daily maintenance requirements for pregnancy. The treated groups involved the progeny of females fed with the same diet but fulfilling either 160% or 50% of pregnancy requirements during the entire gestation (OVERFED and UNDERFED, respectively or 100% of requirements until Day 35 of pregnancy and 50% of such amount from Day 36 onwards (LATE-UNDERFED. OVERFED and UNDERFED offspring were more prone to higher corpulence and fat deposition from early postnatal stages, during breast-feeding; adiposity increased significantly when exposed to obesogenic diets, especially in females. The effects of sex were even more remarkable in LATE-UNDERFED offspring, which had similar corpulence to CONTROL piglets; however, females showed a clear predisposition to obesity. Furthermore, the three groups of pigs with maternal malnutrition showed evidences of metabolic syndrome and, in the case of individuals born from OVERFED sows, even of insulin resistance and the prodrome of type-2 diabetes. These findings support the main role of early nutritional programming in the current rise of obesity and associated diseases in ethnics with leptin resistance.

  12. The evaluation of the classical Kirby-Bauer antibiogram method for the determination of antibiotic resistant microorganisms in tap water

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    Siedlecka Agata

    2017-01-01

    Full Text Available Water supply systems are the main source of potable water for many inhabitants. The European Union and Polish laws demand high quality of tap water, but the aspect of antibiotic resistant bacteria (ARB is not mentioned. The special emphasis is placed on the presence of pathogenic microorganisms in water, determining by the presence of chosen indicators. Although these regulations provide quite good quality of drinking water, the neglect of resistance vectors could lead to a serious threat to human health. In this study the randomly chosen sample of water from the Wroclaw water supply system was tested in order to evaluate the usefulness of Kirby-Bauer antibiogram method for the assessment of the presence of ARB. The susceptibility testing with 6 chosen antibiotics was performed on bacterial strains isolated from the sample. The diameters of growth inhibition zones were measured and the preliminary identification of strains was carried out, including Gram staining and bacterial cellular morphologies assessments. Although full recognition of the drug resistance phenomenon demands the identification of bacterial species for the comparison with susceptibility testing guidelines, this preliminary research could answer the question, whether the Kirby-Bauer method is sufficient for investigations of ARB dwelling in Wroclaw tap water or the other solution should be applied.

  13. Laboratory determination of chemotherapeutic drug resistance in tumor cells from patients with leukemia, using a fluorometric microculture cytotoxicity assay (FMCA).

    Science.gov (United States)

    Larsson, R; Kristensen, J; Sandberg, C; Nygren, P

    1992-01-21

    An automated fluorometric microculture cytotoxicity assay (FMCA) based on the measurement of fluorescence generated from cellular hydrolysis of fluorescein diacetate (FDA) to fluorescein was employed for chemotherapeutic-drug-sensitivity testing of tumor-cell suspensions from patients with leukemia. Fluorescence was linearly related to cell number, and reproducible measurements of drug sensitivity could be performed using fresh or cryopreserved leukemia cells. A marked heterogeneity with respect to chemotherapeutic drug sensitivity was observed for a panel of cytotoxic drugs tested in 43 samples from 35 patients with treated or untreated acute and chronic leukemia. For samples obtained from patients with chronic lymphocytic and acute myelocytic leukemia, sensitivity profiles for standard drugs corresponded to known clinical activity and the assay detected primary and acquired drug resistance. Individual in vitro/in vivo correlations indicated high specificity with respect to the identification of drug resistance. The results suggest that the FMCA may be a simple and rapid method for in vivo-representative determinations of chemotherapeutic drug resistance in tumor cells obtained from patients with leukemia.

  14. Determination antimicrobial resistance profile of Acinetobacter strains isolated from hospitalized patients in Different Part of Taleghani Hospital (Ahvaz, Iran

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    Khadijah Ahmadi

    2014-10-01

    Full Text Available Background: The members of the genus Acinetobacter are Gram-negative cocobacilli that are frequently found in the environment but also in the hospital setting where they have been associated with outbreaks of nosocomial infections such as meningitis, endocarditis, skin and soft tissue infections, urinary tract infection, conjunctivitis, burn wound infection and bacteremia. This organism has been shown resistance to different antimicrobial agents. The aim of this study was to determination antibiotic resistance profile of Acinetobacter strains isolated from hospitalized patients in Taleghani hospital (Ahvaz, Iran. Materials and Methods: This cross-sectional study was conducted on 43 Acinetobacter 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: Acinetobacter strains were isolated from different specimens consisting biopsy 24 (55.8%, wound 13 (30/2% and blood 6 (14%. In antimicrobial susceptibility testing, colistin exhibited the greatest activity (60.5% against isolated strains. 33 (76/7% isolates demonstrated resistance to imipenem. Conclusion: In outbreak situations, surveillance cultures of patients involved in the outbreak or who are deemed at risk for colonization/infection with the outbreak organism are often parts of the planned intervention.

  15. Crystal Structure of the Substrate-Binding Domain from Listeria monocytogenes Bile-Resistance Determinant BilE

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    Stephanie J. Ruiz

    2016-12-01

    Full Text Available BilE has been reported as a bile resistance determinant that plays an important role in colonization of the gastrointestinal tract by Listeria monocytogenes, the causative agent of listeriosis. The mechanism(s by which BilE mediates bile resistance are unknown. BilE shares significant sequence similarity with ATP-binding cassette (ABC importers that contribute to virulence and stress responses by importing quaternary ammonium compounds that act as compatible solutes. Assays using related compounds have failed to demonstrate transport mediated by BilE. The putative substrate-binding domain (SBD of BilE was expressed in isolation and the crystal structure solved at 1.5 Å. Although the overall fold is characteristic of SBDs, the binding site varies considerably relative to the well-characterized homologs ProX from Archaeoglobus fulgidus and OpuBC and OpuCC from Bacillus subtilis. This suggests that BilE may bind an as-yet unknown ligand. Elucidation of the natural substrate of BilE could reveal a novel bile resistance mechanism.

  16. The efficacy of oxytetracycline treatment at batch, pen and individual level on Lawsonia intracellularis infection in nursery pigs in a randomised clinical trial.

    Science.gov (United States)

    Larsen, Inge; Nielsen, Søren Saxmose; Olsen, John Elmerdahl; Nielsen, Jens Peter

    2016-02-01

    Antimicrobial consumption in animal husbandry is of great scientific and political concern due to the risk of selection of resistant bacteria. Whilst a reduction in the use of antimicrobials is therefore preferable, the efficacy of treatment must be maintained in order to ensure animal welfare and profitability of pig production. The objective of this study was to evaluate the efficacy of three treatment strategies under field conditions against Lawsonia intracellularis (LI)-related diarrhoea. A randomised clinical trial was carried out in four Danish pig herds, including a total of 520 pigs from 36 nursery batches. A high prevalence of LI was demonstrated in all herds prior to the initiation of the study. Treatment efficacy was assessed by faecal shedding of LI, the occurrence of diarrhoea and average daily weight gain (ADG) after treatment. All strategies were implemented at batch level at presence of LI-related diarrhoea and included daily treatment with 10mg oxytetracycline (OTC) per kilogram of bodyweight for 5 days, though the OTC was administered differently: either by oral treatment of all pigs in a batch, by oral treatment of pigs in diarrhoeic pens only, or by intramuscular treatment of individual diarrhoeic pigs only. The treatment strategies were randomly allocated to batches and were initiated at the presence of diarrhoea. From the included batches, 100% of the trial pigs were medicated in the batch treatment strategy, 87% in the pen treatment strategy and 55% in the individual treatment strategy. All strategies reduced the occurrence of diarrhoea and faecal shedding of LI after treatment. However, batch treatment was found to be most efficient in reducing both high-level LI shedding and diarrhoea when compared to the treatment of diarrhoeic pens or individual diarrhoeic pigs. There was no significant difference identified in ADG between the treatment strategies. In conclusion, batch treatment of all pigs in a section resulted in the highest efficacy

  17. Characterisation and determination of virus resistance among cowpea [Vigna unguiculata (L.) Walp.] Genotypes

    International Nuclear Information System (INIS)

    Tettey, Carlos Kweku

    2017-07-01

    Several households in Ghana feed on cowpea [Vigna unguiculata (L.) Walp.] which serves as good source of protein. However, cowpea viral diseases and the lack of adaptable cultivars have become a limiting factor in cowpea production. This work therefore sought to explore morphogenetic diversity and viral resistance traits in cowpea germplasm to improve productivity. Thirty-eight exotic and local cowpea genotypes were cultivated at the Teaching and Research Field of the School of Agriculture, the University of Cape Coast. Two plants were maintained per stand at planting distance of 50 cm x 30 cm with three replications in a randomized complete block layout during the major (June – September) and minor seasons (November – February). The cowpea genotypes were characterised using both morphological and molecular methods to assess diversity in the coastal savanna agro-ecological zone of Ghana. They were also screened for resistance to cowpea viruses using visual scale on-field and DAS-ELISA protocol. The cowpeas showed significant (P < 0.05) variations in plant height, canopy diameter, number of branches, area of leaf, days to 50% flowering, days to pod maturity, pod length, number of seeds per pod and hundred seed weight. There were significant and positive correlations between pod weight and seed yield (r = 0.985, P < 0.05), plant height and canopy diameter (r = 0.576, P < 0.05), canopy diameter and number of branches (r = 0.576) as well as pod length and the number of seeds per pod (r = 0.530, P < 0.05). Hundred seed weight ranged from 10.03 g to 22.7 g. On the whole, 23 quantitative and qualitative parameters differentiated the cowpea genotypes into two main clusters with sub-clusters. Genomic analysis involving nine polymorphic SSR primers showed a mean genetic diversity of 0.7, polymorphic information content of 0.67 and allele frequency of 0.4 among the cowpea genotypes, which were differentiated into two main clusters with sub-clusters. Incidence and severity

  18. UV-vis, IR and 1H NMR spectroscopic studies and characterization of ionic-pair crystal violet-oxytetracycline

    Science.gov (United States)

    Orellana, Sandra; Soto, César; Toral, M. Inés

    2010-01-01

    The present study shows the formation and characterization of the ionic-pair between the antibiotic oxytetracycline and the dye crystal violet in ammonia solution pH 9.0 ± 0.2 extracted into chloroform. The characterization was demonstrated using UV-vis spectrophotometry, 1H NMR, measurement of relaxation times T1 and IR spectroscopy, using a comparison between the signals of individual pure compounds with the signals with the mixture CV-OTC in different alkaline media. The formation of ionic-pair was also corroborated by new signals and chemical shifts. (2D) NMR spectroscopy experiments show that the interaction is electrostatic.

  19. Novel molecular determinants of viral susceptibility and resistance in the lipidome of Emiliania huxleyi.

    Science.gov (United States)

    Fulton, James M; Fredricks, Helen F; Bidle, Kay D; Vardi, Assaf; Kendrick, B Jacob; DiTullio, Giacomo R; Van Mooy, Benjamin A S

    2014-04-01

    Viruses play a key role in controlling the population dynamics of algae, including Emiliania huxleyi, a globally distributed haptophyte with calcite coccoliths that comprise ca. 50% of the sinking carbonate flux from the surface ocean. Emiliania huxleyi viruses (EhVs) routinely infect and terminate E. huxleyi blooms. EhVs are surrounded by a lipid envelope, which we found to be comprised largely of glycosphingolipids (GSLs) with lesser amounts of polar glycerolipids. Infection appears to involve membrane fusion between the virus and host, and we hypothesized that specific polar lipids may facilitate virus attachment. We identified three novel intact polar lipids in E. huxleyi strain CCMP 374 and EhV86, including a GSL with a monosaccharide sialic acid headgroup (sGSL); for all 11 E. huxleyi strains we tested, there was a direct relationship between sGSL content and sensitivity to infection by EhV1, EhV86 and EhV163. In mesocosms, the E. huxleyi population with greatest initial sGSL content had the highest rate of virus-induced mortality. We propose potential physiological roles for sGSL that would be beneficial for growth but leave cells susceptible to infection, thus furthering the discussion of Red Queen-based co-evolution and the cost(s) of sensitivity and resistance in the dynamic E. huxleyi-EhV system. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

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

    Science.gov (United States)

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

    2016-03-21

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