keyword
MENU ▼
Read by QxMD icon Read
search

antibiotic residues

keyword
https://www.readbyqxmd.com/read/28088025/residues-of-2-hydroxy-3-phenylpyrazine-a-degradation-product-of-some-%C3%AE-lactam-antibiotics-in-environmental-water-in-vietnam
#1
Nguyen Van Sy, Kazuo Harada, Megumi Asayama, Minae Warisaya, Le Hong Dung, Yoshinori Sumimura, Khong Thi Diep, Le Viet Ha, Nguyen Nam Thang, Tran Thi Tuyet Hoa, Tran Minh Phu, Pham Ngoc Khai, Nguyen Thanh Phuong, Le Danh Tuyen, Yoshimasa Yamamoto, Kazumasa Hirata
Antibiotic-resistant bacteria have become a serious problem worldwide, caused in part by the excessive use and discharge of antibiotics into the environment. Ampicillin (ABPC) is a widely used antibiotic. However, this chemical rapidly decomposes in water containing divalent cations like Ca(2+) and Mg(2+), thus, detection of ABPC in environmental water is difficult. This study was carried out to evaluate the presence of 2-hydroxy-3-phenylpyrazine (HPP), one of the degradation products of ABPC and β-lactam antibiotics with an ABPC substructure, in environmental water...
January 2, 2017: Chemosphere
https://www.readbyqxmd.com/read/28087620/e152a-substitution-drastically-affects-ndm-5-activity
#2
Gaurav Kumar, Bagre Issa, Debasish Kar, Sarmistha Biswal, Anindya S Ghosh
New Delhi Metallo beta-lactamase (NDM) is of significant public health concern due to its enormous potential to hydrolyse all major beta-lactams including carbapenems. Amino acid substitutions outside the active site reportedly affect NDM beta-lactamase activities. Here, the effect of amino acid substitutions in the possible omega-like loop region of NDM-5 has been elucidated. Overall, three substitution mutations near active site of NDM-5 were done, namely, E152A, S191A, and D223A and subsequently, the change in antimicrobial resistance was monitored upon expressing each mutant in a suitable host...
January 12, 2017: FEMS Microbiology Letters
https://www.readbyqxmd.com/read/28079218/zinc-ion-induced-conformational-changes-in-new-delphi-metallo-%C3%AE-lactamase-1-probed-by-molecular-dynamics-simulations-and-umbrella-sampling
#3
Jianzhong Chen, Jinan Wang, Weiliang Zhu
The hydrolysis of a β-lactam core ring caused by new Delphi metallo-β-lactamase 1 (NDM-1) with the help of two zinc cofactors induces significant resistance toward β-lactam antibiotics. Molecular dynamics (MD) simulations and the umbrella sampling method are integrated to study the conformational change mechanism of NDM-1 mediated by zinc ion binding. The statistical analyses of interaction contacts of the antibiotic ampicillin (AMP) with residues based on MD trajectories suggest that two Zn ions are essential for maintaining the binding of AMP with NDM-1...
January 12, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28075068/binding-and-processing-of-%C3%AE-lactam-antibiotics-by-the-transpeptidase-ldtmt2-from-mycobacterium-tuberculosis
#4
Eva Maria Steiner, Gunter Schneider, Robert Schnell
β-lactam antibiotics represent a novel direction in the chemotherapy of tuberculosis that brings the peptidoglycan layer of the complex mycobacterial cell wall in focus as therapeutic target. Peptidoglycan stability in Mycobacterium tuberculosis especially during infection relies on the non-conventional peptide cross-links formed by L,D-transpeptidases. These enzymes are known to be inhibited by β-lactams, primarily carbapenems, leading to a stable covalent modification at the enzyme active site. A panel of sixteen β-lactams antibiotics was characterized by inhibition kinetics, mass spectrometry and x-ray crystallography to identify efficient compounds and study their action on the essential transpeptidase LdtMt2 ...
January 11, 2017: FEBS Journal
https://www.readbyqxmd.com/read/28074907/insights-into-an-evolutionary-strategy-leading-to-antibiotic-resistance
#5
Chun-Feng D Hou, Jian-Wei Liu, Charles Collyer, Nataša Mitić, Marcelo Monteiro Pedroso, Gerhard Schenk, David L Ollis
Metallo-β-lactamases (MBLs) with activity towards a broad-spectrum of β-lactam antibiotics have become a major threat to public health, not least due to their ability to rapidly adapt their substrate preference. In this study, the capability of the MBL AIM-1 to evade antibiotic pressure by introducing specific mutations was probed by two alternative methods, i.e. site-saturation mutagenesis (SSM) of active site residues and in vitro evolution. Both approaches demonstrated that a single mutation in AIM-1 can greatly enhance a pathogen's resistance towards broad spectrum antibiotics without significantly compromising the catalytic efficiency of the enzyme...
January 11, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28063198/functional-and-structural-studies-on-the-neisseria-gonorrhoeae-gmha-the-first-enzyme-in-the-glycero-manno-heptose-biosynthesis-pathways-demonstrate-a-critical-role-in-lipooligosaccharide-synthesis-and-gonococcal-viability
#6
Igor H Wierzbicki, Ryszard A Zielke, Konstantin V Korotkov, Aleksandra E Sikora
Sedoheptulose-7-phosphate isomerase, GmhA, is the first enzyme in the biosynthesis of nucleotide-activated-glycero-manno-heptoses and an attractive, yet underexploited, target for development of broad-spectrum antibiotics. We demonstrated that GmhA homologs in Neisseria gonorrhoeae and N. meningitidis (hereafter called GmhAGC and GmhANM , respectively) were interchangeable proteins essential for lipooligosaccharide (LOS) synthesis, and their depletion had adverse effects on neisserial viability. In contrast, the Escherichia coli ortholog failed to complement GmhAGC depletion...
January 7, 2017: MicrobiologyOpen
https://www.readbyqxmd.com/read/28062224/water-metagenomic-analysis-reveals-low-bacterial-diversity-and-the-presence-of-antimicrobial-residues-and-resistance-genes-in-a-river-containing-wastewater-from-backyard-aquacultures-in-the-mekong-delta-vietnam
#7
Tatsuya Nakayama, Tran Thi Tuyet Hoa, Kazuo Harada, Minae Warisaya, Megumi Asayama, Atsushi Hinenoya, Joon Won Lee, Tran Minh Phu, Shuhei Ueda, Yoshinori Sumimura, Kazumasa Hirata, Nguyen Thanh Phuong, Yoshimasa Yamamoto
The environmental pathways for the dissemination of antibiotic resistance have recently received increased attention. Aquatic environments act as reservoirs or sources of antimicrobial-resistant bacteria, antimicrobial residues, and antimicrobial resistance genes (ARGs). Therefore, it is imperative to identify the role of polluted water in the dissemination of antimicrobial resistance. The aim of this study was to evaluate the antimicrobial residues, ARGs, and microbiota in the freshwater systems of the Mekong Delta...
January 3, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28061011/simultaneous-enantiomeric-analysis-of-pharmacologically-active-compounds-in-environmental-samples-by-chiral-lc-ms-ms-with-a-macrocyclic-antibiotic-stationary-phase
#8
D Camacho-Muñoz, B Kasprzyk-Hordern
This paper presents a multi-residue method for direct enantioselective separation of chiral pharmacologically active compounds in environmental matrices. The method is based on chiral liquid chromatography and tandem mass spectrometry detection. Simultaneous chiral discrimination was achieved with a macrocyclic glycopeptide-based column with antibiotic teicoplanin as a chiral selector working under reverse phase mode. For the first time, enantioresolution was reported for metabolites of ibuprofen: carboxyibuprofen and 2-hydroxyibuprofen with this chiral stationary phase...
January 6, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28059088/insights-into-the-mechanistic-basis-of-plasmid-mediated-colistin-resistance-from-crystal-structures-of-the-catalytic-domain-of-mcr-1
#9
Philip Hinchliffe, Qiu E Yang, Edward Portal, Tom Young, Hui Li, Catherine L Tooke, Maria J Carvalho, Neil G Paterson, Jürgen Brem, Pannika R Niumsup, Uttapoln Tansawai, Lei Lei, Mei Li, Zhangqi Shen, Yang Wang, Christopher J Schofield, Adrian J Mulholland, Jianzhong Shen, Natalie Fey, Timothy R Walsh, James Spencer
The polymixin colistin is a "last line" antibiotic against extensively-resistant Gram-negative bacteria. Recently, the mcr-1 gene was identified as a plasmid-mediated resistance mechanism in human and animal Enterobacteriaceae, with a wide geographical distribution and many producer strains resistant to multiple other antibiotics. mcr-1 encodes a membrane-bound enzyme catalysing phosphoethanolamine transfer onto bacterial lipid A. Here we present crystal structures revealing the MCR-1 periplasmic, catalytic domain to be a zinc metalloprotein with an alkaline phosphatase/sulphatase fold containing three disulphide bonds...
January 6, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28054670/ultra-sensitive-detection-of-kanamycin-for-food-safety-using-a-reduced-graphene-oxide-based-fluorescent-aptasensor
#10
Na-Reum Ha, In-Pil Jung, Im-Joung La, Ho-Sup Jung, Moon-Young Yoon
Overuse of antibiotics has caused serious problems, such as appearance of super bacteria, whose accumulation in the human body through the food chain is a concern. Kanamycin is a common antibiotic used to treat diverse infections; however, residual kanamycin can cause many side effects in humans. Thus, development of an ultra-sensitive, precise, and simple detection system for residual kanamycin in food products is urgently needed for food safety. In this study, we identified kanamycin-binding aptamers via a new screening method, and truncated variants were analyzed for optimization of the minimal sequence required for target binding...
January 5, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28050849/glycin-rich-antimicrobial-peptide-yd1-from-b-amyloliquefaciens-induced-morphological-alteration-in-and-showed-affinity-for-plasmid-dna-of-e-coli
#11
Md Saifur Rahman, Yun Hee Choi, Yoon Seok Choi, Jin Cheol Yoo
Antimicrobial peptides (AMPs), low-molecular-weight proteins with broad-spectrum antimicrobial activity, are the most promising candidates for the development of novel antimicrobials. A powerful cationic glycine-rich AMP YD1 (MW ~ 1.0 kDa) was purified from Bacillus amyloliquefaciens CBSYD1 isolated from traditional Korean fermented food kimchi, for the treatment of multidrug-resistant (MDR) bacteria. Strain CBSYD1 was identified 99.79% similar to Bacillus amyloliquefaciens subsp. plantarum FZB42(T) by 16S rRNA sequence analysis...
December 2017: AMB Express
https://www.readbyqxmd.com/read/28045097/in-situ-degradation-of-antibiotic-residues-in-medical-intravenous-infusion-bottles-using-high-energy-electron-beam-irradiation
#12
Min Wang, Lele Zhang, Guilong Zhang, Tao Pang, Xin Zhang, Dongqing Cai, Zhengyan Wu
This study reported an immediate approach for the degradation of three antibiotic (amoxicillin, ofloxacin, and cefradine) residues in medical intravenous infusion bottles (MIIBs) using high energy electron beam (HEEB) irradiation. The effects of irradiation doses, initial concentrations, initial pH, and scavengers of active radicals on the degradation of three antibiotic residues (ARs) were investigated, and the results displayed that 97.02%, 97.61% and 96.87% of amoxicillin, ofloxacin, and cefradine residues could be degraded in situ through HEEB irradiation respectively...
January 3, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28042939/oral-fluid-as-a-biological-material-for-ante-mortem-detection-of-oxytetracycline-in-pigs-by-liquid-chromatography-tandem-mass-spectrometry
#13
Anna Gajda, Artur Jablonski, Tomasz Bladek, Andrzej Posyniak
The presence of antibiotic residues in pig tissues, urges the search of new methods to their ante-mortem detection. To find an alternative for post-mortem pig carcass analysis, an oral fluid was tested. To prove the suitability of oral fluid for the detection of antibiotics administered by injection, oxytetracycline (OTC) was chosen. Research was conducted on two groups of animals: group 1 - 100% pigs treated and group 2- 50% pigs treated and 50 % pigs untreated. OTC was assayed by high performance liquid chromatography - tandem mass spectrometry method...
January 2, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28042035/structural-and-functional-characterization-of-the-alanine-racemase-from-streptomyces-coelicolor-a3-2
#14
Raffaella Tassoni, Lizah T van der Aart, Marcellus Ubbink, Gilles P van Wezel, Navraj S Pannu
The conversion of L-alanine (L-Ala) into D-alanine (D-Ala) in bacteria is performed by pyridoxal phosphate-dependent enzymes called alanine racemases. D-Ala is an essential component of the bacterial peptidoglycan and hence required for survival. The Gram-positive bacterium Streptomyces coelicolor has at least one alanine racemase encoded by alr. Here, we describe an alr deletion mutant of S. coelicolor which depends on D-Ala for growth and shows increased sensitivity to the antibiotic D-cycloserine (DCS). The crystal structure of the alanine racemase (Alr) was solved with and without the inhibitors DCS or propionate, at 1...
December 29, 2016: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/28035988/antibiotic-resistant-superbugs-assessment-of-the-interrelationship-of-occurrence-in-clinical-settings-and-environmental-niches
#15
REVIEW
Anthony Ayodeji Adegoke, Adekunle Christopher Faleye, Gulshan Singh, Thor Axel Stenström
The increasing threat to global health posed by antibiotic resistance remains of serious concern. Human health remains at higher risk due to several reported therapeutic failures to many life threatening drug resistant microbial infections. The resultant effects have been prolonged hospital stay, higher cost of alternative therapy, increased mortality, etc. This opinionated review considers the two main concerns in integrated human health risk assessment (i.e., residual antibiotics and antibiotic resistant genes) in various compartments of human environment, as well as clinical dynamics associated with the development and transfer of antibiotic resistance (AR)...
December 27, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28035803/molecularly-imprinted-membrane-electrospray-ionization-for-direct-sample-analyses
#16
Tianyi Li, Liusheng Fan, Yingfeng Wang, Xuebin Huang, Jianguo Xu, Jinxing Lu, Mei Zhang, Wei Xu
Typically dealing with practical samples with very complex matrices, ambient ionization mass spectrometry suffers from low detection sensitivity. In this study, molecular imprinting technology was explored and integrated with membrane electrospray ionization (MESI) method for direct sample analyses. By enriching targeted analytes on molecularly imprinted membrane (MIM), 10- to 50-fold limit of quantitation improvement could be achieved compared to conventional nano-electrospray ionization method or other ambient ionization method...
December 28, 2016: Analytical Chemistry
https://www.readbyqxmd.com/read/28028885/antibiotic-spider-silk-site-specific-functionalization-of-recombinant-spider-silk-using-click-chemistry
#17
David Harvey, Philip Bardelang, Sara L Goodacre, Alan Cockayne, Neil R Thomas
In a new, versatile approach to fun-ction-alizing recombinant spider silk, L-azidohomoalanine is introduced residue-specifically in the minispidroin protein 4RepCT through expression in an E. coli methionine auxotroph. Both fluorophores and the antibiotic levofloxacin are attached to this bio-orthogonal amino acid using copper-catalyzed click chemistry, either before or after the silk fibers are self-assembled.
December 28, 2016: Advanced Materials
https://www.readbyqxmd.com/read/28025443/direct-and-indirect-antibacterial-effects-of-various-concentrations-of-triple-antibiotic-pastes-loaded-in-a-methylcellulose-system
#18
Sarmad M Alyas, Benjamin I Fischer, Ygal Ehrlich, Kenneth Spolnik, Richard L Gregory, Ghaeth H Yassen
We investigated the direct and indirect (residual) antibacterial effects of various concentrations of triple antibiotic paste (TAP) loaded into a methylcellulose system. Enterococcus faecalis (E. faecalis) was grown on sterilized dentin blocks (n = 60) and treated with clinically used TAP (1,000 mg/mL), low concentrations of methylcellulose-based TAP (100, 10, and 1 mg/mL), placebo paste, or 1.5% NaOCl (n = 10). The pastes were then removed, and biofilm disruption assays were performed. Additional dentin blocks (n = 120) were pretreated with the same experimental groups (n = 20)...
2016: Journal of Oral Science
https://www.readbyqxmd.com/read/28017778/rhoa-s-nitrosylation-as-a-regulatory-mechanism-influencing-endothelial-barrier-function-in-response-to-g-bacterial-toxins
#19
F Chen, Y Wang, R Rafikov, S Haigh, W B Zhi, S Kumar, P T Doulias, O Rafikova, H Pillich, T Chakraborty, R Lucas, A V Verin, J D Catravas, J X She, S M Black, D J R Fulton
Disruption of the endothelial barrier in response to Gram positive (G(+)) bacterial toxins is a major complication of acute lung injury (ALI) and can be further aggravated by antibiotics which stimulate toxin release. The integrity of the pulmonary endothelial barrier is mediated by the balance of disruptive forces such as the small GTPase RhoA, and protective forces including endothelium-derived nitric oxide (NO). How NO protects against the barrier dysfunction is incompletely understood and our goal was to determine whether NO and S-nitrosylation can modulate RhoA activity and whether this mechanism is important for G(+) toxin-induced microvascular permeability...
December 22, 2016: Biochemical Pharmacology
https://www.readbyqxmd.com/read/28012383/effects-of-multiple-antibiotics-exposure-on-denitrification-process-in-the-yangtze-estuary-sediments
#20
Guoyu Yin, Lijun Hou, Min Liu, Yanling Zheng, Xiaofei Li, Xianbiao Lin, Juan Gao, Xiaofen Jiang, Rong Wang, Chendi Yu
Denitrification is a dominant reactive nitrogen removal pathway in most estuarine and coastal ecosystems, and plays a significant role in regulating N2O release. Although multiple antibiotics residues are widely detected in aquatic environment, combined effects of antibiotics on denitrification remain indistinct. In this work, 5 classes of antibiotics (sulfonamides, chloramphenicols, tetracyclines, macrolides, and fluoroquinolones) were selected to conduct orthogonal experiments in order to explore their combined effects on denitrification...
December 18, 2016: Chemosphere
keyword
keyword
85069
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"