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https://www.readbyqxmd.com/read/29348071/a-focused-fragment-library-targeting-the-antibiotic-resistance-enzyme-oxacillinase-48-synthesis-structural-evaluation-and-inhibitor-design
#1
Sundus Akhter, Bjarte Aarmo Lund, Aya Ismael, Manuel Langer, Johan Isaksson, Tony Christopeit, Hanna-Kirsti S Leiros, Annette Bayer
β-Lactam antibiotics are of utmost importance when treating bacterial infections in the medical community. However, currently their utility is threatened by the emergence and spread of β-lactam resistance. The most prevalent resistance mechanism to β-lactam antibiotics is expression of β-lactamase enzymes. One way to overcome resistance caused by β-lactamases, is the development of β-lactamase inhibitors and today several β-lactamase inhibitors e.g. avibactam, are approved in the clinic. Our focus is the oxacillinase-48 (OXA-48), an enzyme reported to spread rapidly across the world and commonly identified in Escherichia coli and Klebsiella pneumoniae...
December 30, 2017: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/29344288/gp73-level-determines-chemotherapeutic-resistance-in-human-hepatocellular-carcinoma-cells
#2
Jia-Zhou Ye, Shu-Mei Yan, Chun-Ling Yuan, Hui-Ni Wu, Jin-Yan Zhang, Zhi-Hui Liu, Yong-Qiang Li, Xiao-Ling Luo, Yan Lin, Rong Liang
Objective GP73 is a new hepatocellular carcinoma (HCC) marker, which is highly expressed in hepatocellular carcinoma and closely relates to prognosis. This study was to investigate the effects of GP73 on cellular proliferation, apoptosis, oxaliplatin (OXA) resistance and secretory clusterin (sCLU) of HCC cells. Materials and Methods Western blot and immunofluorescence was used to detect the expression of GP73 in 8 types of commonly used HCC cell lines. Drug resistance was induced by increasing concentration gradient method...
2018: Journal of Cancer
https://www.readbyqxmd.com/read/29341954/carbapenemase-production-of-clinical-isolates-acinetobacter-baumannii-and-pseudomonas-aeruginosa-from-a-bulgarian-university-hospital
#3
Atanaska P Petrova, Irina D Stanimirova, Ivan N Ivanov, Michael M Petrov, Tsonka M Miteva-Katrandzhieva, Vasil I Grivnev, Velichka S Kardjeva, Todor V Kantardzhiev, Mariana A Murdjeva
BACKGROUND: Production of Bla OXA-23, OXA-24, OXA-58 and hyperexpression of OXA-51 due to ISAba1 insertion sequence are the leading causes of carbapenem resistance in Acinetobacter baumannii. The loss of OprD transmembrane protein and the overexpression of some effl ux pumps are considered to be the main factors for carbapenem resistance in Pseudomonas aeruginosa whereas metallo-enzymes' production has a secondary role. AIM: Тo examine the carbapenem resistance due to carbapenemase production among clinically signifi cant Gram-negative non-fermenters from St George University hospital, Plovdiv: A...
December 20, 2017: Folia Medica
https://www.readbyqxmd.com/read/29337862/therapeutic-management-of-pseudomonas-aeruginosa-bloodstream-infection-non-susceptible-to-carbapenems-but-susceptible-to-old-cephalosporins-and-or-to-penicillins
#4
Ronit Zaidenstein, Asaf Miller, Ruthy Tal-Jasper, Hadas Ofer-Friedman, Menachem Sklarz, David E Katz, Tsillia Lazarovitch, Paul R Lephart, Bethlehem Mengesha, Oran Tzuman, Mor Dadon, Chen Daniel, Jacob Moran-Gilad, Dror Marchaim
It is unknown as to whether other beta-lactams can be used for bloodstream infections (BSI) resulting from Pseudomonas aeruginosa (PA) which are non-susceptible to one or more carbapenem. We conducted a retrospective cohort study at the Assaf Harofeh Medical Center (AHMC) from January 2010 to August 2014. Adult patients with PA-BSI non-susceptible to a group 2 carbapenem but susceptible to ceftazidime or piperacillin (with or without tazobactam), were enrolled. We compared the outcomes of patients who received an appropriate beta-lactam antibiotic ("cases") to those who received an appropriate non-beta-lactam antibiotic ("controls")...
January 16, 2018: Microorganisms
https://www.readbyqxmd.com/read/29332105/the-emergence-of-carbapenem-resistant-klebsiella-pneumoniae-isolates-producing-oxa-48-and-ndm-in-the-southern-asir-province-saudi-arabia
#5
Ibrahim A Al-Zahrani, Bander A Alsiri
To identify the prevalence of carbapenem-resistant Klebsiella pneumoniae (CRKP) and the most common types of cabapenemases among CRKP in the Southern (Asir) province hospitals, Saudi Arabia. Methods: The cross-sectional study was conducted between late April and September in 2015. A total of 54 Klebsiella pneumoniae (K. pneumoniae) isolates with reduced sensitivity to carbapenems were obtained from various clinical specimens of the 2 largest hospitals in the Southern province. Minimum inhibitory concentrations (MICs) of carbapenems were confirmed using E-test...
January 2018: Saudi Medical Journal
https://www.readbyqxmd.com/read/29326210/complete-genome-sequencing-of-acinetobacter-sp-strain-logew2-3-isolated-from-the-pellet-of-a-white-stork-reveals-a-novel-class-d-beta-lactamase-gene
#6
Ulrike Blaschke, Evelyn Skiebe, Michael Kaatz, Paul G Higgins, Yvonne Pfeifer, Gottfried Wilharm
Whole-genome sequencing of Acinetobacter sp. strain LoGeW2-3, isolated from the pellet of a white stork (Ciconia ciconia), reveals the presence of a plasmid of 179,399 bp encoding a CRISPR-Cas (clustered regularly interspaced short palindromic repeats and associated genes) system of the I-F type, and the chromosomally encoded novel class D beta-lactamase OXA-568.
January 11, 2018: Genome Announcements
https://www.readbyqxmd.com/read/29320720/simultaneous-emergence-and-rapid-spread-of-three-oxa-23-producing-acinetobacter-baumannii-st208-strains-in-intensive-care-units-confirmed-by-whole-genome-sequencing
#7
Qiong Chen, Jia-Wei Zhou, Jian-Zhong Fan, Sheng-Hai Wu, Li-Hui Xu, Yan Jiang, Zhi Ruan, Yun-Song Yu, Dao-Jun Yu, Xian-Jun Wang
Carbapenem-resistant Acinetobacter baumannii (CRAB) is a common nosocomial bacterial pathogen with limited treatment options. CRAB outbreaks are disastrous for critically ill patients. This study investigated carbapenemase-produced A. baumannii outbreaks in a tertiary hospital. Although multiple outbreaks were suggested by pulse-field gel electrophoresis, the genetic lineages and evolution between these isolates were not clear. To investigate the genomic epidemiology of these outbreaks and to reveal possible transmission routes, whole genome sequences (WGS) were compared and analyzed...
January 8, 2018: Infection, Genetics and Evolution
https://www.readbyqxmd.com/read/29318095/green-and-red-fluorescent-dyes-for-translational-applications-in-imaging-and-sensing-analytes-a-dual-color-flag
#8
REVIEW
Elisabete Oliveira, Emilia Bértolo, Cristina Núñez, Viviane Pilla, Hugo M Santos, Javier Fernández-Lodeiro, Adrian Fernández-Lodeiro, Jamila Djafari, José Luis Capelo, Carlos Lodeiro
Red and green are two of the most-preferred colors from the entire chromatic spectrum, and red and green dyes are widely used in biochemistry, immunohistochemistry, immune-staining, and nanochemistry applications. Selective dyes with green and red excitable chromophores can be used in biological environments, such as tissues and cells, and can be irradiated with visible light without cell damage. This critical review, covering a period of five years, provides an overview of the most-relevant results on the use of red and green fluorescent dyes in the fields of bio-, chemo- and nanoscience...
January 2018: ChemistryOpen
https://www.readbyqxmd.com/read/29311088/antibiotic-resistance-plasmids-cointegrated-into-a-megaplasmid-harbouring-the-blaoxa-427-carbapenemase-gene
#9
Stefanie Desmet, Suruchi Nepal, Jan Maarten van Dijl, Marc Van Ranst, Monika A Chlebowicz, John W Rossen, Jeroen K J Van Houdt, Piet Maes, Katrien Lagrou, Erik Bathoorn
OXA-427 is a new class-D carbapenemase encountered in different species of Enterobacteriaceae in a Belgian hospital. To study the dispersal of this gene, we describe the comparative analysis of two plasmids containing the blaOXA-427 gene isolated from a Klebsiella pneumoniae and an Enterobacter cloacae complex strain. The two IncA/C2 plasmids containing blaOXA-427 share the same backbone, however, in the K. pneumoniae this plasmid is cointegrated into an IncFIB plasmid forming a 321 kb megaplasmid with multiple multi-resistance regions...
January 8, 2018: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/29310399/blaoxa-23-like-and-blatem-rather-than-blaoxa-51-like-contributed-to-a-high-level-of-carbapenem-resistance-in-acinetobacter-baumannii-strains-from-a-teaching-hospital-in-xi-an-china
#10
Lei Han, Jine Lei, Jiru Xu, Shaoshan Han
Acinetobacter baumannii is one of the major threats in clinical infections due to its antibiotic resistance ability. It shows increasing resistance to carbapenems, mainly due to β-lactamase mediated mechanisms. The aim of this study was to investigate carbapenem resistance (CR) profiles and analyze β-lactamases genes composition of clinical A. baumannii strains from a teaching hospital in Xi'an. The resistance patterns to imipenem and meropenem were checked for 51 clinical A. baumannii strains. The existence of 15 β-lactamases genes was detected by polymerase chain reaction (PCR), and the positive genes were sequenced...
December 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/29309610/carbapenem-resistant-acinetobacter-baumannii-st294-harbouring-the-oxa-72-carbapenemase-from-a-captive-grey-parrot
#11
Peter Klotz, Lisa Jacobmeyer, Ivonne Stamm, Ursula Leidner, Yvonne Pfeifer, Torsten Semmler, Ellen Prenger-Berninghoff, Christa Ewers
No abstract text is available yet for this article.
December 21, 2017: Journal of Antimicrobial Chemotherapy
https://www.readbyqxmd.com/read/29305547/evaluation-of-the-amplidiag-carbar-vre-kit-for-the-accurate-detection-of-carbapenemase-producing-bacteria
#12
Saoussen Oueslati, Delphine Girlich, Laurent Dortet, Thierry Naas
As carbapenemase-producing Gram-negative bacilli (CP-GNB) (Enterobacteriaceae, Pseudomonadaceae and Acinetobacter spp.) are becoming a major public health issue, there is an urgent need for accurate and fast diagnostic tests. Amplidiag® Carba-R+VRE assay is a multiplex nucleic acid-based in-vitro diagnostic test intended for the detection of CP-GNB and vancomycin resistant enterococci (VRE) from cultured colonies.We have evaluated its ability to detect carbapenemases genes in 100 well-characterized GNB, and in 200 consecutive enterobacterial isolates with reduced susceptibility to carbapenems and that were referred to the French National Reference Center for carbapenem-resistance...
January 5, 2018: Journal of Clinical Microbiology
https://www.readbyqxmd.com/read/29303197/catalytic-enantioselective-synthesis-of-carboxy-substituted-2-isoxazolines-by-cascade-oxa-michael-cyclization
#13
Hyo-Jun Lee, Bora Eun, Eonseon Sung, Gil Tae Hwang, Young Kwan Ko, Chang-Woo Cho
An efficient quinidine-based phase-transfer-catalyzed enantioselective cascade oxa-Michael-cyclization reaction of hydroxylamine with various β-carboxy-substituted α,β-unsaturated ketones has been achieved for the preparation of chiral carboxy-substituted 2-isoxazolines. This cascade reaction provided the desired products in good yields (up to 98%) with excellent enantioselectivities (91-96% ee). In addition, the cascade reaction was effectively applied to the first catalytic asymmetric synthesis of the herbicide (S)-methiozolin...
January 5, 2018: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/29301193/antibiotic-resistance-of-acinetobacter-spp-isolates-from-the-river-danube-susceptibility-stays-high
#14
Clemens Kittinger, Alexander Kirschner, Michaela Lipp, Rita Baumert, Franz Mascher, Andreas H Farnleitner, Gernot E Zarfel
Acinetobacter spp. occur naturally in many different habitats, including food, soil, and surface waters. In clinical settings, Acinetobacter poses an increasing health problem, causing infections with limited to no antibiotic therapeutic options left. The presence of human generated multidrug resistant strains is well documented but the extent to how widely they are distributed within the Acinetobacter population is unknown. In this study, Acinetobacter spp. were isolated from water samples at 14 sites of the whole course of the river Danube...
December 30, 2017: International Journal of Environmental Research and Public Health
https://www.readbyqxmd.com/read/29299207/first-report-of-oxa-143-lactamase-producing-acinetobacter-baumannii-in-qom-iran
#15
Zohreh Sarikhani, Razieh Nazari, Mahmoud Nateghi Rostami
Objectives: Antibiotic resistance in Acinetobacter baumannii and outbreaks caused by this organism have been reported from several areas of the world. The present study aimed at determining the antibiotic susceptibility profiles and the distribution of OXA-type beta-lactamases among Iranian Acinetobacter baumannii isolates from Qom of Iran. Materials and Methods: For this study, 108 non-duplicate A. baumannii isolates were obtained from clinical specimens in four teaching hospitals in Qom in the central of Iran...
November 2017: Iranian Journal of Basic Medical Sciences
https://www.readbyqxmd.com/read/29291442/new-insights-into-structure-activity-relationship-of-ipomoeassin-f-from-its-bioisosteric-5-oxa-aza-analogues
#16
Guanghui Zong, Xianwei Sun, Rima Bhakta, Lucas Whisenhunt, Zhijian Hu, Feng Wang, Wei Q Shi
Ipomoeassin F, a plant-derived macrolide, exhibited single-digit nanomolar growth inhibition activity against many cancer cell lines. In this report, a series of 5-oxa/aza analogues was prepared and screened for cytotoxicity. Replacement of 5-CH2 with O/NH simplified the synthesis and led to only a small activity loss. N-methylation almost completely restored the potency. Further studies with additional 5-oxa analogues suggested, for the first time, that size and flexibility of the ring also significantly influence the bioactivity of ipomoeassin F...
December 12, 2017: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/29288024/trichiconlides-cf-four-new-limonoids-with-1-2-seco-phragmalin-type-carbon-skeleton-from-the-fruits-of-trichilia-connaroides
#17
Fa-Liang An, Dong-Mei Sun, Xiao-Bing Wang, Lei Yang, Yong-Yin, Jun Luo, Ling-Yi Kong
Phytochemical investigation of the fruits from Trichilia connaroides led to the isolation of four rare 1,2-seco phragmalin-type limonoids (1-4) with C-7/28 δ-lactone ring along with two known triterpenoids (5-6). An oxygen bridge between C-1 and C-2 formed an rare 9-oxa-tricyclo[3.3.2.17,10]undecane-2-ene moiety in structure of 1 and 2, and 3-4 possessed a bicyclo[5.2.14,10]decane skeleton. Their structures were established based on extensive spectroscopic methods and their absolute configurations of 1 were confirmed by TDDFT/ECD calculation and comparative analysis...
December 26, 2017: Fitoterapia
https://www.readbyqxmd.com/read/29283077/species-distribution-sequence-types-and-antimicrobial-resistance-of-acinetobacter-spp-from-cystic-fibrosis-patients
#18
G A Rocha, D F Lima, E R Rodrigues, R S Leão, T W Folescu, M C Firmida, R W F Cohen, R M Albano, E A Marques
Acinetobacter spp. are important healthcare pathogens, being closely linked to antibiotic resistance and outbreaks worldwide. Although such species are rarely observed in patients with cystic fibrosis (CF), we describe the characteristics of 53 strains of Acinetobacter spp. isolated from the sputum of 39 Brazilian patients with CF. The species distribution was A. baumannii (n = 29), A. pittii (n = 13), A. nosocomialis (n = 8), A. seifertii (n = 1), A. soli (n = 1) and A. variabilis (n = 1) determined by partial rpoB gene sequencing...
December 28, 2017: Epidemiology and Infection
https://www.readbyqxmd.com/read/29275158/in-vivo-and-in-vitro-admet-profiling-and-in-vivo-pharmacodynamic-investigations-of-a-selective-%C3%AE-7-nicotinic-acetylcholine-receptor-agonist-with-a-spirocyclic-%C3%AE-2-isoxazoline-molecular-skeleton
#19
Carlo Matera, Giulio Dondio, Daniela Braida, Luisa Ponzoni, Marco De Amici, Mariaelvina Sala, Clelia Dallanoce
(±)-3-Methoxy-1-oxa-2,7-diaza-7,10-ethanospiro[4.5]dec-2-ene sesquifumarate (±)-1 was previously characterized as the most selective agonist at α7 neuronal nicotinic acetylcholine receptors in a series of spirocyclic quinuclidinyl-Δ2-isoxazoline derivatives. In this study, we performed different in vitro biological assays aimed at characterizing the ADMET properties of (±)-1. Then, we tested the compound in vivo in behavioral studies including classical novel object recognition and inhibitory avoidance tests in the rat, and a spatial memory assay in zebrafish involving a rapid T-maze task...
December 21, 2017: European Journal of Pharmacology
https://www.readbyqxmd.com/read/29274802/susceptibility-testing-and-detection-of-%C3%AE-lactam-resistance-mechanisms-in-enterobacteriaceae-a-multicentre-national-proficiency-study
#20
María Díez-Aguilar, María-Carmen Conejo, María-Isabel Morosini, Núria Tormo Palop, Concepción Gimeno, Rafael Cantón, Álvaro Pascual
A nationwide study was developed to evaluate the ability of 60 Spanish clinical microbiology laboratories to predict the underlying β-lactam resistance mechanisms of 12 Enterobacteriaceae strains (CCS01-CCS12). Results obtained by two reference laboratories were compared with those reported by the participants that used their own routine susceptibility testing methodology. CLSI interpretive criteria were used in 53.3% of the centres, while 46.7% used EUCAST. The overall categorical agreement (CA) was 85.5%...
December 21, 2017: International Journal of Antimicrobial Agents
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