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https://www.readbyqxmd.com/read/28912880/spectroscopic-analysis-and-docking-simulation-on-the-recognition-and-binding-of-tem-1-%C3%AE-lactamase-with-%C3%AE-lactam-antibiotics
#1
Jianting Yang, Qian Li, Liujiao Bian
The interaction between TEM-1 β-lactamase and antibiotics is very important in the hydrolysis of antibiotics. In the present study, the recognition and binding of TEM-1 β-lactamase with three β-lactam antibiotics, including penicillin G, cefalexin and cefoxitin, was investigated by fluorescence and ultraviolet-visible absorption spectra in combination with molecular docking in the temperature range of 278-288 K and under simulated physiological conditions. The results demonstrated that the fluorescence emissions of TEM-1 β-lactamase were extinguished by static quenching and the energy of TEM-1 β-lactamase was transferred in a non-radioactive manner...
October 2017: Experimental and Therapeutic Medicine
https://www.readbyqxmd.com/read/28887772/fortuitous-detection-of-cmy-2-and-dha-1-from-esbl-producing-escherichia-coli-in-senegal
#2
S Lo, F Robin, A Ba-Diallo, O F Diallo, M L Dia, R Beyrouthy, A Gaye-Diallo, A I Sow, R Bonnet
Cephalosporinases, which are naturally present in some enterobacterial species, can be mobilized by transposons, migrate to plasmids, and spread into other species such as Escherichia coli. The aim of this study was to characterize genes responsible for the production of extended-spectrum β-lactamases (ESBL) in E. coli isolates from urinary origin isolated in two hospitals in Senegal. Thus, a fortuitous discovery of plasmidic cephalosporinase in two isolates was noted. One of the isolates produced dha-1 associated with ESBL CTX-M-14, the other produced cmy-2, ESBL CTXM-15, tem-1 penicillinase, and oxa-1...
September 8, 2017: Bulletin de la Société de Pathologie Exotique
https://www.readbyqxmd.com/read/28835096/reversibility-of-covalent-broad-spectrum-serine-%C3%AE-lactamase-inhibition-by-the-diazabicyclooctenone-etx2514
#3
Adam B Shapiro, Ning Gao, Haris Jahić, Nicole M Carter, April Chen, Alita A Miller
ETX2514 is a non-β-lactam serine β-lactamase inhibitor in clinical development that has greater potency and broader spectrum of β-lactamase inhibition than the related diazabicyclooctanone avibactam. Despite opening of its cyclic urea ring upon acylation, avibactam can recyclize and dissociate intact from certain β-lactamases. We investigated reversibility of ETX2514 acylation of 10 serine β-lactamases representing Ambler classes A, C, and D. Dissociation rate constants varied widely between enzymes and were lowest for class D...
August 28, 2017: ACS Infectious Diseases
https://www.readbyqxmd.com/read/28812563/multicopy-plasmids-potentiate-the-evolution-of-antibiotic-resistance-in-bacteria
#4
Alvaro San Millan, Jose Antonio Escudero, Danna R Gifford, Didier Mazel, R Craig MacLean
Plasmids are thought to play a key role in bacterial evolution by acting as vehicles for horizontal gene transfer, but the role of plasmids as catalysts of gene evolution remains unexplored. We challenged populations of Escherichia coli carrying the blaTEM-1 β-lactamase gene on either the chromosome or a multicopy plasmid (19 copies per cell) with increasing concentrations of ceftazidime. The plasmid accelerated resistance evolution by increasing the rate of appearance of novel TEM-1 mutations, thereby conferring resistance to ceftazidime, and then by amplifying the effect of TEM-1 mutations due to the increased gene dosage...
November 7, 2016: Nature ecology & evolution
https://www.readbyqxmd.com/read/28725038/genomic-characterization-of-novel-incfii-type-multidrug-resistant-plasmids-p0716-kpc-and-p12181-kpc-from-klebsiella-pneumoniae
#5
Jiao Feng, Zhe Yin, Qiangyuan Zhao, Yachao Zhao, Defu Zhang, Xiaoyuan Jiang, Weili Wu, Weijun Chen, Hui Wang, Yajun Song, Yigang Tong, Jinglin Wang, Yanjun Li, Dongsheng Zhou
This study aimed to genetically characterize two fully-sequenced novel IncFII-type multidrug resistant (MDR) plasmids, p0716-KPC and p12181-KPC, recovered from two different clinical Klebsiella pneumoniae isolates. p0716-KPC and p12181-KPC had a very similar genomic content. The backbones of p0716-KPC/p12181-KPC contained two different replicons (belonging to a novel IncFII subtype and the Rep_3 family), the IncFIIK and IncFIIY maintenance regions, and conjugal transfer gene sets from IncFIIK-type plasmids and unknown origins...
July 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28699625/mutation-supply-and-the-repeatability-of-selection-for-antibiotic-resistance
#6
Thomas van Dijk, Sungmin Hwang, Joachim Krug, Arjan Gm de Visser, Mark Peter Zwart
Whether evolution can be predicted is a key question in evolutionary biology. Here we set out to better understand the repeatability of evolution, which is a necessary condition for predictability. We explored experimentally the effect of mutation supply and the strength of selective pressure on the repeatability of selection from standing genetic variation. Different sizes of mutant libraries of antibiotic resistance gene TEM-1 β-lactamase in Escherichia coli, generated by error-prone PCR, were subjected to different antibiotic concentrations...
July 12, 2017: Physical Biology
https://www.readbyqxmd.com/read/28687975/prevalence-and-drug-resistance-characteristics-of-carbapenem-resistant-enterobacteriaceae-in-hangzhou-china
#7
Yan Yang, Jian Chen, Di Lin, Xujian Xu, Jun Cheng, Changgui Sun
With the abuse of antimicrobial agents in developing countries, increasing number of carbapenem-resistant Enterobacteriaceae (CRE) attracted considerable public concern. A retrospective study was conducted based on 242 CRE strains from a tertiary hospital in Hangzhou, China to investigate prevalence and drug resistance characteristics of CRE in southeast China. Bacterial species were identified. Antimicrobial susceptibility was examined by broth microdilution method or epsilometer test. Resistant β-lactamase genes were identified by polymerase chain reaction and sequencing...
July 8, 2017: Frontiers of Medicine
https://www.readbyqxmd.com/read/28687066/genomic-characterization-of-a-large-plasmid-containing-a-bla-ndm-1-gene-carried-on-salmonella-enterica-serovar-indiana-c629-isolate-from-china
#8
Wei Wang, Zulqarnain Baloch, Zixin Peng, Yujie Hu, Jin Xu, Séamus Fanning, Fengqin Li
BACKGROUND: The bla NDM-1 gene in Salmonella species is mostly reported in clinical cases, but is rarely isolated from red and white meat in China. METHODS: A Salmonella Indiana (S. Indiana) isolate was cultured from a chicken carcass procured from a slaughterhouse in China. Antimicrobial susceptibility was tested against a panel of agents. Whole-genome sequencing of the isolate was carried out and data was analyzed. RESULTS: A large plasmid, denoted as plasmid pC629 (210,106 bp), containing a composite cassette, consisting of IS26-bla NDM-1-ble MBL -△trpF-tat-cutA-ISCR1-sul1-qacE△1-aadA2-dfrA12-intI1-IS26 was identified...
July 7, 2017: BMC Infectious Diseases
https://www.readbyqxmd.com/read/28667632/monitoring-effector-translocation-using-the-tem-1-beta-lactamase-reporter-system
#9
Julie Allombert, Anne Vianney, Xavier Charpentier
Among the bacterial secretion systems, the Type III, IV, and VI secretion systems enable bacteria to secrete proteins directly into a target cell. This specific form of secretion, referred to as translocation, is essential for a number of pathogens to alter or kill targeted cells. The translocated proteins, called effector proteins, can directly interfere with the normal processes of the targeted cells, preventing elimination of pathogens and promoting their multiplication. The function of effector proteins varies greatly depending on the considered pathogen and the targeted cell...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28643490/characterization-of-extended-spectrum-%C3%AE-lactamase-genes-of-shigella-flexneri-isolates-with-fosfomycin-resistance-from-patients-in-china
#10
Yanyan Liu, Yue Cheng, Haifei Yang, Lifen Hu, Jun Cheng, Ying Ye, Jiabin Li
BACKGROUND: The emergence of fosfomycin resistance and extended-spectrum β-lactamase (ESBL) genes is a serious threat to public health and a new challenge in shigellosis treatment. The purpose of this study was to identify fosfomycin resistance and characterize β-lactamase genes in fos-carrying isolates of Shigella flexneri from patients in China. METHODS: A total of 263 S. flexneri isolates were collected from 34 hospitals in the Anhui Province of China during September 2012-September 2015 and screened for fosA3, fosA, and fosC2 by PCR amplification and sequencing...
September 2017: Annals of Laboratory Medicine
https://www.readbyqxmd.com/read/28631253/portal-branch-ligation-does-not-counteract-the-inhibiting-effect-of-temsirolimus-on-extrahepatic-colorectal-metastatic-growth
#11
Sebastian Senger, Jens Sperling, Barbara Oberkircher, Martin K Schilling, Otto Kollmar, Michael D Menger, Christian Ziemann
The mTor-inhibitor temsirolimus (TEM) has potent anti-tumor activities on extrahepatic colorectal metastases. Treatment of patients with advanced disease may require portal branch ligation (PBL). While PBL can induce intrahepatic tumor growth, the effect of PBL on extrahepatic metastases under TEM treatment is unknown. Therefore, we analyzed the effects of TEM treatment on extrahepatic metastases during PBL-associated liver regeneration. GFP-transfected CT26.WT colorectal cancer cells were implanted into the dorsal skinfold chamber of BALB/c-mice...
June 19, 2017: Clinical & Experimental Metastasis
https://www.readbyqxmd.com/read/28589129/whole-genome-sequence-analysis-of-antimicrobial-resistance-genes-in-streptococcus-uberis-and-streptococcus-dysgalactiae-isolates-from-canadian-dairy-herds
#12
Julián Reyes Vélez, Marguerite Cameron, Juan Carlos Rodríguez-Lecompte, Fangfang Xia, Luke C Heider, Matthew Saab, J Trenton McClure, Javier Sánchez
The objectives of this study are to determine the occurrence of antimicrobial resistance (AMR) genes using whole-genome sequence (WGS) of Streptococcus uberis (S. uberis) and Streptococcus dysgalactiae (S. dysgalactiae) isolates, recovered from dairy cows in the Canadian Maritime Provinces. A secondary objective included the exploration of the association between phenotypic AMR and the genomic characteristics (genome size, guanine-cytosine content, and occurrence of unique gene sequences). Initially, 91 isolates were sequenced, and of these isolates, 89 were assembled...
2017: Frontiers in Veterinary Science
https://www.readbyqxmd.com/read/28524864/mistranslation-can-enhance-fitness-through-purging-of-deleterious-mutations
#13
Sinisa Bratulic, Macarena Toll-Riera, Andreas Wagner
Phenotypic mutations are amino acid changes caused by mistranslation. How phenotypic mutations affect the adaptive evolution of new protein functions is unknown. Here we evolve the antibiotic resistance protein TEM-1 towards resistance on the antibiotic cefotaxime in an Escherichia coli strain with a high mistranslation rate. TEM-1 populations evolved in such strains endow host cells with a general growth advantage, not only on cefotaxime but also on several other antibiotics that ancestral TEM-1 had been unable to deactivate...
May 19, 2017: Nature Communications
https://www.readbyqxmd.com/read/28515902/sites-of-colonization-in-hospitalized-patients-with-infections-caused-by-extended-spectrum-beta-lactamase-organisms-a-prospective-cohort-study
#14
Zeina A Kanafani, Sukayna M Fadlallah, Sarah Assaf, Khalil Anouti, Kohar Annie B Kissoyan, Jad Sfeir, Tamara Nawar, Mohamad Yasmin, Ghassan M Matar
BACKGROUND: The objective of this study was to determine whether patients infected with extended-spectrum beta-lactamase (ESBL)-producing organisms are colonized at multiple body sites. METHODS: This was a prospective cohort study at a tertiary care center in Beirut, Lebanon. Hospitalized patients with infections caused by ESBL-producing organisms were included. Cultures were obtained from the primary site of infection as well as from other sites (skin, nasopharynx, urine, rectum)...
2017: Antimicrobial Resistance and Infection Control
https://www.readbyqxmd.com/read/28492977/chaperone-substrate-interactions-monitored-via-a-robust-tem-1-%C3%AE-lactamase-fragment-complementation-assay
#15
Ling Bai, Wei He, Tianpeng Li, Cuiting Yang, Yingping Zhuang, Shu Quan
OBJECTIVE: To investigate the application of the TEM-1 β-lactamase protein fragment complementation assay (PCA) in detecting weak and unstable protein-protein interactions as typically observed during chaperone-assisted protein folding in the periplasm of Escherichia coli. RESULTS: The TEM-1 β-lactamase PCA system effectively captured the interactions of three pairs of chaperones and substrates. Moreover, the strength of the interactions can be quantitatively analyzed by comparing different levels of penicillin resistance, and the assay can be performed under 0...
May 10, 2017: Biotechnology Letters
https://www.readbyqxmd.com/read/28485945/direct-observation-of-interactions-between-nanoparticles-and-nanoparticle-self-assembly-in-solution
#16
Shu Fen Tan, See Wee Chee, Guanhua Lin, Utkur Mirsaidov
Hierarchically organized nanoparticles (NPs) possess unique properties and are relevant to various technological applications. An important "bottom-up" strategy for building such hierarchical nanostructures is to guide the individual NPs into ordered nanoarchitectures using intermolecular interactions and external forces. However, our current understanding of the nanoscale interactions that govern such self-assembly processes usually relies on post-synthesis/assembly or indirect characterization. Theoretical models that can derive these interactions are presently constrained to systems with only a few particles or on short time scales...
May 9, 2017: Accounts of Chemical Research
https://www.readbyqxmd.com/read/28462854/characterization-of-carbapenemases-esbls-and-plasmid-mediated-quinolone-determinants-in-carbapenem-insensitive-escherichia-coli-and-klebsiella-pneumoniae-in-riyadh-hospitals
#17
Mohamed H Al-Agamy, Abduelah Aljallal, Hesham H Radwan, Atef M Shibl
The main objective of this work was to characterize carbapenemases, extended-spectrum β-lactamases (ESBLs), and plasmid-mediated quinolone resistance (PMQR) among carbapenem-insensitive Klebsiella pneumoniae and Escherichia coli clinical isolates which were isolated from three hospitals in Riyadh. Thirty-one carbapenem-insensitive isolates (21 K. pneumoniae and 10 E. coli) were recovered from March 2014 to May 2014. Susceptibility testing and phenotypic detection tests were used to characterize the classes of β-lactamases...
April 24, 2017: Journal of Infection and Public Health
https://www.readbyqxmd.com/read/28413506/active-efflux-pump-adeb-is-involved-in-multidrug-resistance-of-acinetobacter-baumannii-induced-by-antibacterial-agents
#18
Tingting Zhang, Min Wang, Yixin Xie, Xianping Li, Zhihui Dong, Yanhua Liu, Ling Wang, Min Yang, Huan Song, Hong Cao, Wei Cao
The aim of the present study was to investigate the resistance of Acinetobacter baumannii, which was induced by cefepime (FEP), cefoperazone-sulbactam (SCF), tazobactam (TZP), levofloxacin (LEV), amikacin (AK), imipenem (IPM), and ciprofloxacin (CIP), in vitro. Multi-step drug resistance selection of 16 A. baumannii strains was performed using seven antibacterial agents (FEP, TZP, CIP, AK, IPM, SCF, and LEV). The minimum inhibitory concentration (MIC) was determined using the agar dilution method. Random amplified polymorphic DNA polymerase chain reaction was performed to analyze the genotypes and the carrying rates of aac(3)-I, aac(6')-I, ant(3)-I, aph(3)-Via, OXA-23, OXA-24, AmpC, TEM-1, metallo-β-lactamase gene (IMP), armA, rmtA, rmtB, parC, gyrA and adeB...
April 2017: Experimental and Therapeutic Medicine
https://www.readbyqxmd.com/read/28412384/molecular-epidemiology-of-penicillinase-producing-neisseria-gonorrhoeae-isolates-in-france
#19
M Micaëlo, A Goubard, G La Ruche, E Denamur, O Tenaillon, E Cambau, H Jacquier, B Bercot
OBJECTIVES: Characterizing the molecular epidemiology of antibiotic resistance is crucial for a better understanding of the evolution and spread of resistance in Neisseria gonorrhoeae. Here, we examine the molecular epidemiology of penicillinase-producing N. gonorrhoeae (PPNG) isolates in France. METHODS: We investigated 176 PPNG isolates collected between 2010 and 2012 by the National Reference Centre in France. Genotyping was performed using the NG-MAST technique, blaTEM genes were Sanger-sequenced, and plasmids were characterized by PCR-typing...
April 13, 2017: Clinical Microbiology and Infection
https://www.readbyqxmd.com/read/28378066/genetic-background-of-%C3%AE-lactamases-in-enterobacteriaceae-isolates-from-environmental-samples
#20
Daniele V de Oliveira, Luciana S Nunes, Afonso Luís Barth, Sueli T Van Der Sand
The prevalence of β-lactamase-producing Enterobacteriaceae has increased worldwide. Although antibiotic-resistant bacteria are usually associated with hospitals, there are a growing number of reports of resistant bacteria in other environments. Concern about resistant microorganisms outside the hospital setting highlights the need to investigate mechanisms of antibiotic resistance in isolates collected from the environment. The present study evaluated the resistance mechanism to β-lactam antibiotics in 40 isolates from hospital sewage and surface water from the Dilúvio Stream, Porto Alegre City, Southern Brazil...
April 4, 2017: Microbial Ecology
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