Search results for "lactam"
showing 10 items of 198 documents
Real-world effectiveness of ombitasvir/paritaprevir/ritonavir±dasabuvir±ribavirin in patients with hepatitis C virus genotype 1 or 4 infection: A met…
2017
The direct-acting antiviral regimen of ombitasvir (OBV)/paritaprevir (PTV)/ritonavir (r) ± dasabuvir (DSV) ± ribavirin (RBV) demonstrated high rates of sustained viral response at post-treatment week 12 (SVR12) in clinical trials for treatment of hepatitis C virus (HCV) genotypes (GT) 1 and 4. To confirm the effectiveness of this regimen in the real world, we conducted meta-analyses of published literature on 30 April 2016. Freeman-Tukey transformation determined the SVR rate within GTs 1a, 1b, and 4, as well as specific SVR rates by cirrhosis or prior treatment experience status. Rates of virologic relapse, hepatic decompensation, drug discontinuation, and serious adverse events were also …
Evaluation of the DNA microarray “AMR Direct Flow Chip Kit” for detection of antimicrobial resistance genes from Gram-positive and Gram-negative bact…
2019
Abstract Introduction The AMR Direct Flow Chip assay allows the simultaneous detection of a large variety of antibiotic resistance genetic markers. To assess this kit's performance, we use isolated colonies as starting material. The assay has been approved by the European Economic Area as a suitable device for in vitro diagnosis (CE IVD) using clinical specimens. Methods A total of 210 bacterial isolates harbouring either one or more antimicrobial resistance genes including plasmid-encoded extended-spectrum β-lactamases (SHV, CTX-M) and carbapenemases (GES, SME, KPC, NMC/IMI, SIM, GIM, SPM, NDM, VIM, IMP, and OXA), mecA, vanA and vanB, and 30 controls were included. Results The assay displa…
Two new Salmonella genomic islands 1 from Proteus mirabilis and description of blaCTX-M-15 on a variant (SGI1-K7)
2018
Objectives To characterize the structure of Salmonella genomic islands 1 (SGI1s) from two clinical Proteus mirabilis isolates: one producing an ESBL and the other a penicillinase. Methods WGS completed by PCR and Sanger sequencing was performed to determine sequences of SGI1s from Pm2CHAMA and Pm37THOMI strains. Results Two new variants of SGI1 named SGI1-Pm2CHAMA (53.6 kb) and SGI1-K7 (55.1 kb) were identified. The backbone of SGI1-Pm2CHAMA shared 99.9% identity with that of SGI1. Its MDR region (26.3 kb) harboured two class 1 integrons (an In2-type integron and an In4-type integron) containing in particular a qacH cassette (encoding a quaternary ammonium compound efflux pump). These two i…
Mutational Events in Cefotaximase Extended-Spectrum β-Lactamases of the CTX-M-1 Cluster Involved in Ceftazidime Resistance
2008
ABSTRACT CTX-M β-lactamases, which show a high cefotaxime hydrolytic activity, constitute the most prevalent extended-spectrum β-lactamase (ESBL) type found among clinical isolates. The recent explosive diversification of CTX-M enzymes seems to have taken place due to the appearance of more efficient enzymes which are capable of hydrolyzing both cefotaxime and ceftazidime, especially among the CTX-M-1 cluster. A combined strategy of in vitro stepwise evolution experiments using bla CTX-M-1 , bla CTX-M-3 , and bla CTX-M-10 genes and site-directed mutagenesis has been used to evaluate the role of ceftazidime and other β-lactam antibiotics in triggering the diversity found among enzymes belong…
Characterization of the carbapenem-hydrolyzing oxacillinase OXA-58 in an Acinetobacter phenon 6/ct13TU clinical isolate
2008
The bla(OXA-58) gene identified in the Acinetobacter phenon 6/ct13TU clinical isolate presented 100% homology with the same gene in Acinetobacter baumannii. Its location in a plasmid suggests that these resistance genes may be transferred from 1 species to another.
A novel VIM‐type metallo‐beta‐lactamase (VIM‐14) in a Pseudomonas aeruginosa clinical isolate from a neonatal intensive care unit
2011
AbstractA Pseudomonas aeruginosa highly resistant to carbapenems was isolated in a neonatal intensive care unit in Palermo, Italy. The strain was found to carry a novel VIM‐type enzyme, classified as VIM‐14. The novel enzyme differs from VIM‐4 in a G31S mutation. VIM‐14 was harboured in a class 1 integron with a new organization. The integron carried the genes aac7, blaVIM‐14, blaOXA‐20 and aac4 in that order.
An electrochemical DNA biosensor for the detection of CTX-M extended-spectrum β-lactamase-producing Escherichia coli in soil samples
2013
International audience; An electrochemical hybridization assay involving neutravidin-coated carbon screen-printed electrodes and an HRP-based detection have been shown to provide an effective tool for the genotypic analysis of extended-spectrum beta-lactamase-producing E. coli strains in complex samples such as soil. (c) 2012 Elsevier B.V. All rights reserved.
Ongoing spread of colistin-resistant Klebsiella pneumoniae in different wards of an acute general hospital, Italy, June to December 2011.
2012
We describe polyclonal spread of colistin-resistant Klebsiella pneumoniae in an acute general hospital in Italy. Between June and December 2011, 58 colistin-resistant K. pneumoniae isolates were recovered from 28 patients admitted to different wards, but mainly in the intensive care units. All isolates were tested for drug susceptibility and the presence of beta-lactamase (bla) genes. Clonality was investigated by repetitive extragenic palindromic (rep)-PCR and multilocus sequence typing (MLST). Fifty-two isolates had minimum inhibitory concentrations (MICs) for colistin of 6-128 mg/L, carried blaKPC3 and were attributed to sequence type ST258. The remaining six isolates were susceptible to…
Organometallic complexes with biological molecules II. Synthesis, solid-state characterization andin vivo Cytotoxicity of Diorganotin(IV)chloro and T…
1994
Several new diorganotin(IV)chloro and triorganotin(IV)chloro penicillin G derivatives have been prepared. The isolated compounds showed 1:1 stoichiometry, with formulae R2SnClpenG and R3SnClpenGNa, respectively (penG− = penicillin G− = 4- thia - 1 - azabicyclo[3.2.0]heptane-2-carboxylate, 3,3-dimethyl-7-oxo-6-(2-phenylacet-amido) anion; R = Me, Bu, Ph). The coordination environment around the the tin(IV) atom, in all of the complexes, was trigonal bipyramidal. Penicillin G behaved as a monoanionic, bismonodentate ligand in R2SnClpenG through the β-lactamic carbonyl and unidentate ester-type carboxylate anion, and as unidentate through the β-lactamic carbonyl in R3SnClpenGNa, as inferred on …
Catalytic Asymmetric Formal [3+2] Cycloaddition of 2-Isocyanatomalonate Esters and Unsaturated Imines: Synthesis of Highly Substituted Chiral γ-Lacta…
2017
[EN] Unlike their isocyano and isothiocyanato analogues, isocyanato esters remain almost unexplored as formal 1,3-dipoles in asymmetric catalytic reactions. The first asymmetric formal [3+2] cycloaddition involving isocyanato esters and electrophilic alkenes is reported. Diisopropyl 2-isocyanatomalonate reacts with a,b-unsaturated N-(o-anisidyl) imines in the presence of a Mg(OTf)2¿BOX complex to give highly substituted chiral pyrrolidinones featuring a conjugate exocyclic double bond with excellent yields and enantiomeric excesses up to 99%. Several transformations of the resulting heterocycles, including the synthesis of a pyroglutamic acid derivative, have been carried out.