Read by QxMD icon Read


Run Fan, Dexi Li, Andrea T Feßler, Congming Wu, Stefan Schwarz, Yang Wang
A novel transferable oxazolidinone-phenicol resistance gene, optrA, which confers resistance to linezolid, the next-generation oxazolidinone tedizolid, and also to chloramphenicol and florfenicol, has been identified in enterococcal and staphylococcal species. Here, we investigated the epidemiology of optrA in florfenicol-resistant Staphylococcus spp. isolates of pig origin, and characterized the genetic context of oxazolidinone resistance genes in 20 optrA-positive florfenicol- and methicillin-resistant S...
October 2017: Veterinary Microbiology
Andrew Spaulding, Khuloud Takrouri, Pornachandran Mahalingam, Dillon C Cleary, Harold D Cooper, Paola Zucchi, Westley Tear, Bilyana Koleva, Penny J Beuning, Elizabeth B Hirsch, James B Aggen
Previously we reported the results from an effort to improve Gram-negative antibacterial activity in the oxazolidinone class of antibiotics via a systematic medicinal chemistry campaign focused entirely on C-ring modifications. In that series we set about testing if the efflux and permeation barriers intrinsic to the outer membrane of Escherichia coli could be rationally overcome by designing analogs to reside in specific property limits associated with Gram-negative activity: i) low MW (<400), ii) high polarity (clogD7...
October 16, 2017: Bioorganic & Medicinal Chemistry Letters
Ruru Bi, Tingting Qin, Wenting Fan, Ping Ma, Bing Gu
Enterococcus is a significant pathogen of numerous infections, particularly nosocomial infections, thus conferring a great challenge to clinicians. Linezolid (an oxazolidinone antibiotic) is an important therapeutic option for infections caused by Gram-positive bacterial pathogens, especially vancomycin-resistant Enterococcus (VRE). To characterize these infections with respect to epidemiological, microbiological and clinical scenarios, we make a systematic review of literature available on linezolid-resistant Enterococcus (LRE)...
October 31, 2017: Journal of Global Antimicrobial Resistance
Laurent Dortet, Philippe Glaser, Najiby Kassis-Chikhani, Delphine Girlich, Philippe Ichai, Marc Boudon, Didier Samuel, Elodie Creton, Dilek Imanci, Rémy Bonnin, Nicolas Fortineau, Thierry Naas
Objectives: Patient- and procedure-related changes in modern medicine have turned CoNS into one of the major nosocomial pathogens. Treatments of CoNS infections are challenging owing to the large proportion of MDR strains and oxazolidinones often remain the last active antimicrobial molecules. Here, we have investigated a long-lasting outbreak (2010-13) due to methicillin- and linezolid-resistant (LR) CoNS (n = 168), involving 72 carriers and 49 infected patients. Methods: Antimicrobial susceptibilities were tested by the disc diffusion method and MICs were determined by broth microdilution or Etest...
October 30, 2017: Journal of Antimicrobial Chemotherapy
Yewon Choi, Sang Won Lee, Anhye Kim, Kyungho Jang, Heesook Nam, Young Lag Cho, Kyung-Sang Yu, In-Jin Jang, Jae-Yong Chung
Background: LCB01-0371 is a new oxazolidinone antibiotic, which targets most Gram-positive organisms. High rates of adverse reactions including myelosuppression have been reported for existing oxazolidinones, limiting their long-term use. Objectives: The safety, tolerability and pharmacokinetics (PK) of 21 day multiple oral administrations of LCB01-0371 in healthy male subjects ( NCT02540460) were investigated. Methods: In this randomized, double-blind, placebo-controlled study, subjects received 800 mg of LCB01-0371 once or twice daily or 1200 mg of LCB01-0371 twice-daily for 21 days in a fasting state...
October 23, 2017: Journal of Antimicrobial Chemotherapy
Claire Roger, Jason A Roberts, Laurent Muller
Oxazolidinones are a class of synthetic antimicrobial agents with potent activity against a wide range of multidrug-resistant Gram-positive pathogens including methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci. Oxazolidinones exhibit their antibacterial effects by inhibiting protein synthesis acting on the ribosomal 50S subunit of the bacteria and thus preventing formation of a functional 70S initiation complex. Currently, two oxazolidinones have been approved by the US Food and Drug Administration: linezolid and more recently tedizolid...
October 23, 2017: Clinical Pharmacokinetics
Serhan Turkyilmaz, Craig S Wilcox
Sorting tags are oligomeric structures that can be used as protecting groups or chiral auxiliaries enabling solution-phase mixture syntheses of multiple tagged compounds in one pot and allowing for facile and predictable chromatographic separation of products at the end of synthetic sequences. Perfluorinated hydrocarbon and oligomeric ethylene glycol (OEG) derivatives are known classes of sorting tags. Herein we describe the preparation of OEGylated chiral oxazolidinones and their use in asymmetric solution-phase mixture aldol reactions...
May 24, 2017: Tetrahedron Letters
Yasunori Toda, Shuto Gomyou, Shoya Tanaka, Yutaka Komiyama, Ayaka Kikuchi, Hiroyuki Suga
Preparation of a range of oxazolidinones, including enantioenriched N-aryl-substituted oxazolidinones, in which tetraarylphosphonium salts (TAPS) catalyze the [3 + 2] coupling reaction of isocyanates and epoxides effectively, is described. The key finding is a Brønsted acid/halide ion bifunctional catalyst that can accelerate epoxide ring opening with high regioselectivity. Mechanistic studies disclosed that the ylide generated from TAPS, along with the formation of halohydrins, plays a crucial role in the reaction with isocyanates...
October 17, 2017: Organic Letters
Erica Yookyung Lee, Aisling Caffrey
Several studies have suggested the risk of thrombocytopenia with tedizolid, a second-in-class oxazolidinone antibiotic (approved 06/2014), is less than that observed with linezolid (first-in-class oxazolidinone). Using data from the Food and Drug Administration Adverse Event Reporting System (07/2014-12/2016), we observed a significantly increased risk of thrombocytopenia of similar magnitude with both antibiotics: linezolid reporting odds ratio [ROR] 37.9 (95% confidence interval [CI] 20.78-69.17); tedizolid ROR 34...
October 16, 2017: Antimicrobial Agents and Chemotherapy
Ana R Freitas, Houyem Elghaieb, Ricardo León-Sampedro, Mohamed Salah Abbassi, Carla Novais, Teresa M Coque, Abdennaceur Hassen, Luisa Peixe
Objectives: Oxazolidinone resistance is a serious limitation in the treatment of MDR Enterococcus infections. Plasmid-mediated oxazolidinone resistance has been strongly linked to animals where the use of phenicols might co-select resistance to both antibiotic families. Our goal was to assess the diversity of genes conferring phenicol/oxazolidinone resistance among diverse enterococci and to characterize the optrA genetic environment. Methods: Chloramphenicol-resistant isolates (>16 mg/L, n = 245) from different sources (hospitals/healthy humans/wastewaters/animals) in Portugal, Angola and Tunisia (1996-2016) were selected...
September 26, 2017: Journal of Antimicrobial Chemotherapy
Vasilios Athans, Michael P Veve, Susan L Davis
Antimicrobial-impregnated bone cement (AIBC) is a staple of contemporary orthopedic surgery and has been used to either treat or prevent prosthetic joint infection. Applied intraoperatively during primary arthroplasty or prosthetic joint exchange, this drug-delivery vehicle has become a popular means of maximizing drug concentrations within a joint space while minimizing systemic exposure. Antimicrobial characteristics conducive to cement loading include availability of a crystalline powder formulation, molecular characteristics, minimal impact on cement integrity, and other variables promoting drug elution...
October 4, 2017: Pharmacotherapy
Naser F Al-Tannak, Oludotun A Phillips
Twelve N-substituted-glycinyl triazolyl oxazolidinone derivatives were screened for antimycobacterial activity against susceptible (Mycobacteriumtuberculosis (Mtb) H37Rv) and resistant (isoniazid (INH)-resistant Mtb (SRI 1369), rifampin (RMP)-resistant Mtb (SRI 1367), and ofloxacin (OFX)-resistant Mtb (SRI 4000)) Mtb strains. Most of the compounds showed moderate to strong antimycobacterial activity against all strains tested, with minimum inhibitory concentration (MIC) value ranges of 0.5-11.5, 0.056-11.6, 0...
October 2, 2017: Scientia Pharmaceutica
Dominika Jacková, Miroslava Martinková, Jozef Gonda, Kvetoslava Stanková, Martina Bago Pilátová, Peter Herich, Jozef Kožíšek
The convergent synthesis of broussonetinines related congeners 3 and 4 with the simple C13 alkyl side chain and differently configured pyrrolidine skeleton has been achieved. Our approach relied on the [3,3]-sigmatropic rearrangements of chiral allylic substrates derived from d-xylose. Cross metathesis of the common oxazolidinone intermediates 7 and 8 with tridec-1-ene followed by alkylative cyclization completed the construction of both C-alkyl iminosugars. The targeted compounds 3 and 4 were screened for antiproliferative/cytotoxic activities against multiple cancer cell lines by MTT assay...
September 19, 2017: Carbohydrate Research
Alexandros Lazaris, David C Coleman, Angela M Kearns, Bruno Pichon, Peter M Kinnevey, Megan R Earls, Breida Boyle, Brian O'Connell, Gráinne I Brennan, Anna C Shore
Background: Linezolid is often the drug of last resort to treat infections caused by Gram-positive cocci. Linezolid resistance can be mutational (23S rRNA or L-protein) or, less commonly, acquired [predominantly cfr , conferring resistance to phenicols, lincosamides, oxazolidinones, pleuromutilins and streptogramin A compounds (PhLOPS A ) or optrA , encoding oxazolidinone and phenicol resistance]. Objectives: To investigate the clonality and genetic basis of linezolid resistance in 13 linezolid-resistant (LZDR) methicillin-resistant Staphylococcus epidermidis (MRSE) isolates recovered during a 2013/14 outbreak in an ICU in an Irish hospital and an LZDR vancomycin-resistant Enterococcus faecium (VRE) isolate from an LZDR-MRSE-positive patient...
August 28, 2017: Journal of Antimicrobial Chemotherapy
Adamantia Liapikou, Catia Cillóniz, Antoni Torres
Community acquired pneumonia is one of the main infections, remaining as a global cause of considerable morbidity and mortality. Successful treatment hinges on expedient delivery of appropriate antibiotic therapy tailored to both the likely pathogens and the severity of disease. Although antibiotic resistance is increasing and pharmaceutical companies continue to debate the profitability of introducing new antibacterial agents, an encouraging number of new molecules have recently been unveiled which target multidrug-resistant bacteria...
November 2017: Expert Opinion on Investigational Drugs
Aurélie Paulen, Françoise Hoegy, Béatrice Roche, Isabelle J Schalk, Gaëtan L A Mislin
Pseudomonas aeruginosa is a Gram-negative pathogenic bacterium responsible for severe infections, and it is naturally resistant to many clinically approved antibiotic families. Oxazolidinone antibiotics are active against many Gram-positive bacteria, but are inactive against P. aeruginosa. Increasing the uptake of oxazolidinones through the bacterial envelope could lead to an increased antibiotic effect. Pyochelin is a siderophore of P. aeruginosa which delivers external iron to the bacterial cytoplasm and is a potential vector for the development of Trojan Horse oxazolidinone conjugates...
September 18, 2017: Bioorganic & Medicinal Chemistry Letters
Pan-Lin Shao, Zi-Rui Li, Zhi-Peng Wang, Ming-Hui Zhou, Qi Wu, Ping Hu, Yun He
The first formal [3 + 2] cycloaddition reaction of in situ generated azaoxyallyl cation with cyclic ketones has been developed using mild reaction conditions. A variety of spiro-4-oxazolidinones was obtained in excellent yields (up to 99%). The high efficiency of this process, coupled with the operational simplicity, makes it an attractive method for the synthesis of spiro-4-oxazolidinones.
September 26, 2017: Journal of Organic Chemistry
Mahtab Beitdaghar, Roya Ahmadrajabi, Afsaneh Karmostaji, Fereshteh Saffari
BACKGROUND: The increasing incidence of antimicrobial resistance has led to research on finding new antimicrobial agents or identifying drug combinations with synergistic effects. Enterococcal infections, particularly those associated with vancomycin-resistant enterococci (VREs), are therapeutic problems. Linezolid (LZD), an oxazolidinone antibiotic, shows good activity against Gram-positive bacteria including enterococci. To avoid the emergence of linezolid-resistant subpopulations and achieve enhanced activity or bactericidal effect, the use of combined therapy has been considered...
September 18, 2017: Wiener Medizinische Wochenschrift
Barbara A Brown-Elliott, Richard J Wallace
There is a paucity of efficacious antimicrobials (especially oral) against clinically relevant species of Nocardia To date, all species of Nocardia have been susceptible to linezolid, the first commercially available oxazolidinone. Tedizolid is a new oxazolidinone with previously reported improved in vitro and in vivo (intracellular) potency against multidrug resistant strains of Mycobacterium sp., and Nocardia brasiliensis Using the current Clinical and Laboratory Standards Institute recommended broth microdilution method, 101 isolates of Nocardia spp, including 29 N...
September 18, 2017: Antimicrobial Agents and Chemotherapy
Pauline Ract, Caroline Piau-Couapel, Fabrice Compain, Michel Auzou, Jocelyn Michon, Vincent Cattoir
Tedizolid, a second-generation oxazolidinone that displays a potent activity against Gram-positive pathogens, could be an interesting option for the treatment of bone and joint infections (BJIs). The aim of the study was to determine minimal inhibitory concentration (MIC) of tedizolid against a collection of 359 clinical isolates involved in clinically-documented BJIs and to compare them to those of comparator agents used in Gram-positive infections. Of the 104 Staphylococcusaureus and 102 coagulase-negative staphylococci (CoNS) isolates, 99 and 92 % were categorized as susceptible to tedizolid, respectively (MIC25=0...
October 2017: Journal of Medical Microbiology
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"