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1.
Vet Microbiol ; 293: 110103, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38718528

RESUMEN

Oxazolidinones are potent antimicrobial agents used to treat human infections caused by multidrug-resistant Gram-positive bacteria. The growing resistance to oxazolidinones poses a significant threat to public health. In August 2021, a linezolid-resistant Enterococcus faecium BN83 was isolated from a raw milk sample of cow in Inner Mongolia, China. This isolate exhibited a multidrug resistance phenotype and was resistant to most of drugs tested including linezolid and tedizolid. PCR detection showed that two mobile oxazolidinones resistance genes, optrA and poxtA, were present in this isolate. Whole genome sequencing analysis revealed that the genes optrA and poxtA were located on two different plasmids, designated as pBN83-1 and pBN83-2, belonging to RepA_N and Inc18 families respectively. Genetic context analysis suggested that optrA gene on plasmid pBN83-1 was located in transposon Tn6261 initially found in E. faecalis. Comprehensive analysis revealed that Tn6261 act as an important horizontal transmission vector for the spread of optrA in E. faecium. Additionally, poxtA-bearing pBN83-2 displayed high similarity to numerous plasmids from Enterococcus of different origin and pBN83-2-like plasmid represented a key mobile genetic element involved in movement of poxtA in enterococcal species. The presence of optrA- and poxtA-carrying E. faecium in raw bovine milk represents a public health concern and active surveillance is urgently warranted to investigate the prevalence of oxazolidinone resistance genes in animal-derived food products.


Asunto(s)
Antibacterianos , Enterococcus faecium , Leche , Oxazolidinonas , Animales , Bovinos , Enterococcus faecium/genética , Enterococcus faecium/efectos de los fármacos , Enterococcus faecium/aislamiento & purificación , Leche/microbiología , China/epidemiología , Oxazolidinonas/farmacología , Antibacterianos/farmacología , Pruebas de Sensibilidad Microbiana , Farmacorresistencia Bacteriana Múltiple/genética , Plásmidos/genética , Linezolid/farmacología , Secuenciación Completa del Genoma , Infecciones por Bacterias Grampositivas/microbiología , Infecciones por Bacterias Grampositivas/veterinaria , Infecciones por Bacterias Grampositivas/epidemiología , Genes Bacterianos/genética
2.
Infection ; 52(3): 787-800, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38717734

RESUMEN

PURPOSE: The principal objective of this project was to review and thoroughly examine the chemical characteristics, pharmacological activity, and quantification methods associated with contezolid. METHODS: The article was based on published and ongoing preclinical and clinical studies on the application of contezolid. These studies included experiments on the physicochemical properties of contezolid, in vitro antimicrobial research, in vivo antimicrobial research, and clinical trials in various phases. There were no date restrictions on these studies. RESULTS: In June 2021, contezolid was approved for treating complicated skin and soft tissue infections. The structural modification of contezolid has resulted in better efficacy compared to linezolid. It inhibits bacterial growth by preventing the production of the functional 70S initiation complex required to translate bacterial proteins. The current evidence has indicated a substantial decline in myelosuppression and monoamine oxidase inhibition without impairing its antibacterial properties. Contezolid was found to have a more significant safety profile and to be metabolised by flavin monooxygenase 5, reducing the risk of harmful effects due to drug-drug interactions. Adjusting doses is unnecessary for patients with mild to moderate renal or hepatic insufficiency. CONCLUSION: As an oral oxazolidinone antimicrobial agent, contezolid is effective against multi-drug resistant Gram-positive bacteria. The introduction of contezolid provided a new clinical option.


Asunto(s)
Antibacterianos , Infecciones por Bacterias Grampositivas , Oxazolidinonas , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Oxazolidinonas/farmacología , Oxazolidinonas/uso terapéutico , Humanos , Infecciones por Bacterias Grampositivas/tratamiento farmacológico , Infecciones por Bacterias Grampositivas/microbiología , Bacterias Grampositivas/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Infecciones de los Tejidos Blandos/tratamiento farmacológico , Infecciones de los Tejidos Blandos/microbiología , Animales , Piridonas
4.
Acta Crystallogr E Crystallogr Commun ; 80(Pt 4): 375-377, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38584728

RESUMEN

The structure of (S)-5-(3-acetyl-5-chloro-2-ethoxy-6-fluorophenyl)-2-oxazolidinone, C13H13ClFNO4, at 100 K has monoclinic (P21) symmetry. The compound has a polymeric structure propagated by a screw axis parallel to the b axis with N-H⋯O hydrogen bonding. It is of inter-est with respect to efforts in the synthesis of a candidate anti-cancer drug, parsaclisib.

5.
ACS Infect Dis ; 10(5): 1679-1695, 2024 05 10.
Artículo en Inglés | MEDLINE | ID: mdl-38581700

RESUMEN

Linezolid is a drug with proven human antitubercular activity whose use is limited to highly drug-resistant patients because of its toxicity. This toxicity is related to its mechanism of action─linezolid inhibits protein synthesis in both bacteria and eukaryotic mitochondria. A highly selective and potent series of oxazolidinones, bearing a 5-aminomethyl moiety (in place of the typical 5-acetamidomethyl moiety of linezolid), was identified. Linezolid-resistant mutants were cross-resistant to these molecules but not vice versa. Resistance to the 5-aminomethyl molecules mapped to an N-acetyl transferase (Rv0133) and these mutants remained fully linezolid susceptible. Purified Rv0133 was shown to catalyze the transformation of the 5-aminomethyl oxazolidinones to their corresponding N-acetylated metabolites, and this transformation was also observed in live cells of Mycobacterium tuberculosis. Mammalian mitochondria, which lack an appropriate N-acetyltransferase to activate these prodrugs, were not susceptible to inhibition with the 5-aminomethyl analogues. Several compounds that were more potent than linezolid were taken into C3HeB/FeJ mice and were shown to be highly efficacious, and one of these (9) was additionally taken into marmosets and found to be highly active. Penetration of these 5-aminomethyl oxazolidinone prodrugs into caseum was excellent. Unfortunately, these compounds were rapidly converted into the corresponding 5-alcohols by mammalian metabolism which retained antimycobacterial activity but resulted in substantial mitotoxicity.


Asunto(s)
Antituberculosos , Mycobacterium tuberculosis , Oxazolidinonas , Profármacos , Profármacos/farmacología , Profármacos/química , Antituberculosos/farmacología , Antituberculosos/química , Mycobacterium tuberculosis/efectos de los fármacos , Oxazolidinonas/farmacología , Oxazolidinonas/química , Animales , Pruebas de Sensibilidad Microbiana , Ratones , Humanos , Linezolid/farmacología , Linezolid/química , Farmacorresistencia Bacteriana , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo
6.
Molecules ; 29(5)2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38474667

RESUMEN

A convenient protocol for the synthesis of 25,26,27-tribenzoyl-28-[((S)-1-diphenylphos- phanyl-propan-2-yl)oxy]-calix[4]arene via stereospecific methylation on Evans' oxazolidinone moiety was reported. According to the 13C NMR analysis of this phosphine, the calix[4]arene skeleton adopted a 1,3-alternate conformation. The latter conformation of the macrocycle and the (S)-chirality of the carbon atom bearing the methyl substituent were confirmed by a single-crystal X-ray diffraction study. After coordination of the phosphinated ligand to the dimeric [RuCl2(p-cymene)]2 organometallic precursor, the resulting arene-ruthenium complex was tested in the asymmetric reduction of acetophenone and alcohol was obtained with modest enantiomeric excess.

7.
Eur J Med Chem ; 269: 116326, 2024 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-38513340

RESUMEN

Bacterial infections cause a variety of life-threatening diseases, and the continuous evolution of drug-resistant bacteria poses an increasing threat to current antimicrobial regimens. Gram-positive bacteria (GPB) have a wide range of genetic capabilities that allow them to adapt to and develop resistance to practically all existing antibiotics. Oxazolidinones, a class of potent bacterial protein synthesis inhibitors with a unique mechanism of action involving inhibition of bacterial ribosomal translation, has emerged as the antibiotics of choice for the treatment of drug-resistant GPB infections. In this review, we discussed the oxazolidinone antibiotics that are currently on the market and in clinical development, as well as an updated synopsis of current advances on their analogues, with an emphasis on innovative strategies for structural optimization of linezolid, structure-activity relationship (SAR), and safety properties. We also discussed recent efforts aimed at extending the activity of oxazolidinones to gram-negative bacteria (GNB), antitumor, and coagulation factor Xa. Oxazolidinone antibiotics can accumulate in GNB by a conjugation to siderophore-mediated ß-lactamase-triggered release, making them effective against GNB.


Asunto(s)
Antiinfecciosos , Oxazolidinonas , Antibacterianos/química , Oxazolidinonas/farmacología , Oxazolidinonas/química , Linezolid/farmacología , Relación Estructura-Actividad , Antiinfecciosos/farmacología , Bacterias Gramnegativas , Pruebas de Sensibilidad Microbiana
8.
Antimicrob Agents Chemother ; 68(4): e0140023, 2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38415667

RESUMEN

Contezolid is a novel oxazolidinone antibiotic with a promising safety profile. Oral contezolid and its intravenous (IV) prodrug contezolid acefosamil (CZA) are in development for treatment of diabetic foot and acute bacterial skin and skin structure infections (ABSSSI). The prodrug CZA is converted to active contezolid via intermediate MRX-1352. This study aimed to provide the pharmacokinetic rationale for safe, effective, and flexible dosage regimens with initial IV CZA followed by oral contezolid. We simultaneously modeled plasma concentrations from 110 healthy volunteers and 74 phase 2 patients with ABSSSI via population pharmacokinetics (using the importance sampling estimation algorithm), and optimized dosage regimens by Monte Carlo simulations. This included data on MRX-1352, contezolid, and its metabolite MRX-1320 from 66 healthy volunteers receiving intravenous CZA (150-2400 mg) for up to 28 days, and 74 patients receiving oral contezolid [800 mg every 12 h (q12h)] for 10 days. The apparent total clearance for 800 mg oral contezolid with food was 16.0 L/h (23.4% coefficient of variation) in healthy volunteers and 17.7 L/h (53.8%) in patients. CZA was rapidly converted to MRX-1352, which subsequently transformed to contezolid. The proposed dosage regimen used an IV CZA 2000 mg loading dose with 1000 mg IV CZA q12h as maintenance dose(s), followed by 800 mg oral contezolid q12h (with food). During each 24-h period, Monte Carlo simulations predicted this regimen to achieve consistent areas under the curve of 91.9 mg·h/L (range: 76.3-106 mg·h/L) under all scenarios. Thus, this regimen was predicted to reliably achieve efficacious contezolid exposures independent of timing of switch from IV CZA to oral contezolid.IMPORTANCEThis study provides the population pharmacokinetic rationale for the dosage regimen of the intravenous (IV) prodrug contezolid acefosamil (CZA) followed by oral contezolid. We developed the first integrated population model for the pharmacokinetics of the MRX-1352 intermediate prodrug, active contezolid, and its main metabolite MRX-1320 based on data from three clinical studies in healthy volunteers and phase 2 patients. The proposed regimen was predicted to reliably achieve efficacious contezolid exposures independent of timing of switch from IV CZA to oral contezolid.


Asunto(s)
Oxazolidinonas , Profármacos , Humanos , Antibacterianos/farmacocinética , Oxazolidinonas/farmacocinética , Piridonas/farmacocinética
9.
J Glob Antimicrob Resist ; 36: 336-344, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38336229

RESUMEN

OBJECTIVES: Linezolid is a last-resort antimicrobial in human clinical settings to treat multidrug-resistant Gram-positive bacterial infections. Mobile linezolid resistance genes (optrA, poxtA, and cfr) have been detected in various sources worldwide. However, the presence of linezolid-not-susceptible bacteria and mobile linezolid resistance genes in Japan remains uncertain. Therefore, we clarified the existence of linezolid-not-susceptible bacteria and mobile linezolid resistance genes in farm environments in Japan. METHODS: Enterococci isolates from faeces compost collected from 10 pig and 11 cattle farms in Japan in 2021 were tested for antimicrobial susceptibility and possession of mobile linezolid resistance genes. Whole-genome sequencing of optrA and/or poxtA genes positive-enterococci was performed. RESULTS: Of 103 enterococci isolates, 12 from pig farm compost were not-susceptible (2 resistant and 10 intermediate) to linezolid. These 12 isolates carried mobile linezolid resistance genes on plasmids or chromosomes (5 optrA-positive Enterococcus faecalis, 6 poxtA-positive E. hirae or E. thailandicus, and 1 optrA- and poxtA-positive E. faecium). The genetic structures of optrA- and poxA-carrying plasmids were almost identical to those reported in other countries. These plasmids were capable of transferring among E. faecium and E. faecalis strains. The optrA- and poxtA-positive E. faecium belonged to ST324 (clade A2), a high-risk multidrug-resistant clone. The E. faecalis carrying optrA gene on its chromosome was identified as ST593. CONCLUSIONS: Although linezolid is not used in livestock, linezolid-not-susceptible enterococci could be indirectly selected by frequently used antimicrobials, such as phenicols. Moreover, various enterococci species derived from livestock compost may serve as reservoirs of linezolid resistance genes carried on globally disseminated plasmids and multidrug-resistant high-risk clones.


Asunto(s)
Antiinfecciosos , Compostaje , Enterococcus faecium , Animales , Humanos , Bovinos , Porcinos , Linezolid/farmacología , Enterococcus/genética , Antibacterianos/farmacología , Ganado , Granjas , Japón , Enterococcus faecium/genética , Farmacorresistencia Bacteriana/genética , Antiinfecciosos/farmacología
10.
Food Chem ; 445: 138711, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38354645

RESUMEN

Although furazolidone (FZD) was completely banned from livestock production in many countries many years ago due to its mutagenicity and carcinogenicity, the abuse of FZD is still common today. Accurate and rapid detection of FZD residues in animal-derived food products is highly important for human health. Here, a time-resolved fluorescence immunochromatography (TRFI) test strip for rapid and quantitative detection of 3-amino-2-oxazolidinone (AOZ) residues in animal foods was developed and validated. Its limit of detection and limit of quantification were 0.05 and 0.14 µg/kg, respectively. The typical recovery rates were 95-105 % in chicken breast samples spiked with the AOZ standard substance at concentrations of 0.05-2 µg/kg, with a coefficient of variation value ≤8.5 %. The cross-reaction rates of the TRFI-AOZ test strips with 3-amino-5-morpholinomethyl-2-oxazolidone, semicarbazide, and 1-amino-imidazolidin-2,4-dione were less than 1 %. The newly developed TRFI test strip has high sensitivity, high specificity, cost effectiveness and user-friendly control, and is suitable for the rapid and large-scale screening of AOZ residues in animal foods.


Asunto(s)
Furazolidona , Mutágenos , Animales , Humanos , Furazolidona/análisis , Cromatografía de Afinidad/métodos , Sensibilidad y Especificidad , Mutágenos/análisis
11.
Chemistry ; 30(4): e202303478, 2024 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-37897110

RESUMEN

In the last decade, magnesium complexes have emerged as a viable alternative to transition-metal catalysts for the hydrofunctionalization of unsaturated bonds. However, their potential for advanced catalytic reactions has not been thoroughly investigated. To address this gap, we have developed a novel magnesium amide compound (3) using a PNP framework that is both bulky and flexible. Our research demonstrates that compound 3 can effectively catalyze the synthesis of biologically significant oxazolidinone derivatives. This synthesis involves a tandem reaction of hydroalkoxylation and cyclohydroamination of isocyanate using propargyl alcohol. Furthermore, we conducted comprehensive theoretical calculations to gain insights into the reaction mechanism. It is important to note that these types of transformations have not been reported for magnesium and would significantly enhance the catalytic portfolio of the 7th most abundant element.

12.
Antibiotics (Basel) ; 12(12)2023 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-38136740

RESUMEN

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are a global health concern. The propensity of MRSA to form biofilms is a significant contributor to its pathogenicity. Strategies to treat biofilms often involve small molecules that disperse the biofilm into planktonic cells. Linezolid and, by extension, theoxazolidinones have been developed to treat infections caused by Gram-positive bacteria such as MRSA. However, the clinical development of these antibiotics has mainly assessed the susceptibility of planktonic cells to the drug. Previous studies evaluating the anti-biofilm activity of theoxazolidinones have mainly focused on the biofilm inhibition of Enterococcus faecalis and methicillin-sensitive Staphylococcus aureus, with only a few studies investigating the activity of oxazolidinones for eradicating established biofilms for these species. Very little is known about the ability of oxazolidinones to eradicate MRSA biofilms. In this work, five oxazolidinones were assessed against MRSA biofilms using a minimum biofilm eradication concentration (MBEC) assay. All oxazolidinones had inherent antibiofilm activity. However, only ranbezolid could completely eradicate MRSA biofilms at clinically relevant concentrations. The susceptibility of the MRSA biofilms to ranbezolid was synergistically enhanced by coadministration with the nitroxide biofilm dispersal agent C-TEMPO. We presume that ranbezolid acts as a dual warhead drug, which combines the mechanism of action of the oxazolidinones with a nitric oxide donor or cytotoxic drug.

13.
J Biomol Struct Dyn ; : 1-16, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-38100567

RESUMEN

Oxazolidinones are used as various potent antibiotics, in organisms it acts as a protein synthesis inhibitor, focusing on an initial stage that encompasses the tRNA binding process. Novel intramolecular aza-Michael reactions devoid of metal catalysts have been introduced in an oxazolidone synthesis pathway, different from α,ß-unsaturated ketones. Oxazolidinone derivatives were tested against acetylcholinesterase (AChE), carbonic anhydrase I and II (hCA I and hCA II) enzymes. All the synthesized compounds had potent inhibition effects with Ki values in the range of 13.57 ± 0.98 - 53.60 ± 6.81 µM against hCA I and 9.96 ± 1.02 - 46.35 ± 3.83 µM against hCA II in comparison to the acetazolamide (AZA) (Ki = 50.46 ± 6.17 µM for hCA I) and for hCA II (Ki = 41.31 ± 5.05 µM). Also, most of the compounds demonstrated potent inhibition ability towards AChE enzyme with Ki values 78.67-231.75 nM and compared to tacrine (TAC) as standard clinical inhibitor (Ki = 142.48 nM). Furthermore, ADMET analysis and molecular docking were calculated using the AChE, hCA I and hCA II enzyme proteins to correlate the data with the experimental data. In this work, recent applications of a stereoselective aza-Michael reaction as an efficient tool for of nitrogen-containing heterocyclic scaffolds and their useful to pharmacology analogs are reviewed and summarized.Communicated by Ramaswamy H. Sarma.

14.
Environ Sci Pollut Res Int ; 30(56): 119151-119167, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37919493

RESUMEN

We report on the preparation of copper iodide nanoparticles (NPs) immobilized on vitamin B3-modified graphene (CuI/GO-VB) nanocomposite and its application for the synthesis of oxazolidinone compounds using a remarkable carboxylative cyclization method via the reaction of arylacetylene, aldehyde and benzylamine derivatives under an atmospheric pressure of CO2 gas. The CuI/GO-VB catalyst was prepared from graphene oxide (GO), vitamin B3 (VB) and CuI using a two-step procedure; firstly graphene-based composite (GO-VB) was synthesized by the reaction of GO and nicotinoyl chloride, followed by the immobilization of CuI NPs on GO-VB. The CuI/GO-VB nanocomposite was fully identified with X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), inductively coupled plasma optical emission spectroscopy (ICP-OES), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). The catalytic performance of the CuI/GO-VB heterogeneous catalyst was investigated in carboxylative cyclization for the synthesis of oxazolidinone compounds under an atmospheric pressure of CO2 gas at 100οC in solvent-, base-, and additive-free conditions; the corresponding oxazolidinone compounds were obtained in 79-94% yield. The hot filtration results indicated that CuI/GO-VB nanocomposite was a heterogeneous catalyst and showed a good reusability for 5 runs without a significant decrease in its catalytic performance.


Asunto(s)
Grafito , Nanocompuestos , Nanopartículas , Oxazolidinonas , Cobre/química , Grafito/química , Oxindoles , Dióxido de Carbono , Yoduros , Espectroscopía Infrarroja por Transformada de Fourier , Nanopartículas/química , Nanocompuestos/química , Catálisis , Vitaminas
15.
Antimicrob Agents Chemother ; 67(11): e0079623, 2023 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-37902402

RESUMEN

Contezolid acefosamil (also known as MRX-4), a prodrug of contezolid, is under development for treatment of multidrug-resistant Gram-positive bacterial infections. A phase I single ascending dose (SAD) and multiple-dose placebo-controlled study was conducted to assess the safety, tolerability, and pharmacokinetics (PK) of contezolid acefosamil in healthy Chinese subjects following intravenous (IV) and oral administration. Adverse events (AEs) and PK parameters were assessed appropriately. All subjects (n = 70) completed the trial. Overall, 67 cases of treatment-emergent adverse events (TEAEs) were observed in 49.1% (27 of 55) of the subjects receiving contezolid acefosamil. All TEAEs were mild in severity. No serious AEs or deaths were reported. After IV SAD (500-2,000 mg), the corresponding C max of the active drug contezolid increased from 1.95 ± 0.57 to 15.61 ± 4.88 mg/L, AUC0-inf from 40.25 ± 10.12 to 129.41 ± 38.30 h·mg/L, median T max from 2.00 to 2.75 h, and mean t 1/2 from 13.33 to 16.74 h. Plasma contezolid reached steady state on day 6 after multiple IV doses, with an accumulation ratio of 2.20-2.96. Oral SAD of 500 and 1,500 mg resulted in contezolid C max of 8.66 ± 2.60 and 37.10 ± 8.66 mg/L, AUC0-inf of 30.44 ± 7.33 and 162.36 ± 47.08 h·mg/L, and median T max of 2.50 and 2.98 h. Contezolid reached steady state on day 5 after multiple oral doses of 1,500 mg without significant accumulation. Contezolid C max and AUC0-inf increased with the dose of contezolid acefosamil. The good safety and PK profiles in this SAD and multiple-dose study can support further clinical development of contezolid acefosamil.


Asunto(s)
Oxazolidinonas , Humanos , Administración Oral , Antibacterianos/farmacocinética , Área Bajo la Curva , China , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Voluntarios Sanos , Oxazolidinonas/efectos adversos , Oxazolidinonas/farmacocinética , Piridonas/efectos adversos , Piridonas/farmacocinética
16.
ACS Infect Dis ; 9(9): 1711-1729, 2023 09 08.
Artículo en Inglés | MEDLINE | ID: mdl-37610012

RESUMEN

A series of pleuromutilin derivatives containing an oxazolidinone skeleton were synthesized and evaluated in vitro and in vivo as antibacterial agents. Most of the synthesized derivatives exhibited potent antibacterial activities against three strains of Staphylococcus aureus (including MRSA ATCC 33591, MRSA ATCC 43300, and MSSA ATCC 29213) and two strains of Staphylococcus epidermidis (including MRSE ATCC 51625 and MSSE ATCC 12228). Compound 28 was the most active antibacterial agent in vitro (MIC = 0.008-0.125 µg·mL-1) and exhibited a significant bactericidal effect, low cytotoxicity, and weak inhibition (IC50 = 20.66 µmol·L-1) for CYP3A4, as well as exhibited less possibility to cause bacterial resistance. Furthermore, in vivo activities indicated that the compound was effective in reducing MRSA load in a murine thigh infection model. Moreover, it clearly facilitated the healing of MRSA skin infection and inhibited the secretion of the TNF-α, IL-6, and MCP-1 inflammatory factors in serum. These results suggest that oxazolidinone pleuromutilin is a promising therapeutic candidate for drug-resistant bacterial infections.


Asunto(s)
Diterpenos , Oxazolidinonas , Animales , Ratones , Antibacterianos/farmacología , Oxazolidinonas/farmacología , Oxindoles , Pleuromutilinas
17.
Microb Drug Resist ; 29(9): 438-442, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37523292

RESUMEN

To investigate the occurrence of oxazolidinone resistance genes, 18 florfenicol-resistant enterococci were isolated from 66 fecal samples collected from several cattle farms in central Italy. The PCR screening indicated that only a bovine florfenicol-resistant isolate, Enterococcus faecium 249031-C, was positive for the presence of optrA and poxtA genes. The strain was tested for its susceptibility to florfenicol, chloramphenicol, linezolid, tedizolid, tetracycline, erythromycin, and vancomycin. Whole Genome Sequencing analysis showed that E. faecium 249031-C, belonging to the ST22 lineage, harbored two plasmids: the optrA-carrying p249031-S (179 kb) and the poxtA-carrying p1818-c (23 kb). p249031-S, containing a new optrA-carrying Tn7695 transposon, was closely related to the plasmid pF88_1 of E. faecium F88, whereas p1818-c had already been detected in a human E. faecium, both enterococci were from Switzerland. The linezolid resistance genes were cotransferred to the E. faecium 64/3 recipient. Circular forms from both optrA- and poxtA-carrying genetic contexts were obtained. The occurrence of oxazolidinone resistance genes in a bovine E. faecium isolate and their localization on conjugative and mobilizable plasmids pose a risk for public health.


Asunto(s)
Enterococcus faecium , Oxazolidinonas , Bovinos , Animales , Humanos , Enterococcus , Antibacterianos/farmacología , Linezolid/farmacología , Suiza , Enterococcus faecalis , Farmacorresistencia Bacteriana/genética , Pruebas de Sensibilidad Microbiana , Plásmidos/genética , Heces
18.
Microb Genom ; 9(7)2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37410656

RESUMEN

Linezolid is used as first-line treatment of infections caused by vancomycin-resistant Enterococcus faecium. However, resistance to linezolid is increasingly detected. The aim of the present study was to elucidate the causes and mechanisms for the increase in linezolid-resistant E. faecium at Copenhagen University Hospital - Rigshospitalet. We therefore combined patient information on linezolid treatment with whole-genome sequencing data for vancomycin- or linezolid-resistant E. faecium isolates that had been systematically collected since 2014 (n=458). Whole-genome sequencing was performed for multilocus sequence typing (MLST), identification of linezolid resistance-conferring genes/mutations and determination of phylogenetically closely related strains. The collection of E. faecium isolates belonged to prevalent vancomycin-resistant MLST types. Among these, we identified clusters of closely related linezolid-resistant strains compatible with nosocomial transmission. We also identified linezolid-resistant enterococcus isolates not genetically closely related to other isolates compatible with de novo generation of linezolid resistance. Patients with the latter isolates were significantly more frequently exposed to linezolid treatment than patients with related linezolid-resistant enterococcus isolates. We also identified six patients who initially carried a vancomycin-resistant, linezolid-sensitive enterococcus, but from whom vancomycin-resistant, linezolid-resistant enterococci (LVRE) closely related to their initial isolate were recovered after linezolid treatment. Our data illustrate that linezolid resistance may develop in the individual patient subsequent to linezolid exposure and can be transmitted between patients in a hospital setting.


Asunto(s)
Enterococcus faecium , Enterococos Resistentes a la Vancomicina , Humanos , Linezolid/farmacología , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Enterococcus faecium/genética , Vancomicina/farmacología , Vancomicina/uso terapéutico , Centros de Atención Terciaria , Tipificación de Secuencias Multilocus , Enterococos Resistentes a la Vancomicina/genética
19.
Crit Rev Anal Chem ; : 1-30, 2023 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-37378883

RESUMEN

Gram-positive bacterial infections are among the most serious diseases related with high mortality rates and huge healthcare costs especially with the rise of antibiotic-resistant strains that limits treatment options. Thus, development of new antibiotics combating these multi-drug resistant bacteria is crucial. Oxazolidinone antibiotics are the only totally synthetic group of antibiotics that showed activity against multi-drug resistant Gram positive bacteria including MRSA because of their unique mechanism of action in targeting protein synthesis. This group include approved marketed members (tedizolid, linezolid and contezolid) or those under development (delpazlolid, radezolid and sutezolid). Due to the significant impact of this class, larger number of analytical methods were required to meet the needs of both clinical and industrial studies. Analyzing these drugs either alone or with other antimicrobial agents commonly used in ICU, in the presence of pharmaceutical or endogenous biological interferences, or in the presence of matrix impurities as metabolites and degradation products poses a big analytical challenge. This review highlights current analytical approaches published in the last decade (2012-2022) that dealt with the determination of these drugs in different matrices and discusses their advantages and disadvantages. Various techniques have been described for their determination including chromatographic, spectroscopic, capillary electrophoretic and electroanalytical methods. The review comprises six sections (one for each drug) with their related tables that depict critical figures of merit and some experimental conditions for the reviewed methods. Furthermore, future perspectives about the analytical methodologies that can be developed in the near future for determination of these drugs are suggested.

20.
Trials ; 24(1): 382, 2023 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-37280643

RESUMEN

BACKGROUND: Linezolid is an effective, but toxic anti-tuberculosis drug that is currently recommended for the treatment of drug-resistant tuberculosis. Improved oxazolidinones should have a better safety profile, while preserving efficacy. Delpazolid is a novel oxazolidinone developed by LegoChem Biosciences Inc. that has been evaluated up to phase 2a clinical trials. Since oxazolidinone toxicity can occur late in treatment, LegoChem Biosciences Inc. and the PanACEA Consortium designed DECODE to be an innovative dose-ranging study with long-term follow-up for determining the exposure-response and exposure-toxicity relationship of delpazolid to support dose selection for later studies. Delpazolid is administered in combination with bedaquiline, delamanid and moxifloxacin. METHODS: Seventy-five participants with drug-sensitive, pulmonary tuberculosis will receive bedaquiline, delamanid and moxifloxacin, and will be randomized to delpazolid dosages of 0 mg, 400 mg, 800 mg, 1200 mg once daily, or 800 mg twice daily, for 16 weeks. The primary efficacy endpoint will be the rate of decline of bacterial load on treatment, measured by MGIT liquid culture time to detection from weekly sputum cultures. The primary safety endpoint will be the proportion of oxazolidinone class toxicities; neuropathy, myelosuppression, or tyramine pressor response. Participants who convert to negative liquid media culture by week 8 will stop treatment after the end of their 16-week course and will be observed for relapse until week 52. Participants who do not convert to negative culture will receive continuation phase treatment with rifampicin and isoniazid to complete a six-month treatment course. DISCUSSION: DECODE is an innovative dose-finding trial, designed to support exposure-response modelling for safe and effective dose selection. The trial design allows assessment of occurrence of late toxicities as observed with linezolid, which is necessary in clinical evaluation of novel oxazolidinones. The primary efficacy endpoint is the change in bacterial load, an endpoint conventionally used in shorter dose-finding trials. Long-term follow-up after shortened treatment is possible through a safety rule excluding slow-and non-responders from potentially poorly performing dosages. TRIAL REGISTRATION: DECODE was registered in ClinicalTrials.gov before recruitment start on 22 October 2021 (NCT04550832).


Asunto(s)
Oxazolidinonas , Tuberculosis Pulmonar , Adulto , Humanos , Moxifloxacino/efectos adversos , Linezolid , Quimioterapia Combinada , Antituberculosos , Oxazolidinonas/efectos adversos , Tuberculosis Pulmonar/diagnóstico , Resultado del Tratamiento
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