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1.
Mater Today Bio ; 23: 100839, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38024837

ABSTRACT

STING (Stimulator of Interferon Genes) agonists have emerged as promising agents in the field of cancer immunotherapy, owing to their excellent capacity to activate the innate immune response and combat tumor-induced immunosuppression. This review provides a comprehensive exploration of the strategies employed to develop effective formulations for STING agonists, with particular emphasis on versatile nano-delivery systems. The recent advancements in delivery systems based on lipids, natural/synthetic polymers, and proteins for STING agonists are summarized. The preparation methodologies of nanoprecipitation, self-assembly, and hydrogel, along with their advantages and disadvantages, are also discussed. Furthermore, the challenges and opportunities in developing next-generation STING agonist delivery systems are elaborated. This review aims to serve as a reference for researchers in designing novel and effective STING agonist delivery systems for cancer immunotherapy.

2.
Int J Nanomedicine ; 18: 6001-6019, 2023.
Article in English | MEDLINE | ID: mdl-37901361

ABSTRACT

Background: Olaparib, a poly (adenosine diphosphate-ribose) polymerase (PARP) inhibitor has demonstrated promising efficacy in patients with triple-negative breast cancer (TNBC) carrying breast cancer gene (BRCA) mutations. However, its impact on BRCA wild-type (BRCAwt) TNBC is limited. Hence, it is crucial to sensitize BRCAwt TNBC cells to olaparib for effective clinical practice. Novobiocin, a DNA polymerase theta (POLθ) inhibitor, exhibits sensitivity towards BRCA-mutated cancer cells that have acquired resistance to PARP inhibitors. Although both of these DNA repair inhibitors demonstrate therapeutic efficacy in BRCA-mutated cancers, their nanomedicine formulations' antitumor effects on wild-type cancer remain unclear. Furthermore, ensuring effective drug accumulation and release at the cancer site is essential for the clinical application of olaparib. Materials and Methods: Herein, we designed a progressively disassembled nanosystem of DNA repair inhibitors as a novel strategy to enhance the effectiveness of olaparib in BRCAwt TNBC. The nanosystem enabled synergistic delivery of two DNA repair inhibitors olaparib and novobiocin, within an ultrathin silica framework interconnected by disulfide bonds. Results: The designed nanosystem demonstrated remarkable capabilities, including long-term molecular storage and specific drug release triggered by the tumor microenvironment. Furthermore, the nanosystem exhibited potent inhibitory effects on cell viability, enhanced accumulation of DNA damage, and promotion of apoptosis in BRCAwt TNBC cells. Additionally, the nanosystem effectively accumulated within BRCAwt TNBC, leading to significant growth inhibition and displaying vascular regulatory abilities as assessed by magnetic resonance imaging (MRI). Conclusion: Our results provided the inaugural evidence showcasing the potential of a progressively disassembled nanosystem of DNA repair inhibitors, as a promising strategy for the treatment of BRCA wild-type triple-negative breast cancer.


Subject(s)
Triple Negative Breast Neoplasms , Humans , Triple Negative Breast Neoplasms/drug therapy , Triple Negative Breast Neoplasms/genetics , Triple Negative Breast Neoplasms/pathology , Novobiocin/pharmacology , Novobiocin/therapeutic use , DNA Repair , Poly(ADP-ribose) Polymerases/metabolism , Poly(ADP-ribose) Polymerase Inhibitors/pharmacology , Poly(ADP-ribose) Polymerase Inhibitors/therapeutic use , Cell Line, Tumor , Tumor Microenvironment
3.
Int J Nanomedicine ; 18: 3663-3694, 2023.
Article in English | MEDLINE | ID: mdl-37427368

ABSTRACT

Glioblastoma (GBM), a highly aggressive form of brain cancer, is considered one of the deadliest cancers, and even with the most advanced medical treatments, most affected patients have a poor prognosis. However, recent advances in nanotechnology offer promising avenues for the development of versatile therapeutic and diagnostic nanoplatforms that can deliver drugs to brain tumor sites through the blood-brain barrier (BBB). Despite these breakthroughs, the use of nanoplatforms in GBM therapy has been a subject of great controversy due to concerns over the biosafety of these nanoplatforms. In recent years, biomimetic nanoplatforms have gained unprecedented attention in the biomedical field. With advantages such as extended circulation times, and improved immune evasion and active targeting compared to conventional nanosystems, bionanoparticles have shown great potential for use in biomedical applications. In this prospective article, we endeavor to comprehensively review the application of bionanomaterials in the treatment of glioma, focusing on the rational design of multifunctional nanoplatforms to facilitate BBB infiltration, promote efficient accumulation in the tumor, enable precise tumor imaging, and achieve remarkable tumor suppression. Furthermore, we discuss the challenges and future trends in this field. Through careful design and optimization of nanoplatforms, researchers are paving the way toward safer and more effective therapies for GBM patients. The development of biomimetic nanoplatform applications for glioma therapy is a promising avenue for precision medicine, which could ultimately improve patient outcomes and quality of life.


Subject(s)
Brain Neoplasms , Glioblastoma , Glioma , Humans , Drug Delivery Systems/methods , Prospective Studies , Quality of Life , Glioma/drug therapy , Glioblastoma/drug therapy , Glioblastoma/pathology , Brain Neoplasms/drug therapy , Brain Neoplasms/pathology
4.
Bioresour Technol ; 386: 129520, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37468006

ABSTRACT

An effective approach for glucose and furfural production by converting cellulose and hemicelluloses from corn stalk in a biphasic system of molten salt hydrate (MSH) and organic solvent using H2SO4 as catalyst was reported. Results showed that the system with LiBr·3H2O and dichloromethane (DCM) had excellent performance in cellulose and hemicelluloses conversion. Under the optimal reaction conditions (corn stalk:LiBr·3H2O:DCM ratio = 0.35:10:20 g/mL/mL, 0.05 mol/L H2SO4, 120 °C, 90 min), 58.9% glucose and 72.5% furfural were yielded. Meanwhile, lignin was obviously depolymerized by the cleavage of ß-O-4' linkages and fractionated with high purity and low molecular weight for potential coproducts. Fluorescence microscopy and confocal Raman microscope displayed that the LiBr·3H2O/DCM treatment caused decreasing intensities in carbohydrate and lignin, suggesting the degradation of the main components of biomass. This research provided a promising biorefinery technology for the comprehensive utilization of corn stalk.


Subject(s)
Furaldehyde , Lignin , Zea mays , Glucose , Solvents , Cellulose , Sodium Chloride , Biomass
5.
Pharmaceuticals (Basel) ; 16(2)2023 Feb 07.
Article in English | MEDLINE | ID: mdl-37259396

ABSTRACT

New nanotechnologies for imaging molecules are widely being applied to visualize the expression of specific molecules (e.g., ions, biomarkers) for disease diagnosis. Among various nanoplatforms, nanozymes, which exhibit enzyme-like catalytic activities in vivo, have gained tremendously increasing attention in molecular imaging due to their unique properties such as diverse enzyme-mimicking activities, excellent biocompatibility, ease of surface tenability, and low cost. In addition, by integrating different nanoparticles with superparamagnetic, photoacoustic, fluorescence, and photothermal properties, the nanoenzymes are able to increase the imaging sensitivity and accuracy for better understanding the complexity and the biological process of disease. Moreover, these functions encourage the utilization of nanozymes as therapeutic agents to assist in treatment. In this review, we focus on the applications of nanozymes in molecular imaging and discuss the use of peroxidase (POD), oxidase (OXD), catalase (CAT), and superoxide dismutase (SOD) with different imaging modalities. Further, the applications of nanozymes for cancer treatment, bacterial infection, and inflammation image-guided therapy are discussed. Overall, this review aims to provide a complete reference for research in the interdisciplinary fields of nanotechnology and molecular imaging to promote the advancement and clinical translation of novel biomimetic nanozymes.

6.
Pharmaceutics ; 15(4)2023 Apr 11.
Article in English | MEDLINE | ID: mdl-37111692

ABSTRACT

Abnormal tumor vasculature and a hypoxic tumor microenvironment (TME) limit the effectiveness of conventional cancer treatment. Recent studies have shown that antivascular strategies that focus on antagonizing the hypoxic TME and promoting vessel normalization effectively synergize to increase the antitumor efficacy of conventional therapeutic regimens. By integrating multiple therapeutic agents, well-designed nanomaterials exhibit great advantages in achieving higher drug delivery efficiency and can be used as multimodal therapy with reduced systemic toxicity. In this review, strategies for the nanomaterial-based administration of antivascular therapy combined with other common tumor treatments, including immunotherapy, chemotherapy, phototherapy, radiotherapy, and interventional therapy, are summarized. In particular, the administration of intravascular therapy and other therapies with the use of versatile nanodrugs is also described. This review provides a reference for the development of multifunctional nanotheranostic platforms for effective antivascular therapy in combined anticancer treatments.

7.
Bioresour Technol ; 369: 128392, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36435421

ABSTRACT

The developing of pretreatment method to break the biomass barrier of lignocellulosic is a challenging task for achieve high value utilization. A fast microwave-assisted choline chloride/1,2-propanediol/methyl isobutyl ketone biphasic system was constructed for pretreating Eucalyptus to the production of furfural and cellulose-rich residues and the extraction of lignin. Results showed that the combination of AlCl3·6H2O and HCl had the best catalytic ability for furfural production among the examined catalysts. Under the optimal conditions (140 °C, 15 min, 0.075 M AlCl3·6H2O, 0.05 M HCl), the furfural yield of 55.4 %, the glucose yield of 90.3 % and the delignification rate of 92.4 % could be achieved. Moreover, the extracted lignin samples with a low polydispersity (1.55-1.73) and molecular weight (1380-2040 g/mol) are promising to act as precursor for the value-add products processing. These findings demonstrated an ultrafast pretreatment process with excellent results in biomass fractionation and comprehensive utilization of biomass components.


Subject(s)
Eucalyptus , Lignin , Lignin/chemistry , Propylene Glycol , Furaldehyde , Biomass , Choline/chemistry , Microwaves , Solvents/chemistry , Hydrolysis
8.
ChemSusChem ; 15(15): e202200553, 2022 Aug 05.
Article in English | MEDLINE | ID: mdl-35593890

ABSTRACT

Deep eutectic solvents (DESs) have unique advantages in biomass conversion. However, the migration and transformation mechanism of lignin in the cell wall during the DES pretreatment is still elusive. In this work, Eucalyptus blocks were pretreated in choline chloride/lactic acid DES to reveal the lignin migration. Meanwhile, the remaining lignin in the pretreated residue, the regenerated DES lignin, and the solubilized degraded lignin in the recovered DES were investigated to decipher the lignin transformation. Results showed that the DES pretreatment resulted in the penetration of DES from the cell lumen to the cell wall, and lignin in the secondary wall was more easily dissolved than that in the cell corner middle lamella. The syringyl unit of lignin was better stabilized in the DES than the guaiacyl unit of lignin. The condensed lignin fraction mainly remained in the pretreated residue, while the solubilized degraded lignin fraction was monomeric aromatic ketone compounds. This study elucidates the fate of lignin during the DES pretreatment, which could also promote the development of a modern lignocellulosic pretreatment technique.


Subject(s)
Eucalyptus , Lignin , Biomass , Deep Eutectic Solvents , Hydrolysis , Lignin/chemistry , Solvents/chemistry
9.
Int J Biol Macromol ; 209(Pt B): 1792-1800, 2022 Jun 01.
Article in English | MEDLINE | ID: mdl-35483510

ABSTRACT

Understanding of the morphological changes at different growth stages and lignin accumulation pattern for pine biomass plays the key role in facilitating the further development of value-added utilization and downstream conversion processes. This work systematically revealed the morphological change and lignin accumulation pattern in Chinese pine branches cell walls via confocal Raman microscopy (CRM) technology. Meanwhile, the structural characteristics of isolated lignin samples from different growth stages were synthetically characterized by nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC) techniques. The results indicated that the content of pith in adult pine new branch was bigger than juvenile trees. With the increase of physiological age, the branches in adult pine could accumulate more lignin both in overall content and the concentration of cell corner middle layer. Moreover, the significantly increases of molecular weights and the ß-O-4, ß-ß linkages content revealed that the lignin macromolecule of pine would polymerize faster in the adult stage (14, 35 years). The panorama generated from the structural and chemical features of pine native lignin not only benefited to understand the biosynthetic pathways and lignin macromolecules structural variation in plant cell walls from different growth stages but also contributed to the valorization and deconstruction of biomass.


Subject(s)
Lignin , Pinus , Biomass , Cell Wall/chemistry , China , Lignin/chemistry
10.
Carbohydr Polym ; 288: 119420, 2022 Jul 15.
Article in English | MEDLINE | ID: mdl-35450662

ABSTRACT

The alkali-soluble hemicelluloses extracted with 10% KOH solution from corn bran were further isolated with different concentrations of aqueous ethanol solutions. Herein 92.2% of the original hemicelluloses can be obtained and the cellulase enzymatic hydrolysis rate of the alkali treated corn bran can reach to 97.2%. The corn bran hemicelluloses were mainly glucuronoarabinoxylan, in which xylose (48.4-53.8%) and arabinose (27.8-33.2%) were the main components. More linear hemicelluloses with high molecular weight tended to be precipitated in low concentration aqueous ethanol solutions. Furthermore, the relationship between the structural features of these alkali-soluble corn bran hemicelluloses and their furfural yield was investigated in MIBK (methyl isobutyl ketone)/H2O biphasic system. Results showed that the hemicelluloses with high xylose content are benefit to the furfural production, and the highest furfural yield of 67.7% was obtained.


Subject(s)
Furaldehyde , Xylose , Alkalies/chemistry , Ethanol/chemistry , Furaldehyde/chemistry , Hydrolysis , Water/chemistry , Zea mays/chemistry
11.
Bioresour Technol ; 352: 127065, 2022 May.
Article in English | MEDLINE | ID: mdl-35351557

ABSTRACT

An aspirational pretreatment method for efficient fractionation and tailored valorization of large industrial biomass can ensure the realizability of sustainable biorefinery strategies. In this study, an ultrafast alkaline deep eutectic solvents (DES) pretreatment strategy was developed to efficiently extract the lignin nanoparticles and retain cellulose residues that could be readily enzymatic saccharified to obtain fermentative glucose for the bioenergy production from industrial xylose residue. Results showed that the DES pretreatment had excellent delignification performance and the regenerated DES lignin nanoparticles exhibited well-preserved structures and excellent antioxidant activity, as well as low molecular weights and relatively uniform size distribution, which could facilitate downstream catalytic degradation for production of chemicals and preparation of lignin-based materials. Under the optimal condition (DES pretreatment: 80 °C, 10 min; saccharification: 10 FPU/g, 5 wt%, 100 mg/g Tween 80), the glucose yield of 90.12% could be achieved, which was dramatically increased compared to raw materials.


Subject(s)
Lignin , Xylose , Biomass , Deep Eutectic Solvents , Glucose , Hydrolysis , Lignin/chemistry , Solvents/chemistry
12.
Bioresour Technol ; 352: 127074, 2022 May.
Article in English | MEDLINE | ID: mdl-35346816

ABSTRACT

Developing a biorefinery process for a highly integrated valorization and fractionation of lignocellulose is crucial for its utilization. Herein, a biphasic system comprising choline chloride/lactic acid and 2-methyltetrahydrofuran with Al2(SO4)3 and H2SO4 as catalysts was applied to pretreat Eucalyptus. Results showed that under the optimized conditions (150 °C, 30 min, 0.2 M Al2(SO4)3, 0.075 M H2SO4), the furfural yield and enzymatic hydrolysis efficiency could reach 54.7% and 97.0%, respectively. The efficient cellulose conversion was attributed to remarkable removal of lignin (91.0%) and hemicelluloses (100.0%), thereby causing the disruption of cell wall structure and enhancement of cellulose accessibility. Meanwhile, confocal Raman microscope and atomic force microscope displayed that the pretreatment resulted in the decreasing intensities of carbohydrates and lignin different regions of cell walls, and exposing of the embedded microfibers from noncellulosic polymers. Overall, the deep eutectic solvent-based biphasic system displayed high performance for effective utilization of carbohydrate components in lignocellulose.


Subject(s)
Furaldehyde , Lignin , Biomass , Carbohydrates , Cellulose , Deep Eutectic Solvents , Hydrolysis , Lignin/chemistry , Solvents
13.
Carbohydr Polym ; 281: 119050, 2022 Apr 01.
Article in English | MEDLINE | ID: mdl-35074121

ABSTRACT

Exploration of lignocellulosic biomass provides a sustainable and eco-friendly route for producing liquid fuels, materials, and chemicals. However, direct utilization of lignocelluloses is limited by the stable and complicated cross-linking structure of the plant cell wall. Hydrothermal pretreatment (HTP) is a green and cost-effective technology because it can disrupt lignin-carbohydrate complex (LCC) linkages, dissolve hemicelluloses and lignin, and redistribute lignin in the cell wall layers without utilization of any chemicals. Thus, HTP is expected to achieve industrial scale in second-generation biorefineries and circular bioeconomies. This review analyzed the deconstruction of lignocelluloses by HTP, with particular emphasis on the formation mechanism of hemicellulose degradation products and the structural evolution of hemicelluloses and lignin accompanying HTP. Meanwhile, the formation mechanism of pseudolignin and its effect on the enzymatic hydrolysis of cellulose as well as strategies for inhibiting lignin recondensation were discussed.


Subject(s)
Lignin , Polysaccharides , Biomass , Hydrolysis , Lignin/chemistry , Solubility
14.
Bioresour Technol ; 342: 125961, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34852440

ABSTRACT

Hydrothermal processes are an attractive clean technology and cost-effective engineering platform for biorefineries based in the conversion of biomass to biofuels and high-value bioproducts under the basis of sustainability and circular bioeconomy. The deep and detailed knowledge of the structural changes by the severity of biomasses hydrothermal fractionation is scientifically and technological needed in order to improve processes effectiveness, reactors designs, and industrial application of the multi-scale target compounds obtained by steam explosion and liquid hot water systems. The concept of the severity factor [log10 (Ro)] established>30 years ago, continues to be a useful index that can provide a simple descriptor of the relationship between the operational conditions for biomass fractionation in second generation of biorefineries. This review develops a deep explanation of the hydrothermal severity factor based in lignocellulosic biomass fractionation with emphasis in research advances, pretreatment operations and the applications of severity factor kinetic model.


Subject(s)
Biofuels , Steam , Biomass , Chemical Fractionation , Lignin , Water
15.
Biotechnol Biofuels ; 14(1): 72, 2021 Mar 19.
Article in English | MEDLINE | ID: mdl-33741045

ABSTRACT

BACKGROUND: In view of the natural resistance of hemicelluloses in lignocellulosic biomass on bioconversion of cellulose into fermentable sugars, alkali extraction is considered as an effective method for gradually fractionating hemicelluloses and increasing the bioconversion efficiency of cellulose. In the present study, sequential alkaline extractions were performed on the delignified ryegrass material to achieve high bioconversion efficiency of cellulose and comprehensively investigated the structural features of hemicellulosic fractions for further applications. RESULTS: Sequential alkaline extractions removed hemicelluloses from cellulose-rich substrates and degraded part of amorphous cellulose, reducing yields of cellulose-rich substrates from 73.0 to 27.7% and increasing crystallinity indexes from 31.7 to 41.0%. Alkaline extraction enhanced bioconversion of cellulose by removal of hemicelluloses and swelling of cellulose, increasing of enzymatic hydrolysis from 72.3 to 95.3%. In addition, alkaline extraction gradually fractionated hemicelluloses into six fractions, containing arabinoxylans as the main polysaccharides and part of ß-glucans. Simultaneously, increasing of alkaline concentration degraded hemicellulosic polysaccharides, which resulted in a decreasing their molecular weights from 67,510 to 50,720 g/mol. CONCLUSIONS: The present study demonstrated that the sequential alkaline extraction conditions had significant effects on the enzymatic hydrolysis efficiency of cellulose and the investigation of the physicochemical properties of hemicellulose. Overall, the investigation the enzymatic hydrolysis efficiency of cellulose-rich substrates and the structural features of hemicelluloses from ryegrass will provide useful information for the efficient utilization of cellulose and hemicelluloses in biorefineries.

16.
Carbohydr Polym ; 252: 117164, 2021 Jan 15.
Article in English | MEDLINE | ID: mdl-33183615

ABSTRACT

Herein, a two-step hydrothermal pretreatment combined with alkali extraction method was applied to deconstruct the poplar cell walls for enzymatic hydrolysis. Results revealed that 88.1 % of hemicelluloses and 77.6 % of lignin were removed during the integrated treatment performed at 180 °C and a maximum enzymatic hydrolysis efficiency of 96.1 % was achieved. Confocal Raman microscopy suggested that the removal of hemicelluloses from cell walls was inhomogeneous, and most hemicelluloses were released from the secondary wall. In addition, 35.2-56.8 % of hemicelluloses were isolated from the integrated treatment. Detailed structural analysis revealed that the water-soluble hemicelluloses possessed more branched structure than the alkali-soluble hemicelluloses and the hemicelluloses isolated from the poplar were mainly composed of a linear backbone of (1→4)-ß-d-Xylp with 4-O-Me-α-d-GlcpA attached as side chains. This work provides an efficient pathway to transform poplar into fermentable sugars and hemicelluloses with considerable yield.

17.
Bioresour Technol ; 299: 122685, 2020 Mar.
Article in English | MEDLINE | ID: mdl-31918970

ABSTRACT

Different pretreatments strategies have been developed over the years mainly to enhance enzymatic cellulose degradation. In the new biorefinery era, a more holistic view on pretreatment is required to secure optimal use of the whole biomass. Hydrothermal pretreatment technology is regarded as very promising for lignocellulose biomass fractionation biorefinery and to be implemented at the industrial scale for biorefineries of second generation and circular bioeconomy, since it does not require no chemical inputs other than liquid water or steam and heat. This review focuses on the fundamentals of hydrothermal pretreatment, structure changes of biomass during this pretreatment, multiproduct strategies in terms of biorefinery, reactor technology and engineering aspects from batch to continuous operation. The treatise includes a case study of hydrothermal biomass pretreatment at pilot plant scale and integrated process design.


Subject(s)
Lignin , Steam , Biomass , Cellulose , Chemical Fractionation , Engineering , Hydrolysis
18.
Bioresour Technol ; 297: 122471, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31787511

ABSTRACT

Hereon, tobacco stalk was deconstructed by lyophilization, ball-milling, ultrasound-assisted alkali extraction, hydrothermal pretreatment (HTP), and alkali presoaking, respectively, followed by dilute alkali cooking to both improve its enzymatic digestibility and isolate the hemicellulosic streams. It was found that a maximum cellulose saccharification rate of 93.5% was achieved from the integrated substrate by ball-milling and dilute alkali cooking, which was 4.4-fold higher than that from the raw material. Interestingly, in this case, 76.9% of hemicelluloses were simultaneously recovered during the integrated treatment. Structural determination indicated that the hemicelluloses released from tobacco stalk by dilute alkali cooking were mixed polysaccharides, and the (1 â†’ 4)-linked ß-D-Xylp backbone branched with L-Araf units at O-2/O-3 and 4-O-Me-α-D-GlcpA units at O-2 of the xylose residues was the main structure. In comparison, ultrasound-assisted alkali extraction, ball-milling, and HTP favored the extraction of hemicelluloses with less branched structure and lower molecular weights in the following alkali cooking.


Subject(s)
Cellulose , Nicotiana , Hydrolysis , Molecular Weight , Polysaccharides
19.
Biomed Environ Sci ; 31(5): 389-393, 2018 May.
Article in English | MEDLINE | ID: mdl-29866221

ABSTRACT

Penicillin-binding proteins (PBPs) are the target of ß-lactam antibiotics (the major treatment for Streptococcus pneumoniae infections), and mutations in PBPs are considered as a primary mechanism for the development of ß-lactam resistance in S. pneumoniae. This study was conducted to investigate the mutations in the PBPs of clinical S. pneumoniae isolates in Hangzhou, China, in correlation with ß-lactam resistance. Results showed that 19F was the predominant serotype (7/27) and 14 of the S. pneumoniae isolates were resistant to both penicillin G and cephalosporin. Genotyping results suggested that ß-lactam-resistant isolates primarily exhibited single-site mutations in both the STMK and SRNVP motifs of pbp1a in combination with double-site mutations in the STMK motif of pbp2x, which might be the primary mechanisms underlying the ß-lactam resistance of the isolates in this study.


Subject(s)
Anti-Bacterial Agents/pharmacology , Pneumococcal Infections/microbiology , Streptococcus pneumoniae/drug effects , Streptococcus pneumoniae/genetics , beta-Lactams/pharmacology , China/epidemiology , Drug Resistance, Bacterial , Humans , Pneumococcal Infections/epidemiology
20.
Article in English | WPRIM (Western Pacific) | ID: wpr-690645

ABSTRACT

Penicillin-binding proteins (PBPs) are the target of β-lactam antibiotics (the major treatment for Streptococcus pneumoniae infections), and mutations in PBPs are considered as a primary mechanism for the development of β-lactam resistance in S. pneumoniae. This study was conducted to investigate the mutations in the PBPs of clinical S. pneumoniae isolates in Hangzhou, China, in correlation with β-lactam resistance. Results showed that 19F was the predominant serotype (7/27) and 14 of the S. pneumoniae isolates were resistant to both penicillin G and cephalosporin. Genotyping results suggested that β-lactam-resistant isolates primarily exhibited single-site mutations in both the STMK and SRNVP motifs of pbp1a in combination with double-site mutations in the STMK motif of pbp2x, which might be the primary mechanisms underlying the β-lactam resistance of the isolates in this study.


Subject(s)
Humans , Anti-Bacterial Agents , Pharmacology , China , Epidemiology , Drug Resistance, Bacterial , Pneumococcal Infections , Epidemiology , Microbiology , Streptococcus pneumoniae , Genetics , beta-Lactams , Pharmacology
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