Objectives: The emergence and expansion of carbapenem-resistant Klebsiella pneumoniae infections is a concern due to the lack of 'first-line' antibiotic treatment options. The ceftazidime/avibactam is an important clinical treatment for carbapenem-resistant K. pneumoniae infections but there is an increasing number of cases of treatment failure and drug resistance. Therefore, a potential solution is combination therapies that result in synergistic activity against K. pneumoniae carbapenemase: producing K. pneumoniae (KPC-Kp) isolates and preventing the emergence of KPC mutants resistant to ceftazidime/avibactam are needed in lieu of novel antibiotics.
Methods: To evaluate their synergistic activity, antibiotic combinations were tested against 26 KPC-Kp strains. Antibiotic resistance profiles, molecular characteristics and virulence genes were investigated by susceptibility testing and whole-genome sequencing. Antibiotic synergy was evaluated by in vitro chequerboard experiments, time-killing curves and dose-response assays. The mouse thigh model was used to confirm antibiotic combination activities in vivo. Additionally, antibiotic combinations were evaluated for their ability to prevent the emergence of ceftazidime/avibactam resistant mutations of blaKPC.
Results: The combination of ceftazidime/avibactam plus meropenem showed remarkable synergistic activity against 26 strains and restored susceptibility to both the partnering antibiotics. The significant therapeutic effect of ceftazidime/avibactam combined with meropenem was also confirmed in the mouse model and bacterial loads in the thigh muscle of the combination groups were significantly reduced. Furthermore, ceftazidime/avibactam plus meropenem showed significant activity in preventing the occurrence of resistance mutations.
Conclusions: Our results indicated that the combination of ceftazidime/avibactam plus meropenem offers viable therapeutic alternatives in treating serious infections due to KPC-Kp.
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http://dx.doi.org/10.1093/jac/dkae074 | DOI Listing |
Nat Prod Res
January 2025
Department of Medical Microbiology, Faculty of Medicine, Erciyes University, Kayseri, Turkey.
Drone larvae (DL) has many biological activities thanks to the bioactive components it contains, but there are very few studies on its antimicrobial activity. The aim of this research was to determine the antifungal activity of DL (raw and lyophilised) water and ethanol extracts against fluconazole (FLU) sensitive and resistant yeast strains. The 87 fungal strains obtained from clinical samples were identified by phenotypic and molecular methods, and broth microdilution test was used for antifungal activity.
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January 2025
Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, College of Environmental Science and Engineering, Hunan University, Changsha 410082, China.
Electrocatalytic dehalogenation is a promising method for the remediation of chlorinated organic pollutants. The dehalogenation performance is controlled by catalytic activity, and the underlying electrocatalytic dehalogenation mechanisms need to be carefully investigated for guiding the design of catalyst. Here we report the preparation of a new Pd-based catalyst with a nanosheet structure (Pd NS) by a simple wet-chemical reduction method.
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January 2025
Department of Thyroid Surgery, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, 710000, China.
Chemodynamic therapy (CDT) has garnered significant attention in the field of tumor therapy due to its ability to convert overexpressed hydrogen peroxide (HO) in tumors into highly toxic hydroxyl radicals (•OH) through metal ion-mediated catalysis. However, the effectiveness of CDT is hindered by low catalyst efficiency, insufficient intra-tumor HO level, and excessive glutathione (GSH). In this study, a pH/GSH dual responsive bimetallic nanocatalytic system (CuFeMOF@GOx@Mem) is developed by modifying red blood cell membranes onto glucose oxidase (GOx)-loaded Fe-Cu bimetallic MOFs, enhancing the efficacy of CDT through a triple-enhanced way by HO self-supply, catalysts self-cycling, and GSH self-elimination.
View Article and Find Full Text PDFAdv Mater
January 2025
Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, P. R. China.
Metastasis, the leading cause of mortality in cancer patients, presents challenges for conventional photodynamic therapy (PDT) due to its reliance on localized light and oxygen application to tumors. To overcome these limitations, a self-sustained organelle-mimicking nanoreactor is developed here with programmable DNA switches that enables bio-chem-photocatalytic cascade-driven starvation-photodynamic synergistic therapy against tumor metastasis. Emulating the compartmentalization and positional assembly strategies found in living cells, this nano-organelle reactor allows quantitative co-compartmentalization of multiple functional modules for the designed self-illuminating chemiexcited PDT system.
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January 2025
State Key Laboratory of Petroleum Molecular & Process Engineering, Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200062, China.
Copper-based electrocatalysts are recognized as crucial catalysts for CO electroreduction into multi-carbon products. However, achieving copper-based electrocatalysts with adjustable valences via one-step facile synthesis remains a challenge. In this study, Cu/CuO heterostructure is constructed by adjusting the anion species of the Cu ions-containing electrolyte during electrodeposition synthesis.
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