Pseudomonas aeruginosa is intrinsically resistant to a variety of antimicrobials and can develop resistance during anti-pseudomonal chemotherapy both of which compromise treatment of infections caused by this organism. Resistance to multiple classes of antimicrobials (multidrug resistance) in particular is increasingly common in P. aeruginosa, with a number of reports of pan-resistant isolates treatable with a single agent, colistin. Acquired resistance in this organism is multifactorial and attributable to chromosomal mutations and the acquisition of resistance genes via horizontal gene transfer. Mutational changes impacting resistance include upregulation of multidrug efflux systems to promote antimicrobial expulsion, derepression of ampC, AmpC alterations that expand the enzyme's substrate specificity (i.e., extended-spectrum AmpC), alterations to outer membrane permeability to limit antimicrobial entry and alterations to antimicrobial targets. Acquired mechanisms contributing to resistance in P. aeruginosa include β-lactamases, notably the extended-spectrum β-lactamases and the carbapenemases that hydrolyze most β-lactams, aminoglycoside-modifying enzymes, and 16S rRNA methylases that provide high-level pan-aminoglycoside resistance. The organism's propensity to grow in vivo as antimicrobial-tolerant biofilms and the occurrence of hypermutator strains that yield antimicrobial resistant mutants at higher frequency also compromise anti-pseudomonal chemotherapy. With limited therapeutic options and increasing resistance will the untreatable P. aeruginosa infection soon be upon us?
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3128976 | PMC |
http://dx.doi.org/10.3389/fmicb.2011.00065 | DOI Listing |
Adv Sci (Weinh)
January 2025
Department of Cardiology, The First People's Hospital of Wenling, Wenling Hospital of Wenzhou Medical University, Wenling, Zhejiang, 317500, China.
Immobilizing enzymes onto solid supports having enhanced catalytic activity and resistance to harsh external conditions is considered as a promising and critical method of broadening enzymatic applications in biosensing, biocatalysis, and biomedical devices; however, it is considerably hampered by limited strategies. Here, a core-shell strategy involving a soft-core hexahistidine metal assembly (HmA) is innovatively developed and characterized with encapsulated enzymes (catalase (CAT), horseradish peroxidase, glucose oxidase (GOx), and cascade enzymes (CAT+GOx)) and hard porous shells (zeolitic imidazolate framework (ZIF), ZIF-8, ZIF-67, ZIF-90, calcium carbonate, and hydroxyapatite). The enzyme-friendly environment provided by the embedded HmA proves beneficial for enhanced catalytic activity, which is particularly effective in preserving fragile enzymes that will have been deactivated without the HmA core during the mineralization of porous shells.
View Article and Find Full Text PDFChembiochem
January 2025
Chinese Academy of Medical Sciences & Peking Union Medical College Institute of Materia Medica, State Key Laboratory of Bioactive Substances and Function of Natural Medicine, 1 Xian Nong Tan Street, 100050, Beijing, CHINA.
Bacterial infections, particularly those caused by drug-resistant bacteria, represent a pressing global health challenge. During the interaction between pathogen infection and host defense, bacterial infections initiate the host's immune response, which involves the activation of proteases that play a critical role in antibacterial defense. Granzyme B (GzmB), a key immune-related biomarker associated with cytotoxic T lymphocytes (CTLs), plays a pivotal role in this process.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Department of General Surgery, Tangdu Hospital, Air Force Medical University, Xi'an, 710038, P. R. China.
Leaky and structurally abnormal blood vessels and increased pressure in the tumor interstitium reduce the infiltration of CAR-T cells in solid tumors, including triple-negative breast cancer (TNBC). Furthermore, high burden of tumor cells may cause reduction of infiltrating CAR-T cells and their functional exhaustion. In this study, various effector-to-target (E:T) ratio experiments are established to model the treatment using CAR-T cells in leukemia (high E:T ratio) and solid tumor (low E:T ratio).
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Orthopedic Institute, Department of Orthopedic Surgery, Medical 3D Printing Center, The First Affiliated Hospital, Changzhou Geriatric hospital, MOE Key Laboratory of Geriatric Diseases and Immunology, School of Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, 215000, P. R. China.
Repair of infectious bone defects remains a serious problem in clinical practice owing to the high risk of infection and excessive reactive oxygen species (ROS) during the early stage, and the residual bacteria and delayed Osseo integrated interface in the later stage, which jointly creates a complex and dynamic microenvironment and leads to bone non-union. The melatonin carbon dots (MCDs) possess antibacterial and osteogenesis abilities, greatly simplifying the composition of a multifunctional material. Therefore, a multifunctional hydrogel containing MCDs (GH-MCD) is developed to meet the multi-stage and complex repair needs of infectious bone injury in this study.
View Article and Find Full Text PDFJ Obstet Gynaecol Res
January 2025
Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
The Women's Health Care Committee was established in 2010 to improve the health of women. In the current academic year, this committee established seven subcommittees aimed at understanding diseases related to various age groups of women, including adolescence, sexual maturity, and menopause, and promoting research to improve the quality of life. Additionally, socially significant research has focused on infections, particularly resistant bacteria.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!