Extended-spectrum beta-lactamases (ESBL) of the TEM, SHV, or CTX-M type confer resistance to beta-lactam antibiotics in gram-negative bacteria. The activity of these enzymes against beta-lactam antibiotics and their resistance against inhibitors can be influenced by genetic variation at the single-nucleotide level. Here, we describe the development and validation of an oligonucleotide microarra...

the nosocomial infections, caused by multi-drug resistant bacteria, are the most important cause of mortality throughout the world. one important mechanism against beta-lactam antibiotics is the production of beta-lactamases. enterobacteriaceae and non-fermentative bacteria, like pseudomonas aeruginosa and acinetobacter baumannnii may produce these enzymes. currently, there is no vaccine to pre...

Production of β-lactamases of one of four molecular classes (A, B, C and D) is the major mechanism of bacterial resistance to β-lactams, the largest class of antibiotics, which have saved countless lives since their inception 70 years ago. Although several hundred efficient class D enzymes have been identified in Gram-negative pathogens over the last four decades, none have been reported in Gra...

beta-Lactamase inhibitors such as sulbactam are beta-lactam compounds that have low antimicrobial activity but are able to inhibit enzymes (beta-lactamases) that destroy beta-lactam antibiotics like penicillins and cephalosporins. The main activity of beta-lactamase inhibitors is directed against plasmid-mediated transferable enzymes and various extended-spectrum enzymes. Sulbactam is also acti...

Abstract Objective: Compare outcomes of patients receiving high-dose oral beta-lactam versus standard therapy for Enterobacterales bacteremia from a urinary tract infection (UTI). Design: Retrospective, multicenter, observational cohort. Setting: Three Michigan community teaching hospitals. Patients: Adult admitted between February 1, 2020, and October 2022, with gram-negative source were evalu...

Beta-lactam antibiotics serve as a cornerstone in the management of bacterial infections because of their wide spectrum of activity and low toxicity. Since resistance rates among bacteria are continuously on the rise and the pipeline for new antibiotics does not meet this trend, an optimization of current beta-lactam treatment is needed. This review provides an overview of optimization through ...

β-lactams are antibiotic molecules able to inhibit cell wall biosynthesis. Among other mechanisms, resistance in Gram-negative bacteria is mostly associated with production of β-lactamase enzymes able to bind and hydrolyze the β-lactam ring. Extended-spectrum β-lactamases extend this ability also to third- and fourth-generation cephalosporins, as well as to carbapenems and monobactams. Vibrio c...

To determine whether the widespread clinical use of -lactams has been selective for Citrobacter freundiiderived alleles of plasmid ampC genes, we generated a Bayesian consensus phylogeny of the published ampC sequences and compared the MICs of 16 -lactam antibiotics for Escherichia coli strains containing cloned copies of the C. freundii ampC alleles. We found that for the majority of compounds...

Since the 1940s β-lactam antibiotics have been used to treat bacterial infections. However, emergence and dissemination of β-lactam resistance has reached the point where many marketed β-lactams no longer are clinically effective. The increasing prevalence of multidrug-resistant bacteria and the progressive withdrawal of pharmaceutical companies from antibiotic research have evoked a strong rea...

In this issue of Clinical Infectious Diseases, Shelburne et al report their development and validation of a clinical prediction model for β-lactam resistance in viridans group streptococci (VGS) causing bloodstream infection (BSI) and offer guidance for the use of vancomycin (or gram-positive spectrum antibiotics) for empiric therapy of febrile neutropenia (FN) [1]. Although VGS cause a signifi...