Production of chromosome-encoded β-lactamases confers resistance to β-lactams in many Gram-negative bacteria. Some inducible β-lactamases, especially the class C β-lactamase AmpC in Enterobacteriaceae, share a common regulatory mechanism, the ampR-ampC paradigm. Induction of ampC is intimately linked to peptidoglycan recycling, and the LysR-type transcriptional regulator AmpR plays a central ro...

The high prevalence of methicillin resistance among Staphylococcus aureus bacteremias leads to common use of vancomycin as empirical therapy. However, investigators have reported poor outcomes with vancomycin treatment for methicillin-susceptible Staphylococcus aureus bacteremia. We review the evidence supporting empirical combination of both vancomycin and a β-lactam agent for Staphylococcus a...

Bacterial resistance to standard (i.e., β-lactam-based) antibiotics has become a global pandemic. Simultaneously, research into the underlying causes of resistance has slowed substantially, although its importance is universally recognized. Key to unraveling critical details is characterization of the noncovalent interactions that govern binding and specificity (DD-peptidases, antibiotic target...

OBJECTIVES plasmid pB1000 bearing bla(ROB-1) is responsible for high-level β-lactam resistance in Haemophilus influenzae as well as in Pasteurella multocida and Haemophilus parasuis isolates from Spain. Here, we explore the presence of ROB-1 in Italy and investigate the relative contribution of penicillin-binding protein 3 (PBP3) mutations and ROB-1 to the β-lactam resistance phenotype in H. in...

Acidovorax sp. strain MR-S7 was isolated from activated sludge in a treatment system for wastewater containing β-lactam antibiotic pollutants. Strain MR-S7 demonstrates multidrug resistance for various types of β-lactam antibiotics at high levels of MIC. The draft genome sequence clarified that strain MR-S7 harbors unique β-lactamase genes.

BACKGROUND The extensive use of the β-lactam antibiotics in hospitals and in the community has created major resistance problems which has led to increased morbidity, mortality and healthcare costs. The use of the β-lactamase inhibitors in combination with the β-lactam antibiotics is currently the most successful strategy used for circumventing the resistance mechanisms. OBJECTIVE To evaluate...

The prevalence of antibiotic resistance genes in pathogenic bacteria is a major challenge to treating many infectious diseases. The spread of these genes is driven by the strong selection imposed by the use of antibacterial drugs. However, in the absence of drug selection, antibiotic resistance genes impose a fitness cost, which can be ameliorated by compensatory mutations. In Streptococcus pne...

Kingella kingae is a human pathogen that causes pediatric osteoarticular infections and infective endocarditis in children and adults. The bacterium is usually susceptible to β-lactam antibiotics, although β-lactam resistance has been reported in rare isolates. This study was conducted to identify β-lactam-resistant strains and to characterize the resistance mechanism. Screening of a set of 90 ...

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...

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...