Due to the ongoing concern about the reliability of Staphylococcus breakpoints (interpretive criteria) for other β-lactam agents, the Clinical and Laboratory Standards Institute recently approved the elimination of all breakpoints for antistaphylococcal β-lactams except for penicillin, oxacillin or cefoxitin, and ceftaroline. Routine testing of penicillin and oxacillin or cefoxitin should be us...

Background.  Successful treatment of infections caused by multidrug-resistant (MDR) Pseudomonas aeruginosa is thwarted by the emergence of antibiotic resistance and biofilm formation on prosthetic devices. Our aims were to decipher the molecular basis of resistance in a unique case of prosthetic valve endocarditis (PVE) caused by MDR P. aeruginosa. Methods.  Five sequential MDR P. aeruginosa bl...

BACKGROUND Indigenous children in Australia and Alaska have very high rates of chronic suppurative lung disease (CSLD)/bronchiectasis. Antibiotics, including frequent or long-term azithromycin in Australia and short-term beta-lactam therapy in both countries, are often prescribed to treat these patients. In the Bronchiectasis Observational Study we examined over several years the nasopharyngeal...

β-Lactam antibiotics have long been a treatment of choice for bacterial infections since they bind irreversibly to Penicillin-Binding Proteins (PBPs), enzymes that are vital for cell wall biosynthesis. Many pathogens express drug-insensitive PBPs rendering β-lactams ineffective, revealing a need for new types of PBP inhibitors active against resistant strains. We have identified alkyl boronic a...

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 ...

Belgian data on the treatment of respiratory tract infections with antibiotics in ambulatory care showed that fluoroquinolone use remains well controlled. Belgian guidelines have recommended moxifloxacin for CAP outpatients with comorbid conditions or outpatients in whom infection with atypical pathogens needs to be considered. Moxifloxacin is recommended in case of IgE-mediated ß-lactam allerg...

OBJECTIVES To decipher the mechanisms and their associated genetic determinants responsible for β-lactam resistance in a Proteus mirabilis clinical isolate. METHODS The entire genetic structure surrounding the β-lactam resistance genes was characterized by PCR, gene walking and DNA sequencing. RESULTS Genes encoding the carbapenemase NDM-1 and the ESBL VEB-6 were located in a 38.5 kb MDR st...

Methicillin-resistant Staphylococcus aureus (MRSA) is intrinsically cross-resistant to virtually all β-lactam antibiotics. The central determinant for the MRSA phenotype is the mecA gene, whose transcriptional control may be mediated by a repressor (mecI) and a sensor/inducer (mecR1). The mecI-mecR1-mediated induction of mecA takes several hours rendering the strains phenotypically susceptible ...

Antibiotic resistance is an increasing global problem resulting from the pressure of antibiotic usage, greater mobility of the population, and industrialization. Many antibiotic resistance genes are believed to have originated in microorganisms in the environment, and to have been transferred to other bacteria through mobile genetic elements. Among others, β-lactam antibiotics show clinical eff...

The AmpC β-lactamases are clinically important because they confer resistance to the narrow-, expandedand the broad-spectrum cephalosporins, the β-lactam-β-lactamase inhibitor combinations and aztreonam. The clinical microbiology laboratories should be able to detect the bacterial strains which produce AmpC, since these strains may appear to be susceptible to a particular β-lactam antibiotic in...