penicillin-binding proteins
Editor's Pick Mechanisms of ResistanceMultiple Low-Reactivity Class B Penicillin-Binding Proteins Are Required for Cephalosporin Resistance in EnterococciEnterococcus faecalis and Enterococcus faecium are commensals of the gastrointestinal tract of most terrestrial organisms, including humans, and are major causes of health care-associated infections. Such infections are difficult or impossible to treat, as the enterococcal strains responsible are...
SusceptibilitySusceptibility of Methicillin-Resistant Staphylococcus aureus to Five Quinazolinone AntibacterialsThe in vitro activities of five quinazolinone antibacterials, compounds Q1 to Q5, were tested against 210 strains of methicillin-resistant Staphylococcus aureus (MRSA). The MIC50/MIC90 values (in μg/ml) were as follows: Q1, 0.5/2; Q2, 1/4; Q3, 2/4; Q4, 0.06/0.25; and Q5, 0.125/0.5.
Mechanisms of Action: Physiological EffectsInfluence of the α-Methoxy Group on the Reaction of Temocillin with Pseudomonas aeruginosa PBP3 and CTX-M-14 β-LactamaseThe prevalence of multidrug-resistant Pseudomonas aeruginosa has led to the reexamination of older “forgotten” drugs, such as temocillin, for their ability to combat resistant microbes. Temocillin is the 6-α-methoxy analogue of ticarcillin, a carboxypenicillin with well-characterized antipseudomonal properties. The α-methoxy modification confers resistance to serine β...
Editor's Pick SusceptibilityBicarbonate Resensitization of Methicillin-Resistant Staphylococcus aureus to β-Lactam AntibioticsEndovascular infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are a major health care concern, especially infective endocarditis (IE). Standard antimicrobial susceptibility testing (AST) defines most MRSA strains as “resistant” to β-lactams, often leading to the use of costly and/or toxic treatment regimens. In this investigation, five prototype...
Mechanisms of Action: Physiological EffectsIn Vitro Activity of Tebipenem (SPR859) against Penicillin-Binding Proteins of Gram-Negative and Gram-Positive BacteriaTebipenem (SPR859) is the microbiologically active form of SPR994 (tebipenem-pivoxil), an orally available carbapenem with activity against extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae. Measurement of the relative binding of SPR859 to the bacterial cell targets revealed that it is a potent inhibitor of multiple penicillin-binding proteins (PBPs) but primarily a Gram-negative PBP 2 inhibitor, similar to...
Mechanisms of ResistanceGenetic Determinants of Penicillin Tolerance in Vibrio choleraeMany bacteria are resistant to killing (tolerant) by typically bactericidal antibiotics due to their ability to counteract drug-induced cell damage. Vibrio cholerae, the cholera agent, displays an unusually high tolerance to diverse inhibitors of cell wall synthesis.
- Epidemiology and SurveillanceMulticlonal Expansion and High Prevalence of β-Lactamase-Negative Haemophilus influenzae with High-Level Ampicillin Resistance in Japan and Susceptibility to Quinolones
β-Lactam-resistant Haemophilus influenzae is a clinical concern. A high prevalence (>40%) of β-lactamase-negative high-level ampicillin-resistant H. influenzae (high-BLNAR) isolates in Japan has been reported.