Objective(s) Resistance to the new generation of cephalosporins which is mediated by Extended-Spectrum beta-lactamases (ESBLs) has been found among Escherichia coli isolates throughout the world. These resistance genes and their producers, the micro-organisms carrying beta-lactamases, are responsible for serious clinical and therapeutic problems among inpatients and it is necessary to pay more...

BACKGROUND The addition of an aminoglycoside to a beta -lactam therapy regimen has been suggested to have a beneficial effect in delaying or preventing the development of antimicrobial resistance. We studied the effect of aminoglycoside/ beta -lactam combination therapy versus beta-lactam monotherapy on the emergence of resistance. METHODS We performed a meta-analysis of randomized, controlle...

BACKGROUND To determine the cost-effectiveness of strategies of preferred antibiotic treatment with beta-lactam/macrolide combination or fluoroquinolone monotherapy compared to beta-lactam monotherapy. METHODS Costs and effects were estimated using data from a cluster-randomized cross-over trial of antibiotic treatment strategies, primarily from the reduced third payer perspective (i.e. hospi...

Fifty-four milk samples from commercial sources that tested positive for beta-lactam antibiotics were analyzed by a multiresidue liquid chromatographic (LC) procedure based on LC fractionation. Penicillin G and cephapirin were the beta-lactam antibiotics found most frequently. Some samples did not contain detectable beta-lactam antibiotics. In a few, the presence of a beta-lactam antibiotic was...

Definitions: Beta-lactam antimicrobials are characterized by having a four-membered cyclic amide (beta-lactam ring) as part of their chemical structure (Figure 1) [1]. This broad group includes the penicillins, cephalosporins, carbapenems, and monobactams [1]. All beta-lactams have a similar mechanism of action; they inhibit bacterial cell wall synthesis [1]. Resistance to beta-lactam antimicro...

There have been conflicting data about the interactions between vancomycin and beta-lactam agents against Staphylococcus aureus strains with heterogeneous resistance to vancomycin. We evaluated the efficacy of these combinations against Mu 3 and heterogeneously vancomycin-resistant S. aureus (hetero-VRSA) strains which were isolated from Korean patients using a population analysis method. Antag...

Anti-bacterial drugs have “selective toxicity”, that is they interact with a target present on the bacterial cell, the prokaryote, that is not present in the mammalian host, the eukaryote. For the ß-lactam drugs, this target is the cell wall. Mammalian cells lack cell walls, which for the bacteria are a critically important barrier protecting the organism from not only the vagaries of osmotic s...

BACKGROUND The choice of empirical antibiotic treatment for patients with clinically suspected community-acquired pneumonia (CAP) who are admitted to non-intensive care unit (ICU) hospital wards is complicated by the limited availability of evidence. We compared strategies of empirical treatment (allowing deviations for medical reasons) with beta-lactam monotherapy, beta-lactam-macrolide combin...

AcrAB exports some beta-lactam antibiotics in the periplasm out of cells via an outer-membrane channel, TolC. It has been reported that eight drug transporters in Escherichia coli cooperate with TolC. In this study, the roles of the drug exporters of E. coli in beta-lactam resistance were examined. We found that five of five resistance-nodulation-cell division-type drug exporters confer beta-la...

Against most test strains of Gram-negative bacilli, the in vitro effect of FR-31564 together with beta-lactam antibiotics or trimethoprim was strongly synergistic; with tetracycline and nalidixic acid the effect was additive; and with gentamicin and sulfamethoxazole the effect was additive or antagonistic. FR-31564 was markedly synergistic with beta-lactam antibiotics against beta-lactam antibi...