conclusions: considering the low rate of ceftriaxone resistance amongst isolated pneumcocci.in this study, only ceftriaxone treatment of adult patients with invasive pneumococcal infections (other than cns infections) is sufficient; but pediatric patients and patients with cns infections should be treated with ceftriaxone and vancomycin. apparently, diminution of vancomycin use can be resulted ...

From November 1997 to April 1998, 1,601 clinical isolates of Streptococcus pneumoniae were obtained from 34 U.S. medical centers. The overall rate of strains showing resistance to penicillin was 29. 5%, with 17.4% having intermediate resistance. Multidrug resistance, defined as lack of susceptibility to penicillin and at least two other non-ss-lactam classes of antimicrobial drugs, was observed...

We identified mutated genes in highly resistant subpopulations of methicillin-resistant Staphylococcus aureus (MRSA) that are most likely responsible for the historic failure of the β-lactam family of antibiotics as therapeutic agents against these important pathogens. Such subpopulations are produced during growth of most clinical MRSA strains, including the four historically early MRSA isolat...

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.

-lactamases are a major cause of resistance to the -lactam antibiotics. Many classes of -lactamases have been described depending on substrate specificity and susceptibility to inhibitors [1]. Amp C -lactamases are able to hydrolyse all penicillins and cephalosporins and are not inhibited by clavulanic acid. Bacteria that produce these enzymes are resistant to all penicillins including lac...

background :  pathogenic bacteria because of beta-lactam antibiotic resistance genes are dangerous to society. this resistance due to esbl genes, plasmids and transposons that by receiving or mutation occurs. the most important factor beta-lactam antibiotic resistance is beta lactamase enzymes. the purpose of this study was to evaluate the frequency of hospital opportunistic pathogenic bacteria...

Streptococcus pneumoniae and Neisseria meningitidis have very similar mechanisms of resistance to penicillin G. Although penicillin resistance is now common in S. pneumoniae, it is still rare in N. meningitidis. Using a mathematical model, we studied determinants of this difference and attempted to anticipate trends in meningococcal resistance to penicillin G. The model predicted that pneumococ...

Using clinical strains of Serratia marcescens with low and high resistance to extended-spectrum beta-lactam antibiotics, the relative contribution of chromosomal beta-lactamase and defective outer membrane porins to resistance was determined. Low-level resistance was caused by overproduced beta-lactamase alone. High-level resistance was due to beta-lactamase overproduction and defects of porin ...

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...