Background There have been no standard methods to predict the hypersensitivity to cephalosporin. The relationship between cephalosporin hypersensitivity and history of beta-lactam hypersensitivity is not clear. This retrospective study is to evaluate the reliability of routine prophylactic skin test with cefazolin in general population and the relationship between results of cefazolin skin test...

Using a nitrocefin competition assay, I determined the relative substrate affinity index (RSAI) values of nine clinically significant beta-lactamase enzymes against a range of beta-lactams. Using selected beta-lactam substrates, I observed large differences in the RSAI values of the nine enzymes that were sufficient in many cases to positively identify specific enzymes. I made use of the unique...

Resistance to beta-lactams and quinolones in two isogenic Enterobacter cloacae isolates was studied. One was susceptible to cefoxitin and amoxicillin-clavulanate. The other one showed its natural beta-lactam resistance pattern. Both isolates had a nonfunctional AmpR regulator. However, within the second one, the presence of a plasmid carrying ampR and qnrA1 allowed reversion to the wild-type be...

Eight new beta-lactam antibiotics and rosaramicin were tested for their activity against penicillin-susceptible and multiply resistant pneumococci. All of the beta-lactam drugs were 50- to 150-fold less active against the drug-resistant pneumococci when compared with their activity against penicillin-susceptible pneumococci. Rosaramicin activity was similar to that of erythromycin.

This study aimed to evaluate the antimicrobial susceptibility profiles of 364 Streptococcus pneumoniae isolates and studied the genotypes of S. pneumoniae with high level beta-lactam resistance in Taiwan. Clonal complexes related to Spain(23F)-1, Taiwan(19F)-14, and Taiwan(23F)-15 were responsible for the spread of isolates with high beta-lactam resistance.

This study compares beta-lactam and vancomycin among intravenous drug users with infective endocarditis caused by methicillin-susceptible Staphylococcus aureus. Patients who received vancomycin had higher infection-related mortality, even if they were switched to beta-lactam once culture results became available; this relationship persisted after logistic regression analysis controlling for cli...

Linear regression analysis was used to compare penicillin MICs determined with 3,129 recent clinical isolates of Streptococcus pneumoniae to MICs obtained with nine other beta-lactam antimicrobial agents. A strong correlation between penicillin MICs and those obtained with other beta-lactams was demonstrated. It may be possible to test penicillin and use MICs obtained with penicillin to predict...

beta-Lactam-resistant mutants of Escherichia coli K-12 were selected by using 12 different beta-lactam derivatives. The mutants fell into three categories showing (i) altered permeation through reduction or loss of outer membrane porin proteins (including ompF, ompR, and envZ alleles); (ii) increase in the rate of synthesis of chromosomally mediated beta-lactamase; or (iii) defective synthesis ...

Linear regression analysis was used to compare penicillin MICs determined with 3,129 recent clinical isolates of Streptococcus pneumoniae to MICs obtained with nine other beta-lactam antimicrobial agents. A strong correlation between penicillin MICs and those obtained with other beta-lactams was demonstrated. It may be possible to test penicillin and use MICs obtained with penicillin to predict...

Both ampicillin and cefuroxime therapy of neonates selected drug- and species-dependent beta-lactam resistance patterns in fecal strains of Escherichia coli and Klebsiella spp. This was in contrast to our previous findings that ampicillin, but not cefuroxime, contributed to the emergence of beta-lactam resistance also by the promotion of nosocomial spread of resistant strains.