Cefotaxime breakpoint for Streptococcus pneumoniae

Very low cefotaxime concentrations select for hypermutable Streptococcus pneumoniae populations.

A mixed culture of an hypermutable hexA Streptococcus pneumoniae mutant strain and its hexA(+) isogenic ancestor was challenged with low cefotaxime concentrations. Despite identical original cefotaxime MICs, the hexA mutant population was significantly selected at very low concentrations, and all of the tested selected variants harbored the Thr550-->Ala mutation in pbp2x. Since cefotaxime selec...

Genomic analysis and reconstruction of cefotaxime resistance in Streptococcus pneumoniae.

OBJECTIVES To identify non-penicillin-binding protein (PBP) mutations contributing to resistance to the third-generation cephalosporin cefotaxime in Streptococcus pneumoniae at the genome-wide scale. METHODS The genomes of two in vitro S. pneumoniae cefotaxime-resistant isolates and of two transformants serially transformed with the genomic DNA of cefotaxime-resistant mutants were determined ...

Bactericidal activities of ceftizoxime and cefotaxime against Streptococcus pneumoniae.

Patel et al. (4) compared the serum bactericidal titers (SBTs) and the time serum drug concentrations remained above the MICs (T . MIC) of ceftizoxime and cefotaxime against three intermediately penicillin-resistant Streptococcus pneumoniae isolates. MICs were # 1.0 mg/ml, SBTs were . 1:2, and T . MIC exceeded 50% of dosage intervals. They concluded that ceftizoxime’s longer T . MIC compensates...

Importance of using current NCCLS breakpoints to interpret cefotaxime and ceftriaxone MICs for Streptococcus pneumoniae.

Efficacy of multiplex PCR procedure for Iranian Streptococcus pneumoniae isolates

Background: Identifying regional types and evaluating the frequency of pneumococcal strains has become increasingly important especially in vaccination. The purpose of this study was the identification and frequency determination of our regional serotype and evaluation of the performance of recent type specific multiplex PCR for the diagnosis of streptococcus pneumonia serotypes. Methods: All ...