Standardized methods and quality control limits for agar and broth microdilution susceptibility testing of Mycoplasma pneumoniae, Mycoplasma hominis, and Ureaplasma urealyticum.

An international multilaboratory collaborative study was conducted to develop standard media and consensus methods for the performance and quality control of antimicrobial susceptibility testing of Mycoplasma pneumoniae, Mycoplasma hominis, and Ureaplasma urealyticum using broth microdilution and agar dilution techniques. A reference strain from the American Type Culture Collection was designated for each species, which was to be used for quality control purposes. Repeat testing of replicate samples of each reference strain by participating laboratories utilizing both methods and different lots of media enabled a 3- to 4-dilution MIC range to be established for drugs in several different classes, including tetracyclines, macrolides, ketolides, lincosamides, and fluoroquinolones.

Differences in the DNA sequences in the upstream attenuator region of erm(A) in clinical isolates of Streptococcus pyogenes and their correlation with macrolide/lincosamide resistance.

The regulatory regions of 52 erm(A) [formerly erm(TR)] clinical Streptococcus pyogenes isolates were studied. Differences in the upstream regulatory region of erm(A) correlated with macrolide/lincosamide resistance patterns. Nine macrolide/lincosamide/streptogramin B-resistant isolates had changes in the leader sequence of erm(A) including base changes, insertions, or deletions.

Once daily clarithromycin extended-release vs twice-daily amoxicillin/clavulanate in patients with acute bacterial sinusitis: a randomized, investigator-blinded study.

Objective: To compare the efficacy and tolerability of clarithromycin extended-release (ER) to amoxicillin/ clavulanate in patients diagnosed with acute bacterial sinusitis.

Research Design And Methods: In a controlled, multicenter, investigator-blinded study, 437 ambulatory patients at least 12 years old with signs/symptoms and radiographic findings of acute sinusitis were randomized to receive clarithromycin ER 1000 mg once daily or amoxicillin/ clavulanate 875 mg/l25 mg twice daily for 14 days.

Main Outcome Measures: Clinical and bacteriological response rates were determined at a test-of-cure visit, which was conducted up to 10 days following the completion of treatment.

Comparison of emm typing and ribotyping with three restriction enzymes to characterize clinical isolates of Streptococcus pyogenes.

A total of 336 Streptococcus pyogenes isolates recently recovered from patients with pharyngitis from 13 countries were characterized by emm typing and riboprinting using an automated Riboprinter (Dupont/Qualicon) based on the patterns produced by three restriction enzymes, EcoRI, PstI, and HindIII. Three enzymes were necessary to increase the discrimination of ribogroups formed by each enzyme. A total of 40 ribogroups and 38 emm sequences (not counting allelic variations) were identified.