Antimicrobial susceptibility of community-acquired lower respiratory tract bacterial pathogens isolated in the UK during the 1995-1996 cold season.

The antimicrobial susceptibility of 1078 isolates of Haemophilus influenzae, 348 Streptococcus pneumoniae and 258 Moraxella catarrhalis was determined. Overall 15.1% of H. influenzae produced beta-lactamase; 98.8% were susceptible to co-amoxiclav, 85.8% to cefaclor, 96% to clarithromycin and 100% to ciprofloxacin. The majority (94.2%) of M. catarrhalis produced beta-lactamase. The overall prevalence of low-level penicillin resistance (MIC = 0.12-1 mg/L) amongst isolates of S. pneumoniae was 3.4% and that of high-level resistance (MIC > or = 2 mg/L) was 3.7%. Most (96.3%) of the isolates of S. pneumoniae were susceptible to amoxycillin (MIC < or = 0.5 mg/L), 96% to cefaclor (MIC < or = 8 mg/L), 90.7% to clarithromycin (MIC < or = 0.25 mg/L) and 89% to ciprofloxacin (MIC < or = 1 mg/L).