Resistance surveillance of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis isolated in the United States, 1997–1998

Abstract

A multicentre, collaborative study was performed in Asia and Europe during the winter of 1997-1998 to determine the in vitro activity of selected antimicrobial agents against common respiratory pathogens. Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis isolates were collected from 48 sites in China, France, Germany, Italy, Japan, Spain and the UK and tested in a central laboratory in the USA. Broth microdilution MICs were determined for beta-lactams (penicillin, amoxycillin/clavulanate, cefuroxime, ceftriaxone), macrolides (azithromycin, clarithromycin), sulphonamides (co-trimoxazole), glycopeptides (vancomycin) and fluoroquinolones (levofloxacin). The percentage of isolates susceptible to each antimicrobial class varied substantially by country. Penicillin susceptibility amongst pneumococci ranged from 34% in France and Spain to 92% in Germany, and macrolide susceptibility varied between 26% in China and 91% in the UK. In most countries beta-lactam, macrolide and cotrimoxazole resistance was more prevalent amongst penicillin-intermediate and -resistant S. pneumoniae isolates. However, little or no resistance was detected to levofloxacin (0.3% intermediate and resistant) or vancomycin (0% intermediate and resistant). For H. influenzae the prevalence of beta-lactamase production varied from 6% in China and Germany to 32% in Spain, and for M. catarrhalis, from 79% in Germany to 98% in Japan. With the exception of ampicillin, beta-lactamase production had a minimal effect on beta-lactam activity against H. influenzae or M. catarrhalis. Our findings demonstrate that antimicrobial resistance profiles of common respiratory isolates differ dramatically between countries in Asia and Europe.