Antibiotic susceptibilities among recent clinical isolates of Haemophilus influenzae and Moraxella catarrhalis from fifteen countries

Between July 1998 and July 1999, 3,060 Haemophilus influenzae and 1,486 Mor axella catarrhalis strains were isolated in 31 centers in 15 countries in o rder to determine their antimicrobial susceptibilities and the presence of beta -lactamase production in Haemophilus influenzae. Overall 17.1% of the Haemophilus influenzae isolates were beta -lactamase positive, while more t han 95% were susceptible to amoxicillin/ clavulanate, cefaclor, loracarbef, cefuroxime, azithromycin and ciprofloxacin. Eleven (0.3%) isolates were be ta -lactamase positive and ampicillin resistant and 7 (0.2%) isolates were ciprofloxacin resistant. The minimum inhibitory concentrations for 90% of t he isolates tested were lowest for ciprofloxacin (0.03) and highest for cef prozil (8) against Moraxella catarrhalis.