In Vitro Susceptibilities of 180 Clinical Isolates of Haemophilus Influenzae to Ampicillin, Amoxycillin/Clavulanate, Cefaclor, Cefuroxime, Cefotaxime, Clarithromycin, and Azithromycin

Summary

One hundred eighty consecutive, unduplicate isolates of Haemophilus influenzae from clinical specimens collected from November 1994 through February 1995 in nine general hospitals throughout Belgium were examined for p-lactamase production using a nitrocefin-based test, and for their in vitro susceptibilities to ampicillin, amoxycillin/clavulanate, cefaclor, cefuroxime, cefotaxime, clarithromycin and azithromycin by means of the NCCLS agar dilution test. The isolates were all from respiratory tract specimens. The prevalence of capsular type b was 1.1 %, and the overall rate of p-lactamase production 16.7%. Rates of P-lactamase production were higher in isolates from children (22.0%) than in those from adults (15.3%), and in isolates from upper respiratory tract specimens (22.0%) than in those from the lower resj Piratory tract (15.1%). Beta-lactamase-negative ampicillin resistance amounted to 1.1%. Cefotaxime had the highest activity on a weight basis [MIC (minimal