Abstract
We determined the MICs of ampicillin, methicillin, cefaclor, cefixime, cefteram, ofloxacin and ciprofloxacin against a total of 1, 448 strains from 11 species: 464 strains of Staphylococcus aureus, 306 strains of Streptococcus pneumoniae, 114 strains of Streptococcus pyogenes, 37 strains of Branhamella catarrhalis, 329 strains of Haemophilus influenzae, 32 strains of Escherichia coli, 66 strains of Klebsiella pneumoniae, 26 strains of Enterobacter cloacae, 20 strains of Serratia marcescens, 12 strains of Pseudomonas aeruginosa and 42 strains of Acinetobacter calcoaceticus, isolated from the throat swab and the sputum of 2, 539 patients with respiratory infections who visited 21 private clinics in Tohoku ditrict of Japan during the period from January to April in 1989. Ciprofloxacin and ofloxacin were more active against S. aurues, B. catarrhalis, P. aeruginosa and A. calcoaceticus than other antibiotics. Ampicillin and cefteram were more active against S. pneumoniae and S. pyogenes than other antibiotics. New-quinolones and cephems of new-generation were active against H. influenzae, E. coli, K pneumoniae, E. cloacae and S. marcescens. Of 30 strains of S. aureus which were resistant (MIC≥12.5μg/ml) to ampicillin, only one strain was resistant (MIC≥12.5μg/ml) to methicllin. Twenty strains (6.5%) of S. pneumoniae and 49 strains (14.9%) of H. influenzae were resistant (MIC≥1.56 μg/ml) to ampicillin. Of 101 strains of H. influenzae of which their β-lactamase activity was determined by Nitrocephin-method, 27 (26.7%) were β-lactamase-positive strains. The above results indicated that MRSA is only rarely found in primary care clinics but the incidence of amplicillinresistant H. influenzae in primary care clinics is almost the same as that of the intensive care clinic, i. e. medical school-affiliated hospitals. Therefore caution should be exercised as regards antibiotic resistance of the causative organism even in primary care clinics.
