1994 Volume 42 Issue 10 Pages 1103-1113
The minimum inhibitory concentration (MIC) of ciprofloxacin (CPFX), ofloxacin (OFLX), cefpodoxime (CPDX), cefaclor (CCL), ampicillin (ABPC) and oxacillin (MPIPC) for a total of 9, 639 isolates from throat swabs and sputum of 13, 225 patients with respiratory tract infections, who visited 1, 165 primary care clinics in Japan in November and December 1992 and in February and March 1993 were determined. MIC was measured according to the broth microdilution method described by the Japan Society of Chemotherapy. The following results were obtained.
1. Group A Streptococcus spp. and Streptococcus pneumoniae were the most sensitive to ABPC and CPDX and Staphylococcus aureus and gram-negative rods were the most sensitive to new quinolones (NQs).
2. Isolates other than Streptococcus spp. had a low level of resistance (MIC≥1.56μg/ml) to NQs.
3. Nineteen of 684 S. aureus strains were methicillin-resistant S. aureus strains (2.8%)(MRSA: MIC of MPIPC≥6.25μg/ml).4. Penicillin-insensitive S. pneumoniae (MIC of ABPC≥0.1μg/ml) was isolated from 25.9%(37/143).
5. Penicillin-resistant Haemophilus influenzae (MIC of ABPC≥1.56 μ/ml) was isolated from 7.9%(19/240).
6. The incidence of MRSA in primary care clinics was only 2.8%(19/684), much lower than in intensive care units. On the other hand, the incidence of penicillin-insensitive S. pneumoniae in primary care clinics was similar to that in intensive care clinics and penicillin resistant S. pneumoniae strains have been increasing. Though the incidence of penicillinresistant H. influenzae in primary care clinics (7.9%) was a little lower than in intensive care units, it was suggested that, β-lactamase-producing H. influenzae were isolated also from primary care clinics.
