Antimicrobial resistance and serotype distribution of Streptococcus pneumoniae infections in Kaohsiung from 1996 through 1999.

ABSTRACT

A total of 89 isolates of Streptococcus pneumoniae were obtained from 86 patients during the period from November 1996 through September 1999 at the Kaohsiung Medical University Hospital. The purpose of this study was to determine the antimicrobial susceptibilities and the distribution of serotypes of these isolates, and to correlate these findings with the clinical characteristics of patients. Twenty-one (23.6%) isolates were obtained from patients aged below 5 years, and 38 (42.7%) from patients aged over 65 years. These 86 patients included 53 pneumonia, 13 bacteremia (including 6 with septic shock), 8 urinary tract infection, 8 soft tissue infections, 7 acute exacerbation of chronic bronchitis, 2 ophthalmic infection, and 2 cholecystitis cases. The most frequent serotypes were types 20 (10.1%), 6 (9%), 10 (9%), 11 (9%), and 23 (9%). All isolates were included in the serotypes represented in the 23-valent pneumococcal vaccine. Thirty-four (38.2%) isolates showed reduced penicillin susceptibility by the E-test. The predominant serotypes of penicillin-resistant S. pneumoniae were types 11 (17.6%), 7 (14.7%), 6 (8.8%), 8 (8.8%), and 23 (8.8%). All isolates were susceptible to vancomycin. Resistance rate to erythromycin was 49.4%, chloramphenicol, 20.2%; and trimethoprim/sulfamethoxazole, 61.8%. Multiple resistance (> or = 3 classes of antibiotics) was found in 28 (31.5%) isolates, of which the majority were serotypes 11 (14.3%), 7 (14.3%), 6 (10.7%), 8 (10.7%), and 23 (10.7%).