KARLOWSKY JA, ZHANEL GG, HOBAN DJ; Interscience Conference on Antimicrobial Agents and Chemotherapy.

Abstr Intersci Conf Antimicrob Agents Chemother Intersci Conf Antimicrob Agents Chemother. 1999 Sep 26-29; 39: 110 (abstract no. 822).

Univ. of Manitoba and Health Sci. Ctr., Winnipeg, Manitoba, CANADA.

BACKGROUND: Penicillin-resistant and multiply-antibiotic-resistant clinical isolates of S. pneumoniae have recently emerged as a significant problem in North America and worldwide. Prior to the introduction of grepafloxacin (GREPA), levofloxacin (LEVO) and trovafloxacin (TROVA), quinolones (ciprofloxacin [CIPRO], ofloxacin) were generally not recommended for the treatment of S. pneumoniae infections. Given their recent introduction into clinical use, the purpose of the present study was to determine the prevalence of resistance to the new respiratory quinolones and CIPRO among 1998-1999 clinical isolates of S. pneumoniae collected from across Canada.METHODS: Antibiotic susceptibilities to quinolones and comparative agents were determined using the NCCLS (M7-A4, 1997) microbroth dilution method. All quinolone-resistant MICs were confirmed by repeat microbroth dilution testing, disk diffusion testing, and E-test. Ciprofloxacin resistance was defined as a MIC >/= 4 microg/ml.RESULTS: Seven isolates (7/ 1179, 0.6%) of S. pneumoniae resistant to CIPRO (range, 4->32microg/ml) were identified in 1998. In 1999, to date, 8 (8/645, 1.2%) isolates of S. pneumoniae have been identified and confirmed as CIPRO resistant (range, 4->32microg/ml). The MIC[90]s of GREPA, LEVO and TROVA against the 15 isolates of CIPRO-resistant S. pneumoniae were 4 (range, 0.25-8microg/ml), 8 (range, 2-8microg/ml) and 8 (range, 0.25-16microg/ml), respectively. Isolates with CIPRO MICs >/= 32 microg/ml were uniformly resistant to GREPA, LEVO and TROVA. Four of the 15 isolates demonstrated intermediate-level resistance to penicillin, 2/15 were resistant to cefuroxime, 2/15 were resistant to erythromycin, while 8/15 demonstrated intermediate- or high-level resistance to trimethoprim/sulfamethoxazole.CONCLUSIONS: In conclusion, the rate of isolation of CIPRO-resistant S. pneumoniae from 18 Canadian centres participating in a 1998-1999 surveillance study was 0.6-1.2%. S. pneumoniae isolates with CIPRO MICs >/= 32 microg/ml were uniformly resistant to GREPA, LEVO and TROVA.

Publication Types:

• Meeting Abstracts

Keywords:

• Anti-Bacterial Agents
• Canada
• Ciprofloxacin
• Erythromycin
• Fluoroquinolones
• Microbial Sensitivity Tests
• Naphthyridines
• North America
• Ofloxacin
• Penicillins
• Quinolones
• Streptococcus pneumoniae
• grepafloxacin
• trovafloxacin

Other ID:

• GWAIDS0007427

UI: 102244923

From Meeting Abstracts