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Characterisation of fluoroquinolone non-susceptible clinical isolates of Streptococcus pneumoniae in Germany: 1992–2005

Abstract number: 1733_492

Al-Lahham A., van der Linden M., Heeg C., Seegmueller I., Reinert R.

Objectives:S. pneumoniae belongs to the main human infectious agents worldwide. In several nationwide studies on resistance development in pneumococcal disease fluoroquinolone resistant pneumococcal isolates were collected and charachterised.

Methods: Strains were serotyped using Neufeld's Quellungreaction and MICs of penicillin G (PEN), cefotaxime (CEF), amoxicillen (AMOX), erythromycin A (ERY), clindamycin (CLI), tetracycline (TET), ciprofloxacin (CIP), levofloxacin (LEV), sparfloxacin (SPA), grepafloxacin (GRE), clinafloxacin (CLX), moxifloxacin (MOX), gatifloxacin (GAT) and gemifloxacin (GEM) were determined using the microdilution method according to the CLSI guidelines. Fluoroquinolone resistant genotypes were checked using PCR followed by DNA-sequencing of gyrA, gyrB, parC and parE according to standard methods. MLST was performed according to standard methods.

Results: Between Jan. 1992 and Dec. 2005, 13.230 isolates from 315 laboratories were included in this study. A total of 42 fluoroquinolone resistant strains (MIC CIP >2 mg/mL) were identified (0.2–1.2%). The predominant serotypes were 6A (14.3%), 6B (11.9%) and 9V, 23F and 11A (7.1% each). MIC50 and MIC90 for 17 different antibiotics were as follows (mg/mL): Penicillin (0.016, 1), cefotaxime (0.016, 1), amoxicillin (0.016, 0.5), erythromycin (0.125, 32), clindamycin (0.125, 32), tetracycline (0.5, 32), chloramphenicole (<4, <4), telithromycin (0.016, 0.016), quinupristin-dalfopristin (1, 1), ciprofloxacin (16, >32), levofloxacin (4, 32), sparfloxacin (4, 32), grepafloxacin (1, 32), clinafloxacin (0.25, 0.5), moxifloxacin (0.25, 4), gatifloxacin (1, 4) and gemifloxacin (0.125, 2). Predominant mutations were S81F (11.9%) and S114G (11.9%) for gyr(A), S79F (33.3%) and S79Y (23.8%) for par(C) and I460V (47.8%) for par(E). One isolate possesses a combination of both gyr(A) (E85G) and gyr(B) (R571T) mutations. A fourfold reduction of the ciprofloxacin MIC in the presence of reserpine was only observed in 14 isolates. In multi locus sequence typing, 4 clones were observed for the first time in Germany ST1551, ST1983, ST2007, and ST2008.

Conclusions: The overall incidence of fluoroquinolone resistance in Germany remains low, nevertheless the spread of FQ resistance to multi-drug resistant clones with worldwide distribution is worrisome. A clonal relatedness of strains could not be affirmed using MLST.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Subject:
Location: ICC, Munich, Germany
Presentation type:
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