Fluoroquinolone Resistance in Penicillin-resistantStreptococcus pneumoniaeClones, Spain

Adela G De La Campa,Josefina Liñares,Carmen Ardanuy,Emilio Pérez-Trallero,Luz Balsalobre,Asunción Fenoll

doi:10.3201/eid1010.040382

Abstract

Among 2,882 Streptococcus pneumoniae sent to the Spanish Reference Laboratory during 2002, 75 (2.6%) were ciprofloxacin-resistant. Resistance was associated with older patients (3.9% in adults and 7.2% in patients > or =65 years of age), with isolation from noninvasive sites (4.3% vs. 1.0%), and with penicillin and macrolide resistance. Among 14 low-level resistant (MIC 4-8 microg/mL) strains, 1 had a fluoroquinolone efflux phenotype, and 13 showed single ParC changes. The 61 high-level ciprofloxacin-resistant (MIC > or =16 microg/mL) strains showed either two or three changes at ParC, ParE, and GyrA. Resistance was acquired either by point mutation (70 strains) or by recombination with viridans streptococci (4 strains) at the topoisomerase II genes. Although 36 pulsed-field gel electrophoresis patterns were observed, 5 international multiresistant clones (Spain23F-1, Spain6B-2, Spain9V-3, Spain14-5 and Sweden15A-25) accounted for 35 (46.7%) of the ciprofloxacin-resistant strains. Continuous surveillance is needed to prevent the dissemination of these clones.

Highlights

Among 2,882 Streptococcus pneumoniae sent to the Spanish Reference Laboratory during 2002, 75 (2.6%) were ciprofloxacin-resistant
Bacterial Strains, Serotyping, and Susceptibility Tests We studied 2,882 S. pneumoniae strains submitted from 78 hospitals nationwide to the Spanish Reference Laboratory during 2002
Among the 75 ciprofloxacin-resistant strains, 67% were isolated from sputum, whereas 19% were from blood, 13% from lower respiratory tract samples, and 1.3% from pus

Summary

Introduction

Among 2,882 Streptococcus pneumoniae sent to the Spanish Reference Laboratory during 2002, 75 (2.6%) were ciprofloxacin-resistant. Resistance of Streptococcus pneumoniae to multiple antibacterial agents, including β-lactams, macrolides, tetracyclines, and co-trimoxazole, has emerged worldwide in the 1980s and 1990s [1,2,3] and has emphasized the need for new therapeutic alternatives, such as newer fluoroquinolones. Older fluoroquinolones, such as ciprofloxacin and ofloxacin, have been widely used in the last 2 decades, but their activity against gram-positive pathogens is limited. The emergence of fluoroquinolone-resistant S. pneumoniae strains, worldwide prevalence is low, is a concern to clinicians who manage respiratory tract infections. RESEARCH showed ciprofloxacin-resistant pneumococci emerging in a patient who had received long-term ciprofloxacin therapy to treat persistent bronchiectasis with Pseudomonas aeruginosa infection [14]

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