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Fluoroquinolone resistance in penicillin-resistant Streptococcus pneumoniae clones, Spain

Adela G de la Campa1, Luz Balsalobre, Carmen Ardanuy

  • 1Unidad de Genética Bacteriana, Centro Nacional de Microbiología, Instituto de Salud Carlos III, 28220 Majadahonda, Madrid, Spain. agcampa@isciii.es

Emerging Infectious Diseases
|October 27, 2004
PubMed

Insights

Ciprofloxacin resistance in Streptococcus pneumoniae is a growing concern, particularly in older adults and with co-resistance to other antibiotics. Surveillance is crucial to monitor and prevent the spread of resistant bacterial clones.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Genetics

Background:

  • Streptococcus pneumoniae is a significant human pathogen.
  • Antibiotic resistance, including to fluoroquinolones like ciprofloxacin, is an increasing global health threat.
  • Understanding the mechanisms and epidemiology of resistance is vital for effective treatment strategies.

Purpose of the Study:

  • To investigate the prevalence and characteristics of ciprofloxacin-resistant Streptococcus pneumoniae strains in Spain.
  • To identify genetic mechanisms and epidemiological factors associated with ciprofloxacin resistance.
  • To assess the role of specific bacterial clones in the dissemination of resistance.

Main Methods:

  • Analysis of 2,882 Streptococcus pneumoniae isolates collected in 2002.
  • Determination of ciprofloxacin minimum inhibitory concentrations (MICs).
  • Molecular characterization including gyrA, parC, and parE gene sequencing, pulsed-field gel electrophoresis (PFGE), and assessment of efflux phenotypes.
  • Correlation of resistance with patient demographics and isolation site.

Main Results:

  • 75 (2.6%) of isolates were ciprofloxacin-resistant.
  • Resistance was more common in older patients (> or =65 years) and isolates from noninvasive sites.
  • Low-level resistance was associated with single ParC mutations, while high-level resistance involved multiple mutations in gyrA, parC, and parE.
  • Resistance mechanisms included point mutations and recombination with viridans streptococci.
  • Five international multiresistant clones accounted for 46.7% of resistant strains.

Conclusions:

  • Ciprofloxacin resistance in Streptococcus pneumoniae is present in Spain, associated with specific patient groups and genetic alterations.
  • Multidrug-resistant clones play a significant role in the epidemiology of resistance.
  • Continuous surveillance is essential to control the spread of resistant strains and guide antimicrobial therapy.

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