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A Murine Model of Group B Streptococcus Vaginal Colonization
10:19

A Murine Model of Group B Streptococcus Vaginal Colonization

Published on: November 16, 2016

Frequency of antimicrobial resistance among invasive and colonizing Group B streptococcal isolates

Stephanie M Borchardt1, Joan H DeBusscher, Patricia A Tallman

  • 1Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan, USA. sborchar@idph.state.il.us

BMC Infectious Diseases
|March 22, 2006
PubMed
Abstract

Insights

Group B Streptococcus (GBS) resistance to clindamycin and erythromycin is high in both invasive and colonizing strains, especially in college students. This increasing antimicrobial resistance impacts GBS treatment and prophylaxis for penicillin-intolerant individuals.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Antimicrobial Resistance

Background:

  • Group B Streptococcus (GBS) remains susceptible to penicillin.
  • However, resistance to clindamycin and erythromycin has increased since 1996.
  • This study examines age-specific antibiotic susceptibility and capsular type distribution in GBS.

Purpose of the Study:

  • To determine the antibiotic susceptibility profiles of invasive and colonizing Group B Streptococcus (GBS) strains.
  • To analyze the distribution of capsular types among these GBS isolates.
  • To assess age-specific resistance patterns to clindamycin and erythromycin.

Main Methods:

  • Tested 486 invasive GBS isolates (Wisconsin, 1998-2002) and 167 colonizing strains (Michigan, 2001).
  • Performed antimicrobial susceptibility testing using disk diffusion or Etest.
  • Conducted capsular typing via DNA dot blot hybridization.

Main Results:

  • High resistance rates observed: 20.0% invasive and 40.7% colonizing isolates resistant to clindamycin; 24.5% invasive and 41.9% colonizing isolates resistant to erythromycin.
  • Colonizing isolates showed significantly higher resistance to both clindamycin and erythromycin compared to invasive isolates.
  • Invasive isolates from persons aged 18-49 years exhibited the highest proportion of clindamycin and erythromycin resistance. Capsular type Ia predominated in infants, while type V was common in adults.

Conclusions:

  • Clindamycin and erythromycin resistance rates are notably high in both colonizing and invasive GBS isolates.
  • Age-specific resistance patterns indicate a higher prevalence among adults aged 18-49 years.
  • Rising antimicrobial resistance poses challenges for GBS disease management and intrapartum prophylaxis in penicillin-allergic patients.

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