title: [Susceptibility of vertically transmitted Group B streptococci to antimicrobial agents. Multicenter study].
abstract: BACKGROUND
  To investigate the susceptibility of group B streptococci (GBS) to macrolides and lincosamides and assess alternatives for intrapartum chemoprophylaxis in women allergic to penicillin and colonized by a GBS strain resistant to these antibiotics.
  
  
  METHODS
  Multicenter study performed with 131 strains isolated between 1997-2002 from newborns diagnosed with early-onset GBS disease and 479 strains collected in 2002 from the vagina or rectum of pregnant women.
  
  
  RESULTS
  All the GBS (100%) were susceptible to penicillin, ampicillin, vancomycin, quinupristin/dalfopristin, levofloxacin and teicoplanin. Resistance rates were as follows: 12.45% to erythromycin and azithromycin, 11.80% to clindamycin, 11.31%, to josamycin, 1.80% to telithromycin and 0.32% to fosfomycin. Seventy-nine strains had a constitutive MLSB phenotype of resistance, 4 an inducible MLSB phenotype, 3 an M phenotype and 3 were resistant to clindamycin but susceptible to macrolides. The MIC for erythromycin and azithromycin was > 32 mg/L in more than 85% of GBS strains with a constitutive MLSB phenotype, from 0.5 to 4 mg/L in those with an inducible MLSB, and 4 mg/L in those with phenotype M. Fifty-one telithromycin-sensitive strains (all with a constitutive MLSB phenotype) showed induced resistance to telithromycin when erythromycin was present. No significant differences in antimicrobial resistance were found between GBS strains producing invasive neonatal disease and maternal isolates, or among strains from different geographic areas.
  
  
  CONCLUSIONS
  The high rate of resistance to macrolides and lincosamides in our area makes susceptibility testing mandatory for GBS strains isolated from pregnant women allergic to penicillin.
authors.affiliation: Servicio de Microbiología, Hospital Vall d'Hebron, Barcelona, Spain.
authors.forename: Juan José
authors.initials: JJ
authors.lastname: González
authors.forename: Antonia
authors.initials: A
authors.lastname: Andreu
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000145:classification / Q000494:pharmacology / Q000627:therapeutic use; D001769:Blood / Q000382:microbiology; D002555:Cerebrospinal Fluid / Q000382:microbiology; D004351:Drug Resistance; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D055231:Lincosamides; D018942:Macrolides / Q000494:pharmacology / Q000627:therapeutic use; D008826:Microbial Sensitivity Tests; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology / Q000382:microbiology; D018805:Sepsis / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D013030:Spain / Q000453:epidemiology; D013290:Streptococcal Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission; D013292:Streptococcus agalactiae / Q000187:drug effects* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D055231:Lincosamides; D018942:Macrolides