title: [Streptococcus agalactiae increase in resistance to erythromycin and clindamycin in vaginal-anal colonization in third quarter of pregnancy in one decade of universal screening].
abstract: BACKGROUND
  Streptococcus agalactiae (GBS) is the main causative agent of early perinatal sepsis. The acquisition of prevention policies has led to frequent use of intrapartum antibiotics. Surveillance of antimicrobial resistance is indispensable for defining drugs of choice and alternatives for such prophylaxis.
  
  
  OBJECTIVE
  To determine the evolution of antimicrobial resistance of GBS from maternal colonization to drugs used in the prevention of neonatal sepsis, between 2002 and 2008.
  
  
  METHODS
  We studied 100 GBS positive vaginal and anal samples from pregnant women. Disc diffussion susceptibility method was performed for penicillin, ampicillin, cefazolin, erythromycin and clindamycin according to the Clinical and Laboratory Standards Institute (CLSI).
  
  
  RESULTS
  We analyzed the susceptibility of 99 strains. Seventeen were resistant to erythromycin (17.1%) and 13 were resistant to clindamycin (13.1%). Thirteen of the 17 strains resistant to erythromycin had the MLS phenotype (resistance to erythromycin and clindamycin) and 4 had the M phenotype (resistance to erythromycin only). Within the MLS phenotype, resistance was constitutive in 9 strains, and induced in 4 strains (positive D test). Compared with 2002 there was a significant increase in resistance to clindamycin (from 3.27% to 13.1% p < 0.002) and erythromycin (1.09% to 17% p < 0.001). 100% GSB remained sensitive to penicillin and ampicillin.
  
  
  CONCLUSIONS
  GBS remains highly susceptible to drugs of choice for prevention of perinatal sepsis. There is a significant increase in antimicrobial resistance to clindamycin and erythromycin. Therefore, it is necessary to request susceptibility testing in GBS from third trimester of pregnancy screening in patients allergic to penicillin.
authors: Facultad de Medicina, División de Ginecología y Obstetrícia, Pontificia Universidad Católica de Chile, Santiago, Chile. fabarzua@med.puc.cl
authors: Fernando
authors: F
authors: Abarzúa
authors: Alejandra
authors: A
authors: Arias
authors: Patricia
authors: P
authors: García
authors: Constanza
authors: C
authors: Ralph
authors: Jaime
authors: J
authors: Cerda
authors: Ingrid
authors: I
authors: Riedel
authors: Cynthia
authors: C
authors: Gárate
mesh_terms: D001003:Anal Canal / Q000382:microbiology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002981:Clindamycin / Q000494:pharmacology*; D052978:Disk Diffusion Antimicrobial Tests; D024881:Drug Resistance, Bacterial; D004917:Erythromycin / Q000494:pharmacology*; D005260:Female; D006801:Humans; D010641:Phenotype; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000175:diagnosis / Q000382:microbiology*; D011263:Pregnancy Trimester, Third; D011296:Prenatal Diagnosis; D018805:Sepsis / Q000151:congenital / Q000382:microbiology / Q000517:prevention & control; D013290:Streptococcal Infections / Q000175:diagnosis / Q000382:microbiology* / Q000517:prevention & control; D013292:Streptococcus agalactiae / Q000187:drug effects* / Q000302:isolation & purification; D014621:Vagina / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D002981:Clindamycin; D004917:Erythromycin