title: [Occurrence of the hypervirulent ST-17 clone of Streptococcus agalactiae in pregnant women and newborns].
abstract: OBJECTIVES. The ST-17 clone of Streptococcus agalactiae (Group B Streptococcus, GBS) identified by Multi Locus Sequence Typing (MLST) is recognized as a hypervirulent international clone mainly associated with invasive neonatal infections. There is no data on the occurrence of the ST-17 clone of GBS in pregnant women and newborns in Poland.
  
  
  METHODS
  169 strains of GBS, isolated from pregnant women's carriage, and 42 from newborns with invasive infection or asymptotic carriage, which were derived from the collection of the Chair of Microbiology Jagiellonian University Medical College, collected between 2006-2010, were genetically characterized. The PCR with specific primers ST17S and ST17AS was adopted to characterize the gbs2018 gene variant specific to ST-17 clone. All positive results in direction of ST-17 were confirmed by MLST. The genetic relatedness of the ST-17 clone was determined by PFGE.
  
  
  RESULTS
  The hypervirulent ST-17 clone was detected in 2.4% of women with GBS asymptotic carriage, whereas it was detected in 18.2% newborns with invasive infection. No ST-17 was isolated from healthy neonates. Statistically significant correlation between the presence of ST-17 and neonatal GBS infection was showed, in comparison to healthy neonates colonized by GBS (p = 0.0398) and to GBS-positive pregnant women (p <0.00001). The ST-17 strains belonged to 2 clearly distinguishable PFGE type, but were closely related to one another at a level of 60% similarity. CONCLUSIONS. The results emphasize the necessity of a regular study of the ST-17 GBS clone occurrence among pregnant women and newborns in Poland.
authors.affiliation: Zakład Bakteriologii, Epidemiologii Drobnoustrojów i Parazytologii Uniwersytetu Jagiellońskiego Collegium Medicum, Kraków, Polska. mbrzych@cm-uj.krakow.pl
authors.forename: Monika
authors.initials: M
authors.lastname: Brzychczy-Włoch
authors.forename: Tomasz
authors.initials: T
authors.lastname: Gosiewski
authors.forename: Dorota
authors.initials: D
authors.lastname: Pawlik
authors.forename: Anna
authors.initials: A
authors.lastname: Szumała-Kakol
authors.forename: Alfred
authors.initials: A
authors.lastname: Samead
authors.forename: Piotr B
authors.initials: PB
authors.lastname: Heczko
mesh_terms: D000328:Adult; D001483:Base Sequence; D002353:Carrier State / Q000382:microbiology*; D005260:Female; D014644:Genetic Variation; D006801:Humans; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000382:microbiology*; D008969:Molecular Sequence Data; D011247:Pregnancy; D012703:Serotyping; D013045:Species Specificity; D013290:Streptococcal Infections / Q000382:microbiology*; D013292:Streptococcus agalactiae / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D014774:Virulence