Enhanced invasiveness of bovine-derived neonatal sequence type 17 group B streptococcus is independent of capsular serotype.

Journal article

BACKGROUND: A defined geographical area (Oxford, United Kingdom) was investigated for the role of group B Streptococcus (GBS) as a human pathogen. METHODS: GBS carriage in pregnant women and invasive disease in neonates and adults >60 years of age was studied over a 3-year period. Multilocus sequence typing and capsular serotyping were used to study 369 isolates of GBS from carriage in pregnant women (n=190) and invasive disease in neonates (n=109) and adults >60 years of age (n=70). RESULTS: A total of 20.3% of pregnant women carried GBS. Invasive GBS disease occurred at a rate of 0.9 cases per 1000 live births and 11 cases per 100,000 population >60 years of age per annum. Four sequence types (STs) (ST-17, ST-19, ST-23, and ST-1) that were identified with use of multilocus sequence typing accounted for >50% of carried and invasive strains. A single sequence type (ST-17), previously shown to be phylogenetically of bovine origin, was significantly associated with increased invasiveness in neonates (P=.00002), and this was independent of capsular serotype III. In contrast, among adults >60 years of age, no STs exhibited increased invasiveness, compared with STs carried in pregnant women. CONCLUSIONS: Enhanced invasiveness associated with ST-17 is specific to neonates and is independent of capsular serotype.

Authors: Jones, N; Oliver, K; Barry, J; Harding, R; Bisharat, N

• Publication status: Published
• Journal: Clinical infectious diseases : an official publication of the Infectious Diseases Society of America
• Volume: 42
• Issue: 7
• Pages: 915-924
• Publication date: 2006-04-01
• DOI: 10.1086/500324
• EISSN: 1537-6591
• ISSN: 1058-4838
• Language: English
• Keywords: Streptococcal Infections; Middle Aged; Aged; Humans; Adult; Bacterial Capsules; Streptococcus agalactiae; Male; Vagina; Female; Infant, Newborn; Carrier State; Pregnancy; Serotyping; Oxford Group B Streptococcus Consortium; Animals; Cattle