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Table 1 Number of group B streptococcal isolates (n = 529) screened via dot blot hybridization and characteristics of each collection*.

From: The frequency of genes encoding three putative group B streptococcal virulence factors among invasive and colonizing isolates

GBS Collection Isolation source Culture date Age range Race/ethnicity Number of strains
1a. Sexually active college women with UTI receiving care from a Student Health Services at the University of Michigan (UM) [22]. urine, anal orifice, vaginal Sept. 1996 to April 1999 18–30 White (76%), Non-White (24%) Colonizing (n = 102), Invasive† (n = 2)
1b. Most recent male sex partner of women with UTI receiving care from the Student Health Services at UM [22]. urine, anal orifice Sept. 1996 to April 1999 18–35 White (71%), Non-White (29%) Colonizing (n = 43), Invasive† (n = 0)
2a. Sexually active college women without UTI presenting to the Student Health Services at UM [22]. urine, anal orifice, vaginal Sept. 1996 to April 1999 18–28 White (80%), Non-White (20%) Colonizing (n = 57), Invasive† (n = 0)
2b. Most recent male sex partner of women without UTI presenting to the Student Health Services at UM [22]. urine, anal orifice Sept. 1996 to April 1999 19–33 White (73%), Non-White (27%) Colonizing (n = 35), Invasive† (n = 0)
3. Newborns with early onset disease from hospitals affiliated with Baylor College of Medicine [19]. blood, CSF 1993 to 2000 < 7 days Hispanic (56%), African American (24%), Caucasian (16%), Asian (4%) Colonizing (n = 0), Invasive† (n = 100)
4a. Random sample of college aged women from the UM community [21] urine, anal orifice, vaginal Sept. to Nov. 1998 17–49 Caucasian (65%), Asian (16%), African American (10%), Hispanic (5%), Other (5%) Colonizing (n = 29), Invasive† (n = 1)
4b. Random sample of college aged men from the UM community [21] urine, anal orifice Sept. to Nov. 1998 19–45 Caucasian (60%), Asian (28%), African American (4%), Hispanic (3%), Other (4%) Colonizing (n = 23), Invasive† (n = 1)
5. Pregnant women presenting at the UM Medical Center for prenatal care [34]. urine, rectal, vaginal, placental Aug. 1999 to Mar. 2000 16–42 Caucasian (67%), African American (18%), Other (7%), Unknown (9%) Colonizing (n = 49), Invasive† (n = 53), Unknown (n = 29)
  1. * Seventeen individuals (7 from collection 1a, 4 from collection 2a, 3 from collection 2b, and 3 from collection 4b) were colonized with two genetically distinct strains, as determined by pulsed-field gel electrophoresis.
  2. †Invasive isolates originated from the blood or cerebrospinal fluid of newborns <7 days of age, the urine of adults at ≥100,000 cfu/ml, pregnant women presenting for prenatal care associated with GBS isolation from the urine, and the placenta following delivery. Colonizing GBS were from the anal orifice, lower vagina, cervix or urine of healthy individuals, and sexually active college women with a urinary tract infection not caused by GBS.