25 years old female non pregnant with group b strep positive?

Pretty common: GBS is a common germ in the digestive tract of humans. Women occasionally have it in their genital tract because of the near location of the anus & the mucus vaginal secretions that are favorable to the germs growth. It will occasionally cause a urinary tract infection in women. Since surveillance is important during pregnancy we know it is transiently found in ~1/3 women. It's no big deal.