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Identification: Normal Flora/Contaminants

  • Even if the sampling procedure has been carried out meticulously, urine samples will often contain normal flora that will grow in the large section of the test.
  • The content of normal flora in urine samples is variable.
  • Normal flora consists primarily of coagulase-negative staphylococci (CNS) . The normal flora will grow into small white colonies.

Photo 1. Staphylococcus sp.= Normal flora. Small white colonies present in the large section only : No bacterial UTI

Photo 2. Small white colonies present as  background of large section only.  A few red colonies are also present (= contaminants): No bacterial UTI

Photo 3. Small white colonies present as  background in the large section. A few red and blue colonies are  also present (=contaminants): No bacterial UTI