Urine Culture and Sensitivity

Urine is normally sterile. However, in the process of collecting the urine, some contamination from skin bacteria is frequent. For that reason, up to 10,000 colonies of bacteria/ml are considered normal. Greater than 100,000 colonies/ml represents urinary tract infection. For counts between 10,000 and 100,000, the culutre is indeterminate.

Sensitivity refers to the antibiotics tested to be effective in stopping the bacteria. While clinical response will generally follow therapy guided by sensisitivity testing, clinical response can be variable.

Normal Values*

Negative <10,000 colonies/ml
Indeterminate 10,000-100,000 colonies/ml
Positive >100,000 colonies/ml

*These are general values taken from a variety of sources. The actual normal values may vary from lab to lab and from one type of testing protocol to another.

Source: Operational Medicine 2001,  Health Care in Military Settings, NAVMED P-5139, May 1, 2001, Bureau of Medicine and Surgery, Department of the Navy, 2300 E Street NW, Washington, D.C., 20372-5300

OB-GYN 101: Introductory Obstetrics & Gynecology
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