The human body naturally hosts vast communities of microorganisms, collectively known as flora, on various surfaces like the skin, gut, and genital areas. These microbes coexist harmlessly, often offering protective benefits against harmful invaders. Genital flora refers to the specific collection of microorganisms residing on and around the external reproductive organs. When detected in a urine sample, their presence can sometimes lead to confusion. This article clarifies what genital flora is and what its detection in a urine sample may indicate.
What is Genital Flora
Genital flora is the natural population of microorganisms, primarily bacteria and some fungi, that live on the external genital areas of both males and females. This microbial community helps maintain the health of these regions. For instance, in females, Lactobacillus species are common inhabitants of the vaginal area, producing lactic acid that helps maintain an acidic environment. This acidity discourages the growth of many harmful bacteria and yeasts.
The skin of both male and female external genitalia harbors Staphylococcus species and other bacteria. These organisms are normal residents of the skin and mucous membranes, contributing to the body’s natural defense mechanisms. Their presence is a sign of a healthy, balanced microbial ecosystem rather than an infection.
Genital Flora in Urine Samples
Urine, as it forms within the kidneys and bladder, is considered sterile, containing no microorganisms or only very low numbers. However, as urine exits the body during urination, it passes through the urethra and over the external genital areas. During this passage, it can pick up some normal genital flora residing on these surfaces. This is known as sample contamination.
The presence of a few organisms from genital flora in a urine sample indicates the sample was collected without proper “clean catch” technique. Such contamination can lead to confusion when interpreting laboratory results, as these normal skin inhabitants might be mistaken for an infection. Even with a careful clean catch, a small number of urethral organisms can be detected in very low counts. These low counts are not considered indicative of an infection within the bladder.
When Genital Flora in Urine is a Concern
While genital flora in a urine sample is often due to contamination, microorganisms can indicate a medical concern. A urinary tract infection (UTI) occurs when bacteria multiply significantly within the urinary system, commonly affecting the bladder or urethra. The most frequent cause of UTIs is Escherichia coli (E. coli), a bacterium that resides in the gut flora but can cause infection if it enters and ascends the urinary tract.
Symptoms that warrant medical attention include painful or burning urination, increased frequency or urgency to urinate, cloudy or strong-smelling urine, lower abdominal discomfort, or fever and back pain in severe cases. While some bacteria found in the genital area can cause UTIs, diagnosis depends on the type and quantity of bacteria in the sample, coupled with symptoms. Other conditions, such as sexually transmitted infections (STIs), can also present with urinary symptoms or lead to specific organisms in urine that are not part of the genital flora. Therefore, medical interpretation of urine test results, considering both laboratory findings and patient symptoms, is important for accurate diagnosis and appropriate treatment.
Collecting a Clean Urine Sample
Collecting a “midstream clean-catch” urine sample is an important step to minimize contamination from genital flora and ensure accurate test results. The process begins with thoroughly washing hands with soap and water before touching any collection equipment or the genital area. For females, it involves separating the labia and cleaning the area from front to back with antiseptic wipes provided by the clinic or laboratory. For males, the tip of the penis should be wiped with an antiseptic pad.
After cleaning, the individual should begin urinating into the toilet for a few seconds to flush out any bacteria from the initial part of the urethra. Without stopping the flow, the collection cup is then positioned to collect the “midstream” portion of the urine. Once enough urine is collected, the remaining urine can be passed into the toilet. Replace the lid carefully, avoiding touching the inside, and deliver the sample to the laboratory promptly or refrigerate if there is a delay. Following these steps helps ensure the collected sample accurately reflects the contents of the bladder, making it easier to distinguish between normal flora and an infection.