Cultures - meconium

Alternative names:

meconium stool culture

Definition:

A laboratory test to isolate and identify organisms in the newborn feces (meconium) that may cause gastrointestinal symptoms and overt disease.

How the test is performed:

A recommended way of collecting stool from an infant involves lining the diaper with clear plastic wrap, then removing with stool in the protected clear plastic wrap and transferring it to a waterproof container. A sample of the specimen is placed in culture media to encourage the growth of microorganisms. The culture is observed for growth at regular intervals in the laboratory. When growth is observed, the organisms are identified. Further tests to determine sensitivity of the organisms to antimicrobial therapy may also be carried out. An alternative method is a stool sample obtained by swabbing the rectum with a sterile swab then placing the material in culture media.

How to prepare for the test:

A collection container will be provided for the stool specimen. Return the sample to the laboratory as soon as possible. The specimen should not include tissue of any kind or urine. Because meconium is passed only during the first few days of life the meconium stool sample is usually obtained by the nurses in the newborn nursery.

How the test will feel:

There is no discomfort.

Why the test is performed:

Meconium is the tarry stool of newborns that lasts for the first three days after birth. It is composed of amniotic fluid, salts, bile, cells, and normally is free of bacteria. While bacteria in the gut are a common and necessary part of life after birth, life in utero is normally sterile, and therefore there are no organisms in the meconium. If your child has been exposed to infected amniotic fluid, then this test may be positive for infective organisms and indicate the need for intervention and close attention.

Update Date: 02/09/00
Updated by: J. Gordon Lambert, MD, Associate Medical Director, Utah Health Informatics and adam.com editorial