Culture - meconium
A laboratory test to isolate and identify organisms in the newborn feces (meconium) that may cause gastrointestinal symptoms like diarrhea and Vomiting or to determine the cause of a disease in the infant.
How the test is performed
One way of collecting stool from an infant involves lining the diaper with clear plastic wrap, then removing the wrap with the stool inside it and transferring it to a waterproof container. Some diapers contain antibacterials, which is why this plastic wrap is recommended to protect the specimen and ensure accurate results.
A sample of the specimen is then placed in culture media to encourage the growth of microorganisms. The culture is observed at regular intervals in the laboratory. When growth is observed, the organisms are identified. Further tests to determine sensitivity of the organisms to antibiotics 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. A stool sample is usually obtained by the nurses in the newborn nursery because meconium is passed only during the first few days of life.
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.
Normal values show no organisms in the meconium stool of the newborn.
What abnormal results mean
An abnormal finding indicates bacterial growth in the meconium stool. This is of concern since the infant’s immune system is underdeveloped and unprepared for invading organisms. Therefore a newborn infection could be serious and lead to newborn sepsis.
by Janet G. Derge, M.D.
All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.