Culture, Mycobacteria


Acid-fast bacilli (AFB) culture and smear, tuberculosis (TB) culture and smear, Mycobacterium culture and smear.

To assist in the diagnosis of tuberculosis.

Patient Preparation
Instruct the patient undergoing a procedure requiring anesthesia, and during which cultures may be collected, that to reduce the risk of aspiration related to nausea and vomiting, solid food and milk or milk products are restricted for at least 6 hr, and clear liquids are restricted for at least 2 hr prior to general anesthesia, regional anesthesia, or sedation/analgesia (monitored anesthesia). The patient may be required to be NPO at midnight. The American Society of Anesthesiologists has fasting guidelines for risk levels according to patient status. More information can be located at Regarding the collection of most other specimen types (e.g., urine or stool), there are no food, fluid, or activity restrictions unless by medical direction. Whenever possible, specimens for culture should be collected before antimicrobial therapy begins, as these medications will delay or inhibit growth of pathogens.

Ensure that oxygen has been administered 20 to 30 min before the procedure if the specimen is to be obtained by tracheal suction.

Regarding the patient’s risk for bleeding, the patient should be instructed to avoid taking natural products and medications with known anticoagulant, antiplatelet, or thrombolytic properties or to reduce dosage, as ordered, prior to the procedure. Number of days to withhold medication is dependent on the type of anticoagulant. Protocols may vary among facilities.

Patients on beta blockers before the surgical procedure should be instructed to take their medication as ordered during the perioperative period.Normal Findings
(Method: Culture on selected media, microscopic examination of sputum by acid-fast or auramine-rhodamine fluorochrome stain) Rapid methods include chemiluminescent-labelled DNA probes that target ribosomal RNA of the Mycobacterium radiometric carbon dioxide detection from 14C-labelled media, polymerase chain reaction/amplification techniques.

  • Culture: No growth
  • Smear: Negative for AFB
  • Rapid Testing Method: Negative

Critical Findings and Potential Interventions

  • Smear: Positive for AFB
  • Rapid Testing Method: Positive for Mycobacterium
  • Culture: Growth of pathogenic bacteria

Timely notification to the requesting health-care provider (HCP) of any critical findings and related symptoms is a role expectation of the professional nurse.

Specific infectious organisms are required to be reported to local, state, and national departments of health. Lists of specific organisms may vary among facilities. State health departments provide information regarding reportable diseases, which can be accessed at each state health department Web site. The CDC provides information regarding national notifiable diseases at

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