Antimicrobial Susceptibility Testing (AST) forMycobacterium tuberculosiscomplex

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Contact Information

State Public Health Laboratory
101 N. Chestnut Street
PO Box 570
Jefferson City, MO 65102-0570
Directions to the Laboratory
Phone:  573-751-3334
Fax:  573-526-2754
Email: labweb1@health.mo.gov

For laboratory-related public health emergencies occurring after normal business hours, contact the Department of Health and Senior Services at 1-800-392-0272.
Reachable 24 hours a day, 7 days a week.

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Brief Description

Antimicrobial susceptibility testing (AST) determines the ability of the four primary antitubercular drugs to inhibit the growth (in vitro) of Mycobacterium tuberculosis complex (MTBC) in a broth macrodilution matrix which utilizes critical concentrations of drug tested. AST is important to the proper treatment and management of patients with tuberculosis (TB). AST guides the physician in the selection of the most appropriate drug treatment regimen and alerts the physician when drug resistance may be a consideration in patient management.

Laboratory Unit

Tuberculosis

Methodology

Broth macrodilution using BACTEC™ MGIT™ system

Specimen Collection

Viable isolate of MTBC in pure culture of solid or liquid media

Mixed or non-viable MTBC organism is acceptable for molecular-based AST; however, growth-based AST may not be available.

Storage/Transport

Submit isolates using the tuberculosis (TB) Category A carrier provided by the MSPHL in accordance with the Infectious Substance, Category A shipping guidelines.

Acceptable Specimen Type(s)

Submit a slant (L-J, Middlebrook, or Mitchison) or liquid broth culture (MGIT, VersaTREK, or MP).

Test Request Form(s)

Tuberculosis Test Request Form

Possible Results

Susceptible
Resistant

Unacceptable Conditions

No name or patient identifier on specimen
Specimen leaked during transport to the laboratory
Mixed or non-viable organism

Interfering Substances

N/A

Result Reported

4 - 17 days after MTBC identified

Fees

N/A

CPT Codes

87188 x5

LOINC/SNOMED Codes

29579-0

Additional Information

MTBC showing resistances to any drug are referred to the Centers for Disease Control and Prevention (CDC) for second-line AST.

19 CSR 20-20.080 Duties of Laboratories

"Isolates or specimens positive for [M. tuberculosis complex] must be submitted to the State Public Health Laboratory for epidemiological or confirmation purposes"