1. MDCH STATE LABORATORY TUBERCULOSIS TESTING Specimens/Tests/Reports
Dale E. Berry, B.S.
TB Lab Manager
(517)
Title slide

2. MDCH STATE LABORATORY LANSING, MICHIGAN
Picture of lab.

3. TYPES OF SPECIMENS SPUTUM PULMONARY ASPIRATES GASTRIC ASPIRATES
BODY FLUIDS
TISSUES
BLOOD
FECES
OTHER

4. SPECIMEN QUALITY Three specimens on three successive days
Early morning specimens (First thing out!)
Adequate specimen volume (>7 ml)
Sputum not saliva (epithelial cells?)
Condition of specimen (pH, etc.)
Appropriate specimen container
Complete and accurate information
Proper packaging (i.e. US Postal Service)
“Prompt” delivery to MDCH

5. MDCH – TESTS for AFB AFB Slide Examination
Direct Amplified Genetic Probe (M.tb complex)
Direct Susceptibility
AFB Culture and Isolation
Pre-Identification (Genetic Probe/HPLC)
Final Identification (Biochemical, etc.)
Pre-Indirect Susceptibility (Primary Drugs(1st Line))
Final-Indirect M.tb. Susceptibility (2nd/3rd Line)
MOTT Susceptibility
DNA Fingerprinting

6. AFB Slide Examination Least Sensitive AFB Test Requires 100,000 AFB/ml
Requires an adequate specimen
Negative smear – Does not rule out AFB
Positive smear – AFB present (viability?)
AFB Positive = Mycobacterium spp., etc.
Help support TB diagnosis
Quantitation: Positive/Positive Few/ Negative

7. MTD – Direct Amplified Probe
Rapid Test & Sensitive
Specific – M.tuberculosis complex
Not a test of viability or cure
Pulmonary Specimens only
Specimen MDCH only
Reduces subsequent test sensitivity
Delays culture & susceptibility results
97%/100% Sensitive/Specific

8. AFB Culture and Isolation
More sensitive than slide
Requires only 10 AFB/ ml of specimen
AFB Growth in 1-2 weeks (Bactec)
Genetic Probes and HPLC Rapid ID
Fewer AFB/ml – Delayed growth
“AFB Growth” required for other tests
Mixed cultures require subcultures

9. Preliminary AFB Identification
Genetic Probe/HPLC
One day after culture positive
Probe for M.tuberculosis complex
HPLC for MOTT
Helps confirm antibiotic therapy

10. Preliminary TB Susceptibility
Approximately 1 week after pre-ID
Tests “Primary” anti-Tuberculosis drugs
Direct and Indirect testing
Bactec methodology
Confirmed by“Proportion Plate Method”

11. Final AFB Identification
Required to differentiate M.tb complex
Required to confirm HPLC ID’s
Required to clarify unresolved ID’s
Requires additional time (3-4 weeks)
Final Report ASAP

12. TB Susceptibility - Additional
Proportion Plate Method
Requires additional 3 weeks
To increases choices for therapy
Performed for drug resistant TB cases
Tests 2nd and 3rd line antibiotics
Confirms results of “Broth Method”

13. MOTT Susceptibility Testing
Test according to latest NCCLS Guidelines
M.avium complex - Clarithromycin
M.kansasii/M.marinum - Rifampin/Ethambutol
M.fortuitum/M.chelonae – Refer to CDC
Additional antibiotics not offered by MDCH Refer to National Jewish Hospital in Denver, Colorado

14. RFLP – DNA Fingerprinting
For TB outbreak investigations
Check for “reactivation vs re-infection
Check for lab cross-contamination
Performed on approved requests only

15. MDCH AFB TEST TIME-LINE
PRE ID
PROBE
HPLC
SPECIMEN
SLIDE
MTD
CULTURE
TB SENS
FINAL ID
FINAL CULT
24 HRS
48 HRS
7-10 DA
12-18 DA
3 WKS
6 WKS
8-14 DA
AFB
FOUND
NOT FOUND
MYCOBACTERIUM
FOUND
FINAL ID
SPECIES
CONFIRMATION
TB complex RNA
DETECTED
NOT DETECTED
PRELIM ID
M.tb complex
NOT M.tb complex
MOTT
SUSCEPTIBILITY
PRIMARY
ANTIBIOTICS
MYCOBACTERIUM
NOT FOUND
REFERRED CULTURE
24-48 HRS
7-10 DA
2-3 WKS

16. QUESTIONS > CALL MDCH TB Laboratory Dale Berry Lab Manager
@ (517)
Steve Church Microbiologist
Angie Schooley Microbiologist
Jolene Vanneste Microbiologist

17. CONTACT INVESTIGATION
Complete Networking
TB CONTACT
PRIVATE
LAB
SLIDE
CULTURE
PRELIM ID
TB PATIENT
SYMPTOMS
HEALTH CARE
PROVIDER (DR)
DIAGNOSIS
COUNTY
HEALTH
DEPARTMENT
TREATMENT
CONTACT INVESTIGATION
STATE LAB
SLIDE
MTD
CULTURE
IDENTIFICATION
DNA FINGERPRINT
STATE
DISEASE
CONTROL