Microbiology Test Results: What do they mean?

1. Microbiology Test Results: What do they mean? Christie Massen M.S., MLS(ASCP) Microbiologist III – QA/CLIA Coordinator North Dakota Department of Health Division of Laboratory Services - Microbiology

2. Objectives • Upon completion of this presentation, participants will be able to: • Summarize various microbiological testing methods. • List the components of a laboratory report. • Interpret various microbiology test results. • Summarize antibiotic susceptibility testing and results. • Compare various serological test results.

3. Infectious Diseases • Bacterial • Viral • Fungal • Parasitic

4. Supporting Laboratory Results • Viral • Identification of virus • Normal or Decreased WBC Count • Increased Lymphocyte Count • Parasitic • Identification of parasite • Increased Eosinophil Count • Bacterial • Identification of bacteria • Increased WBC Count • Increased Neutrophil Count • Left-shift in Neutrophil Cell Line • Increased CRP • Increased Sed-Rate • Fungal • KOH Prep Test • Identification of fungal elements

5. Laboratory Reports

6. Bacterial Culture • Grow and isolate bacteria • Various media • Identify a pathogen • Pros • Identify the isolate • Very specific • Cons • Lengthy • Normal flora

7. Biochemical Testing

8. Identification

9. Antibiotic Susceptibility Testing • Determine antibiotic susceptibility or resistance

10. Antibiotic Susceptibility Testing

11. Case 1

12. Case 1: Report

13. Case 2

14. Case 2: Report

15. Modified Hodge Test • Purpose: • Detection of carbapenemase production in identified organisms • Interpretation: • Positive • Clover leaf-like indentation along the streak line • Negative • No growth along the streak line

16. Case 3

17. Case 3: Report

18. Virology

19. Virology Culture • Cytopathic Effect (CPE)

20. Case 4

21. Case 4: Report

22. Parasitology & Mycology • Direct Examination • Macroscopic and Microscopic

23. Molecular Testing • DNA Probes • DNA sequencing • Nucleic acid sequences (16s) • Whole genome sequencing • Nucleic Acid Amplification Testing (NAAT) • Polymerase Chain Reaction (PCR) • Ligase Chain Reaction (LCR) • Transcription Mediated Amplification (TMA)

24. PCR • Developed in 1985 • First NAA method • How it works: • DNA Polymerase replicates the target DNA molecules • RNA can be replicated • Heat and cool cycles utilized • DNA Primers hybridize the target and initiate polymerization of new DNA Molecules • End product: Billions of copies of the target DNA • Read for presence of DNA target

26. Immunology Test Methods • Detects: • Antigens • Antibodies • Test Methods: • Agglutination • Nephlometry • Double Diffusion • Radial Immunodiffusion • Electrophoresis • Western Blot • Flocculation • ELISA • Immunoflorescence assay • Radioimmunoassay

27. Antibody Review

28. Antibody Review

29. Case 5

30. Case 5: Report

31. Case 6

32. Case 6: Report

33. Case 7

34. Case 7: Report

35. Case 8

36. Vaccine Preventable DiseaseCase 8: Report

37. Questions?

38. References • Kiser, K.M., Payne, W.C., & Taff, T.A. (2011). Clinical Laboratory Microbiology: A Practical Approach. Upper Saddle River, NJ: Pearson Education. • Amjad, A., Mirza, I.A., Zia, F. (2011). Modified Hodge test: A simple and effective test for detection of carbapenemase production. Iran Journal of Microbiology. Retrieved from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3330182/ • New Directions in Molecular Testing: An Educational Guide for Clinical Laboratory Professionals. Gen-Probe Inc. Retrieved from: www.gen-probe.com