1 / 14

MLAB 2434 – MICROBIOLOGY KERI BROPHY-MARTINEZ

MLAB 2434 – MICROBIOLOGY KERI BROPHY-MARTINEZ. Use of Colony Morphology for Presumptive ID of Microorganism. Importance of Colonial Morphology as a Diagnostic Tool. Provide a presumptive diagnosis in times of critical need

elden
Télécharger la présentation

MLAB 2434 – MICROBIOLOGY KERI BROPHY-MARTINEZ

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. MLAB 2434 – MICROBIOLOGYKERI BROPHY-MARTINEZ Use of Colony Morphology for Presumptive ID of Microorganism

  2. Importance of Colonial Morphology as a Diagnostic Tool Provide a presumptive diagnosis in times of critical need Best guess giving type of specimen and what is seen before confirmatory tests Help jump-start therapy Enhance quality of patient care through rapid results and cost effectiveness Prevents time-consuming testing that yields few results Play a significant role in quality control Helps maintain accuracy of commercial or automated systems Troubleshoot mixed cultures or errors in commercial systems

  3. Colony Morphology (cont’d) • Initial Observation & Interpretation of Cultures • “Read” routine cultures after 18 to 24 hours of incubation • If cultures cannot be read after 24 hours, refrigerate to prevent overgrowth and drying

  4. Colony Morphology (cont’d) • Compare growth on different media • Examples: • If good growth on BAP but no growth on MAC, the bacteria is probably a gram positive organism • If MAC growth is pink, the organism is a lactose fermenter

  5. Fermenting vs. Non-Fermenting

  6. Colony Morphology (cont’d) • Gross Colony Characteristics • Hemolysis on BAP (Chocolate agar does not show true hemolysis) • α hemolysis • green discoloration on the media • Due to partial lysing of the RBC’s

  7. Colony Morphology (cont’d) • β hemolysis – complete clearing of blood around colonies on BAP

  8. Colony Morphology (cont’d) • Gamma hemolysis • Absence of hemolysis, nonhemolytic

  9. Colony Morphology (cont’d) • Size ( large, medium, small, pinpoint) • Margin or edge (smooth, filamentous) • Elevation ( raised, convex, flat) • Density( transparent, translucent, opaque) • Consistency (brittle, creamy, dry) • Pigment (production of color) • Odor (fruity, old sock)

  10. Colony Morphology (cont’d) Shape, edge and elevation of bacterial colonies

  11. Liquid Media Environment

  12. Growth of Organisms in Liquid Media • Streamers or vines are associated with certain streps • Puff balls associated with streps

  13. Growth of Organisms in Liquid Media • Turbidity • Cloudiness of the medium • Often see gas

  14. References • Engelkirk, P., & Duben-Engelkirk, J. (2008). Laboratory Diagnosis of Infectious Diseases: Essentials of Diagnostic Microbiology . Baltimore, MD: Lippincott Williams and Wilkins. • Mahon, C. R., Lehman, D. C., & Manuselis, G. (2011). Textbook of Diagnostic Microbiology (4th ed.). Maryland Heights, MO: Saunders.

More Related