1. Chapter 45: Microbiology
Lab Procedures
Chapter 45: Microbiology

2. Introduction
The field of microbiology is the study of living organisms too small to be seen with the naked eye (microorganisms)
Antonie van Leeuwenhoek’s invention of the microscope in 1674 allowed humankind to observe microbes for the first time
Louis Pasteur (father of microbiology) developed methods for culturing and identifying microbes in the lab
Normal flora: beneficial bacteria that helps us resist pathogens, naturally found in and on the body

3. Role of MA in Microbiology
Proper use of PPE
Monitoring equipment for repairs if needed
Performing QC checks on equipment
Patient teaching
Confidentiality concerning the pt and test results
Proper collection and testing of certain specimens
Instructing patient on proper collection of urine, stool or sputum specimens
Make patients as comfortable as possible
Perform CLIA waived tests (if the office allows)
Observe HIPAA

4. Classifications of Microorganisms
Naming microorganisms
Each organism has two names; genus (capitalized) and species (lowercase)
Structural characteristics
Retention of dyes
Gram statin, named after Dr. Hans C. J. Gram, is common for staining bacteria
Gram-positive retains the violet color of the stain
Gram-negative has the pink color of counterstain
Use of oxygen
Aerobes: survive in oxygen
Anaerobes: die in oxygen

5. Classification of Microorganisms
Hemolytic properties
Culture medium: promote microorganism growth
Agar: gelatin-like substance added to culture media to provide nutrition and semisolid surface on which microbes can grow
Colony: growth of one type of microorganism visible with the naked eye on surface of culture media
Other identifying characteristics
motile or non-motile
flagella or cilia
biochemical analysis

6. Types of Microorganisms
morphology: shape
Bacterium/bacteria
Virus/viruses
Protozoan/protozoa
Fungus/fungi
Parasites
Worms
Insects
Medication-resistant microorganisms
Proper and consistent had washing and personal hygiene are critically important in decreasing the prevalence of these difficult microorganisms

7. Specimen Collection and Transport
First step in specimen collection is proper patient education
Second step is to follow the basic guidelines for specimen collection (guidelines 45-1)
Laboratory request information
Specimen label
Pt name, date and time of collection, type and source or specimen, doctor’s name and your initials
Requisition
Pt address, ID number, age, gender, insurance info, specific info regarding the type and source of specimen, test requested, medication pt receiving, dx, MD info, special info or orders
Outside lab will reject specimen if info on label, the requisition or both is incomplete or if specimen is insufficient in quantity or improperly packaged

8. Specimen Collection and Transport
Collection devices – figure 45-15
Sterile swabs
Cotton swabs
Culturette system
Smear: thin layer of microorganisms spread on a glass slide for ID purposes
Exudates: wound drainage material made of serum, WBC and fibrin
Transporting specimens to an outside lab
Courier
Mail

9. Diagnosing Infection
Students to read through with Professor – own notes
Inoculated: microorganisms placed on or in media
Wet mount: preparation in a liquid that will preserve motility of the microbe

10. Microbiology Equipment and Procedures
Typical MD office will have microscope, incubator, autoclave, refrigerator, biohazard waste container, and a variety of specimen collections devices and containers
Inoculating equipment
Loop: long instrument with a small loop on the end designed to pick up fluids and transfer them to culture media
Needle: long, straight instrument with a pointed end used to sample individual colonies of microorganisms
Bunsen burner: used to heat up culture media

11. Microbiology Equipment and Procedures
Culture media
Broth: liquid
Agar: semi-solid
Media classifications
Supportive
Selective
Differential
Enrichment
Inoculating media – table 45-3
Main goal in growing cultures is to separate pathogenic colonies of organisms from colonies of normal flora
Sensitivity testing – figure 45-22
Determine which antibiotic will kill the bacteria
Direct examination
Direct smear (procedure 45-1)
Wet mount preparation (procedure 45-2)
Staining specimens (procedure 45-3)

12. Types of Specimens Throat (procedure 45-4) Sputum (procedure 45-5)
Urine (procedure 45-6)
Stool (procedures 45-7, 45-8 and 45-9)
Wound specimens
Sterile swab to obtain specimen from wound, abscess, or incision to test for pathogenic microorganisms (figure 45-33)
Other types of specimens
CSF
Blood cultures

13. Serology Testing
Serology: study of the antigen and antibody reactions of the body’s immune system
Frequently used for pregnancy, RA, mono, and strep
Strep test
Group A Strep Screen
Done while pt waits
Agglutination: clumping together