1. Physical Factors Exp 15: Temperature Exp 16: pH Exp 17/18: O 2 Requirements Week 11B Last week: We Start our Unknown Project today! Exp. 69: Species Identification of Unknown Bacterial Cultures Part 1: Gram Stain and Isolation Technique New This Week: Exp 43: Chemical Agents of Control: Chemotherapeutic Agents; Part A: Kirby Bauer Antibiotic Sensitivity Test

2. Exp 15: Physical Factors: Temperature Any organism has a Min., Max. and an Optimum growing temperature. –High temperatures: enzyme denatures and cells die. –Low temperatures: enzyme activity is lower & cell deprived of H 2 O. Organisms will grow at various temperature ranges: –Psychrophile cold-loving -5 o - 20 o C –Mesophile- moderate temps. – will grow at body temps 20 o - 45 o C most pathogens grow @ 37 o C –Thermophile - heat loving 35 o C

3. Exp 16: Physical Factors: pH of the Extracellular Environment pH - measure of [H+] ion concentration in a solution –Low pH - end products of carbohydrate metabolism are organic acids (yeasts). –High pH - end products of breakdown of proteins are amines and ammonia. Specific pH needs reflect adaptations to environment (ex enteric bacteria can survive in broad pH while bacterial blood parasites have a narrow pH range). Lab medium frequently adjusted to neutral pH since best for growth thus use buffers.

4. Exp 17/18: Physical Factors: Atmospheric Oxygen Requirements

5. Exp. 69: Species Identification of Unknown Bacterial Cultures Unknown project overview. Requisition Forms. Written report. Part 1: –Isolation Technique –Gram Stain –Differential Media

6. Epidemiology: the science of when and where diseases occur and how they are transmitted Descriptive (data on occurrence) Analytical (probable cause) Experimental (hypothesis, test) CDC, Center for Disease Control, US Public Health Service

7. Exp 43: Chemical Agents of Control: Chemotherapeutic Agents Part A: Kirby Bauer Antibiotic Sensitivity Test

8. Measures drug efficacy by measuring diameter of zone of inhibition Susceptibility of organism to drug is determined by the size of the zone. Medium of choice for this test is Mueller-Hinton agar

9. 1 2 3 4 1.Tetracycline 2. Erythromycin 3. Ampicillin 4. Chlorenphenicol

10. Exp 43: Chemical Agents of Control: Chemotherapeutic Agents; Part A: Kirby Bauer Antibiotic Sensitivity Test Media: 2 Muller Hinton agar plates, 2 swabs Culture: EC & SA Procedure: (refer to pg. 289) Label plate w/org. Heavily inoculate entire surface of plate. Use forceps to fix disks to agar. 1. Tetracycline 2. Erythromycin 3. Ampicillin 4. Chlorenphenicol Week 11B PER TABLE