MICRO- LAB- EXAM BIOD 171

1. What type of media is best used to eliminate certain bacteria from within a mixed culture? 2. According the lab module, what type of agar plate is the most commonly used nutrient agar? What 3. What was the name of the selective agar plate (shown below) that is similar to a blood agar plate? 4. What type of bacteria does MacConkey agar select for? 5. Sorbitol MacConkey (SMAC) agar is: 6 .What pathogen is best identified using a SMAC agar? 7. What is the purpose of doing a 4-phase dilution strea 8. If you were required to grow 4 types of bacteria on a single agar plate without cross contaminating the samples, what method would you use? 9. Based on the 4-phase dilution streaking experiment, in what phase were bacterial isolates (colonies) observed? 10. Identify the plating method (below) as demonstrated in the lab. 11. Identify the organism growing on the TOP half of the agar and describe the observed hemolytic properties. 12. Would you expect to see a color change when pseudomonas is streaked onto an EMB agar plate? LAB 5 EXAM 1. The Kirby-Bauer method for examining antibiotic sensitivity is also known as what? 2. True or False. The antibiotic discs are placed onto the LB agar plate before spreading the bacterial culture on the plate. False. The antibiotic discs are place onto the plate AFTER the culture has been spread. 3. When performing the Kirby-Bauer method the areas of clearing surrounding an antibiotic disc after an overnight incubation are known as what? 1. Why was an LB agar plate used to test the Staph culture as opposed to a selective/differential agar that only grows Staph? 2. What unit of measurement is used when determining the size of the zones of inhibition? 3. True or False. In order to maintain proper spacing the antibiotic discs should be placed approximately a fingers width from the edge of the plate. 1. Given the following image, determine whether the bacterial sample is resistant or susceptible to the following antibiotics. A—24mm (because radius is given) Susceptible B—9mm Susceptible, despite small zone of inhibition. C—14mm Resistant