Microbiology Review Questions (Lecture 3-4) PDF

How are young individual colonies growing on culture media evaluated? ***Size*** ***Elevation*** ***Form*** ***Hemolysis*** ***Pigment*** ***Density*** ***Texture*** Three types of hemolysis are ***[Alpha]***, ***Beta*** [ ] and ***Gamma*** [ ]. ***Alpha*** -- incomplete hemolysis; narrow g...

How are young individual colonies growing on culture media evaluated? ***Size*** ***Elevation*** ***Form*** ***Hemolysis*** ***Pigment*** ***Density*** ***Texture*** Three types of hemolysis are ***[Alpha]***, ***Beta*** [ ] and ***Gamma*** [ ]. ***Alpha*** -- incomplete hemolysis; narrow greenish ***Beta*** -- complete hemolysis; clear zone around\ bacterial colony ***Gamma*** -- no hemolysis ***Delta*** - double zone of hemolysis 3. The ***[Catalase]*** test is used to differentiate *Staphylococcus* and *Streptococcus* spp. 4. Some strains of [***Pseudomonas aeruginosa***] produce a bluish-green pigment 5. The ***coagulase test is*** used to identify [ **Staphylococcus aureus**.]. For the coagulase test, the sample is incubated in **rabbit plasma** which will gels or coagulates if the bacteria being incubated produces the enzyme **coagulase**. [ ]. 6. What genus and species of Gram + bacteria grows on mannitol salt agar and ferments mannitol? ***Mannitol Salt Agar*** is often used to differentiate\ between ***Staph. spp.*** ***Yellow*** colour change = S. **aureus** ***No*** colour change = S. ***epidermidis*** 7. What does the acronym MRSA stand for? ***Methicillin-resistant Staphylococcus aureus*** 8. What is the significance of *Staphylococcus aureus* infection in animals with mastitis? 9. What agar plates would *Staphylococcus* and *Streptococcus* spp. grow on? Which plates would they not grow on? **Staphylococcus spp.**: - **Grow on**: Blood Agar, Mannitol Salt Agar (MSA), Nutrient Agar - **Do not grow on**: MacConkey Agar (selective for Gram-negative bacteria) **Streptococcus spp.**: - **Grow on**: Blood Agar, Chocolate Agar - **Do not grow on**: MacConkey Agar (selective for Gram-negative bacteria) 10. What causes strangles in horses and what are the clinical signs? **Streptococcus equi**. This highly contagious disease affects the upper respiratory tract and lymph nodes. **Clinical signs** of strangles include3: - Fever - Nasal discharge - Swollen and abscessed lymph nodes - Difficulty swallowing - Loss of appetite - Lethargy 11. What important disease does *Streptococcus agalactiae* cause? ***Mastitis*** 12. The optochin test is used to identify ***S. pneumonia*** [ ] 13. **S. agalactiae = CAMP test.** 14. What is the cause of tetanus and which species of animals are most susceptible to this disease? Where are high numbers of tetanus-causing bacteria found? ***Clostridium tetani =*** Tetanus***\ ⚬ produces a neurotoxin*** ***Horse , Sheep , Human*** ***Found : soil , dust , manure*** 15. What is the cause of limberneck in waterfowl? ***Clostridium botulinum*** 16. List the Gram stain, oxygen requirements and survival tactics of *Clostridium* spp. ***Gram stain:*** Gram-positive ***Oxygen requirements:*** Obligate anaerobes (they thrive in environments without oxygen) ***Survival tactics:*** Clostridium species form ***endospores*** 17. The cause of circling disease in ruminants is ***[Encephalitis]*** 18. A bacterium that causes diamond skin disease in pigs is ***Erysipelothrix rhusiopathia*** 19. The cause of anthrax is ***Bacillus anthracis.*** What survival tactics do anthrax bacteria have? ***Endospore*** 20. A common bacterial cause of pulmonary abscesses in foals is **Rhodococcus equi** [ ]