microbiology an introduction 13th edition test bank

Correct Answer: D

Rationale: Step-by-step rationale: 1. Infectious process triggers an immune response to fight off the invading pathogen. 2. The immune response can lead to inflammation, fever, and production of antibodies. 3. Hypersensitivity reactions can also occur in response to the infection. 4. Options A, B, and C are not defining features of the infectious process. Summary: Option D is correct because an infectious process typically leads to an immune response and possibly hypersensitivity reactions. Options A, B, and C are incorrect as they do not specifically relate to the immune response or hypersensitivity reactions in the context of an infectious process.

Correct Answer: A

Rationale: The correct answer is A: The pyocyanin released by Pseudomonas aeruginosa. Pyocyanin is a blue-green pigment produced by Pseudomonas aeruginosa, a common cause of nosocomial infections in burn patients. The presence of blue-green pus and gram-negative rods in the wound along with fever suggests an infection with Pseudomonas aeruginosa. The other choices are incorrect because E. Coli typically causes gastrointestinal infections and releases enterotoxins, Staphylococcus aureus releases hemolysins causing hemolysis of red blood cells, and Shigella dysenteriae releases shigatoxin causing bloody diarrhea, none of which match the clinical presentation described in the question.

Correct Answer: D

Rationale: The correct answer is D: All of the above. Salmonella enterica, Clostridium botulinum, and Escherichia coli are all bacteria known to cause food poisoning. Salmonella causes symptoms like diarrhea and vomiting; Clostridium botulinum produces a toxin leading to paralysis; Escherichia coli can cause severe stomach cramps and bloody diarrhea. Therefore, selecting "All of the above" is correct because all three bacteria are commonly associated with foodborne illnesses. Choices A, B, and C on their own are incorrect as they each represent only one bacterium known to cause food poisoning, whereas the correct answer encompasses all three.

Correct Answer: A

Rationale: The most likely diagnosis is Actinomycosis. This is because the patient's presentation of a painful swelling with a fistula containing white granules and yellow-green honeycomb-like tissue is classic for Actinomycosis. Actinomyces is a gram-positive anaerobic bacterium that forms sulfur granules in tissues. Tuberculosis (B) typically presents with caseating granulomas, not sulfur granules. Leprosy (C) presents with skin lesions and nerve damage, not characteristic of this case. Syphilis (D) usually presents with painless ulcers and rash, not the painful swelling and fistula seen in this patient.

Correct Answer: C

Rationale: The correct answer is C: Escherichia coli. E.coli is the most common urinary tract pathogen due to its ability to adhere to and infect the urinary tract epithelium. It accounts for approximately 80-85% of urinary tract infections. It possesses specific virulence factors that enable it to colonize and cause infection in the urinary tract. Proteus mirabilis (A) is known for causing complicated UTIs, but it is less common than E.coli. Staphylococcus aureus (B) is not a common urinary pathogen. Pseudomonas aeruginosa (D) is more commonly associated with hospital-acquired infections, rather than community-acquired urinary tract infections.