ATI RN
medical microbiology test bank Questions
Question 1 of 9
Which of the following characteristics does not refer to the flu vaccine?
Correct Answer: D
Rationale: The correct answer is D because the flu vaccine mainly stimulates systemic immunity, not local immunity. Systemic immunity refers to the immune response throughout the body, while local immunity is specific to a certain area. Choice A is incorrect because the flu vaccine is indeed recommended. Choice B is incorrect as the flu vaccine can be a subunit vaccine, containing only specific antigens. Choice C is incorrect as the flu vaccine is typically administered parenterally, meaning through injection, nasal spray, or oral routes.
Question 2 of 9
A patient with pneumonia had sputum stained by the Gram method. The smear revealed Gram-positive cocci in pairs with a capsule. What is the most likely causative agent?
Correct Answer: A
Rationale: The correct answer is A: Streptococcus pneumoniae. This bacterium is a common cause of pneumonia and is known to appear as Gram-positive cocci in pairs with a capsule. The presence of a capsule is a key characteristic of S. pneumoniae. Staphylococcus aureus (B) is a Gram-positive cocci but typically does not have a capsule. Neisseria meningitidis (C) is a Gram-negative diplococcus, not a Gram-positive cocci. Klebsiella pneumoniae (D) is a Gram-negative rod, not a Gram-positive cocci. Therefore, based on the staining pattern and the presence of a capsule, Streptococcus pneumoniae is the most likely causative agent in this case.
Question 3 of 9
The time in minutes in which 90% of the bacterial population will be killed at a given temperature is called the
Correct Answer: D
Rationale: The correct answer is D: decimal reduction time. This term represents the time required at a specific temperature to kill 90% of a bacterial population. It is a key parameter in microbiology to determine the effectiveness of a given heat treatment. Generation time (A) refers to the time it takes for a population to double in size. Thermal death time (B) is the shortest time needed to kill all organisms at a specific temperature. Sterilization time (C) is a general term and does not specifically refer to the time required to kill 90% of the population.
Question 4 of 9
Which of the following has a contact route of transmission
Correct Answer: D
Rationale: The correct answer is D: HIV. HIV is transmitted through direct contact with certain body fluids such as blood, semen, vaginal fluids, and breast milk. This direct contact route of transmission makes it different from the other choices. Salmonellosis is typically transmitted through contaminated food or water (not direct contact). Tularemia is usually transmitted through insect bites or contact with infected animals. Rubella is primarily transmitted through respiratory droplets. Therefore, HIV is the only option with a contact route of transmission.
Question 5 of 9
Which of the following bacteria produces a toxin that causes severe diarrhea?
Correct Answer: D
Rationale: The correct answer is D because all three bacteria listed can produce toxins that cause severe diarrhea. Clostridium difficile produces toxins that can lead to antibiotic-associated diarrhea, Vibrio cholerae produces a toxin that causes cholera, and certain strains of Escherichia coli produce toxins that result in severe diarrhea. Therefore, choosing option D is correct because all the mentioned bacteria can cause severe diarrhea. Options A, B, and C are incorrect individually because each bacterium listed can produce a toxin resulting in severe diarrhea.
Question 6 of 9
When a pathogen spreads from the original site to other tissues or organs it is called a(n) __________ infection.
Correct Answer: B
Rationale: The correct answer is B: focal. When a pathogen spreads from the original site to other tissues or organs, it is considered a focal infection. This term specifically refers to an infection that is localized to a specific area but can spread to other parts of the body. A: Local infection refers to an infection that is confined to a specific area without spreading to other tissues or organs. C: Natural is not a term commonly used to describe the spread of pathogens within the body. D: Acute refers to the rapid onset of a disease but does not specifically address the spread of pathogens from one site to another. In summary, the term "focal" best describes the scenario provided in the question, making it the correct answer.
Question 7 of 9
The 32-year-old patient has been taking antituberculosis drugs. Later he noticed that his urine had become redorange in color. What drug is conductive to this phenomenon?
Correct Answer: A
Rationale: The correct answer is A: Rifampicin. Rifampicin can cause red-orange discoloration of bodily fluids like urine due to its metabolism. This phenomenon is harmless but alarming to patients. Isoniazid (B) can cause peripheral neuropathy, Pyrazinamide (C) can cause hyperuricemia, and Ethambutol (D) can cause optic neuropathy.
Question 8 of 9
Which of the following statements is NOT TRUE about the fungi?
Correct Answer: D
Rationale: The correct answer is D because fungi do not form flagella. Fungi reproduce sexually and asexually (A) through spores, have a cell wall (B) made of chitin, and are mostly aerobic or facultative anaerobes (C). Flagella are structures found in some protozoa and bacteria, not in fungi. Therefore, option D is the only statement that is not true about fungi.
Question 9 of 9
Which bacteria is responsible for causing the disease known as syphilis?
Correct Answer: A
Rationale: The correct answer is A: Treponema pallidum. This bacterium is responsible for causing syphilis due to its unique spiral shape and ability to penetrate mucous membranes. It is transmitted through sexual contact or from mother to fetus. Neisseria gonorrhoeae causes gonorrhea, Chlamydia trachomatis causes chlamydia, and Escherichia coli is a common bacterium in the gastrointestinal tract. Syphilis is distinct due to its characteristic symptoms and stages, making Treponema pallidum the correct choice.