ATI RN
microbiology test bank Questions
Question 1 of 9
Which bacteria produce toxins that can lead to food poisoning?
Correct Answer: D
Rationale: The correct answer is D because all three bacteria listed (Staphylococcus aureus, Escherichia coli, Clostridium botulinum) can produce toxins leading to food poisoning. Staphylococcus aureus produces heat-stable toxins causing rapid onset of symptoms. Escherichia coli can produce toxins like Shiga toxin leading to severe foodborne illness. Clostridium botulinum produces neurotoxins causing botulism. Choice A, B, and C are incorrect because each bacteria can produce toxins that are harmful if ingested.
Question 2 of 9
The most common causes of urinary tract infections are:
Correct Answer: A
Rationale: The correct answer is A: Bacteria. Urinary tract infections (UTIs) are primarily caused by the invasion of bacteria into the urinary tract. Bacteria, especially Escherichia coli (E. coli), are the most common culprits. They enter the urinary tract through the urethra and can multiply in the bladder, leading to infection. Viruses (choice B) and fungi (choice C) are not typical causes of UTIs. "None of the above" (choice D) is incorrect as bacteria are indeed the main cause of UTIs.
Question 3 of 9
The most common cause of infectious diarrhea in infants and children is:
Correct Answer: C
Rationale: The correct answer is C: rotaviruses. Rotaviruses are the most common cause of infectious diarrhea in infants and children due to their highly contagious nature and ability to spread easily in childcare settings. They are known to cause severe diarrhea, vomiting, and dehydration in young children. Noroviruses (A), adenoviruses (B), and caliciviruses (D) can also cause diarrhea, but rotaviruses are specifically known for their prevalence and severity in the pediatric population. This is why C is the correct answer.
Question 4 of 9
Which of the following organisms is the causative agent of skin infections and toxic shock syndrome?
Correct Answer: B
Rationale: The correct answer is B: Staphylococcus aureus. This bacteria is known to cause skin infections and toxic shock syndrome due to its ability to produce toxins that can lead to severe symptoms. Staphylococcus aureus is commonly found on the skin and can enter the body through cuts or wounds, causing infections. Other choices are incorrect because Pseudomonas aeruginosa typically causes infections in immunocompromised individuals, Micrococcus luteus is a common skin bacterium that is not typically pathogenic, and Propionibacterium acnes is associated with acne, not skin infections or toxic shock syndrome.
Question 5 of 9
During a microscopy session, students examined sputum samples stained using Gram's method. Purple-stained diplococci with a capsule were observed. What microorganism is most likely present?
Correct Answer: A
Rationale: Step-by-step rationale: 1. Purple-stained diplococci suggest Gram-positive cocci. 2. Capsule presence is a characteristic of Streptococcus pneumoniae. 3. S. pneumoniae is known to form diplococci arrangements. 4. Therefore, the microorganism most likely present is Streptococcus pneumoniae. Summary: - B: Klebsiella pneumoniae is a Gram-negative rod, not a cocci. - C: Neisseria meningitidis is a Gram-negative diplococcus, not a capsule producer. - D: Escherichia coli is a Gram-negative rod, not a cocci or capsule producer.
Question 6 of 9
A patient was diagnosed with active focal pulmonary tuberculosis. What drug should be prescribed in the first place?
Correct Answer: A
Rationale: The correct answer is A: Isoniazid. Isoniazid is a first-line drug for treating active pulmonary tuberculosis due to its high efficacy and low toxicity. It works by inhibiting the synthesis of mycolic acids in the bacterial cell wall. Sulfalen, Cyclocerine, and Ethionamide are not first-line drugs for tuberculosis. Sulfalen is used for urinary tract infections, Cyclocerine for drug-resistant tuberculosis, and Ethionamide as a second-line drug for multidrug-resistant tuberculosis. Therefore, Isoniazid is the most appropriate initial choice for treating active focal pulmonary tuberculosis.
Question 7 of 9
Which one is a motile bacterium?
Correct Answer: D
Rationale: The correct answer is D, Salmonella typhi, because it is a motile bacterium due to possessing flagella that aid in movement. Bacillus anthracis (A) is non-motile, Klebsiella pneumoniae (B) lacks flagella for motility, and Shigella flexneri (C) is non-motile as well. Salmonella typhi (D) is known for its flagella-driven motility, allowing it to move and spread within its host and environment. Flagella are essential for bacterial motility, enabling them to navigate and colonize different environments efficiently.
Question 8 of 9
Drugs are excreted from the body primarily via the:
Correct Answer: B
Rationale: The correct answer is B: kidneys. The kidneys are the primary organs responsible for excreting drugs from the body through urine. They filter the blood and remove waste products, including drugs, through the process of urine formation. The lungs primarily excrete gases and volatile substances, not drugs. The small intestines are mainly involved in absorption of nutrients, not drug excretion. The spleen is part of the immune system and does not play a direct role in drug excretion.
Question 9 of 9
According to the data of WHO, for about 250 mln of Earth population fall ill with malaria. This disease is mostly spread in tropical and subtropical regions. Range of its spread falls into the area of the following mosquitoes:
Correct Answer: A
Rationale: Step-by-step rationale: 1. Anopheles mosquitoes are the primary vectors for transmitting malaria. 2. They prefer stagnant water for breeding, common in tropical regions. 3. Culex mosquitoes primarily spread diseases like West Nile virus. 4. Aedes mosquitoes transmit diseases like Zika and dengue fever. 5. Mansonia mosquitoes are known for transmitting filarial diseases. Therefore, the correct answer is A (Anopheles), as they are specifically associated with spreading malaria.