ATI RN
microbiology an introduction tortora test bank Questions
Question 1 of 9
The most common causative agents of bacterial meningitis are:
Correct Answer: B
Rationale: The correct answer is B because Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae are the most common causative agents of bacterial meningitis. Streptococcus pneumoniae is a leading cause in adults, Neisseria meningitidis is common in adolescents and young adults, and Haemophilus influenzae is more frequent in children. The other choices, Rubella virus (C) and Herpangina (D), are not bacterial agents known to cause meningitis.
Question 2 of 9
Family Retroviriade:
Correct Answer: A
Rationale: Step-by-step rationale: 1. Family Retroviridae is known for having a single-stranded RNA genome. 2. The (-) sign indicates that the RNA strand is negative-sense. 3. Therefore, the correct answer A, "Their capsid consists of two copies of ssRNA(-)," is accurate. Summary: - Choice B is incorrect because Retroviridae have simple type of symmetry. - Choice C is incorrect as Retroviridae are not enveloped viruses. - Choice D is incorrect because Retroviridae are enveloped viruses.
Question 3 of 9
Toxicity of disinfectant against microbial cells:
Correct Answer: C
Rationale: The correct answer is C because disinfectants are non-selective and can harm a wide range of microbial cells. Disinfectants work by disrupting cell membranes, proteins, and nucleic acids, affecting both harmful and beneficial microorganisms. Choices A and B are incorrect because disinfectants are designed to be potent and non-selective. Choice D is incorrect because the effects of disinfectants are often permanent and irreversible on microbial cells.
Question 4 of 9
The role of adhesins in gram positive bacteria is carried out by:
Correct Answer: A
Rationale: Adhesins in gram positive bacteria are typically carried out by surface structures such as lipoteichoic acids. These molecules help the bacteria adhere to host cells or tissues. Lipoteichoic acids are specific to gram positive bacteria and play a crucial role in initiating infections. Fimbriae, flagella, and short chain mycolic acids are not primarily responsible for adhesion in gram positive bacteria. Fimbriae are more commonly found in gram negative bacteria, flagella are involved in motility, and short chain mycolic acids are specific to mycobacteria. Therefore, the correct answer is A, lipoteichoic acids.
Question 5 of 9
A 28 y.o. patient without permanent residence was admitted to the hospital with the preliminary diagnosis influenza. On the fith day of illness he got a maculopapular petechial rash on his body and internal surfaces of extremities. Body temperature is 410 C, euphoria, face hyperemia, sclera reddening, tongue tremor, tachycardia, splenomegaly, excitement. What is the most probable diagnosis?
Correct Answer: A
Rationale: Step 1: Initial diagnosis of influenza suggests a viral illness. Step 2: Presence of maculopapular petechial rash and high fever indicates a systemic infection. Step 3: Symptoms like euphoria, hyperemia, tachycardia, splenomegaly, and excitement are characteristic of epidemic typhus. Step 4: Face hyperemia, sclera reddening, and tongue tremor are specific to epidemic typhus. Step 5: Epidemic typhus is transmitted by body lice, which fits the scenario of a patient without permanent residence. Summary: - Delirium alcoholicum is unlikely due to the specific symptoms and lack of history of alcohol abuse. - Leptospirosis typically presents with jaundice and renal symptoms, not seen in this case. - Measles rash is different from the maculopapular petechial rash described.
Question 6 of 9
A wound smear revealed Gram-negative rods producing blue-green pigment. The bacteria had a fruity odor. What is the causative agent?
Correct Answer: A
Rationale: The correct answer is A: Pseudomonas aeruginosa. Pseudomonas aeruginosa is known to produce a blue-green pigment called pyocyanin, which is characteristic of the organism. Additionally, it has a distinct fruity odor due to the production of certain volatile compounds. Escherichia coli (B) does not produce blue-green pigment or have a fruity odor. Klebsiella pneumoniae (C) and Proteus mirabilis (D) also do not exhibit these specific characteristics associated with Pseudomonas aeruginosa.
Question 7 of 9
Bacterial families have general:
Correct Answer: A
Rationale: The correct answer is A: Morphologic features. Bacterial families are classified based on their morphologic features such as shape, size, and arrangement. This classification helps in identifying and studying different bacterial species. Choice B, Geographic features, is incorrect as bacterial classification is not based on their geographic distribution. Choice C, Historical features, is incorrect as it does not play a role in the classification of bacterial families. Choice D, Physiologic features, is also incorrect as physiological characteristics are used for further classification within bacterial families, not as a general characteristic.
Question 8 of 9
Which of the following organisms is a common cause of peptic ulcers?
Correct Answer: C
Rationale: The correct answer is C: Helicobacter pylori. This bacterium is a well-known cause of peptic ulcers due to its ability to survive in the acidic environment of the stomach and produce enzymes that weaken the protective mucous layer of the stomach lining. Treponema pallidum (choice A) causes syphilis, Vibrio cholerae (choice B) causes cholera, and Escherichia coli (choice D) can cause various infections but is not a common cause of peptic ulcers. Therefore, Helicobacter pylori is the correct answer as it is specifically associated with peptic ulcer formation.
Question 9 of 9
A patient with pneumonia had sputum cultured, revealing Gram-negative rods. The bacteria were lactose fermenters and produced green colonies on MacConkey agar. What is the most likely causative agent?
Correct Answer: A
Rationale: Rationale: 1. Gram-negative rods suggest Enterobacteriaceae family. 2. Lactose fermenters narrow down to E. coli. 3. Green colonies on MacConkey agar indicate acid production. 4. E. coli is a common cause of pneumonia. Therefore, the most likely causative agent is Escherichia coli. Other choices are incorrect as Klebsiella is non-lactose fermenter, Pseudomonas is oxidase-positive, and Proteus is non-lactose fermenter.