ATI RN
microbiology an introduction 12th edition test bank Questions
Question 1 of 9
The causative agent of bacterial dysentery belongs to which of the following genera?
Correct Answer: A
Rationale: The correct answer is A: Genus Shigella. Shigella is known to be the causative agent of bacterial dysentery. It invades the intestinal lining, leading to symptoms like severe diarrhea and abdominal cramps. Salmonella (choice B) typically causes food poisoning, not dysentery. Klebsiella (choice C) is associated with pneumonia and urinary tract infections, not dysentery. "None of the above" (choice D) is incorrect as Shigella does belong to a specific genus responsible for bacterial dysentery.
Question 2 of 9
A child with fever and swollen lymph nodes had a Gram-stained smear revealing Gram-negative rods with a safety pin appearance. What is the causative agent?
Correct Answer: A
Rationale: The correct answer is A: Yersinia pestis. This bacterium causes the plague, which presents with fever and swollen lymph nodes. The safety pin appearance on Gram stain is characteristic of Yersinia pestis. B: Francisella tularensis causes tularemia, which presents differently and does not show safety pin appearance on Gram stain. C: Brucella abortus causes brucellosis, which does not typically present with the same symptoms as described in the question. D: Clostridium botulinum causes botulism, which does not show safety pin appearance on Gram stain and does not typically present with fever and swollen lymph nodes.
Question 3 of 9
The process in which bacteria take up foreign DNA from the environment is called:
Correct Answer: A
Rationale: The correct answer is A: Transformation. During transformation, bacteria take up foreign DNA from the environment and incorporate it into their own genetic material. This process allows for genetic diversity and adaptation. Transduction (B) involves transfer of DNA via a virus, conjugation (C) involves direct transfer of DNA between bacterial cells, and binary fission (D) is a form of asexual reproduction in bacteria. Transformation is the only process specifically related to bacteria taking up foreign DNA.
Question 4 of 9
Gram-negative rods producing red colonies on Endo agar were isolated from a fecal sample. The bacteria were lactose-fermenting. What microorganism is likely responsible?
Correct Answer: A
Rationale: The correct answer is A: Escherichia coli. E. coli is a Gram-negative rod that ferments lactose, leading to red colonies on Endo agar. This bacterium is commonly found in the human gut and is known for its ability to ferment lactose. Salmonella and Shigella are also Gram-negative rods but do not ferment lactose, so they would not produce red colonies on Endo agar. Proteus is a Gram-negative rod that is not known for its lactose-fermenting ability and would not produce red colonies on Endo agar. Therefore, based on the characteristics provided, E. coli is the most likely microorganism responsible for the red colonies on Endo agar.
Question 5 of 9
During the examination of a patient, who had been to the mountain pasture and had been hospitalized in a bad condition with fever, the doctor found out the enlargement of inguinal lymph nodes to 8 cm, which were attached to the surrounding tissues, immovable, the skin above them was red and tender. The microscopic examination of the node revealed acute serohemorrhagic inflammation. What disease is it typical for?
Correct Answer: B
Rationale: Rationale: 1. The patient has symptoms of fever, enlarged lymph nodes, red and tender skin, which are indicative of systemic infection. 2. The inguinal lymph nodes in plague become enlarged, tender, and painful, forming buboes. 3. The presence of acute serohemorrhagic inflammation in the lymph node is characteristic of plague. 4. Plague is a zoonotic bacterial infection caused by Yersinia pestis, commonly transmitted through fleas from rodents. 5. Brucellosis, anthrax, and tularemia do not typically present with inguinal lymph node involvement and acute serohemorrhagic inflammation. Summary: - Brucellosis: Usually presents with flu-like symptoms, joint pain, and fever, not inguinal lymph node enlargement. - Anthrax: Presents with skin lesions, respiratory symptoms, or gastrointestinal symptoms, not inguinal lymph node involvement. - Tularemia: Presents with fever, skin ulcers,
Question 6 of 9
Which bacteria are capable of forming spores to survive in extreme conditions?
Correct Answer: C
Rationale: The correct answer is C because both Clostridium botulinum and Bacillus anthracis are capable of forming spores to survive in extreme conditions. Clostridium botulinum is known for causing botulism and produces highly heat-resistant spores, while Bacillus anthracis is the causative agent of anthrax and also forms spores. Choice A is incorrect because only Clostridium botulinum is mentioned, not Bacillus anthracis. Choice B is incorrect because only Bacillus anthracis is mentioned, not Clostridium botulinum. Choice D is incorrect as it states that none of the bacteria can form spores, which is false based on the characteristics of Clostridium botulinum and Bacillus anthracis.
Question 7 of 9
In which of the following especially dangerous infections, the respiratory tract is not damaged:
Correct Answer: D
Rationale: The correct answer is D, Cholera. Cholera is caused by the bacterium Vibrio cholerae and primarily affects the intestines, leading to severe watery diarrhea and dehydration. It does not damage the respiratory tract. Choice A, Tularemia, affects the respiratory tract and other organs. Choice B, Plague, can cause respiratory symptoms like cough and difficulty breathing. Choice C, Anthrax, can affect the respiratory tract if inhaled in its spore form.
Question 8 of 9
Enzymes that remove functional groups from a substrate without adding water, or that add functional groups to a double bond, are called
Correct Answer: D
Rationale: The correct answer is D: lyases. Lyases are enzymes that catalyze the breaking of chemical bonds without the addition of water. They can remove functional groups from substrates or add functional groups to double bonds without the use of water. A: Oxidoreductases involve the transfer of electrons. B: Transferases transfer functional groups from one molecule to another. C: Hydrolases catalyze the breaking of bonds by adding water.
Question 9 of 9
Which of these is not a factor counteracting the mechanisms of the immune system:
Correct Answer: D
Rationale: The correct answer is D: Hyaluronidase synthesis. Hyaluronidase is an enzyme produced by some pathogens to break down hyaluronic acid in the extracellular matrix, aiding their spread. This action does not directly counteract the immune system's mechanisms. Antigenic heterogeneity and mimicry can evade immune recognition. IgA proteases degrade IgA antibodies, impairing mucosal immunity. Therefore, D is the only choice not directly involved in counteracting the immune system.