ATI RN
Microbiology Chapter 13 Test Bank Questions
Question 1 of 5
On a certain territory mass death of rodents was registered. It was suspected that their death might have been caused by plague. What serological reaction should be applied for quick identification of antigen of the causative agent of this epizooty?
Correct Answer: B
Rationale: The correct answer is B: Agglutination. During a suspected plague outbreak, agglutination testing is used to quickly identify the antigen of the causative agent. In this test, specific antibodies are added to a sample containing the suspected antigen. If the antigen is present, it will clump together (agglutinate) with the antibodies, indicating a positive result. This method is rapid and efficient for identifying the presence of the plague-causing agent. Choice A: Precipitation involves the formation of a visible precipitate when antigen and antibody react, but it is not as quick or specific as agglutination for identifying the antigen in this scenario. Choice C: Passive hemagglutination is a variation of agglutination that uses red blood cells as carriers for antigens or antibodies. While it can be useful in certain situations, it is not typically the first choice for rapid identification of plague antigen. Choice D: Complement binding is a different type of
Question 2 of 5
A 16-year-old adolescent was vaccinated with DTP. In eight days there was stiffness and pain in the joints, subfebrile temperature, urticarial skin eruption, enlargement of inguinal, cervical lymph nodes and spleen. What kind of allergic reaction is observed?
Correct Answer: D
Rationale: The correct answer is D: Hypersensitivity of delayed type. The symptoms described occur 5-10 days after exposure to the antigen, consistent with a delayed hypersensitivity reaction. This type of reaction involves T cells and is characterized by cell-mediated immune response, leading to inflammation and tissue damage. Choices A, B, and C are incorrect because they are associated with different mechanisms of allergic reactions. Immunocomplex reactions (choice A) involve antigen-antibody complexes depositing in tissues, immediate hypersensitivity reactions (choice B) involve IgE-mediated mast cell degranulation, and cytotoxic reactions (choice C) involve antibodies targeting specific cells for destruction.
Question 3 of 5
Bacteriological laboratory examines canned meat whether it contains botulinum toxin. For this purpose an extract of test specimen and antitoxic antibotulinic serum of A, B, E types were introduced to a group of mice under examination; a control group of mice got the extract without antibotulinic serum. What serological reaction was applied?
Correct Answer: A
Rationale: The correct answer is A: Neutralization. In this scenario, the antibotulinic serum of types A, B, and E were introduced to neutralize the botulinum toxin in the test specimen. The serological reaction applied here involves the neutralization of the toxin by the specific antibodies present in the serum. This process prevents the toxin from causing harm to the mice. Summary of other choices: B: Precipitation - This involves the formation of insoluble complexes between antigen and antibody, not the specific neutralization seen in this case. C: Complement binding - This involves activation of the complement system leading to cell lysis, not the direct neutralization of toxin. D: Double immune diffusion - This technique is used to determine the presence of specific antibodies or antigens based on their diffusion patterns, not the neutralization of toxin as seen in this scenario.
Question 4 of 5
While studying a microslide obtained from the punctuate of a regional lymph node and stained by Romanovsky-Giemsa method a physician revealed some light pink thin microorganisms with 12-14 regular spiral coils and pointed ends, up to 10-13 micrometer long. This might be the causative agent of the following disease:
Correct Answer: D
Rationale: The correct answer is D: Relapsing fever. The description matches Borrelia species, the causative agent of relapsing fever. The thin, spiral-shaped microorganisms with pointed ends and specific length are characteristic of Borrelia. The number of coils and size mentioned also align with Borrelia morphology. Relapsing fever is transmitted by tick bites and manifests as recurring febrile episodes. Incorrect choices: A: Syphilis - Syphilis is caused by Treponema pallidum, which is not spiral-shaped. B: Trypanosomiasis - Trypanosomiasis is caused by Trypanosoma species, which are not spiral-shaped. C: Leptospirosis - Leptospirosis is caused by Leptospira species, which are not spiral-shaped and do not match the specific description provided.
Question 5 of 5
A 25-year-old patient was delivered to an infectious diseases unit on the 3rd day of illness with complaints of headache, pain in lumbar spine and gastrocnemius muscles, high fever, chill. Objectively: condition of moderate severity. Scleras are icteric. Pharynx is hyperemic. Tongue is dry with dry brown coating. Abdomen is distended. Liver is enlarged by 2 cm. Spleen is not enlarged. Palpation of muscles, especially gastrocnemius muscles, is painful. Urine is dark in color. Stool is normal in color. The most likely diagnosis is:
Correct Answer: A
Rationale: The correct diagnosis is Leptospirosis. Leptospirosis presents with headache, fever, muscle pain, jaundice, and kidney involvement. The patient's symptoms of headache, lumbar and muscle pain, high fever, icteric scleras, and dark urine are classic for Leptospirosis. The enlarged liver could be due to liver involvement in the disease. The absence of splenic enlargement and normal stool color rule out malaria. Infectious mononucleosis typically presents with sore throat and lymphadenopathy, which are absent in this case. Viral hepatitis A may present with similar symptoms, but the presence of muscle pain and dark urine is more indicative of Leptospirosis. Therefore, based on the patient's symptoms and clinical findings, Leptospirosis is the most likely diagnosis.