ATI RN
Microbiology Chapter 12 Test Bank Questions
Question 1 of 9
A 10-year-old child had the mantoux tuberculin test administered. 48 hours later a papule up to 8 mm in diameter appeared on the site of the injection. What type of hypersensitivity reaction developed after the tuberculin injection?
Correct Answer: A
Rationale: The correct answer is A: Type IV hypersensitivity reaction. This type of reaction is characterized by a delayed response involving T cells. In this case, the appearance of a papule after 48 hours indicates a delayed hypersensitivity reaction, which is typical of a Type IV reaction. The other choices are incorrect because: B: Arthus phenomenon is a localized immune complex-mediated reaction, not seen in tuberculin tests. C: Seroreaction typically involves antibodies reacting with soluble antigens, not seen in this scenario. D: Type II hypersensitivity reactions involve antibodies targeting specific cells or tissues, which is not the mechanism at play in this case.
Question 2 of 9
Which of the following bacteria is known for causing Lyme disease?
Correct Answer: A
Rationale: The correct answer is A: Borrelia burgdorferi. This bacterium is known for causing Lyme disease, which is transmitted through tick bites. Borrelia burgdorferi is specifically associated with Lyme disease due to its ability to infect and spread within the body, leading to a range of symptoms if left untreated. Summary of incorrect choices: B: Clostridium difficile - Known for causing gastrointestinal infections, not Lyme disease. C: Streptococcus pneumoniae - Commonly causes pneumonia and other respiratory infections, not Lyme disease. D: Mycobacterium tuberculosis - Causes tuberculosis, a respiratory disease, not Lyme disease.
Question 3 of 9
A family has two children. The younger child is under the year. The child has developed spastic cough attacks. Similar clinical presentation was observed in the elder preschool child one month ago. The doctor suspects pertussis infection. What method enables retrospective diagnostics of this disease?
Correct Answer: A
Rationale: The correct answer is A: Serological. Serological testing involves analyzing blood samples for specific antibodies produced in response to the pertussis infection. This method can detect past infections by identifying the presence of antibodies against the pertussis bacteria in the blood. In this case, since the doctor suspects pertussis infection in both children, serological testing can confirm if they have been exposed to the bacteria. Summary: B: Biological testing does not specifically target pertussis antibodies in the blood. C: Bacteriological testing involves culturing bacteria from samples, which may not be as sensitive for retrospective diagnosis. D: Molecular biological testing focuses on genetic material of the bacteria, which may not provide direct evidence of past infection.
Question 4 of 9
A patient consulted a dentist about itching and burning in the oral cavity; high temperature. The patient was diagnosed with trichomonal gingivostomatitis. What drug should be chosen for his treatment?
Correct Answer: A
Rationale: Step 1: Trichomonal gingivostomatitis is caused by the parasite Trichomonas tenax. Step 2: Metronidazole is the drug of choice for treating infections caused by anaerobic organisms like Trichomonas. Step 3: Metronidazole effectively targets and eliminates Trichomonas parasites in the oral cavity. Step 4: Therefore, the correct drug choice for treating trichomonal gingivostomatitis is Metronidazole. Summary: - Ampicillin (B) is an antibiotic effective against Gram-positive bacteria, not parasites. - Gentamicin sulfate (C) is an antibiotic used for bacterial infections, not parasitic infections. - Nystatin (D) is an antifungal medication used for treating fungal infections, not parasitic infections like trichomonal gingivostomatitis.
Question 5 of 9
Bacillary dysentery is also called:
Correct Answer: B
Rationale: Bacillary dysentery is caused by the bacterium Shigella, hence it is also known as shigellosis. Shigella is the primary pathogen responsible for this infectious disease, leading to severe diarrhea with blood and mucus. Salmonellosis (A) is caused by Salmonella bacteria, not Shigella. Typhoid fever (C) is caused by Salmonella typhi, not Shigella. Campylobacteriosis (D) is caused by Campylobacter bacteria, not Shigella. Therefore, the correct answer is B because Shigella is the specific bacterium associated with bacillary dysentery.
Question 6 of 9
Microscopy of a sputum smear from a pneumonia patient revealed Gram-positive diplococci with pointed ends surrounded by a capsule. What is the causative agent?
Correct Answer: A
Rationale: The correct answer is A: Streptococcus pneumoniae. 1. Gram-positive diplococci with pointed ends: characteristic morphology of Streptococcus pneumoniae. 2. Surrounded by a capsule: S. pneumoniae is encapsulated, important for virulence. 3. Klebsiella pneumoniae (B) is a Gram-negative rod, Neisseria meningitidis (C) is a Gram-negative diplococcus, and Staphylococcus aureus (D) is a Gram-positive cocci in clusters, not diplococci.
Question 7 of 9
Examination of duodenal contents revealed some pyriform protozoa with twin nuclei and four pairs of flagella. There were two supporting filaments between the nuclei and a suctorial disc on the ventral side. What representative of protozoa was revealed in this patient?
Correct Answer: D
Rationale: The correct answer is D: Intestinal trichomonad. This protozoan matches the description provided, with pyriform shape, twin nuclei, four pairs of flagella, supporting filaments, and a suctorial disc. Lamblia (A) lacks flagella and supporting filaments. Toxoplasma (B) is an intracellular parasite with different morphology. Leishmania (C) belongs to a different class with no flagella or supporting filaments. In summary, the unique combination of features described in the question points to an intestinal trichomonad, making it the correct answer.
Question 8 of 9
Your patient is a 22-year-old man. The patient reports that two weeks after unprotected sexual contact, a small ulcer appeared on its penis. The local inguinal lymph nodes are enlarged. Dark field microscopic examination of the ulcer secretions was performed. The test reveals presence of motile, curved spirochete. The most common causative agent of the disease is:
Correct Answer: B
Rationale: The correct answer is B: Treponema pallidum. The scenario describes symptoms of primary syphilis, which is caused by Treponema pallidum. The presence of a painless ulcer (chancre) and enlarged inguinal lymph nodes are characteristic of syphilis. Dark field microscopic examination showing motile, curved spirochetes is highly specific for Treponema pallidum. Incorrect explanations: A: Chlamydia trachomatis typically causes urethritis or cervicitis, not painless ulcers. C: Neisseria gonorrhoeae causes gonorrhea, which presents with purulent discharge, not painless ulcers. D: Herpes simplex virus type 2 causes genital herpes, leading to painful ulcers and vesicles, not painless ulcers seen in syphilis.
Question 9 of 9
A 10-year-old child had the mantoux tuberculin test administered. 48 hours later a papule up to 8 mm in diameter appeared on the site of the injection. What type of hypersensitivity reaction developed after the tuberculin injection?
Correct Answer: A
Rationale: The correct answer is A: Type IV hypersensitivity reaction. This type of reaction is characterized by a delayed response involving T cells. In this case, the appearance of a papule after 48 hours indicates a delayed hypersensitivity reaction, which is typical of a Type IV reaction. The other choices are incorrect because: B: Arthus phenomenon is a localized immune complex-mediated reaction, not seen in tuberculin tests. C: Seroreaction typically involves antibodies reacting with soluble antigens, not seen in this scenario. D: Type II hypersensitivity reactions involve antibodies targeting specific cells or tissues, which is not the mechanism at play in this case.