ATI RN
Foundations in Microbiology Test Bank Questions
Question 1 of 5
A 6-year-old boy is brought to the pediatrician by his mother, who complains of low-grade fever, chronic cough and night sweats in her child. She describes the cough as productive, producing white sputum that is sometimes streaked with blood. She also says that her son has lost some weight in the last month. His vital signs include blood pressure of 115/75 mm Hg, heart rate of 110/min., respiratory rate of 18/min. and temperature of 36,6°C. On physical examination, the patient is ill looking. Pulmonary auscultation reveals some fine crackles in the right upper lobe. The pediatrician suspects an active infection and performs Mantoux test. Intradermal injection of which of the following substances has been most likely used by pediatrician for screening test in this clinical case?
Correct Answer: A
Rationale: The correct answer is A: Tuberculin. In this clinical scenario, the patient presents with symptoms suggestive of tuberculosis, including chronic cough, night sweats, weight loss, and hemoptysis. The Mantoux test, also known as the tuberculin skin test, is used to screen for tuberculosis. Tuberculin, a purified protein derivative (PPD) derived from Mycobacterium tuberculosis, is injected intradermally. The test elicits a delayed-type hypersensitivity reaction in individuals who have been exposed to the organism in the past. A positive Mantoux test indicates exposure to tuberculosis and does not differentiate between active infection and prior exposure. Explanation for other choices: B: Measles - Measles is a viral infection that presents with a characteristic rash and fever, not consistent with the symptoms described in the case. C: Tetanus and diphtheria toxoids vaccine (Td) - Td vaccine is not used for tuberculosis screening and does not elicit
Question 2 of 5
A patient was taken to a hospital with acute food poisoning caused by homemade canned mushrooms. The product analysis revealed some microorganisms that develop only in the absence of oxygen. What microorganisms caused the poisoning?
Correct Answer: A
Rationale: The correct answer is A: Obligate anaerobes. These microorganisms thrive in the absence of oxygen, as seen in the canned mushrooms where oxygen is limited. They produce toxins causing food poisoning. Facultative anaerobes (B) can survive with or without oxygen. Microaerophiles (C) require low levels of oxygen. Obligate aerobes (D) need oxygen to survive and would not be responsible for the poisoning in this case.
Question 3 of 5
After consumption some tinned meat a patient had diplopia, acute headache, deglutition disorder, hard breathing, muscle weakness. The diagnosis was botulism. What factor of pathogenicity are the clinic presentations of this disease connected with?
Correct Answer: A
Rationale: The correct answer is A, Exotoxin. Botulism is caused by the exotoxin produced by Clostridium botulinum bacteria. The symptoms described - diplopia, acute headache, deglutition disorder, hard breathing, muscle weakness - are all consistent with botulism due to the neurotoxic effects of the exotoxin. The exotoxin interferes with neurotransmission at the neuromuscular junction, leading to muscle paralysis and the symptoms mentioned. The other choices (B, C, D, E) are incorrect as they do not correspond to the pathogenic mechanism of botulism and do not explain the specific clinical manifestations observed in this case.
Question 4 of 5
A patient has food poisoning. Laboratory analysis revealed a culture of anaerobic gram-positive spore-forming bacteria. What is the most likely kind of the isolated causative agent?
Correct Answer: A
Rationale: The correct answer is A: C. perfringens. This is because Clostridium perfringens is a gram-positive, anaerobic, spore-forming bacterium commonly associated with food poisoning. It produces toxins that cause gastrointestinal symptoms. Proteus vulgaris (B) and P. mirabilis (C) are gram-negative bacteria not typically associated with food poisoning. Vibrio parahemolyticus (D) is a gram-negative bacterium causing seafood-related gastroenteritis, not spore-forming or anaerobic.
Question 5 of 5
An 18-year-old patient has enlarged inguinal lymph nodes, they are painless, thickened on palpation. In the area of genital mucous membrane there is a small-sized ulcer with thickened edges and "laquer"bottom of greyish colour. What is the most probable diagnosis?
Correct Answer: A
Rationale: The correct answer is A: Syphilis. The presentation of painless inguinal lymph nodes, along with a small-sized ulcer with thickened edges and a "laquer" bottom of greyish color on the genital mucous membrane, is classic for primary syphilis. The painless nature of the lymph nodes and the specific characteristics of the ulcer are key features of syphilitic infection. Primary syphilis is caused by the bacterium Treponema pallidum and typically presents with a single, painless ulcer known as a chancre. It is important to consider syphilis in the differential diagnosis of genital ulcers. Summary of other choices: B: Tuberculosis - Unlikely, as tuberculosis typically presents with pulmonary symptoms and does not cause genital ulcers. C: Lepra - Unlikely, as leprosy does not typically present with painless inguinal lymph nodes and the specific ulcer characteristics described. D: Trophic ulcer - Unlikely