ATI RN
Medical Microbiology Test Bank Questions
Question 1 of 5
A bacteriological laboratory studied the home-made dried fish which had caused a severe food poisoning. Microscopy of the culture grown on the Kitt-Tarozzi medium revealed microorganisms resembling a tennis racket. What is the most likely diagnosis?
Correct Answer: B
Rationale: The correct answer is B: Salmonellosis. The description of microorganisms resembling a tennis racket indicates the presence of Salmonella typhi, which causes salmonellosis. Salmonella bacteria can appear like tennis rackets under a microscope due to their flagella. Botulism (A) is caused by Clostridium botulinum, which does not resemble a tennis racket. Cholera (C) is caused by Vibrio cholerae, which appears as curved rods under the microscope. Dysentery (D) is usually caused by bacteria like Shigella or Entamoeba histolytica, which do not resemble tennis rackets.
Question 2 of 5
A 32 y.o. man is divorced, has an irregular sexual life. He complains of falling out of hair in the region of eyelashes, eyebrows, scalp. Objectively: diffuse alopecia is observed, eyebrow margin is absent, eyelashes are stair-like (Pinkus' sign). What examination should be carried out first of all?
Correct Answer: A
Rationale: The correct answer is A: Wasserman test, IFT. The patient's symptoms of diffuse alopecia and Pinkus' sign are suggestive of secondary syphilis. The Wasserman test and Immunofluorescence Test (IFT) are used to detect antibodies against Treponema pallidum, the bacterium causing syphilis. This would confirm or rule out syphilis as the underlying cause of the patient's symptoms. Choice B (T.pallidum Immobilization Test) is similar to the Wasserman test but less commonly used. Choice C (Detection of the nasal mucous membrane for M.leprae) is irrelevant as leprosy does not present with the described symptoms. Choice D (Consultation of neuropathist) is premature without ruling out syphilis first. Thus, the Wasserman test, IFT should be the initial examination to investigate the likely cause of the patient's symptoms.
Question 3 of 5
Among public catering workers examined by doctors of sanitary and epidemiologic station often occur asymptomatic parasite carriers. This means that a healthy person carries cysts that infect other people. Such parasitizing is possible for the following causative agent:
Correct Answer: A
Rationale: Rationale: 1. Dysenteric amoeba (Choice A) is the correct answer because it can exist asymptomatically in carriers and be transmitted through cysts. 2. Malarial plasmodium (Choice B) causes malaria, not carried asymptomatically in cysts. 3. Intestinal trichomonad (Choice C) causes trichomoniasis, not carried asymptomatically in cysts. 4. Dermatotropic leishmania (Choice D) causes skin lesions, not carried asymptomatically in cysts.
Question 4 of 5
A patient has roundish ulcers on his face, inflammation and enlargement of lymph nodes. These symptoms turned up as a result of mosquito bites. Laboratory examination of discharge from the ulcers revealed unicellular aflagellar organisms. What is the most probable diagnosis?
Correct Answer: A
Rationale: The most probable diagnosis is Dermatotropic leishmaniasis. The roundish ulcers, lymph node enlargement, and presence of unicellular aflagellar organisms in discharge are characteristic of this parasitic infection transmitted by sandfly bites. Leishmania parasites cause skin lesions and lymphadenopathy. Toxoplasmosis (B) presents with flu-like symptoms, not ulcers. Scabies (C) causes intense itching and burrows, not ulcers. Trypanosomiasis (D) presents with fever, not ulcers. In this case, the symptoms align closely with Dermatotropic leishmaniasis, making it the most likely diagnosis.
Question 5 of 5
2 weeks since the blood transfusion a recepient has developed fever. What protozoal disease can it be?
Correct Answer: B
Rationale: The correct answer is B: Malaria. Fever developing 2 weeks post-blood transfusion is characteristic of malaria due to the incubation period of the parasite. Trypanosomiasis presents earlier, amebiasis usually causes GI symptoms, and toxoplasmosis typically manifests with flu-like symptoms. Malaria is the most likely cause based on the timing and clinical presentation.