ATI RN
microbiology chapter 1 test bank Questions
Question 1 of 9
Which of the following agents affect the ribosomes?
Correct Answer: B
Rationale: The correct answer is B: Aminoglycosides. Aminoglycosides are antibiotics that act by binding to the 30S ribosomal subunit, disrupting protein synthesis in bacteria. This interaction affects the ribosomes directly, leading to inhibition of bacterial protein production. Penicillins (A) work by inhibiting cell wall synthesis, Sulfonamides (C) target folic acid synthesis, and Quinolones (D) inhibit DNA gyrase. These mechanisms do not directly affect the ribosomes, making them incorrect choices in this context.
Question 2 of 9
Patient with diarrhoea was admitted to the infection unit. Gram-negative curved rod-like bacteria were founded on bacterioscopic examination of faecal masses. What is the most likely disease in this patient?
Correct Answer: B
Rationale: The correct answer is B: Cholera. Cholera is caused by Gram-negative curved rod-like bacteria called Vibrio cholerae, commonly found in contaminated water or food. The characteristic symptom of cholera is profuse watery diarrhea, which matches the patient's presentation. Typhoid fever (A) is caused by Salmonella typhi, which is not a curved rod-like bacteria. Diphtheria (C) is caused by Corynebacterium diphtheriae, a Gram-positive bacterium, and does not typically cause diarrhea. Intestinal form of plague (D) is caused by Yersinia pestis, which is not a curved rod-like bacteria and does not typically present with diarrhea.
Question 3 of 9
A 30 year old patient consulted a doctor about having diarrhea and stomach aches for 5 days, temperature rise up to 37,50C with chills. The day before the patient was in a forest and drank some water from an open pond. He was diagnosed with amebic dysentery that was bacteriologically confirmed. Name the medication for treatment of this disease:
Correct Answer: A
Rationale: The correct answer is A: Metronidazole. Amebic dysentery is caused by the parasite Entamoeba histolytica, not a bacterium, hence antibiotics like Chloramphenicol or Phthalazole are ineffective. Metronidazole is the drug of choice for treating amebic dysentery due to its efficacy against anaerobic organisms like Entamoeba histolytica. Furasolidone is used for treating bacterial infections, not parasitic ones like amebiasis. The patient's symptoms of diarrhea, stomach aches, and a recent history of drinking water from a potentially contaminated source in the forest are indicative of a parasitic infection, supporting the choice of Metronidazole for treatment.
Question 4 of 9
Which one is true about the laboratory diagnosis of urinary tract infections
Correct Answer: D
Rationale: The correct answer is D because it encompasses the true statements regarding the laboratory diagnosis of urinary tract infections. A: Bacteriuria of less than 10^5 can be significant in treated patients due to the development of antibiotic resistance. B: Staphylococcus aureus, Salmonella typhi, and Mycobacterium tuberculosis may be significant regardless of quantity due to their pathogenic nature. C: Leukocyturia indicates inflammation, and even a lower number of leukocytes can be clinically significant. Therefore, option D covers all these aspects making it the correct choice.
Question 5 of 9
Fimbriae ARE NOT:
Correct Answer: B
Rationale: Step-by-step rationale: 1. Fimbriae are hair-like structures on bacteria, not rope-like. 2. Fimbriae are smaller in diameter compared to flagella. 3. Fimbriae are used for adherence or conjugation, not flagella. Therefore, choice B is correct as it incorrectly describes fimbriae, while choices A, C, and D correctly characterize fimbriae.
Question 6 of 9
All of the following are considered to be zoonotic diseases except:
Correct Answer: D
Rationale: The correct answer is D: salmonellosis. Zoonotic diseases are those that can be transmitted from animals to humans. Salmonella is not directly transmitted from animals to humans, instead, it is typically transmitted through contaminated food or water. Brucellosis (A), undulant fever (B), and plague (C) are all zoonotic diseases that can be directly transmitted from animals to humans through various means. Therefore, salmonellosis does not fit the definition of a zoonotic disease, making it the correct answer.
Question 7 of 9
A puncture sample taken from the lymph node of a patient with preliminary diagnosis of protozoan disease has been investigated. The preparation was processed with Giemsa stain and the following was detected: crescent-shaped bodies with pointed tips, blue cytoplasm and red nuclei. What protozoa have been detected in the preparation?
Correct Answer: D
Rationale: The correct answer is D: Viscerotropic Leishmania. The presence of crescent-shaped bodies with pointed tips, blue cytoplasm, and red nuclei is characteristic of Leishmania species. Viscerotropic Leishmania causes visceral leishmaniasis, also known as kala-azar, which affects the internal organs. Toxoplasma typically presents as tachyzoites, not crescent-shaped bodies. Plasmodium malariae is a malaria parasite with different morphology. Dermatotropic Leishmania causes cutaneous leishmaniasis, not the visceral form indicated by the morphology described in the question.
Question 8 of 9
48 hours after performing tuberculin test (Mantoux test) to a child a 10 mm papule appeared on the spot of tuberculin introduction. What hypersensitivity mechanism underlies these changes?
Correct Answer: D
Rationale: The correct answer is D: Granulomatosis. The appearance of a 10 mm papule 48 hours after the Mantoux test indicates a delayed-type hypersensitivity reaction, which is characteristic of granulomatosis. This type of reaction involves activation of macrophages and T cells, leading to the formation of granulomas. Granulomas are organized collections of immune cells that wall off the antigen, in this case, the tuberculin antigen. A, B, and C are incorrect: A: Cellular cytotoxicity involves the destruction of target cells by immune cells such as cytotoxic T cells or natural killer cells. This mechanism is not associated with the delayed-type hypersensitivity reaction seen in granulomatosis. B: Anaphylaxis is a rapid and severe allergic reaction involving IgE-mediated release of histamine and other inflammatory mediators. This is not the mechanism underlying the delayed-type hypersensitivity reaction in the Mantoux test. C: Antibody-dependent cytotoxic
Question 9 of 9
Patient with vomiting, dizziness, sensation of dubble vision, difficult swallowing was admitted to the hospital. Doctor suspects botulism. What diagnostic methods should be used for diagnosis approving?
Correct Answer: C
Rationale: The correct answer is C: Biological test, bacteriological. Botulism is caused by the toxin produced by Clostridium botulinum bacteria. To diagnose botulism, biological tests such as detecting the toxin in patient samples and bacteriological tests to identify the bacteria are crucial. These tests confirm the presence of the bacteria and its toxin, providing a definitive diagnosis. Choice A is incorrect as it does not specify any relevant diagnostic methods. Choice B is incorrect because mycological tests are not relevant for diagnosing botulism caused by a bacterial toxin. Choice D is incorrect as allergic tests and serological tests are not used for diagnosing botulism.