ATI RN
Medical Microbiology Test Bank Questions
Question 1 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 2 of 5
Several patients with similar complaints came to the doctor. They all present with weakness, pain in the intestines, indigestion. Feces analysis revealed the need for urgent hospitalization of the patient, who had microbial cysts with four nuclei detected in his samples. Such cysts are characteristic of the following protozoon:
Correct Answer: A
Rationale: The correct answer is A: Entamoeba histolytica. This protozoon is known to cause amoebic dysentery, presenting symptoms of weakness, intestinal pain, and indigestion. The presence of microbial cysts with four nuclei in fecal samples is characteristic of Entamoeba histolytica. These cysts are the infective form of the parasite and can cause severe invasive disease in the intestines. Incorrect choices: B: Entamoeba coli does not typically cause invasive disease or severe symptoms like those described in the question. C: Balantidium is a ciliated protozoan that causes balantidiasis, which presents differently from the symptoms described in the question. D: Trichomonad is a flagellated protozoan that typically infects the urogenital tract, not the intestine, and does not form cysts with four nuclei. In summary, the key clues in the question were the symptoms of weakness, intestinal pain,
Question 3 of 5
A patient of oral surgery department has developed a purulent complication. Bacteriological analysis of the wound discharge allowed to isolate a culture producing a blue-and-green pigment. Which of the listed microorganisms may be a causative agent of the infection?
Correct Answer: A
Rationale: The correct answer is A: Pseudomonas aeruginosa. Pseudomonas aeruginosa is known for producing a blue-green pigment called pyocyanin, which is characteristic of its colonies. This bacterium is commonly associated with purulent infections, especially in immunocompromised patients. Proteus vulgaris (B) is not typically associated with blue-green pigment production. Bacillus subtilis (C) is not a common pathogen in wound infections. Klebsiella pneumoniae (D) does not produce blue-green pigment and is more commonly associated with respiratory infections. Therefore, based on the clinical presentation and pigment production, Pseudomonas aeruginosa is the most likely causative agent in this case.
Question 4 of 5
Before a surgery the patient was prescribed a synthetic antiprotozoal drug for prevention of wound infection. The prescribed drug is highly effective against Helicobacter pylori. Name this drug:
Correct Answer: A
Rationale: Step-by-step rationale: 1. Metronidazole is a synthetic antiprotozoal drug commonly used for wound infection prevention. 2. It is highly effective against Helicobacter pylori, a bacterium that causes stomach ulcers. 3. Metronidazole works by disrupting DNA structure in bacteria, leading to their death. 4. Chingamin (Chloroquine) is an antimalarial drug, not effective against Helicobacter pylori. 5. Doxycycline hydrochloride is an antibiotic used for bacterial infections, not specifically for H. pylori. 6. Aciclovir is an antiviral drug used for herpes infections, not effective against H. pylori. Summary: Metronidazole is the correct answer as it is specifically effective against H. pylori and commonly used for wound infection prevention. Other choices are incorrect as they target different types of infections.
Question 5 of 5
An 18-year-old patient has developed candidiasis after the case of pneumonia treated with β- lactam antibiotic. What antimycotic agent should be prescribed?
Correct Answer: B
Rationale: The correct answer is B: Fluconazole. Rationale: 1. Candidiasis is a fungal infection, so an antimycotic agent is needed. 2. β-lactam antibiotics like ampicillin can lead to fungal overgrowth, necessitating an antimycotic. 3. Fluconazole is an antifungal agent effective against Candida species. 4. Streptomycin is an antibiotic, not an antifungal. 5. Phthalylsulfathiazole is an antibacterial sulfonamide, not an antifungal. 6. Ampicillin is an antibiotic, not an antifungal.