ATI RN
Mastering Microbiology Test Bank Questions
Question 1 of 9
A female who had been continuously taking antibiotics for an intestinal infection developed a complication manifested by inflammation of the oral mucosa and white deposit. Bacteriological study of the deposit samples revealed yeast fungi Candida albicans. Which of the following medications is indicated for the treatment of this complication?
Correct Answer: A
Rationale: Rationale for Correct Answer (A: Fluconazole): Fluconazole is an antifungal medication used to treat yeast infections caused by Candida albicans. It targets the fungal cell membrane, disrupting its structure and function. This makes it an effective treatment for oral thrush, which is caused by Candida overgrowth in the oral mucosa. The continuous use of antibiotics can disrupt the normal balance of microorganisms in the body, leading to fungal overgrowth. Fluconazole specifically targets the yeast fungi without affecting bacteria, making it the appropriate choice for this complication. Summary of Incorrect Choices: B: Biseptol - Biseptol is an antibiotic that targets bacteria, not fungi like Candida albicans. C: Tetracycline - Tetracycline is also an antibiotic that targets bacteria, not fungi. D: Furazolidone - Furazolidone is an antibiotic primarily used for treating bacterial infections, not fungal infections like oral thrush caused by Candida
Question 2 of 9
Which of the following is a feature of Gram-negative bacteria?
Correct Answer: B
Rationale: The correct answer is B: Outer membrane with lipopolysaccharides. Gram-negative bacteria have an outer membrane containing lipopolysaccharides (LPS), which are important in pathogenesis and immune response. This feature is unique to Gram-negative bacteria, distinguishing them from Gram-positive bacteria (choice A). Teichoic acids (choice C) are found in the cell walls of Gram-positive bacteria, not Gram-negative. The statement in choice D, absence of a cell wall, is incorrect as all bacteria have a cell wall, although the composition may vary between Gram-negative and Gram-positive bacteria.
Question 3 of 9
The virus most commonly transmitted during pregnancy is:
Correct Answer: A
Rationale: The correct answer is A: cytomegalovirus. CMV is the most common virus transmitted during pregnancy, leading to potential serious complications for the fetus. It can cause birth defects, hearing loss, and developmental delays. CMV is commonly spread through bodily fluids. HIV (B) can also be transmitted during pregnancy but is less common. Herpes simplex virus (C) can be transmitted but typically results in localized infection. Epstein-Barr virus (D) is not commonly transmitted during pregnancy.
Question 4 of 9
A 34-year-old male visited Tajikistan. After return, he complains of fever up to 40oC which occurs every second day and is accompanied by chills, sweating. Hepatosplenomegaly is present. Blood test results: RBC- 3x1012/l, b- 80 g/l, WBC- 4x109/l, eosinophils - 1%, stab neutrophils - 5%, segmented neutrophils - 60%, lymphocytes - 24%, monocytes - 10%, ESR - 25 mm/h. What is the provisional diagnosis?
Correct Answer: A
Rationale: The correct answer is A: Malaria. The patient's travel history to an endemic area like Tajikistan, along with symptoms of fever with chills, sweating, and hepatosplenomegaly, are classic for malaria. The blood test results show anemia (low RBC and hemoglobin levels), which can occur in malaria due to hemolysis. The presence of eosinophils and lymphocytes are not typical for malaria, but the overall clinical picture fits. Infectious mononucleosis (choice B) typically presents with sore throat, lymphadenopathy, and atypical lymphocytosis, which are not seen in this case. Sepsis (choice C) is characterized by systemic inflammatory response syndrome and organ dysfunction due to infection, which does not align with the symptoms and findings in the case. Typhoid fever (choice D) usually presents with gradual onset of sustained fever, abdominal pain, headache, and constipation, which are not present in this patient
Question 5 of 9
Production of auto-antibodies may be due to:
Correct Answer: D
Rationale: Production of auto-antibodies can be due to various factors. Mutant B cell clones can lead to the production of self-reactive antibodies. Antibodies against hidden tissues can also trigger autoimmune responses. Genetic factors play a crucial role in predisposing individuals to autoimmunity. Therefore, the correct answer is D, as all these factors can contribute to the production of auto-antibodies. Choice A is incorrect as it only addresses one possible cause. Choice B is incorrect as it focuses solely on antibodies against hidden tissues. Choice C is incorrect as it overlooks the other potential reasons for auto-antibody production.
Question 6 of 9
Typhoid fever is caused by the bacterium:
Correct Answer: B
Rationale: The correct answer is B: Salmonella enterica. Typhoid fever is caused by the bacterium Salmonella enterica serotype Typhi. This specific strain of Salmonella is responsible for typhoid fever, a serious illness characterized by high fever, abdominal pain, and diarrhea. Escherichia coli (choice A) is not the causative agent of typhoid fever. Shigella flexneri (choice C) causes bacillary dysentery, not typhoid fever. Staphylococcus aureus (choice D) can cause food poisoning but is not associated with typhoid fever.
Question 7 of 9
The Gram stain is used to differentiate bacteria based on:
Correct Answer: B
Rationale: The Gram stain differentiates bacteria based on cell wall structure. It classifies bacteria into Gram-positive (purple) and Gram-negative (pink) based on the presence of peptidoglycan in the cell wall. This method helps in identifying the bacterial species and determining appropriate treatment. Option A (Cell shape) is incorrect because the Gram stain focuses on cell wall composition, not cell shape. Option C (Flagella composition) is incorrect as the Gram stain does not assess flagella. Option D (Nutrient requirements) is incorrect as it does not relate to the purpose of the Gram stain.
Question 8 of 9
A 34 year old male patient consulted a doctor about face carbuncle. Objectively: a loose, painless edema of hypodermic tissue; black crust in the center of carbuncle, vesicular rash around it. Microbiological examination revealed static streptobacilli capable of capsule building. What microorganisms are the causative agents of this disease?
Correct Answer: B
Rationale: The correct answer is B: Staphylococcus aureus. This bacterium is a common causative agent of skin infections like carbuncles. Staphylococcus aureus is known for its ability to produce pus-filled abscesses, which aligns with the symptoms described in the question. The presence of a vesicular rash around the carbuncle further supports this diagnosis, as Staphylococcus aureus can cause skin lesions. The other choices are not correct because: A: Bacillus anthracis causes anthrax, which presents with different symptoms such as fever, malaise, and respiratory symptoms. C: Bacillus subtilis is a harmless soil bacterium commonly used in research and not known to cause skin infections. D: Bacillus anthracoides is not a known pathogen and is not associated with human infections.
Question 9 of 9
A patient has a suspected pneumonia. In his sputum there were revealed gram-positive diplococci, prolonged with the slightly pointed opposite ends. What microorganisms are revealed in the sputum?
Correct Answer: A
Rationale: Rationale: The description matches that of Streptococcus pneumoniae, which appears as gram-positive diplococci with slightly pointed opposite ends. Staphylococcus aureus, Neisseria gonorrhoeae, and Neisseria meningitidis do not match the specific characteristics described in the question. Staphylococcus aureus appears in grape-like clusters, while Neisseria species are typically seen as diplococci but lack the pointed shape described. Therefore, the correct answer is A: Staphylococcus aureus.