microbiology test bank

Correct Answer: C

Rationale: The correct answer is C (25�C) because dimorphic fungi typically grow as molds at lower temperatures. At 25�C, the fungus is likely in its mold phase, which is the preferred temperature range for mold growth. Choices A, B, and D are incorrect because 15�C and 20�C are too low for optimal mold growth, and 37�C is too high as it typically favors the yeast phase of dimorphic fungi. Therefore, the preferred temperature for mold growth of a dimorphic fungus is 25�C.

Correct Answer: D

Rationale: The correct answer is D: P.aeruginosa. This bacterium is commonly found in water and soil, making its presence in indoor air an indicator of poor sanitation. Step 1: P.aeruginosa is an opportunistic pathogen known to cause infections in hospitals. Step 2: Its presence in the air indicates potential contamination and poor air quality. Step 3: Regular monitoring of P.aeruginosa levels can help assess the effectiveness of sanitation measures. Summary: A, B, and C are not suitable indicators of air sanitation in an enclosed space as they are not typically associated with environmental contamination or poor air quality.

Correct Answer: A

Rationale: The correct answer is A: Toxoplasmosis. Toxoplasmosis is a parasitic infection caused by Toxoplasma gondii, which can be transmitted to humans through contact with infected cat feces. During pregnancy, Toxoplasma infection can result in severe birth defects such as microcephaly and mental retardation in the child. In this case, the presence of a cat in the family and the child's abnormalities suggest a possible link to Toxoplasmosis. Other choices are incorrect because: B: Leishmaniasis is a parasitic disease transmitted by sandflies and does not typically cause the specific birth defects mentioned in the scenario. C: Dysentery is a bacterial infection that primarily affects the intestines and does not cause the neurological abnormalities described. D: Balantidiasis is a parasitic infection caused by Balantidium coli, a ciliated protozoan, but it is not associated with

Correct Answer: A

Rationale: Rationale: A is incorrect because whooping cough resurgence is mainly due to decreased vaccine immunity, not changing antigenicity. B is correct as P. aeruginosa can indeed cause infections with blue-green pus due to its pigment production. C is correct as H. influenzae type b capsule is a virulence factor contributing to invasive disease. D is correct as Legionella infection is acquired via inhalation of contaminated water aerosols. Therefore, A is incorrect as the rise in whooping cough is not due to changing antigenicity but vaccine immunity decline.

Correct Answer: C

Rationale: The correct answer is C (25�C) because dimorphic fungi typically grow as molds at lower temperatures. At 25�C, the fungus is likely in its mold phase, which is the preferred temperature range for mold growth. Choices A, B, and D are incorrect because 15�C and 20�C are too low for optimal mold growth, and 37�C is too high as it typically favors the yeast phase of dimorphic fungi. Therefore, the preferred temperature for mold growth of a dimorphic fungus is 25�C.