Researchers Studying Fungal Pathogens Isolated an Ergosterol Biosynthetic Gene by Polymerase

question 299

Multiple Choice

Researchers studying fungal pathogens isolated an ergosterol biosynthetic gene by polymerase chain reaction.  Using homologous recombination, they then developed a new strain of Candida with a mutated allele for that gene.  The mutant strain was cultured in the presence of several different antifungal agents.  Compared to isolates from the wild-type strain, isolates from the mutant Candida strain exhibited enhanced growth in the presence of drug X.  Further investigation revealed that the mechanism of resistance to drug X was a decrease in ergosterol incorporation into the cell membrane.  Based on this data, drug X is likely to be most closely related to which of the following antifungal agents?

• A)Caspofungin
• B)Cyclosporine
• C)Flucytosine
• D)Griseofulvin
• E)Nystatin

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Definitions:

Myxoma Virus

A leporipoxvirus that causes myxomatosis, a disease in rabbits and hares characterized by skin tumors and often leads to death.

Virulent

Characterized by a high degree of pathogenicity; capable of causing disease.

Transmission

The process of transferring something from one place, person, or organism to another, used in various contexts including genetics and infectious diseases.

Parasitism Success

The effectiveness with which a parasite is able to infect, exploit, and potentially reproduce within its host organism.