Question

1. Which two antimicrobial drugs inhibit sequential steps in the synthesis of folic acid?

		penicillin and sulfamethoxazole
		sulfamethoxazole and trimethoprim
		penicillin and gentamicin
		erythromycin and penicillin
		trimethoprim and synercid

1. True/False: Viral infections are generally easier to treat than bacterial infections because viruses do not have a cellular structure.

		True
		False

1. Superinfection is most likely to result from

		a narrow spectrum antibiotic
		an extremely invasive, pathogenic organism that is antibiotic resistant
		the same organism re-infecting a patient after discontinuing antibiotic therapy
		a broad spectrum antibiotic

Acyclovir and closely related drugs (gancyclovir, valcyclovir, famcyclovir) are most often used in the treatment of infections caused by

		Hepatitis C virus
		Rabies virus
		Zika virus
		Herpes viruses
		Measles virus

QUESTION

Methicillin-resistant Staphylococcus aureus (MRSA) is typically  resistant to all “–cillins,” including those –cillins resistant to the effects of beta lactamase as well as to the extended spectrum cillins. This resistance is due to

		beta lactamase enzymes that destroy the –cillins
		a modified target protein (penicillin –binding protein) in the cell membrane of the bacteria that –cillins can no longer bind to
		a membrane pump that pumps the –cillins out of the cell
		a narrower porin molecule that prevents –cillins from getting into the cell

QUESTION 16

1. Which of the following groups of antibiotics must be closely monitored in the patient due to risk of ototoxicity and nephrotoxicty?

		the beta lactam antibiotics
		the monobactams
		aminoglycosides (gentamicin)
		cephalosporins
		the fluoroquinolones

Answer 1

First Question:

The answer will be sulfamethoxazole & trimethoprim (Second option).

Explanation: Sulfamethoxazole inhibits the step of dihydropteroic acid formation from para-aminobenzoic acid. Trimethoprim inhibits the step of tetrahydrofolic acid formation from dihydrofolic acid. So, correct answer will be second option.

Second Question:

The statement is false.

Explanation: Viral infection is difficult to treat than bacterial infection & also they have a cellular structure. As they reside inside body's cells, they are difficult to kill without harming the host cells.

Third Question:

The answer will be a broad spectrum antibiotic (Last option).

Explanation: Superinfection is a condition which occurred when treatment for first infection disrupted the normal microbiome of the body & provide a passage for a second infection. When treating with broad spectrum antibiotic, a large number of microbes are killed & disrupted the normal microbiome of the body. It provides an opportunity for a single drug resistant pathogen to grow & cause an infection. Thus, it is recommended to use narrow spectrum antibiotics whenever possible as it will only kill a targeted organism & will not make major disruption in the normal microbiome of the body.

Fourth Question:

The answer will be herpes viruses (Fourth option).

Explanation: Acyclovir & related drugs are primarily used for treatment against herpes viruses, chickenpox & shingles. So, correct answer will be fourth option.