Antimicrobial Agents and Resistance

Penicillin is in which class of antibiotics?

How have antibiotic developers overcome bacteria that resist B-lactams by preventing them from entering the cell?

In which decade was the first glycopeptide discovered?

Which drug was easier for microbes to develop resistance towards?

Are Mur enzyme inhibitors bacteriostatic or bactericidal?

Reverse transcriptase has poor proofreading activity. What is a consequence of this?

A patient has unprotected sex with someone who is HIV-positive and soon tests positive for HIV. You prescribe AZT and Nelfinavir in combination therapy. The viral load continues to increase rather than decrease. Based merely on this information, what do you think has occurred?

A patient has unprotected sex with someone who is HIV-positive and soon tests positive for HIV. You prescribe AZT and Nelfinavir in combination therapy. Your clinical microbiologist tests your patient’s HIV strain and find that it is currently not resistant to the drugs you have prescribed. Rather, your patient was not taking every dose of the antiviral cocktail. What should you, the doctor, do?

Doxycycline is an Tetracycline antibiotic used to treat a variety of bacterial infections, such as those causing acne, urinary tract infections, eye infections, and gum disease. However, it is imperative that children and pregnant or nursing mothers do not take this drug, as it can cause permanent yellowing/greying of teeth in babies and children. The tooth discoloration is due to the fact that Tetracyclines can chelate (bind and sequester) the calcium ions needed for normal adult tooth development. Other than calcium, what do Tetracyclines bind to?

Doxycycline is an Tetracycline antibiotic used to treat a variety of bacterial infections, such as those causing acne, urinary tract infections, eye infections, and gum disease. However, it is imperative that children and pregnant or nursing mothers do not take this drug, as it can cause permanent yellowing/greying of teeth in babies and children. A pregnant mother has a urinary tract infection. What antibiotic has the same mode of action as Doxycycline but wouldn’t cause the tooth discoloration in her child?

Rabies virus has a negative-sense single-stranded RNA genome. It is a neurotropic virus that spreads through saliva. There is a drug called Favipiravir that is being tested for use against Rabies. What do you think is the mode of action of Favipiravir?

You have a chronic athlete’s foot infection. Which antifungal cream would be the best choice?

Trimethoprim-sulfamethoxaxole is used to treat Shigellosis. What is the mode of action of this Sulfonamide?

[blank_start]Selective toxicity[blank_end] refers to the ability of an antimicrobial drug to harm the target microbe without harming the host?

In the Kirby-Bauer disk diffusion test, the [blank_start]diameter[blank_end] of the zone of inhibition is measured and used for interpretation.

A scientist discovers that a soil bacterium she has been studying produces an antimicrobial that kills gram-negative bacteria. She isolates and purifies the antimicrobial compound, then chemically converts a chemical side chain to a hydroxyl group. When she tests the antimicrobial properties of this new version, she finds that this antimicrobial drug can now also kill gram-positive bacteria. The new antimicrobial drug with broad-spectrum activity is considered to be [blank_start]semi-synthetic[blank_end].

Which clinical situation would be appropriate for treatment with a narrow-spectrum antimicrobial drug?

Narrow-spectrum antimicrobials are commonly used for prophylaxis following surgery.