Corynebacterium diphtheriae & Diphtheria Quiz

Diphtheria and Listeriosis

• Diphtheria is caused by the bacterium Corynebacterium diphtheriae.
• Diphtheria is primarily spread through respiratory droplets from coughs or sneezes, and through direct contact with contaminated surfaces.

Listeria Monocytogenes

• The primary reservoir of Listeria monocytogenes is environmental sources, particularly soil and water, and it is commonly found in contaminated food products.
• Listeriosis, an infection with a high mortality rate, is caused by Listeria monocytogenes.

Growth Conditions of Listeria

• Listeria monocytogenes can grow at refrigeration temperatures due to its ability to thrive in the psychrotolerant range, allowing it to survive in cold environments.

Antibiotics and Mechanisms

• The group of antibiotics that inhibits bacterial cell wall synthesis includes beta-lactams, such as penicillin.
• Penicillin works by interfering with the formation of the bacterial cell wall, leading to cell lysis.

Susceptibility to Penicillin

• Gram-positive bacteria are more susceptible to penicillin due to their thick peptidoglycan layer, which is targeted by the antibiotic.
• A common side effect of penicillin is allergic reactions, which can range from mild rashes to severe anaphylaxis.

Antibiotic Activity

• The group of antibiotics that is more active against Gram-negative bacteria includes aminoglycosides and polymyxins.
• Beta-lactam antibiotics primarily inhibit bacterial cell wall synthesis and are effective against various bacteria.
• The primary mechanism of action of penicillin involves binding to penicillin-binding proteins, which are crucial for cell wall biosynthesis.

Treatment Considerations

• Beta-lactam antibiotics, such as penicillin, are commonly used to treat Gram-positive bacteria, due to their effectiveness against those pathogens.
• The most common side effect of penicillin is gastrointestinal upset, including nausea and diarrhea, alongside allergic reactions.