Antibacterial Agents Quiz

teeth discoloration, hepatotoxicity esp in pregnant women, increased BUN; not metabolized in the liver, lyme disease/periodontal disease, preventative for bubonic plague

not a first choice drug due to typhoid fever, meningitis, infections; can cause reversible bone marrow depression, Gray baby syndrome in infants and aplastic anemia

Co-trimoxazole is DOC for UTI's; can cause Steven-Johnson disease, low allergies, severe jaundice in infants; drugs are sulfa drugs

Cartialage damage in women and children under 18, cause seizures

Used when sepsis/endocarditis is suspected; bact. resistance extends to all; used mostly in combination (neomycin+bacitracin+polymyxin to treat scars after plastic surgery); ototoxicity/nephrotoxicity

The correct answer is "all of the above". Metronidazole's mechanism of action is not fully understood, but it is known to be bactericidal through the production of reactive oxygen species (ROS). It is effective against anaerobic bacteria. Additionally, metronidazole can cause a disulfiram-like effect, which means it can produce unpleasant symptoms like nausea, vomiting, and flushing when consumed with alcohol.

excreted renally and meropenem does not cause seizures

The statement "All of the above" is the correct answer because all the statements mentioned are true. Vancomycin prevents peptidoglycan elongation and is bactericidal, making it effective against penicillin/methicillin-resistant S. aureus. It is often considered a drug of last resort because VRE (vancomycin-resistant enterococci) are usually resistant to all other antibiotics. Vancomycin does have adverse effects such as ototoxicity, nephrotoxicity, and red man syndrome, which is characterized by flushing due to histamine release. Therefore, all the statements mentioned in the question are correct.

The correct answer is "All of the above are correct." Erythromycin is indeed powerless against many Gram-negative bacteria, as it is primarily effective against Gram-positive bacteria. It is also the drug of choice (DOC) for treating Legionnaire's disease and Mycoplasma pneumoniae infections. Therefore, all of the statements provided in the options are accurate.

It is also present in high concentration in the bones and can be used to treat severe anaerobic infections as well as acne when administered topically

The above 3 are resistant to penicillinase

Yes! This is the Cephalosporins' mechanism of action.

They are also excreted in the kidney

They also cause a disulfiram-like reaction after EtOH consumption and can cause allergies and GI symptoms (nausea, vomiting, anorexia, diarrhea)

Macrolides and aminoglycosides are known as inhibitors of protein synthesis. This is because they interfere with the process of protein synthesis in bacterial cells, thereby inhibiting bacterial growth and reproduction. These antibiotics bind to the ribosomes, which are responsible for protein synthesis, and prevent them from functioning properly. As a result, the bacteria are unable to produce essential proteins and eventually die. It is worth noting that penicillins, although mentioned in the options, do not belong to the same class of antibiotics as macrolides and aminoglycosides.

If a microbiologist wants to inhibit the growth of most G+ species, he can culture a mixture in an Erythromycin agar (most of G- will grow)

the above are used against B-lactamase positive S. aureus

Cefepime is the only 4th generation cephalosporin, meaning it is the most advanced generation of this class of antibiotics. It is more resistant to B-lactamase, an enzyme that can break down certain antibiotics, making it more effective against resistant bacteria. Cefepime can only be given parenterally, meaning it is administered through injection or infusion. It has antipseudomonal activity, meaning it is effective against Pseudomonas aeruginosa, a common and often resistant bacteria. Additionally, cefepime has better coverage against Gram-positive bacteria compared to other cephalosporins. It is excreted renally, meaning it is eliminated from the body through the kidneys. Therefore, all of the statements are correct.

The broader the spectrum, the lesser these antibiotics are effective against G+ bacteria :)

Ampicillin is not a narrow spectrum penicillin because it is effective against both gram-positive and gram-negative bacteria. Narrow spectrum penicillins, on the other hand, are only effective against a limited range of bacteria, usually targeting gram-positive bacteria. Examples of narrow spectrum penicillins include Penicillin G, Penicillin V, Benzathine penicillin, and Procaine Penicillin.

The general properties of 1st generation cephalosporins include good coverage against Gram-positive bacteria and moderate activity against Gram-negative bacteria. They do not have any antipseudomonal activity. They are excreted through the kidneys and can be given orally due to their resistance to acid. Therefore, all of the statements provided are true for 1st generation cephalosporins.

Pen. V is resistant to gastric acid destruction

These have a huge G- coverage and anaerobe coverage when combined with penicillinase inhibitors such as clavulanic acid and sulbactam

Cycloserine is a broad-spectrum antibiotic that inhibits the attachment of peptide side chains to the peptidoglycan, which is a component of bacterial cell walls. It is also used specifically to treat tuberculosis as a second-line treatment. Therefore, all of the statements provided in the options are correct, making "all of the above" the correct answer.

The known side effects of Pen. G are hypersensitivity and diarrhea.

G+ cocci include S. pneumoniae, and S. pyrogenes
G- cocci include N. meningitidis and N. gonorrhoeae
G+ bacilli are B. anthracic, C. perfringens, L. monocytogenes, and C. diphtheriae

Bacteria can build resistance against antipseudomonaal penicillins through multiple means. One way is through inactivation, where the penicillins are destroyed by b-lactamase enzymes produced by the bacteria. Another way is through decreased permeability of the bacterial cell wall or the absence of a cell wall, which can prevent the penicillins from entering the bacteria. Additionally, bacteria can develop resistance by altering their penicillin-binding proteins (PBP's), making it difficult for the penicillins to bind and inhibit bacterial growth. Lastly, bacteria can also develop resistance by inactivating autolytic enzymes, which are responsible for breaking down the bacterial cell wall. Therefore, all of the mentioned mechanisms contribute to the development of resistance against antipseudomonaal penicillins.

Penicillin G has NO antipseudomonal activity!

Cell wall inhibitor

The correct answer is "All of the above." This means that all of the options listed (allergy-anaphylactic shock, electrolyte imbalance, GI disturbances, and superinfections) are potential manifestations of penicillin toxicity.

Augmentin (Amoxicillin+clavulanic acid) is given orally only, treats B-lactam organisms, can treat severe otitis media and animal bites

The statement is true because Ampicillin rash is not a hypersensitivity reaction in children or patients with EBV infection. Ampicillin rash is a common side effect of the antibiotic Ampicillin and is not related to an allergic or hypersensitivity reaction. It is characterized by a non-allergic, non-immunologic rash that occurs in individuals who are taking Ampicillin. However, it is important to note that in rare cases, a severe allergic reaction known as anaphylaxis can occur with Ampicillin use, but this is not specific to children or patients with EBV infection.

Antipseudomonal penicillins are acid sensitive, therefore, they can only be given parenterally!

The pair "allergic to penicillins-ampicillins" is mismatched because ampicillin is a type of penicillin. Therefore, if someone is allergic to penicillins, they would also be allergic to ampicillins.

2nd generation cephalosporins do lack antipseudomonal activity, but are acid resistant, therefore they can be administered orally