Cell wall inhibitor synthesis ppt questions Flashcards
The primary mechanism of antibacterial action of the penicillins involves inhibition of:
A. Beta-lactamases
B. Cell membrane synthesis
C. Reactions involving transpeptidation
D. Porin insertion into membranes
C
- Methicillin-resistant Staphylococcus aureus is a common nosocomial pathogen that is increasing in frequency in community settings. Which of the following best describes the most common mechanism of resistance to methicillin or dicloxacillin by S. aureus?
A. Reduced permeability to beta-lactams
B. Acquisition of the novel protein PBP2a
C. Increased efflux of beta-lactams
D. Expression of narrow spectrum beta-lactamases
B
- Select the FALSE statement concerning penicillin G:
A. It is eliminated from the body primarily by renal excretion.
B. It has reliable antimicrobial activity against most gram positive cocci.
C. It is less reliably absorbed following oral administration than penicillin VK.
D. It is effective in treating infections caused by penicillinase-producing organisms.
D
- Select the FALSE statement concerning use of ampicillin:
A. Antibacterial activity is enhanced by sulbactam
B. Causes maculopapular rashes
C. Eradicates most strains of methicillin-resistant Staphylococcus aureus
D. May cause pseudomembranous colitis with extended use
C.
- Amoxicillin (extended-spectrum penicillin) shares all of the following properties with cephalexin (1st C ) EXCEPT:
A. Bactericidal action
B. Elimination primarily by the kidneys
C. Beta-lactam ring in structure
D. High susceptibility to narrow-spectrum beta-lactamases
D.
- A major distinction between 1st and 3rd generation cephalosporins is:
A. 3rd generation agents have less activity against Pseudomonas
B. 1st generation agents have increased penetration into the CNS
C. 3rd generation agents have increased activity against resistant gram-negative organisms
D. 1st generation agents have greater activity against methicillin-resistant Staphylococcus aureus
C
- A 21-year-old man was seen in a clinic with a complaint of dysuria and urethral discharge of yellow pus. Gram stain of the urethral exudate showed gram-negative diplococci. The most appropriate treatment of gonorrhea in this patient is:
A. Ceftriaxone (3rd C) IM X 1
B. Ceftriaxone (3rd C) IM X 1 + Azithromycin po X 1
C. Tetracycline (TCN) orally for 7 days
D. Benzathine penicillin G (nPCN) as a single IM dose
B
m1.A 30-year-old man who only has sex with women presents with nongonococcal urethritis (NGU). Which of the following organisms is the most likely cause of NGU is this patient
A. Neisseria gonorrheae B. Mycoplasma genitalium C. Herpes simplex II D. Escherichia coli E. Chlamydia trachomatis
E.
- Select the FALSE statement concerning inhibitors of cell wall synthesis:
A. Vancomycin and piperacillin/tazobactam have activity against Bacteroides species
B. The concentration of penicillin G in the CSF is higher when administered to patients with meningococcal meningitis than it is when given to normal, uninfected patients.
C. 3rd generation cephalosporins have greater activity against Pseudomonal infections than 1st generation cephalosporins.
D. 1st generation cephalosporins should not be given to patients with a Type I anaphylactic reaction to amoxicillin.
A
. Vancomycin:
A. Is bacteriostatic B. Is active against E. Coli C. Has advantage of oral bioavailability D. Requires dosage reduction in renal impairment E. Is inactivated by beta-lactamases
D
- Which of the following adverse reactions is associated with vancomycin?
A. Flushing reaction if taken with alcohol
B. Red man syndrome
C. Hepatotoxicity
D. Superinfections with C. difficile
B
m2.A 65-year-old man with a 2-day history of sore throat, nasal congestion, and cough comes to your office because his wife told him he needs to take an antibiotic. You could tell him that:
A. He should be treated with a single IM injection of ceftriaxone (Rocephin)
B. He should be treated with 5 days of azithromycin (Z-Pak)
C. Most cases of acute sinusitis and pharyngitis are viral and should not be treated with antibiotics
D. He should be treated with oseltamivir for 5 days
C
m3.The drug of choice for treatment of group A streptococcus pharyngitis in adults is:
A. Clindamycin B. Amoxicillin C. Penicillin V D. Doxycycline E. Trimethoprim/sulfamethoxazole
B
m4.Uncomplicated skin and soft tissue infections in immuno-competent patients are commonly caused by:
A. Pseudomonas aeruginosa B. Streptococcus pyogenes C. Escherichia coli D. Anaerobes E. Staphylococcus aureus
E.
m5.An otherwise healthy woman presents to a walk-in clinic with a cutaneous abscess (purulent) on her forearm. The organism most commonly responsible for this type of infection in many parts of the US is:
A. Streptococcus pyogenes
B. Methicillin-sensitive Staphylococcus aureus (MSSA)
C. Methicillin-resistant Staphylococcus aureus (MRSA)
D. Herpes simplex virus I
E. Escherichia coli
C
