Antibiotics

Question 1

Which medications are protein synthesis inhibitors?

Answer 1

AcTions at 30, CELebrationS at 50:
- Aminoglycosides and Tetracyclines are 30S inhibitors;
- Chloramphenicol/Clindamycin, macrolides (e.g., Erythromycin), Linezolid, and Streptogramin are 50S
inhibitors.

All protein synthesis inhibitors are bacteriostatic, except aminoglycosides (bactericidal) and linezolid (can be either bactericidal or bacteriostatic depending on concentration).

Question 2

Necrotising fasciitis

• Organisms involved
• Treatment

Answer 2

• Life threatening subcutaneous soft tissue infection that may extend to the deep fascia
• Monomicrobial: Strep pyogenes, Staph aureus OR
• Polymicrobial (+ coliforms, anaerobes, other streptcoccus species) + rare eg: Aeromonas, Vibrio

Clinical:

• Erythema
• Oedema
• Fever
• Crepitus
• Constant severe pain, even if skin inflammation is initially limited
• Bullae
• Skin necrosis or bruising
• Hard (‘wooden’) subcutaneous tissue that is painful on palpation
• Oedema beyond the margin of erythema
• Cutaneous anaesthesia

Mx
- SURGICAL DEBRIDEMENT + broad spectrum abx (meropenem, vancomycin, clindamycin)

Strep Pyogenes:
Surgical debridement + benpen + clindamycin/lincomycin + IVIG as a single dose
- Clindamycin INHIBITS endotoxin production

Question 3

Aspiration Pneumoina Tx

Answer 3

• Empirical treatment for CAP/HAP
• Occasionally anaerobes such as bacteroides and prevotella may be implicated: severe periodontal disease, putrid sputum, lung abscess
• If not improving (48 hours) + above risk factors: add metronidazole (or monotherapy: augmentin, clindamycin, moxifloxacin)
• 5-7 days

Question 4

Which organisms can cause autoinfection and hyper infection in renal transplant recipients?

Answer 4

Strongyloides

Question 5

Solid organ prophylaxis

Answer 5

Kidney

• PJP: universal at least 6- 12 months
• CMV: local protocols, D+/R+, D-/R+, D+/R- (universal or pre-emptive treatment)
• HSV: recurrent HSV + local protocols, eg: HSV IgG +ve
• HBV: HbsAg positive
• Strongyloidiasis, B pseudomallei, TB: screening

Liver

Question 6

What infectious precautions are required are required during the 24 hours of appropriate treatment for patients with confirmed meningococcal disease

Answer 6

Droplet precautions

Question 7

Painful and painless genital ulcers

Answer 7

Painful

• HSV
• Chancroid (haemophilus ducreyi) - uncommon

Painless

• Syphilis
• LGV - Lymphogranuloma venereum (LGV) is a disease caused by 3 unique strains of Chlamydia trachomati
• Donovanosis (Klebseilla granulomatosis) - uncommon

Question 8

Screening and treatment for asymptomatic bacteriuria is not recommended except for:

Answer 8

• Pregnant women

- Patients undergoing elective urological procedures except uncomplicated cystoscopic, diagnostic procedures

Question 9

When is colistin used?

Answer 9

Colistin, is an antibiotic medication used as a last-resort treatment for multidrug-resistant Gram-negative infections including pneumonia.

Broad spectrum activity against carbapenem resistant pathogens

Question 10

What can be used to treat or be used as prophylaxis for PJP?

Answer 10

• Bactrim - Trimethoprim / Sulfamethoxazole
• Atovaquone
• Dapsone
• Pentamidine

Question 11

What dose of pred do you consider starting PJP prophylaxis

Answer 11

20 mg per day of prednisolone for ≥14 days