First Aid Microbiology 4

Question 1

If a patient presents with aseptic meningitis of unclear origin, odds are that it is probably. . .

Answer 1

. . . enteroviral

Question 2

Common gram positive cause of cholangitis

Answer 2

Enterococci!

Question 3

Which gram positives are penicillins alone no good against?

Answer 3

• S. pneumoniae
• S. aureus (you need a beta lactamase inhibitor)
• Enterococci
• S. epidermiditis
• Corynebacterium diphtheriae

Question 4

VanA gene

Answer 4

• Gene that makes vancomycin-resistant enterococci so vancomycin resistant
• Changes terminal D-ala-D-ala to D-ala-D-lactate
• Can be horizontally transferred to S. aureus

Question 5

If Strep Intermedius or Angiosus grows from blood culture, . . .

Answer 5

. . . immediately assess for abscess

Question 6

Upper lobe nodule and cavity with air-fluid level indicates ___ as the likely causative organism

Answer 6

Upper lobe nodule and cavity with air-fluid level indicates Rhodococcus equi as the likely causative organism

A rare gram positive bacterial cause of pneumonia. Note that TB does not form cavities with air-fluid levels.

Question 7

Mnemonic for the endemic mycoses

Answer 7

• Fungus cowboy:
  
  • Cock (coccidioides)
  • Blast (blastomyces)
  • Hit (histoplasma)

Question 8

Which endemic mycosis causes desert rheumatism?

Answer 8

Coccidioides

Question 9

Tinea nigra

Answer 9

• Caused by Exophiala werneckii
• KOH prep to diagnose
• Treat like pityriasis (topical selenium sulfide or ketoconazole cream)

Question 10

Chromoblastomycosis

Answer 10

• Caused by Fonsecaea species
• “Cauliflower” dermatitis
• Copper penny bodies on KOH prep
• Treat w/ oral itraconazole

Question 11

Aspergilloma

Answer 11

Ball of aspergillus that grows in a cavitated lung lesion

Question 12

Aflatoxin

Answer 12

Toxin produced by aspergillus that is hepatotoxic and increases risk of HCC

Can cause hepatitis in people with aspergillosis or in those who consume food contamianted with aspergillus

Question 13

An HIV patient presents with a history of bright red blood per rectum and rectal pain. He reports that this has been going on for a couple months but he did not come in because he thought it was simply a hemorrhoid. His CD4 count is 280.

On rectal exam a hard mass is palpaed with an overlying 2x2 cm ulcer. What is the likely infection driving this pathology?

Answer 13

This is a classic example of an HPV-driven anal squamous cell carcinoma

Remember, HIV and anorectal HPV share the common risk factor of penetrative anal sex, so this is not too uncommon

Question 15

___ is an important risk-reducing agent in treating Measles/Rubeola

Answer 15

Vitamin A is an important risk-reducing agent in treating Measles/Rubeola

Question 16

Treatment for enterobiasis

Answer 16

Enterobiasis = pinworms!

Treatment: bendazoles OR pyrantel pamoate

So, for most people, mebendazole or albendazole. If pregnant, it’s gotta be pyrantel pamoate.