Viruses/Fungi/Bacteria [Block 3]

Neisseria meningitis

• gram negative diplococci

• petechial rash

• inc risk in pts with complement deficiency

• utilize IgA protease as virulence factor

• causes petechial rash

• inc risk in pts w/ complement deficiency

Streptococcus pneumoniae

• gram positive lancet diplococci

• utilize IgA protease as virulence factor

Listeria monocytogenes

• gram positive intracellular rod

• significant cause of bacterial meningitis

• transmitted transplacentally/via contamined food

HSV-1/2

• cowdry type A intranuclear inclusions

• multinucleated giant cells

Rabies virus

• bullet-shaped

• negative sense ssRNA

• negri bodies; eosinophilic cytoplasmic inclusions in hippocampal pyramidal cells/purkinje cells in cerebellum

Haemophilus infuenzae

• gram negative bacterium

Coxsackie virus

• enterovirus

• causes hand, foot, mouth disease/herpangina

Common causes of meningitis

• after neurosurgery/head trauma

  • staph aureus

  • staph epidermis

  • pseudomonas

• most common cause of acute VIRAL meningitis

  • enterovirus

  • in adults: HSV

• most common cause of neonatal BACTERIAL meningitis

  • group B strep (s. agalactiae)

  • e. coli, listeria

• immunocompromised pts

  • listeria monocytogenes

  • mycobacterium tb

staphylcoccus aureus

• most common cause for osteomyelitis

Entamoeba histolytica

• treated w/

  • metronidazole/tinidazole → treats invasive (trophozoite) form but doesnt eliminate cysts

  • luminal agent (paromycin/idodoquinol) → clears cysts stage in intestine

Taenia solium

• aka pork tapework

• causes neurocysticercosis

• endemic in Mexico, SA, Asia

• treat w/ albendazole, steroids, analgesics, antiepiletpic drugs

Schistosoma japonicum

• aka bilharzia

• blood fluke

• found in freshwater snails

• ELISA for anti-schistosomal ab

• granuloma formation in brain/liver

• treat w/ praziquantel

pseudallescheria boydii

• resistant to amphotericine b

• miconazole shows efficacy

• causes mycetoma

• polluted water, sewage, swamps