Micro 1 Flashcards
Route of entry for S. aureus meningitis
direct inoculation of surgical procedure or postoperatively through the wound - common in neurosurgical pts
Facultatively intracellular, motile, gram-positive rod that is the 3rd most common cause of meningitis in neonates
Listeria monocytogenes
also causes meningitis in IC pts and elderly
What are the CSF findings in bacterial meningitis?
- increased neutrophils
- increased protein
- decreased glucose
Lancet-shaped gram-positive cocci in pairs
Streptococcus pneumoniae
Leading cause of CAP, otitis media, and meningitis in adults
S. pneumo
What food poisoning is most commonly associated with mayonnaise-containing food like potato or macaroni salad?
S. aureus staphyloenterotoxemia containing highly heat-stable preformed enterotoxin
What are 4 strains of bacteria that result from exotoxin formed after ingestion of the contaminated food?
- ETEC and V. cholera: watery diarrhea
- EHEC and shigella: bloody diarrhea
What are 5 bacteria that invade the gut mucosa?
- Salmonella spp
- Shigella
- Yersinia enterocolitica
- EIEC
- C. jejuni
What is the mode of transmission for staphylococcal food poisoning?
food handler innoculating food with S. aureus and allowing food to incubate at room temperature
Multinulcated giant cells with some intranuclear inclusions + a clinical Hx of vesiculoulcerative gingivitis/lesions of oral mucous membranes and cervical lymphadenopathy in children ages 1-3
HSV1: herpetic gingivostomatitis
may be VZV, but HSV-1 more likely
Reactivation of what virus produces interstitial pneumonitis, retinitis, hepatitis, colitis, and/or generalized disease?
CMV
What could a chronic, transforming latent EBV virus resultin?
B-cell lymphoma
What are two examples of slow viruses that are degenerative disorders of the CNS?
SSPE nd progressive multifocal leukoencephalopathy
Neutropenia associated with leukemias and lymphomas are associated with what monomorphic mold?
Invasive aspergillosis
What is the mode of transmission of invasive aspergillosis?
hematogenous spread - tissue infarcts in skin, paranasal sinuses, kidneys, endocardium, and brain
Oval budding yeast with pseudohyphae (elongated yeast cells)
Candida albicans
Oval budding yeast with a thick capsule and india ink stain of CSF revealing wide clear zone around nucleus
Cryptococcus neoformans
What leads to the autoimmune response of rheumatic fever?
molecular mimicry between bacterial antigens and self antigens
What are the early and late findings of rheumatic fever?
early: migratory arthritis, pancarditis, subQ nodules, erythema multiforme, and sydenham chorea
late: mitral stenosis with rare involvement of aortic valve
Prevention of rheumatic fever complications
prompt Tx of streptococcal pharyngitis with penicillin
Do all strains of S. pyogenes have the ability to result in PSGN?
No, only the nephritogenic strains
What is the recommended treatment for methicillin-resistant S. epidermidis?
Vancomycin combined with rifampin or gentamicin or both
What are the complications of S. epidermidis endocarditis after valve replacement if untreated?
intracardiac abscess formation, dehiscence of the prosthetic valve from the heart, and septic embolization
What are 3 B-lactamase resistant penicillins?
methicillin, oxacillin, and nafcillin