Microbio 1 Flashcards
What does HDV need to infect hepatocytes?
HDV is replication defective – needs to be coated by HBsAg to penetrate hepatocytes – infect, multiply.
Klebsiella
[Findings]
Common in alcoholics.
Colonizes oropharynx – microaspiration while asleep – affects upper lobes.
Findings: currant jelly sputum, lung tissue necrosis, abscess
Roseola Infantum
[Cause, findings]
HHV-6
High fever – maculopapular rash (trunk, then face and extremities).
Possible febrile seizures.
Oral thrush
[Cause, findings, predispositions]
Candida albicans (Pseudomembranous candidiasis).
White plaque is easily scraped off, w/ erythematous mucosa underneath.
Found in denture wearers, immunosuppressed, steroids, antibiotics, chemotherapy.
Candida infections (3)
Oral thrush
Cutaneous candidiasis (“diaper rash”)
Vulvovaginal candidiasis
Cryptococcal meningitis
[Cause, CSF analysis, Dx, Tx]
C. neoformans; common w/ immunocompromised, glucocorticoids.
>CSF: dec. glucose, inc. protein, dec. leukocytes (lymphos)
>Dx: Sabouraud agar (confirm).
>Tx: AmphoB + Flucytosine, ff. by Fluconazole (long term).
Listeria monocytogenes
[Diseases, outbreak from what, predisposition]
> Can cause dse in cell-mediated immunodeficiency (HIV, organ transplant).
Syndromes: febrile gastroenteritis, septicemia, meningoencephalitis.
Outbreaks w/ dairy products (colonizes GIT of cattle)
Q fever
[Causes, Acute vs. Chronic ssx]
Coxiella burnetii; animal waste.
*No rash, no vector (vs Rickettsial dses)
>Acute: fever > 10 days, fatigue, myalgias; retro-orbital headaches w/ photophobia, pneumonia, thrombocytopenia, inc. ALT/AST.
>Chronic: rare, fatal if not treated; infective endocarditis in valvular dse
Patients receiving parenteral nutrition (central venous catheter) are at risk of developing what type of infection?
Candidemia, from the catheter.
Lipid emulsion in the solution may promote growth.
Pulmonary anthrax
[Px, ssx]
“Woolsorter’s dse”
>Spores inhaled – taken by alveolar macrophages – mediastinal lymph nodes – germinated into vegetative cells – anthrax toxin.
>SSx: Hemorrhagic mediastinitis (widened mediastinum); blood pleural effusions, septic shock, death
Scabies
[Presentation, Dx]
Intensely pruritic rash on flexor surfaces of wrist, lateral surface of fingers, finger webs.
Crusted, red papules w/ excoriations
Worse at night; Type IV HSR.
Dx: skin scrapings show mites, ova, feces
Disseminated gonococcal infection
[Cause, SSx, complications]
Neisseria gonorrhoeae, intracellular organism w/in neutrophils.
>Triad: polyarthralgia, skin lesions, tenosynovitis.
>MCC of septic arthritis in sexually active young adults
Legionnaire’s dse
[Cause, presentation, Dx]
Legionella pneumophila.
>Very high fever in a smoker + diarrhea, confusion, cough.
>Gram stain is unreliable – lipopolysaccharide chains of outer membrane prevents staining.
>Dx: Legionella antigen in urine
3 main causes of HIV-associated Esophagitis
[SSx]
> Candida (pseudomembranes).
Herpes simplex virus (vesicles, punched-out lesions).
Cytomegalovirus (linear ulcerations).
SSx: Dysphagia, odynophagia
Common cx of Nontypable H. influenzae
Nontypable H. influenzae don’t produce polysaccharide capsule.
Part of normal flora of URT.
>Acute otitis media, sinusitis, bronchitis in children (90% of H. influenzae strains).
