Micro Flashcards
(32 cards)
8 year old boy presents w/
- behavioral changes, mild intellectual deterioration, and laziness
- develops progressive clumsiness and frequent involuntary jerky movements
- CSF shows increased IgG
- he dies 2 years later
Dx?
Infection d/t?
Subacute sclerosing panencephalitis (SSPE)
infection: measles
- nml infected by age 2 but takes about 6 years for symptoms to occur
Pt presents w/
- raised lesions on finger and toes
- white spots on retina surrounded by hemorrhage
- small non-tender, painless, erythematous lesions on palm or sole
- clots under fingernails
- new onset heart murmur
- fever
Dx
Cause
Staining
Subacute bacterial endocarditis
- osler nodes
- roth spots
- janeway lesions
- splinter hemorrhages
Causes:
- strep viridans : gram positive cocci in chains
- staph aureus: gram positive cocci in clusters
Pt presents w/
- pain that is relieved when leaning forward and worsens w/ inspiration
- scratchy leathery sound upon auscultation
- admitted to having flu-like illness about 2 weeks ago
Dx
EKG findings
MC cause
Dx: pericarditis (friction rub)
EKG: diffuse ST segment elevations and depression of PR
Cause:
- coxsackie B is MC
- picornavirus: positive, single stranded, naked, icosahedral, RNA virus
What lab test help determine MAC from TB in AIDs pt?
MAC presents w/
- anemia
- elevated alk phos
- elevated lactate dehydrogenase
S. Pyogenes toxic shock like syndrome vs s aureus toxic shock like syndrome
S pyogenes: release of exotoxin A causes activation fo T cells
- shock, fever, multi-organ failure
- painful, pre-existing skin infections and positive blood cultures
S. Aureus
- no pre-existing skin infections
- negative blood cultures
Causes endocarditis in pts w/ carcinoma of colon or pre-existing valvular lesions
Dx
Tx
Strep bovis
Tx: penicillin and ceftriaxone
-vanco for beta-lactam allergery
What 5 pathogens cause pharyngitis?
GrACED
- group A strep
- adenovirus
- coxsackie A
- EBV
- corynebacterium dipthetheriae
Mycoplasma pneumonia tx and MOA
Macrolide = 23s ribosomal RNA inhibitor
3 stages of bordetella pertussis
Catarrhal stage: 1-2 wks
-URI: fever, nasal congestion, rhinorrhea
Paroxysmal stage: 2-8 wks
-paroxysmal coughing followed by inspiratory whoop
Convalescent stage: wks-months
-subsiding cough
Types of E coli (who they infect / s/s)
- ETEC
- EIEC
- EPEC
- EHEC
ETEC = T: traveler diarrhea
-non inflammatory diarrhea d/t LT (AC) and ST (GC)
EIEC = I: inflammatory diarrhea
-bloody diarrhea d/t actin formation
EPEC = P: pediatric diarrhea
-non inflammatory d/t adherence of M cells on brush border
EHEC = H: Hamburger
-bloody diarrhea, nonfermentor of sorbitol d/t verotoxin (shigella like toxin) -> lead to HUS and hemorrhagic colitis
Which two microbacteria inhibit ptn synthesis by ADP-ribosylation of eER-2
Pseudomas = ecythyma gangrenosum
Diptheria = heart and nerve
Elementary bodies vs reticulate bodies
Chlamydia
- elementary: extracellular, inert, transmission form
- reticulate: intracellular, replicating form
Thin/gray malodorous discharge from vagina vs thin frothy yellow green
Gray: Gardnerella
Yellow/green: trichomonas
Pt presents w/ progressive weakness of his legs and arms
- has noticed it since childhood: no vaccination history available
- shows: flaccid paralysis, ms atrophy, fasciculations, areflexia
Dx
Where is the lesion
Polio -> poliovirus (+, single stranded RNA, picornavirus)
Attacks ventral horn -> LMN
Pt presents w/
- loss of conscious proprioception and vibration sensation
- areflexia
- pain, temp and ms strength are preserved
- sexually active w/ multiple partners
Dx
Where is the lesion
Tabes dorsalis -> tertiary syphillis
Dorsal columns affected
HIV Pt presents with
- CD4 count of 150
- weakness, disturbance of speech, congnitive abnml, HA, gait disorder, visual impairment and sensory loss
- MRI: shows multiple non enhancing multifocal white matter lesions
Dx
Infectious agent
Dx: progressive multifocal leukoencephalopathy
- circle, double stranded, naked, DNA virus
- CD4 <200
Infectious agent: JC virus -> destruction of myelinating oligodendrocytes
42 year old man returning from vacation in Honduras presents w/
- grandmal seizure accompanied by HA, n/v, and some visual changes
- CT of the brain shows multiple punctate calcifications and two cystic lesions with surrounding edema (swiss cheese)
- tx is began w/ albendazole and praziquantel
Dx
Infectious agent
How did the patient occur this condition
Dx: neurocysticercosis
Infectious agent: taenia solium (tapeworm/cestode)
Acquired infection via: ingestion of eggs (feces contaminated water) or autoinfection (perianal area -> mouth via contaminated fingers)
-oncosphere crosses the intestinal wall -> enters circulation -> gains access to tissues
54 year old pt from Ecuador comes in complaining of
- recurrent HA, n, fatigue, nuchal rigidity for the past year
- CSF shows: increased lymphocytes, plasma cells, macrophages, and fibroblast ; ptn and pressure are also elevated while glucose in decreased
Dx
MC cause
Dx: chronic meningitis
Cause: Mycobacterium tuberculosis
-others: syphilis, brucellosis, fungal infection
CSF fluid in pts w/
- bacterial (purulent)
- aseptic (viral)
- granulomatous (fungal)
*cells, glucose, ptns, and pressure levels
Bacterial: increased neutrophils, ptns, and pressure; decreased glucose
Viral: increased lymphocytes, ptn erythrocytes, nml glucose, and pressure
Granulomatous: increased all cell types, decreased glucose, increased ptn and pressure
33 year old man with AIDs develops multifocal encephalitis
- u/l, vesicular, painful rash on the left side of his back, mid chest, left side of chest and upper abdomen that appeared one month ago
- tx w/ acyclovir began but he died 4 days later
Dx
Infectious agent
Herpes zoster encephalitis
Infectious agent: varciella zoster virus
-d/t its reactivation (rash)
Multinucleated giant cells w/ intranuclear inclusion bodies seen in patients w/ encephalitis
Infectious agent
Herpes simplex virus
- MC cause of sporadic encephalitis in US
- CSF: elevated ptn, lymphocytes, erythrocytes and nml glucose
- MRI: u/l temporal lobe hypointense lesions
Dx
Tx
What would be seen on microscopic exam of the brain
What might be seen on ocular exam
HSV-1 encephalitis
Tx: acyclovir
Brain: cowdry type A inclusions: intranuclear viral inclusion bodies
Ocular: serpignous (snake-like) corneal ulcers
Toxoplasma IgG vs IgM antibodies
IgG: have been infected with it but no s/s
IgM: active infection
What are the 3 most common neonatal pathogens associated with meningitis
Group B strep
E coli
Listeria monocytogenes
