monday - dirty d. and amy p. - infectious disease review Flashcards
Young kid not vacced high pmns fever cloudy csf, high protein, low glucose nuchal rigidity gram positive rod looking organism
what is the most likely cause of infection
what do you treat with
h. flu (because it’s pleomorphic, it can look like a rod.) (it’s a coccobacillus)
treat with ceftriaxone
strep pneumo important virulence factors
changes in penecillin binding prot
capsule
choline binding prot - binds carbohydrates present on surface of epithelial cells
neurominidases - cleave host mucins
pneumolysin - suicide pore forming toxin
iron acquisition A (PiaA)
What special things to you need to culture h. flu to tell it apart from other organisms on a gram stain?
(gram stain looks a lot like p. aeruginosa IMHO)
Hematin (X factor) and NAD (V factor) chocolate agar
antibodies specific for the polyribitol phosphate capsule (this is the capsule that allows it into the CNS)
H. flu vir. factors
specific name of the thing that allow it into the CNS
polyribitol phosphate capsule - lets into CNS
many are beta-lactamase positive
7 bacteria that can cause meningitis
S. pneumoniae Haemophilus influenzae E. coli N. meningitis Treponem pallidum (syphilis) Listeria monocytogenes Mycobacterium tuberculosis
what is used for the H.flu type b vacciene
polyribitol phosphate capsule antigens
other sites of h.flu type b infections
epiglottitis
bacteremia (in blood)
name of the beta lactamase we learned
what is in augmentin
clavulanate
amoxicillin + clavulanate
42 year old man
3 week history of fever, headache, joint pain, dry cough
normal WBC
high eosinophils
just visited arizona
What is most likely causitive organism
what do you see on a KOH prep
coccidioides immitis
dimorphic fungi
see arthroconidia on a KOH stain
they are inhaled into the lung, where they burst and release endospores that can become meningitis
Drugs used to fight fungal meningitis
mech and spectrum
Amphotericin B - binds ergosterol, creating holes in fungi membrane. crosses BBB TOXIC because binds cholesterol. broad spectrum
Flucytosine: nucleic acid synthesis inhibitor. converted to 5-FU in fungi. only treats yeasts (candida, cryptococcus). suppresses bone marrow
azoles - Fluconazole, itraconazole, voriconazole. binds fungal p-450 and blocks production of ergosterol. fairly hepatotoxic, neurotoxic, effected by efflux pumps
fungi that can cause meningitis
Candida Albicans
Cryptococcus
coccidioides immitis
Vir. factors and general characteristics of listeria monocytogenes
definitive therapy: for average patient and for pregnant women
gram + rod, intracellular
internalin INDUCES phagosytosis by epithelial cells of GI tract - trojan horse
phospholipase and listeriolysin O allow escape from vacuole of said cell.
actin tails facilitate pseudopod spread between adjacent cells
therapy - Gentlemen get amped for listerine (cr. Hailey):
gentamycin, ampicillin.
Therapy for pregnant women:
they aren’t gents, they just get amped
high dose ampicillin (gentamycin causes ototoxicity)
What common meningitis drug does listeria not respond to and why
cephalosporins
penicillin binding protein 3 on the listeria doesn’t bind to the cephalosporins
HSV - 1 infections
CNS types
where is it latent
Tx
keratoconjunctivitis
encephalitis
latent in trigeminal ganglia usually
Tx: acyclovir
eye - trifluridine
HSV - 2 infections
CNS types
where is it latent
Tx
aseptic meningitis, myelitis, neonatal herpes-meningitis, cervical carcinogenesis
Sacral Ganglia
acyclovir
