MICROBIOLOGY Flashcards
what rickettsia rashes:
starts in periphery and moves to trunk
starts on trunk and moves to periphery
rickettsia ricketsii = periphery to trunk
(starts on ‘wrists’)
typhus (rickettsia prowazekki) = trunk to periphery
(starts on ‘trunk’)
name the 3 comma shaped rods
campylobacter jejuni (invasive)
vibrio cholera
helicobacter pylori
all oxidase positive
all facultative anaerobes
all gram negative
listeria can cause meningitis in what age group
elderly >60yo
does coxiella cause a rash
no
from spores in animal droppings (aerosol)
obligate intracellular
pneumonia
headache
hepatitis
fever
working with/near animals
coxiella
brucella = undulating fever
spaghetti and meatballs histology
malassezia furfur
francisella tularensis relies on clearance by ?
cell mediated immunity
(T cells & macrophages)
facultative intracellular
i.e. same as listeria, mycobacterium
who is IV penicillin given to to prevent s. agalactiae infection in newborn
mother intrapartum
at 35 weeks - swabbed, can colanise vaginal tract
positive hippurate test
positive CAMP test
seen in
s. agalactiae
(group B strep)
s. pyogenes hippurate test negative
bacitracin resistant
PYR test negative
s. agalactiae
(group B strep)
s. pyogenes bacitracin sensitive
PYR test positive
what is a predisposing factor to mucormycosis/rhizopus
diabetic ketoacidosis
fungus multiplies in blood vessel walls, in location shigh in glucose/ke
fungus with non-septate 90% (wide) angle branching
mucormycosis/rhizopus
febrile illness
followed by weakness, dyspnoea
severe anaemia
low reticulocyte count
sickel cell disease
viral cause
parvo B19
(ss DNA non-enveloped)
aplastic crisis
destruction of erythroid precursor cells
pasteurella multocida can cause
osteomyelitis
dog and cat bite (gram negative coccobacillus)
catalase +, oxidase +, capsule, bipolar staining
also cellulitis
salmonella or shigella acid labile
salmonella = lable
shigella = stable
salmonella infection more risk if less acidid i.e. stomach acid lower
bacteria (4) that increase adenyl cyclase (cAMP)
E coli
V. cholera
B. pertussus
B. anthracis
bordetella pertussus activates adenylate cyclase (cAMP) by inactivating
inhibitory subunit (Gi)
what stain is used for bartonella henselae (cat scratch)
silver stain
hard to identify on stain
facultative intracellular organism - Tx with doxycycline or macrolides (penetrate cell)
what neisseria species is facultative intracellular
N. gonnorrhoea
bite
nontender nodules
blindness
microfilariae in nodules
travel overseas
onchocerca volvulus
black fly
black skin nodules
river blindness
Tx ivermectin
conjugation
transfer of plasmid between 2 bacteria
(conjugal bridge - **sex pilus **used to mate)
transduction
‘packaging error’
bacterial DNA may be packaged into plasmid
infects another bacterium, transferring genes
transposition
transposon copy and excise itself into same/another DNA
bacteria
fever
N & V
periorbital oedema
myalgia
trichinosis
(trichinella spiralis)
encyst in striated ms
undercooked meat
larvae enter bloodstream
intestinal nematode (round worm)
Tx: bendazoles
(mbendazole) - acts on microtubues
fever, chills
myalgias
weakness, headache
haemolytic anaemia
asplenia risk
ring forms / tetrads on Giemsa stain
what vector
borrelia microti
(Ixodes scapularis - deer tick)
malaria-like illness
spirochete
NE USA
Lyme disease
transmitted by Ixodes scapularis
borrelia burgdorferi
VZV extending posteriolaterally to R of umbillicus is located aht which DRG
T10
umbilicus location T10 dermatome
CMV is not susceptible to ___
it does not possess ___
guanosine analogs
(acyclovir, valcyclovir)
thymidine kinase
neonate
hearing loss
seizures
petechial rash
intracranial calcifications
organomegaly
CMV neonate
passes via placenta
mother close contact with children
fever
myalgia
atypical lymphocytosis
abnormal liver enzymes
immunocompromised host
prominent inclusion bodies
atypical: colitis, encephalitis, pneumonia, oesophagitis, retinitis
CMV maternal
measles triad
cough
coryza
conjunctivitis
rash face –> cephalocaudal
measles (rubeola) type of virus
paramyxovirus
(-sense enveloped RNA)
children
fever
cough
coryza
conjunctivitis
maculopapular rash - start at head
(excludes hands/feed)
lymphadenopathy
red macules with blue-ish center buccal mucosa
measles (rubeola)
complications of measles (2)
Subacute Sclerosing Panencephalitis (SSPE)
Giant cell pneumonia
Brain & Lung
Subacute Sclerosing Panencephalitis (SSPE) - (neurodegenerative)
giant cell pneumonia -immunosuppressed
what vitamin is associated with severe measles disease and complications
vitamin A
provide supplement, especially malnourished
West Nile virus causes (2)
meningoencephalitis
acute asymmetric flaccid
flavivirus (+sense enveloped RNA)
HSV lies dormant where?
reactivation causes?
genital HSV
sacral doral root ganglia
recurrent genital ulcers
VZV lies dormant where?
reactivation causes?
sensory dorsal doot ganglion
herpes zoster (shingles)
m/c cause haematogenous osteomyelitis
S aureus (m/c)
S pyogens (2nd)
(adults - vertebrae, IVDU, catheters)
children
long bones
LL
m/c cause osteomyelitis is SSD patients
salmonella
what effect do antibiotic use have on vaginal flora balance
decreased number of gram positive (+) lactobacilli
facilitates candidia growth
E coli can cause sepsis, pneumonia and ___
ARDS
severe diarrhoea in AIDS pt
cryptosporidium parvum
(small round oocysts on colonic epithelial surface)
watery diarrhoea
abdominal cramps
transmission: oocysts in water
wt loss, fever, dehydration, orthostasis, n&v
dX: STOOL ANTIGEN TESTING - LUMINAL OOCYSTS, acid fast staining i.e. carbol fushcin, zeel-neelson
GIARDIA LAMBLIA - also watery diarrhoa & flagellated pear shaped trophozoite, can demonstrate cysts (usually mentions exposure to unfiltered water) - if AIDS more likely cryptosporidium
vector - fleas, animals (cats)
gram negative bacillus, encapsulated
bloody ddiarrhoea
fever, leukcocytosis, abscesses
ulcers, buboes - LN mass
pneumonia
New Mexico (SW USA)
yersinia pestis
bacteremia, DIC
bilateral infiltrates
Tx aminoglycosides, doxycyline
black death
bubonic plaque
cutaneous erythema
warmth
induration
following inocculation injury/abrasion
fever
tachycardia
leukocytosis
cellulitis
strep pyogenes (GAS) - non purulent
staph aureus - purulent
gram positive, chains, B haemolytic, bacitracin sensitive
a cause of cellulitis
or pharyngitis, scarlet fever, necrotising fasciitis, glomerulonephritis, rheumatic fever
strep pyogenes (GAS)
pyogenes is not
anothe cause would be staph aureus - puruent
features of strep pyogenes
GAS
gram positive
chains
B-haemolytic
bacitracin sensitive
non-purulent in cellulitis
Legionella pneumophilia can be treated by
fluroquinolones - i.e. ciprofloxacin
macrolides
HIV
generalised tonic clonic seizure
small solitary enhancing lesione frontal lobe
lymphocytes, plasma cells, macrophages (biopsy)
crescent shaped organisms with central nuceli
Tx with sulfonamide and pyrimethamine
toxoplasma gondii
ingestion of oocyts from cat feaces or infected meat
protozoan parasite
what 2 organisms can enter the brain by crossing the cribiform plate
naegleria fowleri
murcormycosis
**naegleria fowleri **- freshwater amoeba, meningoencephalitis, mortality 100%, affects communocompetent and immunocompromised
murcormycosis - fungal, common in DM, direct sinus invasion
