Blood, Brain, Urine Flashcards

1
Q

2 types of blood borne infections

A

Obligate Intracellular Bacteria (live in RBCs) -*Rickettsia, (Ehrlichia, Anaplasma) -small, gram-negative (do not stain well) -coccobacilli (rod) Spirochetes -Borrelia

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2
Q

Obligate Intracellular bacteria - characteristics

A

-Transmitted via arthropod vector -geography, exposure to vector, type of rash is important for differentiating these: *Where does the rash begin, what areas of the body does it cover? *Rickettsia Ehrlichia Anaplasma

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3
Q

Rickettsia rickettsii / geography

A

Rocky Mountain Spotted Fever -name is misleading more common in southEastern U.S. due to presence of ticks

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4
Q

Rickettsia rickettsii / vector

A

Arthropod: dog tick, wood tick (reservoir: Wild rodents) note the tick mother can pass it to her offspring (Transovarial transmission)

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5
Q

Rickettsia rickettsii / clinical presentation

A

rash: *centripetal*: starts on wrists, arms, palms, ankles, sole and then moves in towards the trunk rash – pin-point red dots – due to damage of blood vessels (Bacteria proliferate in the endothelial lining of small blood vessels causing hemorrhages) (conjunctival redness, myalgia)

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6
Q

Rickettsia rickettsii / Diagnosis

A

microimmunofluorescence MIF: detects antibodies (may take up to 2 weeks)

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7
Q

Rickettsia akari / vector

A

Arthropod: *mite* (invertebrate, similar to ticks) (Reservoir: mice)

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8
Q

Rickettsia akari / geography

A

rickettsialpox

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9
Q

Rickettsia akari / clinical presentation

A

Mild, self-limiting, fever *pox-like rash*: Papule at site of bite progresses to a vesicle 9-14 days later: high fever, severe headache, chills, photophobia, more vesicles appear on the body which crust

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10
Q

Rickettsia prowazekii / geography

A

Epidemic typhus (fast spread, think lice jumping) poverty, overcrowding, war, natural disasters

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11
Q

Rickettsia prowazekii / vector

A

Vector: body lice (Louse - wingless insect) reservoir = humans

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12
Q

Rickettsia prowazekii / clinical presentation

A

8 days incubation: then sudden fever 4-5 days later*rash*: small pink macules on upper trunk (torso) then spreads outward - *NO rash on palms, soles or face*

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13
Q

Rickettsia typhi / geography

A

Endemic typhus - occurs at a low level all the time (NOT EPIDEMIC) *Geography*: worldwide, in -warm, humid areas -U.S. Gulf coast

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14
Q

Rickettsia typhi / vector

A

Vector: flea (Reservoir: rodents)

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15
Q

Rickettsia typhi / clinical presentation

A

rash on chest and abdomen Low mortality even in untreated

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16
Q

Orientia tsutsugamushi / geography

A

Scrub typhus (found in sandy soil / areas of heavy scrub vegetation) endemic to: Geography: *Asia and southwest pacific

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17
Q

Orientia tsutsugamushi / vector

A

Vector: chiggers: soil (reservoir: rodents)

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18
Q

Orientia tsutsugamushi / clinical presentation

A

High fever, headache, myalgias, scab at bite *flat maculopapular rash develops*

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19
Q

Borrelia burgdorferi / geography (Spirochetes)*

A

Lyme disease: most commonly reported tick borne illness in the U.S geography *All along the east coast and along the great lakes (could be that the ticks are traveling with birds)

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20
Q

Borrelia burgdorferi / mode of transmission

A

Vector: tick (Reservoir: white-footed mice, white-tailed deer)

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21
Q

Borrelia burgdorferi / clinical presentation

A

Stage 1: localized -Bulls-eye rash and flulike symptoms; lasts 2-3 weeks Stage 2: disseminated -Fatigue, migratory joint (polyarthralgia - pain in more than one joint), and muscle pain Stage 3: chronic (could have these symptoms for life) -Chronic arthritis, encephalitis

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22
Q

Borrelia burgdorferi / Diagnostics

A

2 Test approach (no simple test exists, can lead to misdiagnosis) 1. enzyme immunoassay or immunofluoresence assay 2. if postive, follow up with a western blot to confirm (consider alternate diagnosis)

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23
Q

2 forms of Relapsing Fever, explain transmission:

A
  1. 15 species of Borrelia -vector: soft tick -endemic (rodents spread it) 2. Borrelia recurrentis -vector: louse -epidemic (humans, living in conditions of poor hygiene, spread it)
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24
Q

What form of Relapsing fever would you get in a RUSTIC CABIN (cabin is falling apart, in poor condition)

A

endemic (rodent spread - vector) soft tick Borrelia spp. (15)

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25
Borrelia recurrentis / vector
vector: louse borne Known as epidemic
26
Borrelia recurrentis / geography
geography: Ethiopia, Rwanda, Chile
27
Borrelia recurrentis / clinical presentation
Relapsing Fever
28
Borrelia recurrentis / Diagnostics
Diagnostics: microscopy No Serology: antigenic variation (the antigens will have change by the time the test is developed)
29
great example of what the Spirochetes looks like Borrelia
30
Which form of the relapsing fever has more relapses?
endemic: 10 epidemic: 1
31
Why is the fever relaspsing?
notice we can detect borrelia in blood smears ![]() - immune system responds with the specific antibody, BUT then the organism changes its antibody - goes on again and again (up to 10 relapses) –treatment with antibiotic would stop this!)
32
What is meningitis?
\*inflammation of the meninges, the lining which surrounds the brain. - this is different than encephalitis (inflammation of brain itself or different lobes) - in this lecture we are only talking about bacterial meningitis (we have talked about bacterial/fungal previosly?)
33
Major causes of Neonatal Meningitis?
group B Strep, S. agalactiae -during birth E. coli -during birth Listeria monocytogenes -crosses placenta all transmitted from the mother (vertical transmission), mother almost certainly didnt have meningitis, but these organisms are part of her ecosysem
34
Streptococcus agalactiae / gram stain
Gram positive cocci
35
Streptococcus agalactiae / lab diagnostics
β-hemolysis (CAMP +) on camp test (not regularly b-hemolytic) – only in the presence of S. aureus
36
Streptococcus agalactiae / virulence
Virulence factor: capsule
37
How is S. agalactiae differentiated from S. pyogenes which is also beta-hemolytic and gram +?
S. agalactiae is resistant to bacitracin S. pyogenes is sensitive. (you will see a zone of inhibition)
38
CAMP plate vertical streak is S. aureus (note the clearing around it). But those horizontal streaks are the Streptococcus agalactiae, and notice the hemolysis gets stronger closer to S. aureus
39
E. Coli / virulence
\*Meningitis: capsule (k antigen) But different virulence factor of ecoli in different infections: UTI: pili Septic shock: LPS HUS: shrigella like toxin
40
E. Coli / Characteristics
* Gram negative rod * Grows on MacConkey agar * Ferments lactose * Indole positive
41
Normal Flora or NOT
Streptococcus agalactiae / Normal flora of GI tract and vagina E. Coli / Most E. coli are non-pathogenic, normal flora of GI tract Listeria monocytogenes / Normally found in soil, vegetation, water and intestinal tract of many animals
42
Listeria monocytogenes / characteristics
\*Able to grow and multiply at low temps (1°C to 45 °C) -could be growing in your fridge! Gram positive rod Facultative, intracellular pathogen (can survive inside or outside of an organism) Highly motile
43
Listeria monocytogenes / 2 types of motility
Flagella (end over end tumbling motility) -for extracellular survival Highjacks Actin tails -for intracellular survival
44
Listeria monocytogenes / Lab diagnosis
culture (remember CAMP test) Weakly b hemolytic, better with S. aureus
45
Listeria monocytogenes / virulence
Invade M Cells Escape phagosome Multiply Use actin tail for motility Infect adjacent cells Avoids immune system
46
Listeria monocytogenes / transmission
Ingestion of contaminated food Must ingest large numbers to result in infection Milk (raw milk, unpasteurized) Soft cheeses Cold cuts, hotdogs Raw vegetables, coleslaw Incubation period: 11-70 days, ave.31 days!!!! (who would remember what they ate 31 days ago - tough to trace)
47
Listeria monocytogenes / vertical transmission (mother to child)
If pregnant women ingest the bacteria (they experience lu-like illness), and the bacteria can: - cross the placenta (transplacental transmission), which is highly fatal, stillbirth - come in contact with the baby during birth (through vaginal canal, during delivery), results in neonatal meningitis
48
Major causes of Bacterial Meningitis in Children/Adults
Neisseria meningitidis Haemophilus influenzae type B S. pneumoniae
49
Neisseria meningitidis / gram stain and other characteristics
* Gram negative, diplococci * Aerobic * Nonmotile * Fastidious * Capnophilic: 5% CO2 * N. gonorrhoeae * N. meningitidis
50
Both meningitidis and gonorrhoeae could get into blood and produce a rash; How can one differentiate between the two?
meningitides (metabolizes maltose and glucose) gonorrhoeae (metabolizes glucose only) note: The test changes the Ph of the broth, which causes a color change
51
What is the buzz word for Neisseria meningitidis?
Buzzword:\*Coffee bean or kidney bean shaped
52
Neisseria / virulence factors
Both are gram negative Pili – important for gonorrhea (antigentic variation) Capsule – important for meningitis Endotoxin - LOS (instead of LPS) – can produce septic shock
53
Neisseria meningitidis / transmission
Respiratory droplets, Attach to mucosal cells, invade mucosal cells, multiply within mucosal cells, move into subepithelial space, LOS stimulates TNFα symptoms Other notes: -viral: common -Bacterial form: not prevelent, but high mortality (If untreated, mortality rate close to 100%) (with treatment 10%) ž\*Approximately 20% of the population are healthy carriers (WOW) - must affect different people in different ways
54
Neisseria meningitidis / symptoms
\*sudden onset is the KEY * Severe headache * Fever * Neck stiffness * Irritability * Photophobia * Malaise * Nausea/ vomiting
55
Petechial rash – on arms – could see gram (-) cocci if scrap rash
Meningococcemia žInvasion of the bloodstream, sepsis, thrombosis of small blood vessels
56
Meningitis / Diagnosis
Spinal tap, Gram stain of CSF (normal CSF is clear, cloudy is bad) ## Footnote * Meningococcemia: Gram stain of blood * Culture on: Thayer-Martin agar (Neiserria Likes chocolate agar, Thayer-Martin agar is chocolate agar With antibiotics added)
57
Haemophilus influenzae / virulence factors
58
Haemophilus influenzae / gram stain
* Gram negative short fat rod * Normal flora of the URT * Capsule or No Capsule * Adhesins * Endotoxin - LPS
59
Haemophilus influenzae / lab diagnostics
* Microscopy/Gram stain * Culture: fastidious (tough to grow) * Does not grown on blood agar or MacConkey agar ## Footnote Likes the chocolate agar (needs those RBCs to be lysed to gain access to nutrients: heme, NAD) heated up blood agar and it becomes chocolate agar
60
Haemophilus influenzae / morphology
61
Streptococcus pneumoniae / gram stain
•Gram positive •Pairs or chains •Alpha hemolytic •CAPSULE •Adhesin IgA protease •Also known as pneumococcus (Typical pneumonia)
62
Streptococcus pneumoniae / lab diagnostic
Lab Tests: Optochin sensitive
63
Streptococcus pneumoniae / morphology
Pairs or chains
64
Streptococcus pneumoniae / virulence
Capsule
65
#1 cause of UTI and its virulence factors
E. Coli •Virulence factor: Pap (pyelonephritis associated pili) pili for adherence to bladder
66
WHat is the organism and virulence associated with kidney stones?
Proteus mirabilis\*, Proteus vulgaris \*buzz word swarming growth virulence factor: Urease (breaks down Urea to ammonia + CO2) Increases urine pH, which leads to formation of kidney stones
67
Differentiate between the 2 types of Staphylococci associated with UTIs
Gram(+) cocci, catalase(+), coagulase(-) Staphylococcus epidermidis \*novobiocin sensitive\* - ability to adhere to plastic (Foley cath) Opportunistic infections of catheters - normal flora of skin Staphylococcus saprophyticus \*novobiocin resistant\* - colonize vaginal tract - cause of UTIs in young sexually active females