Microbiology Flashcards
1
Q
What is difference between bacteremia and sepsis?
A
Bacteremia: the presence of bacteria in blood—>might be asymptomatic—>immune system can clear it out
Sepsis: has clinical presentation
2
Q
What is the relationship between SIRS and sepsis?
A
SIRS (may or may not caused by an infection) + proof of bloodstream infection = sepsis
3
Q
SIRS can be the result from ___?
A
Cytokine storm
4
Q
What is the role of TLR4 play in SIRS?
A
TLR4 recognizes LPS from gram - bacteria—>inflammation
5
Q
What are the clinical presentations of sepsis?
A
Fever/high BR/chill/very low temp/change in mental status (elderly pts)
6
Q
What is severe sepsis?
A
Sepsis plus organ dysfunction/HoTN that can be reversed by fluid
7
Q
What are some of the complication that sepsis/septic shock cause?
A
DIC/ARF/ARDS
8
Q
What does TLR2 do?
A
Recognizes gram + bacteria
9
Q
What happens when the bacteria change the number of acyl chain at the lipid A end of the LPS?
A
It can downregulate the immune response from the host
10
Q
What are the 2 natural modulators for countering sepsis induced DIC?
A
Activated protein C and antithrombin
11
Q
Progression of infection?
A
Infection—>SIRS—>sepsis—>severe sepsis—>shock
12
Q
What is reticuloendothelial system?
A
Liver and spleen
13
Q
What is transient bacteremia?
A
Last for mins to a few hours/teeth brush, biopsy and what not
14
Q
What is the most common cause of bacterial endocarditis ?
A
Mouth floral settles onto heart valve lesion
15
Q
What do we give pts with heart murmur before a dental procedure?
A
Antibiotics
16
Q
What is intermittent bacteremia?
A
Recurring bacteria presence in the blood/often from abscesses
17
Q
What is the most common cause of continuous bacteremia?
A
Endocarditis
18
Q
What are the causes of primary BSIs?
A
Infective endocarditis/mycotic aneurysm/thrombophlebitis/CABSI
19
Q
What is the amount of bacteria in blood that can cause shock?
A
1 in 10ml. Long lasting endocarditis can be around 1 in 100ml—>need to draw multiple (3) samples of blood to confirm
20
Q
What causes mycotic aneurysm?
A
Damage to the endothelial cells lining the arteries
21
Q
What is the common cause of thrombophlebitis?
A
IV leaving in the pt for too long
22
Q
What are some common causes of CABSI?
A
coagulase negative staph/S. aureus/candida
23
Q
What route does extravascular BSI spread?
A
documented portal of bacterial entry and spread through lymphatic system
24
Q
Why do we draw less blood from kids to detect bacteremia?
A
Kids can tolerant more bacterias in their blood stream
25
Elevated PCT is associated with?
Bacterial pneumonia and sepsis
26
What is the level of PCT that has risk for sepsis?
Over 0.5 ng/ml--->PCT is also used to see the effectiveness of a treatment
27
What are the common parasites (protozoan) that cause malaria?
Plasmodium falciparum (most deadly)/vivax/malariae (longest time for symptoms to appear)/ovale
28
What are some genetic protection against malaria?
Gene for HbC/lack of Duffy antigen (protection for P. vivax)/thalassemia
29
What is the progression of malaria symptoms?
Cold stage (RBCs rupture)--->hot stage (immune response to circulating protozan)--->sweating stage (protozan infect more RBCs)
30
What is the difference between faciparum and other species?
Its symptoms doesn't appear in a cycle like others but has a continuous fever
31
What is recrudence and relapse regarding malaria infection?
Recrudence (falciparum)--->parasite remain dormant inside RBCs and then reoccur (fall below detectable level)
Relapse (vivax and ovale)--->parasite goes back to the liver and remain dormant
32
What clinical symptoms does falciparum cause?
Anemia/hypoglycemia/respiratory distress/metabolic acidosis
33
Falciparum binds to RBCs via __?
PfEMP-1 antigen (present on all RBCs--->reason why falciparum is deadly)
34
How is cerebral malaria of falciparum caused?
The infected RBCs sticks to the blood brain barrier--->poor oxygenation of the brain
35
Which 2 receptors can stick with falciparum parasitized RBCs?
CD36 (microvasular endothelial cells) and chondroitin sulphate A (placenta--->caused birth defect and what not)
36
What is the only brand of RDT approved in the US?
Binax NOW
37
What bug transmit Trypanosomiasis (Chagas disease caused by Trypanosoma cruzi)?
Reduviid bugs (need to attach to you for an hour)
38
What is the sign for Chagas infection?
Romana's sign (bugs bite around eyes--->cause inflammation)
39
What does chronic Chagas disease cause?
Megacolon/megaoesophgus/cardiomyopathy
40
Sand fly bit you and threw up on you cause?
Lesihmaniasis--->cause lesion/ulcers
41
Cats poops out ___ can transit ___ to people
Oocyst (infectious form of Toxoplasma gondii)/toxoplasmosis
42
What is the leading cause for foodborn illness?
Toxoplasmosis
43
Most people with toxoplasmosis remain ___?
asymptomatic--->reactivate when immunosuppressed
44
The classic triad of congenital toxoplasmosis is?
Chorioretinitis/hydrocephalus/intracranial calcification (mental deficit)
45
Which trimester has the highest risk of transmitting toxoplasmosis to the fetus? and does the previous infection matters?
3rd/no (only primary infection)
46
When immunosuppressed, T gondii enters ___ and cause ___?
Across the blood brain barrier and cause nuerotoxoplasmosis (HIV pt is susceptible)
47
Recurrence of Toxoplasmosis can affect eye and cause?
eye pain/photosensitivity/tearing/blurry
| Can spot white fluffy patches in the eye
48
Increase in IgM titers of Toxoplasmosis indicate a ___ infection?
Acute
49
P falciparum cause organ damage in the brain/lungs/kidneys by ___?
adhesion of infected RBCs in the capillaries that impair microcirculation
50
How does tick need to attach to the human to transmit lyme disease?
24-48 hrs
51
Does reinfection occur for lyme disease?
Yes (antibodies are not protective)
52
What is the progression of lyme disease?
Stage 1 (bullseye rash is the minority/flu like symptoms)--->stage 2 (cardiac and neurologic involvement)--->stage 3 (arthritis/chronic CNS disease)
53
Is seropositivity testing useful for lyme disease?
No
54
How long do we treat early lyme disease (stage 1)?
Doxycycline (alt ceftriaxone) for 10-30 days and no longer than that
55
What are the 2 bacterias that have human as their natural reservoirs?
Relapsing fever/epidemic typhus (vector is body louse--->bacteria eventually kills the vector)
56
What is typical of all spirochetes?
Immediate access to blood
57
What is the disease progress of relapsing fever?
Bacteria invade the blood--->strong IL-10 response and clear the bacteria (fever)--->bacteria vary their surface antigen and evade immune system--->disease resume--->immune clears again (fever)--->repeat
58
What are the number of average relapses for louse-born and tick-born relapsing fever?
1/3 (tick-born cause pregnancy complications)
59
What to use to diagnose relapsing fever?
Peripheral blood smear (during fever) or culture
60
Treatment for relapsing fever?
tetracycline/doxycycline
use erythromycin for children and prego
louse borne takes 1 dose/tick borne 7-10 days
61
What is the characteristics of richettsia?
small short rod/obligate intracellular replication/hard to stain
62
What are the reservoir for Rocky Mountain Spotted Fever?
Mouse and dog ticks
63
Where do lyme and relapsing fever (the bacteria) replicate?
Extracellular in the bloodstream
64
How is the rash in RMSF caused?
Bacteria infect and reproduce in the vascular endothelium--->cell to cell infection--->cells break--->blood comes out
(rash begins in the extremities and spread to trunk)
65
How to test for RMSF?
Immunochemical staining
66
What drug to use for spotted fever?
Doxycycline (even for prego sometime)--->poor prognosis associated with old age (>40) and delayed treatment
67
How is MSF compares with RMSF?
MSF is characterized by eschar at the bite site/less severe than RMSF/treatment is the same
68
What is the characteristics of typhus rash?
Start around the trunk and then spread to extremities (opposite of RMSF)
69
What is Brill-Zinsser disease?
Recrudescent typhus/less severe than the initial course
70
What are murine and scrub typhus?
Find in warm weather. Murine (rat fleece)/scrub (chiggar)
71
What lab to use to confirm typhus?
IF assay/immunoassay/PCR
72
Treatment for typhus?
Doxy and chloramphenicol (doesnt work for HME)
73
What are the characteristics of ehrlichia?
gram -/obligate intracellular/replicate in WBC/form morulae
74
Does HME (human monocytic ehrlichiosis/ehrlichiosis) often symptomatic/asymptomatic?
Asymptomatic
75
Where does HGA (human granulocytic anaplasmosis) grow?
In neutrophils
76
Difference between HME and HGA?
HGA is more severe
77
What is used to treat HME and HGA?
Doxycycline/chloramphenicol doesnt work
78
All the arboviruses are DNA or RNA viruses?
RNA (high mutation rate)
79
Important factors too look for in history for arboviruses
Season/travel history
80
Tell me about Eastern Equine Encephalitis
1. Bird virus (mosquito feed on birds, 10% of pt develop encephalitis)--->transmitted by mosquito
2. It is one of the 4 alphavirus: the other 3 are WEE/VEE/Everglades.
3. No treatment for it.
81
Tell me about Japanese Encephalitis
1. transmitted by culex mosquito (vector) that feeds at night
2. natural host is pig
3. IXIARO (vaccine)--->need 28 days to work
82
Tell me about yellow fever
1. Yellow fever vaccine can cause viscerotropic disease of yellow fever
2. Endemic In south america and africa
3. Hemorrhagic fever--->throw up blood/renal failure
4. jungle cycle leads to urban cycle
83
Tell me about Dengue virus
1. Petechiae
2. Endemic in Key West now
3. Hemorrhagic--->shock (treat with fluid resuscitation)
84
Features of Group A strep?
gram +/catalase -/beta-hemolytic/bacitracin-sensitive
85
2 way of diagnosing Strep A?
Antibody assay/culture (not sensitive)
86
Strep A sore throat can cause?
peritonsillar abscess (Quinsy)/Ludwig's angina (infect floor of the mouth)--->blocking airway/middle ear infection (need to drain middle ear)/scarlet fever
87
What is a complication from middle ear infection from Strep A?
Mastoiditis
88
What caused scarlet fever?
Erythrogenic toxin from Strep A--->skin and tongue rash (strawberry tongue) (skin is not infected, just toxin)
89
What kinds of M-protein of Strep A leads to Rheumatic fever?
M3/5/13
90
Progression of Rheumatic fever?
Sore throat--->recovery--->fever/arthritis/endocarditis (abnormal heart sound) (autoimmune--->no bacteria anywhere)
91
What test to use to diagnosis rheumatic fever?
look for IgM anti-streptolysin O antibody/endarteritis/Aschoff bodies/heart lesion
92
Does rheumatic fever reoccur?
Oh yes
93
What is the result of rheumatic fever on heart?
Distortion of endothelium--->bacteria settles--->bacterial endocarditis
94
Features of viridian strep
Gram +/catalase -/alpha hemolytic/optochin resistant
95
How does viridian strep cause dental caries?
Metabolize sugar into high molecular weight sugar--->sticky--->dental caries
Breakdown sugar--->make acid--->decalcification of teeth
96
Long standing dental caries with viridian strep can cause?
Abscesses (invade soft tissue)--->unilateral swollen
| Or endocarditis
97
Bacterial endocarditis can cause?
metastatic abscess and hemorrhage (vegetation breaks off)
98
Periodontal disease progression
Gingivitis--->create a pocket by the teeth--->teeth lost
99
What is periodontal disease caused by?
Gram - bacteria
100
Feature of Corynebacterium diphtheriae?
Gram + rod/infect pharyngeal mucous membrane/spread by droplet/toxin cause necrosis of heart muscle/not all are toxic--->need culture and then PCR to determine/have toxoid vaccine
101
What is pseudomembrane?
Diphtheria kills the epithelium--->leaving a lot of dead tissues at the back of the throat
102
Bacteria responsible for bacterial endocarditis are?
Viridian and group A strep
103
Can you get sick from touching subjects (doorknob/keyboard and what not) that a S. aureus infected pt has touched before?
Da (S. aureus can transport either direct or indirect)
104
What is the fraction of the population that is carrying S. aureus?
1/3
105
Which antibiotic is used to treat surface/abscess S. aureus infection?
Mupirocin/cephalosporin
106
Which bacteria cause infection at piercing/catheter site?
Staph epidermidis (S. aureus can infect the catheter site of immunosuppressed pts)
107
How to treat piercing/catheter site infection?
Take out the piercing or catheter
108
Feature of scabies?
Mite that lay eggs on places like wrists/really itchy/treat with permethrin
109
What are the 4 kinds of skin abscesses (follicle and gland infection)? And what bacteria usually cause them?
Furunculitis (sweat gland and hair follicle of the skin)/carbuncle (multiple abscesses fused)/stye (eyelid)/acne
S. aureus
110
What is important about infection of S. aureus treatment?
Need to test antibiotic sensitivity and prevent resistant/also need to remove dead tissue (provide nutrients for staph)
111
What is exfoliatin toxin and what does it cause?
Toxin from S. aureus/cause exfoliation/no bacteria in there
112
What is scaled skin syndrome?
Bad case of widespread exfoliation caused by exfoliatin toxin
113
What bacteria usually cause subcutaneous skin infection?
S. pyogenes (group A strep)
114
Difference between S. aureus and S. pyogenes in terms of spreading?
S. aureus doesn't and S. pyogenes spreads
115
Difference between erysipelas/cellulitis/necrotizing fasciitis?
All are deep skin infection. Erysipelas and cellulitis are the same. Necrotizing fasciitis is deeper.
116
Treatment for erysipelas/cellulitis/necrotizing fasciitis?
Penicillin or cephalosporin for erysipelas and cellulitis. Amputation for NF
117
How to avoid post surgical infection?
Eliminate staph carrier state
118
What causes post strep nephritis?
Happens after strep infection--->autoimmune reaction
119
What is thermal dimorph?
Fungus--->room temp grow as mold/body temp grows as yeast
120
Dermatophytoses only infect ___ and transmitted through ___?
superficial keratinized structures/fomites
121
What causes hypersensitive dermatophytid reaction (vesicles on fingers)?
Circulating fungal antigen (vesicles do not contain fungus)
122
What is the exam for dermatophytoses?
Scraping/treat 10% KOH/microscope
123
Best way to prevent dermatophytoses?
Keep dry and cool
124
Difference between dermatophytoses and tinea veriscolor?
Infection vs. overgrowth
125
What is the route of transmission for tinea nigra?
spores in soil enter injury
126
Azole is a ___ drug?
anti-fungal
127
How does sporotrichosis transmit? and what does it present?
By thorn puncture/painless pustule or ulcer (hand)
128
Which is better for diagnosing sporotrichosis, biopsy or culture?
Culture
129
Which 2 fungal infection have dark hyphae?
Chromomycosis and tinea nigra
130
How does chromomycosis transmit?
Soil in the tropics enters through puncture (feet)
131
What kind of stain is used for mycetoma?
Silver stain
132
How to treat mycetoma?
Surgical excision of abscesses
133
Common candidiasis?
Diaper rash/vaginitis/thrust or esophagitis (immunosuppressed)
134
What follows systemic candidemia?
disseminated candidiasis (organ invasion)
135
Neutropenia is a risk for ___ infection?
Fungal
136
Chronic HSV keratitis and zoster in the face can cause ___?
Vision loss
137
What is herpetic whitlow?
HSV1/2 on the hands/reoccurrence on the hands
138
Zoster is usually uni or bilateral?
Unilateral
139
Oral hairy leukoplakia is caused by?
EBV (immunodeficiency)
140
CMV causes ___ rash?
petechial
141
Roseola is caused by ___?
HHV 6/7 infect CD4+ T cells
142
Roseola progression?
3 day fever followed by a faint rash on the trunk
143
Features of CMV?
Rash and jaundice (liver enzyme elevated)
144
What does coxsackie infect?
Throat/eye/hand, foot and mouth disease (painful blisters)
145
Live smallpox vaccine (vaccinia virus) is dangerous because?
Contraindicated for ppl with eczema/immunosuppressed/ppl who scratch the injection site
146
When rubella infect pregnant women, it causes?
Congenital defect
147
Difference between septic shock and severe septic
Septic shock: HoTN can not be reversed by fluid
148
HLA is the human form of ___?
MHC
149
The diversity of HLA subtypes prevent ___?
Tumor from passing from person to person (only the same strand of HLA tumor can be grew on another person)
150
Can our immune system target the antigens of tumor?
Ya e.g. HER2
151
How does tumor cells that don't express MHC II gets targeted by immune system?
Tumor antigen is picked up by antigen presenting cells--->stimulate CD4--->then CD8--->kill tumor cells
152
3 examples for tumor cells to avoid being killed
Down-regulate MHC I/recruit Treg to protect it/lack co stimulatory protein like B7
153
What is the cytokine that is responsible for Treg activation?
TGF-beta
154
How does BCG works?
Inject into bladder with bladder cancer--->BCG infect bladder cancer cells (highly immunogenic)--->immune system get rid of them
155
Why blocking CTLA-4 (using antibody) is a treatment for tumor?
CTLA-4 inhibit immune response
156
CTLA-4-Ig ___ immunity?
Blocks
157
PD1/PD1-L ___ the function of T cell?
inhibit (so blocking PD1/PD1-L can enhance immunity)
158
ADCC recognizes ___ and then kill the tumor cell
Monoclonal antibodies on the tumor cells
159
___ and ___ can be conjugated to monoclonal antibodies?
Toxin (tumor cells take it in--->die)/radionuclide (tumor cell die from radiation)
160
What is adoptive T cell therapy?
Isolate T cells from a person--->grow it--->put them back (enhance immunity)
161
CAR expressing T cell
Trained to recognize certain tumor antigens
162
How do we use listeria to target tumor cells?
Listeria target dendritic cells naturally--->make listeria to express tumor antigen--->the more immune to listeria you are, the more listeria you take up--->better against tumor
163
CTLA-4 is on ___ cell?
Treg cells
164
Hygiene theory on type I hypersensitivity?
Kids nowadays are not allowed to play in the dirt--->immune system is exposed less to normal organism--->immune system don't learn how to respond appropriately
165
Process of allergen sensitization in type I hypersensitivity (no reaction)
Allergen bind to B cell--->B cell presents it to Th2 cells--->B cell become IgE secreting--->IgE bind on mast cells
166
What happens to subsequent exposure to allergen?
Mast cells degranulation--->immediate (histamine) and late phase (cytokines like TNF/enzyme)
167
Basophils and eosinophils comes in after mast cell degranulation, they need to be ___ to express IgE
activated by mast cells
168
More diffuse swelling of urticaria is called?
angioedema
169
For allergic asthma, Th2 cells makes ___ that activates ___?
IL13/eosinophils
170
The child is atopic if the father/mother is atopic?
Mother
171
What is the mechanism of desensitization of type I hypersensitivity?
IgA and IgG block IgE from cross linking with mast cells
172
How does type II hypersensitivity works?
IgG binds to antigen on a cell--->activate complement to kill the cell/phagocytize the cell
173
ABO incompatibility/Rh hemolytic disease of newborn/graft rejection are type __ hypersensitivity?
Type II (IgG mediated)
174
What is Arthus reaction?
Type III--->localized injected antigen--->antibody-antigen bind to mast cells--->mast cell degranulate--->local inflammation--->attract neutrophil and macrophages--->tissue damage
175
Serum sickness
Type III: antibodies against large amount of foreign protein
176
Delayed type IV hypersensitivity?
Antigen in subcutaneous tissue--->activate Th1 cell--->recruit T cells--->2 days later--->flare (TB test)
177
Contact type IV hypersensitivity?
Poison ivy + skin protein=foreign protein--->CD4 T cell sensitive--->memory T cells--->subsequent exposure--->dermatitis (latex sensitivity also)
178
Difference between transplant rejection and graft vs. host ?
Both type IV: T cell attack the transplant organ in transplant rejection
T cell from the transplant attach the host in graft vs. host
179
How to trigger autoimmunity?
Genetic susceptibility--->infection that activate self-reactive lymphocytes--->autoantibodies production
180
AIRE present ___ to T cell in the ___?
self-antigen to T cell in the thymus
181
Requirement of costimulation for B and T cell help controls ___?
the activation of self reactive B and T cells in the periphery
182
Defect in FoxP3 gene affect?
Treg--->autoimmune disease
183
What is molecular mimicry?
Pathogen derived peptide is similar to self antigen--->cause autoimmune disease
184
What can cause the release of sequestered antigen that cause autoimmune symptoms?
Trauma
185
What is the mechanism of Grave's disease?
Autoantibodies (TSH analog) bind to TSH receptor on thyroid gland--->increase release of T3 and T4--->hyperthyroidism
186
IgG mediated autoimmune disease can be transmitted to ___?
Fetus (plasmaphresis to remove the antibodies)
187
Examples of type IV hypersensitivity autoimmune diseases?
Type I diabetes (target GAD)/RA/MS
188
The toxin of C. tetani is called?
Tetanospasmin (this is what causes all the symptoms)
189
What are the 4 types of C. tetani?
Neonatal/cephalic/local/generalized
190
C. tetani toxin is travelled by ___ in the CNS?
Retrograde axonal transport
191
Babies ingestion C. botulinum in the form of ?
spores (preformed toxin for adults)
192
___ inactivate the botulinum toxin?
Cooking
193
Botulinum toxin is targeting ___ nervous system
peripheral motor
194
What is the definition of zoonoses?
Disease that cycles in animals jump to humans
195
How can we detect Gram + cocci?
culture
196
Endocarditis can be from Strep pyogenes?
Rheumatic fever--->distortion of endothelium--->bacteria lodges there--->endocarditis
197
DNAse is positive for ?
S aureus
198
Glomarular nephritis of strep follows ?
Skin infection
199
S aureus is ___ hemolytic
Beta
200
What does MCV lesion look like?
Pearly/umbilicated (school age children)
201
Symptoms of rubeola (measels)?
Koplik's spots/cough/conjunctivitis/fever/rash (red with bluish center)
202
Primary CMV infection can lead to ?
congenital CMV syndrome
