Microbiology Flashcards
(165 cards)
1
Q
ANCA + asthma+ eosinophils
A
Churg-Strauss syndrome
2
Q
cANCA+ respiratory necrotizing granulomatosis
A
Wegener’s granulomatosis
3
Q
Anti-GBM autoantibodies+ lung hemorrhage
A
Goodpastures syndrome
4
Q
To cause kidney immune disease an antigen must trigger this
A
a local immune inflammatory response
5
Q
Nonrenal antigens mechanism for depositing in the kidney
A
usually bloodborne and attach to a specific antibody, forming immune complexes that circulate to the kidney
6
Q
Berger disease
A
- Focal glomerulonephritis
- Presents with hematuria
- Follows acute upper respiratory infection in young males
- IgA deposits in the glomerular mesangium
7
Q
Where do bacterial antigens complexed with IgG tend to localize?
A
within the GBM
or
on the epithelial side of the GBM because of their smaller sizes
8
Q
An example of a systemic disease associated with Berger’s disease
A
Henoch-Schonlein purpura (HSP)
9
Q
Where is the glomerular capillary bed situated?
A
Between two arterioles NOT between an arteriole and a venule as in other capillary beds
10
Q
What is the high glomerular capillary pressure due to?
A
Resistance afforded by the efferent arterioles
11
Q
Why is capillary pressure always greater than the pressure in Bowman space?
A
Only filtration occurs
12
Q
Describe fluid flow through the glomerular capillary membrane
A
unidirectional with no associated reabsorption by the capillaries
13
Q
Ag-Ab complexes establish immune inflammatory renal injury via:
A
- Type I-IV hypersensitivities
- direct complement activation
- immunodeficiency disorders (AIDS)
14
Q
IgE-mediated (type 1 hypersensitivity) immune response is triggered when..
A
- Allergen sensitive T cells contact specific allergens
- releasing pro-allergic interleukins IL-4 and IL-5
- which enhance production of IgE by class switching and
- activate mast cells and basophils
15
Q
IgE coating of basophils and mast cells in the presence of allergen causes the release of…
A
- vasoactive amines (histamine causing vasospasm)
- chemokines (RANTES)
- prostaglandin synthesis
- platelet mediated coagulation, thrombosis and fibrin deposition
16
Q
When allergen sensitive T cells contact specific allergens in Type I hypersensitivity this causes the release of
A
IL-4 and IL-5
17
Q
IL-4 and IL-5 enhance the production of what?
A
IgE by class switching
18
Q
Allergic tubulointerstitial renal disease due to penicillins is associated with…
A
- penicillin or its metabolic products act as HAPTENS
- IgE deposition on mast cells-activation
- eosinophilia
- eosinophilic infiltration in the kidney
- responsiveness to corticosteroids
- rapid improvement after discontinuation of the causative drug
19
Q
What type of hypersensitivity is Goodpastures disease?
A
Ab mediated (type II) renal disease
20
Q
What is renal damage caused by in Type II (Goodpastures) renal disease?
A
linear deposition of anti-collagen IV antibody
21
Q
C5a
A
anaphylactic and chemotactic
22
Q
Type II renal damage steps
A
- Ag-Ab complex activates complement-MAC
- Tissue injury: creating membrane channels (MAC) and attracting other inflammatory cells to participate in the immune response (C5a fragment attracts neutrophils)
23
Q
What do C5a fragments attract
A
neutrophils
24
Q
A specific antigen component of the neutrophil cytoplasm that ANCA recognizes
A
Myeloperoxidase (MPO)
25
Most common category of the rapidly progressive glomerulonephritides
Pauci-immune (type III) crescentic glomerulonephritis
26
Why is it termed Pauci-immune?
Because there is no detectable IgG or C3 immunofluorescence within the glomerular basement membrane
27
3 conditions associated with ANCA auto Abs:
1. ) type III idiopathic crescentic glomerulonephritis
2. ) Wegener granulomatosis
3. ) microscopic polyangiitis
28
Wegener granulomatosis
c-ANCA
29
ANCA + cytoplasmic antigens activate:
neutrophils
30
Neutrophil beta2 integrins action
| Wegener granulomatosis
attraction and rolling of neutrophils along vascular endothelium of the kidney (ADHESION)
31
What two endothelial surface interaction ligands are upregulated in Wegener granulomatosis?
ICAM-1 and ELAM-1
32
Histopathology of clinical Wegener features
- necrotizing rapidly progressive crescentic glomerulonephritis
- T-cell mediated granulomas in the kidney and respiratory tract
33
Renal biopsy pattern in immune complex-mediated (type III hypersensitivity)
Antibody and complement in these location in a lumby-bumpy pattern
34
Granular "lumpy-bumpy" pattern are deposits of...
- IgG along the GBM of peripheral capillary loops
| - components of the classical pathway of complement
35
Factors affecting localization of immune complex
1. ) Release of vasoactive substances that enhance vascular permeability
2. ) Presence of receptors:
- CR1 receptor of C3b on glomerular epithelial cells
- FcR for Fc fragment of IgG on mesangial and interstitial cells
36
Renal transplant acute rejection is mediated by
T cells (type IV) that are directed against MHC-1
37
During acute renal transplant rejection the release of this induces IL-2 syntesis
IL-1
38
TH cells stimulate these cells in the presence of IL-2 during acute rejection
Tc cells
39
What do activated Tc attack during acute rejection?
Foreign antigens of the graft resulting in cell-mediated immune inflammation
40
During acute rejection alloreactive antibodies contribute to this
vascular injury
41
During chronic rejection alloAgs T cells produce these that induce endothelial and intimal smooth muscle cell proliferation
cytokines
42
The production of cytokines during chronic rejection lead to...
luminal occlusion and graft arteriosclerosis
43
Poststreptococcal glomerulonephritis (PSGN) pathogenesis
- T cells stimulate by streptococcal wall Ags may cross react with renal glomerular Ags resulting in:
- progressive cell death
- sclerosis of the renal parenchyma
44
Hyperacute refection in presensitized host, preformed antibodies react with...
alloantigens on the vascular endothelium of the transplanted kidney
45
Hyperacute rejection results in...
acute renal ischemia, infarction, and transplant loss
46
Where does C3b local immune inflammatory injury occur when C3b deposit?
- In the phagocytic mesangium of the glomerulus
- subendothelially
- along C3b binding sites within the capillary wall
47
C3b
opsonin
48
Half of C3 deposition renal disease patients have this
C3 convertase
49
Type I of Membranoproliferative glomerulonephritis features distinguished on renal biopsy
Immune complex deposit C3 deposited primarily on subendithelial sites along capillary wall
50
Type II of Membranoproliferative glomerulonephritis features distinguished on renal biopsy
associated primarily with dense intramembranous deposits of C3 nephritic factor
51
Type III of Membranoproliferative glomerulonephritis features distinguished on renal biopsy
Mixture between types I and II
52
Pathway activated in MPGN Type I
classic pathway
53
Interposition of mesangial cell cytoplasm between the GBM and endothelial cell + glomerulosclerosis leads to...
renal failure
54
Pathway activated in MPGN Type II
alternative pathway
55
GBM appearance in MPGN Type I
double contours, rail track appearance
56
Basement membrane appearance in MPGN Type II
Appears thick and looks like a ribbon
57
RBC contain C3b/C4b receptor and regulate what?
C3bBb
58
How do RBCs that contain C3b/C4b receptor regulate C3bBb?
By binding C3b in immune complex, making it available for cleavage and inactivation by serum factor I
59
Male, urban, black IV drug users
- proteinuria
| - rapidly pregressive HIV-associated FSGS
60
White homosexual seropositive patients
- Nonproteinuric
| - more slowly progressive HIV nephropathy
61
HIV FSGS is characterized early by...
Focal deposition of IgM and C3 which leads to scarring of the glomeruli
** kidneys can fail
62
Immune complex type renal involvement in patients with HIV probably results from what?
circulation of bacterial, viral, or tumor associated immune complexes to the kidney
63
HLA-B12 (MCH I)
PSGN
64
HLA-B35 (MHC I) and HLA-DR4 (MHC II)
IgA neuropathy
65
HLA-DR2 (MHC II)
Anti-GBM or Goodpastures syndrome
66
Prevalence of asymptomatic bacteriuria in pregnant women
4-7%
67
Prevalence of asymptomatic bacteriuria in young men
0.1%
68
Prevalence of asymptomatic bacteriuria in elderly men
10-20%
69
Prevalence of asymptomatic bacteriuria in elderly females
20%
70
Most common routes ascending UTIs
1. ) ascent of urethral organisms to bladder
2. ) from bladder to ureter
3. ) from ureter to renal pelvis
4. ) from renal pelvis to kidneys
71
Most common routes hematogenous spread
1. ) bacteria reach blood- bacteremia
2. ) from blood they reach renal parenchyma
3. ) produce abscess
72
Promotors of ascending infections
1. )sexual intercourse: honeymoon cystitis
2. ) bladder catheterization (insertion through urethra)
3. ) fecal incontinence
73
Host susceptibility local factors (UTIs): physiological obstructions
1. ) infrequent voiding
2. ) neurogenic or neuropathic bladder (impaired innervation)
3. ) detrusor muscle instability
74
Congenital or acquired anatomical abnormality (UTIs)
vesicoureteral reflux
75
What is the vesicoureteral reflux?
condition in which the urine in the bladder flows back, or refluxes, into the ureter toward the kidney
76
Systemic susceptibility factors of UTI
1. ) HYPEROSMOLARITY (secondary to hyperglycemia in diabetics) of renal medulla--inhibits PMN migration to damaged tissue
2. ) immunological cross reactions between bacterial and host Ags= TOLERANCE to bacteria or autoimmunity
77
An example of susceptibility factor of UTIs in women
Pregnancy: dilation of ureter, pelvis, hormonal effect
78
An example of susceptibility factors of UTIs in elderly
urinary obstruction and REFLUX
79
An example of susceptibility factors of UTIs in children
poor toilet training
80
An example of susceptibility factors of UTIs in immunosuppressed
fungal pyelonephritis
81
Virulence factors of UT pathogens
1. ) ADHERENCE to mucosal surfaces
2. ) K antigens: specific capsular acidic polysaccharides (O1,O2,O4)
3. ) P-fimbriae
4. ) motility
5. ) endotoxins
82
Adherence properties of pathogen in UTIs
1. ) pili
| 2. ) fimbriae
83
Most important adhesin expressed by uropathogenic E. coli
P-fimbriae
84
Virulence factor that facilitates ascending infections
Motility
85
Virulence factor that decreases ureteral peristalsis
endotoxins
86
K antigens MOA
1. ) resistance to bactericidal action of normal serum via Igs and complement
2. ) antiphagocytic
3. ) specific K antigens of E coli in pyelonephritis
87
Example of an organism who uses motility virulence factor
Proteus
88
Acute cystitis
-superficial inflammation/infection of lower UT: bladder
89
Acute cystitis is most commonly a disorder of what population?
young women
90
Predisposing factors of acute cystitis
residual urine in the bladder
91
Symptoms of acute cystitis
1. ) high frequency of urination
2. ) burning pain on urination (dysuria)
3. ) feeling of fullness following voiding
4. ) sometimes hematuria
92
What is affected in pyelonephritis?
tubules and interstitium
93
Pyelonephritis
inflammation of kidney parenchyma and renal pelvis
94
Manifestations of pyelonephritis
1.)small abscesses on kidney
95
Acute pyelonephritis routes of infection
blood stream or ascent from the bladder
96
Contributing factors to acute pyelonephritis
- catheterization
- vesicoureteral reflux
- pregnancy
- neurogenic bladder
97
Clinical symptoms of acute pyelonephritis
- abrupt onset
- chills, fever, headache, back pain
- tenderness costovertebral angle
- dysuria, frequency and urgency
- magnesium ammonium stones
98
bacterial role in magnesium ammonium stones
proteus mirabilis
99
Chronic pyelonephritis is a significant cause of this
renal failure
100
Acute urethral syndrome has similar symptoms to these to infections
chlamydia and herpes
101
UTI infections in pregnancy result from
1. ) estrogen and progesterone induced dilation of uterus, bladder, pelvis
2. ) decreased ureteral peristalsis
102
Complicated UTIs primarily affect:
premenstrual girls and postmenopausal women
103
Most male UTIs are complicated or uncomplicated?
complicated
104
Are men or women at greater risk of acquiring catheter associated UTIs?
Women
105
Most common source of gram negative bacteremia?
Catheters
106
2 most common bacteria causing gram negative UTI
1. ) E. coli
| 2. ) Proteus
107
Gram positive, coagulase negative pathogen associated with UTI
Staphylococcus saprophyticus
108
Enteroccoccus fecaelis
Pathogen associated with UTI, common in nursing homes, resistant to antibiotics
109
Organism associated with >90% acute bacterial cystitis
E coli
110
Most common organism involved in UTIs
E. coli
111
Organism responsible for 30-50% of nosocomial UTIs
E. coli
112
K antigens involved in E. coli UTIs
O1, O2, O4, O6, O7, O75
113
K groups in children pyelonephritis
11, 24, 36, 37
114
All strains of E coli posses this virulence factor that binds to mannose receptors
Type 1 pili
115
Strains from cystitis have HIGHER affinity for these cells than fecal strains
uroepithelial cells
116
Bacteria associated with Hemolytic Uremic Syndrome (HUS)
EHEC
117
How does EHEC involve with renal system?
Hemolytic Uremic Syndrome
118
Hemolytic Uremic Syndrome
1. ) acute renal failure
2. ) thrombocytopenia
3. ) microangiopathic hemolytic anemia
119
What age group is HUS a complication for?
children under 10
120
Epidemics of EHEC are often contributed to consumption of
1. ) undercooked (ground) beef
2) unpasteurized milk
3. ) fruit juices (cider)
121
Ingestion of what number of bacilli can produce EHEC diseases
fewer than 100 bacilli
122
EHEC clinical & symptoms
- mild, uncomplicated diarrhea
- hemorrhagic colitis
- severe abdominal pain
- blood diarrhea
123
Most common serotype of EHEC and what doesn't it ferment?
Serotype: O157:H7
| * does not ferment sorbitol
124
E coli fimbriae have different specificities for what receptors?
Host cell carbohydrate receptors
125
What is phase variation?
an individual bacterium will not express all fimbrial types at any given time
126
Emphysematous pyelonephritis is associated with what populations?
diabetics and women
127
Emphysematous pyelonephritis is characterized by...
gas formation and entrapment in the kidney
128
What organism is commonly involved in Emphysematous pyelonephritis?
E. coli
129
Emphysematous pyelonephritis management
surgery: nephrectomy
| and medical: antibacterials
130
Proteus mirabilis is involved in which kind of UTI?
nosocomial UTIs
131
Organism that produces urease which plays important role in pathogenesis
proteus mirabilis
132
What type of pili does proteus mirabilis posses?
Type 1 pili
133
This organism can alter its own surface composition and escape phagocytosis
proteus mirabilis
134
Organism that displays a fog like swarming when inoculated on plate
proteus mirabilis
135
organism is actively motile: swarming
proteus mirabilis
136
Salmonella in UTIs can cause this
bacteriuria
137
Bacteriuria from salmonella is associated with this
Sepsis
138
Pseudomonas aeruginosa
- involved in nosocomial UTIs
- Oxidase positive
- nonfermenter of glucose
- cause of bacteremia
139
May cause inflammatory infection in urethra leading to nongonococcal urethritis and recurrent urethritis
Mycoplasma genitalium
140
Organism found in healthy male urethra
mycoplasma genitalium
141
A cause of chorioamnionitis and premature delivery
Ureaplasma urealyticum
142
A catalase positive, coagulase positive organism that should not be ignored because it can indicate or precede dangerous bacteremia
Staph aureus
143
Second most common cause of honeymoon cystitis in young women thought to gain access to female urinary tract during sexual intercourse
Staph saprophyticus
144
Coagulase negative, catalase positive, gram positive, nonmotile, opportunistic, found on skin as commensal
Staph epidermidis
145
Gas bubbles in the lumen of bladder
Emphysematous cystitis
146
Pneumaturia
-the passage of gas or air from the urethra during urination or after urination
147
The passage of gas or air from the urethra during urination or after urination results from
1. ) infected urine
| 2. ) intestinal fistulas (most common)
148
Cause of pediatric hemorrhagic cystitis
Adenovirus
149
varicella zoster can cause this type of cystitis
hemorrhagic cystitis
150
Causes of chronic bacterial prostatitis
1.) E. coli (most common)
2.) enterococcus faecalis
3.) proteus mirabilis
4,) Klebsiella pneumoniae
151
Causes first UTI lesion in kidney
Mycobacterium tuberculosis (urinary tuberculosis)
152
Urinary tuberculosis can extend to:
1. ) gall bladder
2. ) prostate
3. ) seminal vesicles
153
How does urinary tuberculosis spread?
Hematogenous route
154
Common symptoms of urinary tuberculosis
pyuria and hematuria
155
How is urinary tuberculosis diagnosed?
Diagnosis based on 3 consecutive (3 mornings) early morning specimens
156
Where does the adult worm reside in urinary schistosomiasis?
venous plexus of the bladder
157
What to the worm eggs induce in urinary schistosomiasis?
granulomatous reaction
158
Inflammation in urinary schistosomiasis leads to this
fibrous tissue and obstruction
159
A cause of bladder carcinoma
urinary schistosomiasis
160
Diagnostic tests for UTIs
urine culture
| -100,000 CFU/ml
161
Exception to urine culture diagnostic levels for UTIs
many women with acute cystitis
have bacteria at 100- 10,000/ml
-similar results with acute pyelonephritis
162
Examples of rapid diagnostic tests in UTIs
1. ) counts by hemocytometer using uncentrifuged urine
| 2. ) gram stain
163
Where do IgA immune complexes deposit in Berger's disease?
IN the mesangium because of the large size of IgA
164
Where do bacterial antigens complexed with IgG tend to localize?
within the GBM or on the epithelial side of GBM because of their smaller size
165
Acute rejection is which type of hypersensitivity?
Type IV (T cell mediated)
