ALL BACTERIA! Flashcards
1
Q
Salmonella (general): Similar to
A
Shigella, E coli (Enterobacteriaceae Family)
2
Q
Enteroaggregative E. coli (EAEC): Similar to
A
EPEC
3
Q
Acinetobacter baumanii: At Risk
A
Hospitals
4
Q
Acinetobacter baumanii: Disease
A
OPPORTUNIST!
Nosocomial infections
5
Q
Acinetobacter baumanii: Gram stain
A
-
6
Q
Acinetobacter baumanii: Negative for: (2)
A
Oxidase
Sugar fermentation
7
Q
Acinetobacter baumanii: Oxygen
A
aerobe
8
Q
Acinetobacter baumanii: Reservoir
A
Hospital
9
Q
Acinetobacter baumanii: Shape
A
short rod
10
Q
Acinetobacter baumanii: Transmission/vector/ habitat
A
Indwelling medical devices
11
Q
Acinetobacter baumanii: Treatment
A
Multidrug resistant
12
Q
Acinetobacter baumanii: Virulence Factors (4)
A
Capsular polysaccharides
Adhesins
Proteolytic/lipolytic enzymes
LPS
13
Q
Bordetella pertussis: At Risk
A
Infants more likely to die
14
Q
Bordetella pertussis: Diagnosis (3)
A
Contact history, classic cough, lymphocytosis
**Requires fresh, Bordetella-optimized media for growth (not typically used)
PCR for repeat insertion sequences
15
Q
Bordetella pertussis: Disease
A
Pertussis (whooping cough)
16
Q
Bordetella pertussis: Epidemiology
A
Major childhood killer pre-1940
–Highest fatality of all among children before vaccine!
Re-emerging now: waning immunity, Agic divergence, decreased vaccination
17
Q
Bordetella pertussis: Gram stain
A
-
18
Q
Bordetella pertussis: Incubation Period
A
7-10 days
19
Q
Bordetella pertussis: Oxygen
A
Obligate aerobe
20
Q
Bordetella pertussis: Pathogenesis (6 steps)
A
- intro via water droplets
- interact w/ciliated epithelial cells (trachea/nasopharynx)
- adherence
- multiplication/toxin production -> local inflammation, mucous secretion, patchy ulcers, cyanosis, pneumonia
- host evasion
- spread
21
Q
Bordetella pertussis: Reservoir
A
NONE - only infects humans
22
Q
Bordetella pertussis: Shape
A
coccobacilli
23
Q
Bordetella pertussis: Symptoms
A
[Catarrhal stage] runny nose, sneezing, low-grade fever, mild cough
[Paroxysmal stage] whooping cough, vomiting, cyanosis
24
Q
Bordetella pertussis: Transmission/vector/habitat
A
Aerosol
25
Bordetella pertussis: Treatment
Treat for hypoxia
Erythromycin (alt: tetracycline or chloramphenicol)
--Resistant to penicillin and ampicillin
Treat household contacts prophylactically
26
Bordetella pertussis: Vaccine
DTP (trivalent): side-effects - encephalopathy and permanent neurologic sequelae (not used anymore)
DTaP (acellular trivalent component) introduced mid-90s
-> contains pertussis toxin, FHA, pertactin, and fimbrae
NO lifelong immunity
27
Bordetella pertussis: Virulence Factors (6)
PERTUSSIS TOXIN (inhibits Gi for adenylate cyclase -> adenylate cyclase activated -> cAMP accumulation -> lymphocytosis, histamine-sensitivity, enhanced insulin secretion)
ADENYLATE CYCLASE toxin (catalyzes cAMP from ATP -> impaired leukocyte function and apoptosis)
DERMONECROTIC toxin (VSM contraction => ischemic necrosis of lung tissue)
TRACHEAL CYTOTOXIN (CILIOSTASIS, kills tracheal epithelial cells, proinflammatory)
Endotoxin (LPS)
Several adhesins: pili, Filamentous hemagglutinin, Pertactin, Tracheal colonization factor (-> colonization)
28
Campylobacter (jejuni): At Risk (3)
Infants to young adults in developed
Infants in developing
Immunocompromised, esp. with humoral immunodeficiency (severe)
29
Campylobacter (jejuni): Diagnosis (4)
Gm stain stool specimen
Enrich with filters (very small)
Hippurate positive (very diagnostic)
Culture at 42C in microaerophilic conditions (body temp of poultry)
30
Campylobacter (jejuni): Disease (2)
Diarrhea from inflammatory enteritis
| Bacteremia (rare)
31
Campylobacter (jejuni): Epidemiology (3)
MOST COMMON cause of diarrhea in the world
Typically sporadic cases
Multiple simultaneous cases usually point to common contaminated source
32
Campylobacter (jejuni): Gram stain
-
33
Campylobacter (jejuni): Incubation Period
3-5 days
34
Campylobacter (jejuni): Infectious dose
Low infectious dose (500 = 1 drop of raw chicken juice)
35
Campylobacter (jejuni): Oxygen
microaerophilic
36
Campylobacter (jejuni): Pathogenesis (3 steps)
1. survive gastric barrier
2. arrive in small/large bowel - inflammation
3. bloodstream (rare)
37
Campylobacter (jejuni): Prevention (2)
Pasteurization of milk, cooking meat (esp. poultry)
38
Campylobacter (jejuni): Reservoir
Animals (esp. poultry -does not make animals sick)
39
Campylobacter (jejuni): Shape
curved or comma with uni or bipolar flagellum
40
Campylobacter (jejuni): Symptoms
Prodrome (fever, malaise, headache)
fever; abd. pain; diarrhea (few days to a week)
Complications = autoimmunity to nerves (Guilliam-Barre syndrome)
41
Campylobacter (jejuni): Transmission/vector/ habitat (3)
Food (esp. raw chicken), milk, or water
42
Campylobacter (jejuni): Treatment
Oral rehydration therapy
Antimicrobial therapy as indicated (erythromycin; alt - cipro)
43
Chlamydophilia (general): Diagnosis (4)
General Diagnosis
1. Check for group antigen
2. Compare acute and convalescent Ab titers
3. Direct fluorescent Ab exam of appropriate clinical specimens
4. PCR
44
Chlamydophilia (general): Gram stain
Gm- (by phylogeny)
45
Chlamydophilia (general): Life Cycle (forms, 3 steps)
Elementary Bodies (EB): small, non-multiplying, with a rigid bacterial-like cell wall -> transmits infection
Initial Bodies (IB) [aka reticulate bodies (RB)]: larger, actively multiplying, lack rigid wall, non-infectious
Intracellular growth
1. EB enter by inducing host phagocytosis (even in non-phagocytotic cells)
2. EB lose cell wall during first 24h, double in diameter, and synthesize RNA to yield IB
3. IB divide by binary fission -> some progeny converted back to EB
46
Chlamydophilia (general): Shape
pleomorphic
47
Chlamydophilia (general): Special growth conditions
OBLIGATE intracellular (canNOT make ATP => depends on host ATP)
EB -> IB (RB) in host cell -> divide -> host cell dies and release EBs
48
Chlamydophilia (general): Treatment
Tetracyclines are effective but single high dose azithromycin may be more indicated
Any antibiotic used must enter cells
49
Chlamydophilia pneumoniae: Diagnosis
Antibody assay
50
Chlamydophilia pneumoniae: Disease
Atypical (diffuse) pneumonia
51
Chlamydophilia pneumoniae: Epidemiology (2)
Causes 10% of pneumonia in adults
| May play a role in coronary atherosclerosis
52
Chlamydophilia pneumoniae: Number of serotypes
1 serotype
53
Chlamydophilia pneumoniae: Symptoms (3)
Pneumonia/bronchitis
Gradual onset of cough
Little/no fever
54
Chlamydophilia pneumoniae: Transmission/vector/ habitat
Person-to-person via aersol
55
Chlamydophilia psittaci: At Risk
Contact w/birds
56
Chlamydophilia psittaci: Diagnosis (2)
Pathogen in blood or sputum
| Antibody assay
57
Chlamydophilia psittaci: Disease
Psittacosis (parrot fever)
58
Chlamydophilia psittaci: Number of serotypes
1 serotype
59
Chlamydophilia psittaci: Pathogenesis
Disseminated infection that targets epithelial cells, endothelial cells, Mos
60
Chlamydophilia psittaci: Reservoir
Birds (induces chronic subclinical infection with constant fecal excretion)
61
Chlamydophilia psittaci: Symptoms (3)
Fever and headache
| Severe -> interstitial pneumonia
62
Chlamydophilia psittaci: Transmission/vector/ habitat
Inhalation of bird feces
63
Chlamydia trachomatis, serotypes L1-3: Diagnosis
Ag testing to differentiate between C. trachomatis serotypes
64
Chlamydia trachomatis, serotypes L1-3: Disease
Lymphogranuloma venereum
65
Chlamydia trachomatis, serotypes L1-3: Symptoms (2)
Painless papule progresses to ulcerating vesicle (2 weeks post-exposure)
Can -> painful suppurating disease of regional lymph nodes
66
Chlamydia trachomatis, serotypes L1-3: Transmission/vector/ habitat
STD
67
Chlamydia trachomatis, serotypes A-C: At Risk (2)
Poor hygiene
| Asia and Africa
68
Chlamydia trachomatis, serotypes A-C: Diagnosis (1)
Ag testing to differentiate between C. trachomatis serotypes
69
Chlamydia trachomatis, serotypes A-C: Disease
Trachoma (chronic conjunctivitis)
70
Chlamydia trachomatis, serotypes A-C: Epidemiology (1)
World's leading cause of preventable blindness
71
Chlamydia trachomatis, serotypes A-C: Pathogenesis
Chronic conjunctival reinfection causes infolding of eyelashes => corneal scarring and blindness
72
Chlamydia trachomatis, serotypes A-C: Prevention (4)
Surgery, prophylactic antibiotics, facial cleanliness, environmental improvements/sanitation
73
Chlamydia trachomatis, serotypes A-C: Special Features: Intra vs extracellular, presence of capsule, invasive or not
More invasive serotypes
74
Chlamydia trachomatis, serotypes A-C: Symptoms (5)
```
Cloudy cornea
Discharge from eye
Swelling of lymph nodes in front of ears
Swollen eyelids
Turned-in eyelashes
```
75
Chlamydia trachomatis, serotypes A-C: Transmission/vector/ habitat (2)
Mechanical (finger to eye)
| Flies
76
Chlamydia trachomatis, serotypes A-C: Treatment
Annual universal treatment with azithromycin
77
Chlamydia trachomatis, serotypes D-K (perinatal): At Risk
Neonates
78
Chlamydia trachomatis, serotypes D-K (perinatal): Diagnosis (1)
Ag testing to differentiate between C. trachomatis serotypes
79
Chlamydia trachomatis, serotypes D-K (perinatal): Disease (2)
```
Inclusion conjunctivitis
Infant pneumonia (usually an extension of ocular disease)
```
80
Chlamydia trachomatis, serotypes D-K (perinatal): Epidemiology (2)
Inclusion conjunctivitis - most common vertically transmitted neonatal disease
Occasionally seen beyond neonatal age where environ. contamination (swimming pools, etc.) is involved
81
Chlamydia trachomatis, serotypes D-K (perinatal): Symptoms (3)
Large lymphoid follicles
Papillary hyperplasia of the conjunctiva
Red, irritable eye with sticky discharge
82
Chlamydia trachomatis, serotypes D-K (perinatal): Transmission/vector/ habitat (3)
Perinatal
Swimming pools
STD
83
Chlamydia trachomatis, serotypes D-K: Diagnosis (2)
Yearly rapid PCR test of urine for sexually active women
Ag testing to differentiate between C. trachomatis serotypes
84
Chlamydia trachomatis, serotypes D-K: Disease (2)
Non-gonoccocal urethritis
| More severe -> epididymytis, salpingitis -> infertility
85
Chlamydia trachomatis, serotypes D-K: Epidemiology (2)
Possibly most common venereal disease
| Infection increases chance of HIV transmission
86
Chlamydia trachomatis, serotypes D-K: Symptoms (2)
Males: usually asymptomatic (purulent urethral discharge)
Females: frequently asymptomatic
87
Chlyamydia trachomatis, serotypes D-K: Transmission/vector/habitat
STD
88
Chlamydia trachomatis, serotypes D-K: Treatment (1)
Single high dose azithromycin for BOTH sexual partners
89
Corynebacterium diphtheriae: At Risk (2)
Developing countries w/inadequate pediatric immunization and medical care
Travelers (need booster DTaP)
90
Corynebacterium diphtheriae: Diagnosis (4)
Tentative: tellurite agar, Tinsdale's medium, and Leoffler media (+ for METACHROMATIC GRANULES)
Definitive:
- -Toxin production (Elek test)
- -PCR for toxin gene
- -Immunoassay of serum
91
Corynebacterium diphtheriae: Disease (1)
Diphtheria: infection of skin and/or throat
92
Corynebacterium diphtheriae: Epidemiology (3)
Once a major cause of death in US -> in pre-immunization era, major fraction of pop. were carriers
Epidemics in poorly immunized pop. w/inadequate medical care
Presents as necrotizing skin infection in the tropics -> spread by contact
93
Corynebacterium diphtheriae: Gram stain
!!+++++++!!
94
Corynebacterium diphtheriae: Incubation Period
2-5 days
95
Corynebacterium diphtheriae: Life Cycle
Do NOT form spores!
96
Corynebacterium diphtheriae: Other
All other corynebacteria (diptheroids) are normal inhabitants of our skin/throat
97
Corynebacterium diphtheriae: Oxygen
aerobe
98
Corynebacterium diphtheriae: Prevention (2)
Immunity depends on presence of Ab against toxin (antitoxin)
Give DTaP booster to travelers
99
Corynebacterium diphtheriae: Reservoir
NONE - only infects humans
100
Corynebacterium diphtheriae: Shape
rod
club-shaped
(pleomorphic)
101
Corynebacterium diphtheriae: Symptoms (3)
Fever, cough, sore throat
Gray PSEUDOMEMBRANE formation in severe cases (thrush)
Inflammation of lymph nodes
102
Corynebacterium diphtheriae: Transmission/vector/habitat
Aerosol
103
Corynebacterium diphtheriae: Treatment (2)
Horse antitoxin immediately (hypersensitivity and anaphylactic shock common)
Penicillin prophylactically or as treatment
104
Corynebacterium diphtheriae: Vaccine
Toxoid - DTaP good for 10 years
105
Corynebacterium diphtheriae: Virulence Factors (1)
DIPHTHERIA EXOTOXIN - blocks eukaryotic cell protein synthesis (inactivates EF2) => produces systemic symptoms)
- -Lethal to eukaryotic cells
- -Targets heart, kidney, nervous system
- -Exotoxin has 2 domains which dissociate within endosome - cell surface receptor (B, promotes endocytosis) and toxin domain (A)
106
Coxiella burnetii: At Risk (2)
Exposure to barn animals, especially birth of barn animals
Cardiac vascular disease can increase risk of endocarditis
107
Coxiella burnetii: Diagnosis (3)
Serologic testing for C. burnetii Ags
Indirect immunofluorescence assay (most dependable)
Immunohistochemical staining and DNA detection methods of infected tissues
108
Coxiella burnetii: Disease (2)
Q fever
| Can progress to chronic endocarditis
109
Coxiella burnetii: Gram stain
-
110
Coxiella burnetii: Prevention (4)
Dispose of birth products of sheep and goats
Restrict access to barns/labs housing potentially infected animals
Vaccination
Counseling
111
Coxiella burnetii: Reservoir
Sheep and cattle -> tick and so on
112
Coxiella burnetii: Special growth conditions
Obligate intracellular
113
Coxiella burnetii: Symptoms (5)
Intersitital pneumonia, fever, headache, rash (some patients), elevated LFTs
114
Coxiella burnetii: Transmission/vector/ habitat (2)
Inhaling Coxiella from placental tissue (carcass) of sheep or cattle
Spore-like stage transmits the infection
115
Coxiella burnetii: Treatment (3)
Doxycycline
Quinolone Abx
Chronic endocarditis -> aggressive therapy, surgery
116
Diffuse adhering E. coli (DAEC): At Risk
Older children in developing countries
117
Diffuse adhering E. coli (DAEC): Diagnosis (2)
PCR for virulence genes
| Tissue culture -> diffuse adherence
118
Diffuse adhering E. coli (DAEC): Disease
Diarrhea
119
E. coli (general): Diagnosis (7)
```
Stool samples
Enrich in Gm- broth
PCR -> virulence factors
Toxin analysis
Antigen testing
Tissue culture assay for adherence
Lac +!
```
120
E. coli (general): Gram stain
-
121
E. coli (general): Negative for: (1)
Oxidase
122
E. coli (general): Oxygen
fac. Anaerobe
123
E. coli (general): Positive for: (3)
Lactose
Glucose (+gas)
Nitrate
124
E. coli (general): Prevention (2)
Grain fed cattle harbor more acid shock resistant E. coli
--Hay feeding leads to a higher pH => lack of adaptation of pathogenic E. coli
Hygiene
125
E. coli (general): Shape
rod
126
Ehrlichioses: At Risk (1)
Exposure to ticks
127
Ehrlichioses: Disease (2)
Monocytic Ehrlichiosis
| Granulocytic Ehrlichiosis
128
Ehrlichioses: Epidemiology (1)
Found in southern US
129
Ehrlichioses: Gram stain
-
130
Ehrlichioses: Pathogenesis (1)
Infects monocytes and granulocytes
131
Ehrlichioses: Special growth conditions (1)
Obligate intracellular
132
Ehrlichioses: Symptoms (3)
Fever, lymphocytopenia, elevated LFTs
133
Ehrlichioses: Transmission/vector/ habitat
Ticks
134
Ehrlichioses: Treatment (1)
Tetracyclines
135
Enteroaggregative E. coli (EAEC): At Risk
Children in developing countries
136
Enteroaggregative E. coli (EAEC): Diagnosis (2)
PCR for virulence genes
| Tissue culture -> aggregative adherence
137
Enteroaggregative E. coli (EAEC): Disease (1)
Chronic Diarrhea
138
Enteroaggregative E. coli (EAEC): Epidemiology (2)
Common in developing countries
2012 outbreak in Germany of O104:H4 due to strain that expressed STX
139
Enteroaggregative E. coli (EAEC): Pathogenesis (1)
Aggressive epithelial cell attachment
140
Enteroaggregative E. coli (EAEC): Special Features: Intra vs extracellular, presence of capsule, invasive or not
No A/E lesions
141
Enteroaggregative E. coli (EAEC): Symptoms (2)
Persistent diarrhea
| Weight loss
142
Enteroaggregative E. coli (EAEC): Treatment (1)
Fluoroquinolones (travelers and HIV+)
143
Enteroaggregative E. coli (EAEC): Virulence Factors (3)
Heat stable-like toxin (EnteroAggregative stable toxin; EAST)
Plasmid encoded toxin (Pet)
Hemolysin
144
Enterobacter cloacae: At Risk (1)
Hospital setting following antibiotic treatment
145
Enterobacter cloacae: Disease (4)
OPPORTUNIST!
| Infections of burns, wounds, respiratory, UT
146
Enterobacter cloacae: Gram stain
-
147
Enterobacter cloacae: Oxygen
fac. Anaerobe
148
Enterobacter cloacae: Pathogenesis
Forms biofilms
149
Enterobacter cloacae: Positive for: (1)
Lactose
150
Enterobacter cloacae: Shape
rod
151
Enterohemorrhagic E. coli (EHEC): At Risk (2)
HUS in ~7% of cases (due to RBC destruction and damage to BV wall lining)
--Acute renal failure (via HUS) in severe cases (children <10; elderly)
152
Enterohemorrhagic E. coli (EHEC): Diagnosis (3)
Sorbitol negative growth (RED on Sorbitol MacConkey Agar)
H7 serology and toxin analysis
PCR/Immunoassay for Shiga-like toxins
153
Enterohemorrhagic E. coli (EHEC): Disease (2)
Bloody diarrhea
| Hemolytic uremic syndrome (HUS) if toxin spreads -> due to Shiga-like toxin
154
Enterohemorrhagic E. coli (EHEC): Incubation Period
3 days
155
Enterohemorrhagic E. coli (EHEC): Infectious dose
Low infectious dose (~100)
156
Enterohemorrhagic E. coli (EHEC): Negative for: (1)
Sorbitol**
157
Enterohemorrhagic E. coli (EHEC): Number of serotypes
O157:H7 = most important
158
Enterohemorrhagic E. coli (EHEC): Pathogenesis (5)
1. COMMON pili-mediated attacment (weak)
2. T3SS induced formation of attach/efface lesions
3. other E. coli proteins recruit host cell actin (alter morphology and impact signal transduction pathways in host cell to form A/E lesions)
4. lesions lead to effacement retraction of host cell microvilli)
5. interaction of other virulence factors to attach (Tir-intimin) and produce pedestals (actin polymerization; role unclear)
159
Enterohemorrhagic E. coli (EHEC): Reservoir
Cattle (immune - lack host glycolipid for Shiga-toxin binding) but 28% shed EHEC
160
Enterohemorrhagic E. coli (EHEC): Similar to
Shigella
161
Enterohemorrhagic E. coli (EHEC): Special Features: Intra vs extracellular, presence of capsule, invasive or not
Mostly extracellular
162
Enterohemorrhagic E. coli (EHEC): Symptoms (3)
Abd. Pain, bloody diarrhea,
NEVER systemic
HUS
163
Enterohemorrhagic E. coli (EHEC): Transmission/vector/ habitat (3)
Food/water
Animals in petting zoos
Person-to-person
164
Enterohemorrhagic E. coli (EHEC): Treatment (2)
Supportive care
| Antibiotics and antimotility agents are contraindicated
165
Enterohemorrhagic E. coli (EHEC): Virulence Factors (8)
T3SS (LEE pathogenicity island)
TIR: T3SS secreted protein delivered to epithelial cell surface for E. coli attachment
INTIMIN: Tir binding protein on E. coli surface
--Facilitates strong attachment
SHIGA-LIKE TOXIN (STX): gene on phage, disrupts euk. protein synthesis (cytotoxic) via RNA cleavage (subunit A), binds to cell (subunit B)
HEMOLYSIN: pore forming protein
Capsule (K-antigen)
LPS
Common pilus
166
Enteroinvasive E. coli (EIEC): Diagnosis (1)
PCR for virulence genes
167
Enteroinvasive E. coli (EIEC): Disease (1)
Diarrhea
168
Enteroinvasive E. coli (EIEC): Epidemiology (1)
Less common in industrialized nations
169
Enteroinvasive E. coli (EIEC): Pathogenesis (3)
1. attaches to cells of colon via non-fimbrial adhesins
2. invades mucosal cells
3. multiplies within cell but does not become systemic.
170
Enteroinvasive E. coli (EIEC): Similar to
Shigella dysentery
171
Enteroinvasive E. coli (EIEC): Special Features: Intra vs extracellular, presence of capsule, invasive or not
Highly invasive
172
Enteroinvasive E. coli (EIEC): Symptoms (1)
Watery diarrhea that can contain blood and mucus (similar to Shigella)
173
Enteroinvasive E. coli (EIEC): Transmission/vector/habitat (1)
Food
174
Enteroinvasive E. coli (EIEC): Virulence Factors (2)
Plasmid encoded genes for invasion, replication, and survival (similar to Shigella)
Attaches via non-fimbrial adhesins
175
Enteropathogenic E. coli (EPEC): Diagnosis (2)
PCR for virulence genes
| Tissue culture -> localized adherence
176
Enteropathogenic E. coli (EPEC): Disease (1)
Childhood Diarrhea
177
Enteropathogenic E. coli (EPEC): Epidemiology (1)
Leading cause of childhood diarrhea (developing countries)
178
Enteropathogenic E. coli (EPEC): Pathogenesis
Localized adherence by bundle-forming pili -> A/E lesions -> malabsorption -> diarrhea
179
Enteropathogenic E. coli (EPEC): Symptoms
Diarrhea
180
Enteropathogenic E. coli (EPEC): Transmission/vector/habitat
Person-to-person
181
Enteropathogenic E. coli (EPEC): Treatment
Antibiotics guided by susceptibility testing for severe or protracted cases
182
Enteropathogenic E. coli (EPEC): Virulence Factors (3)
Attaching/Effacing (A/E) lesions
Bundle-forming pili (Bfp)
NO toxins
183
Enterotoxigenic E. coli (ETEC): At Risk (2)
Travelers, infants in developing countries
184
Enterotoxigenic E. coli (ETEC): Diagnosis (1)
PCR for virulence genes
185
Enterotoxigenic E. coli (ETEC): Disease
Traveler's Diarrhea
186
Enterotoxigenic E. coli (ETEC): Pathogenesis (3)
1. fimbriae adhere to receptors on enterocytes in SI
2. net loss of fluid and electrolytes into lumen of gut (LT/ST)
3. watery diarrhea (LT/ST)
187
Enterotoxigenic E. coli (ETEC): Symptoms
Watery diarrhea
188
Enterotoxigenic E. coli (ETEC): Transmission/vector/ habitat (2)
Food/water
| Person-to-person
189
Enterotoxigenic E. coli (ETEC): Treatment
Loperamide (+fluoroquinolone)
| Azithromycin or rifaximin (for travelers)
190
Enterotoxigenic E. coli (ETEC): Virulence Factors (2)
Heat-labile toxin (LT): targets adenylate cyclase => increased cAMP levels => excess Cl- secretion and blocked Na+ uptake
Heat-stable toxin (ST): alters cGMP levels -> same effects as LT
191
Haemophilus influenzae (type B and other encapsulated, typeable, systemic): At Risk (3)
6-12 months of age (no more passive immunity)
Complement deficiencies
Developing countries
192
Haemophilus influenzae (type B and other encapsulated, typeable, systemic): Diagnosis (5)
History, age of patient
Blood and CSF culture in chocolate agar (will NOT grow on blood agar)
Gm stain CSF
Presence of Type B capsular Ag or PCR detection of capsule genes
Biochemical tests
193
Haemophilus influenzae (type B and other encapsulated, typeable, systemic): Disease (~8)
Start as nasopharyngitis (+ otitis media, sinusitis)
Meningitis
Bacteremia
Epiglottitis (less comon) and obstructive laryngitis (may be fatal within 24h)
Cellulitis (face) or childhood pyarthrosis (pus in joint)
Pneumonia
194
Haemophilus influenzae (type B and other encapsulated, typeable, systemic): Epidemiology (2)
Most common encapsulated strain (type B, most virulent) -> decreasing with vaccination
Previously most common cause of bacterial meningitis in children (<4y)
195
Haemophilus influenzae (type B and other encapsulated, typeable, systemic): Gram stain
-
196
Haemophilus influenzae (type B and other encapsulated, typeable, systemic): Oxygen
fac. Anaerobe
197
Haemophilus influenzae (type B and other encapsulated, typeable, systemic): Pathogenesis (4)
1. respiratory aerosols
2. colonization (weeks to months)
3. IgA protease (may aid in immune evasion)
4. LPS -> systemic infections
198
Haemophilus influenzae (type B and other encapsulated, typeable, systemic): Positive for: (3)
Urease
Ornithine decarboxylase
Indole production
(maybe not important)
199
Haemophilus influenzae (type B and other encapsulated, typeable, systemic): Prevention (1)
Prophylaxis in households with young children
200
Haemophilus influenzae (type B and other encapsulated, typeable, systemic): Reservoir
Carried by 75-80% of the population (5% are encapsulated)
201
Haemophilus influenzae (type B and other encapsulated, typeable, systemic): Shape
coccobacilli (pleiomorphic)
202
Haemophilus influenzae (type B and other encapsulated, typeable, systemic): Special Features: Intra vs extracellular, presence of capsule, invasive or not
Capsule present!
203
Haemophilus influenzae (type B and other encapsulated, typeable, systemic): Special growth conditions (4)
FASTIDIOUS -> MUST use chocolate agar
2 growth factors required (X & V)
- -X (heat stable): hemin
- -V (heat labile): NAD or NADP
Susceptible to disinfectants and drying
204
Haemophilus influenzae (type B and other encapsulated, typeable, systemic): Transmission/vector/habitat
Aerosol
205
Haemophilus influenzae (type B and other encapsulated, typeable, systemic): Treatment (4)
Meningitis:
- -3G cephalosporin immediately
- -Ampicillin/B-lactamase inhibitor if sensitive
- -Add steroids to reduce damage from inflammation
Contacts: rifampin for prophylaxis
206
Haemophilus influenzae (type B and other encapsulated, typeable, systemic): Vaccine
```
Conjugate capsular (effective) - capsule PRP linked to diphtheria toxoid for increased T-cell dependence
=> more immunogenic in children
```
207
Haemophilus influenzae (type B and other encapsulated, typeable, systemic): Virulence Factors (4)
Capsule (antiphagocytic - ribose for Type B vs hexose for others)
IgA protease
LPS
Adhesins
208
Haemophilus influenzae (unencapsulated, nontypeable, nonsystemic): At Risk (3)
COPD, chronic bronchitis, CF -> respiratory disease
Acute sinusitis or CSF leak -> meningitis
Children
209
Haemophilus influenzae (unencapsulated, nontypeable, nonsystemic): Diagnosis (4)
History, age of patient
Blood and CSF culture in chocolate agar (will NOT grow on blood agar)
Gm stain CSF
Biochemical tests
210
Haemophilus influenzae (unencapsulated, nontypeable, nonsystemic): Disease (3)
Otitis media
Conjunctivitis
Respiratory disease
211
Haemophilus influenzae (unencapsulated, nontypeable, nonsystemic): Epidemiology (3)
50% mortality in neonates
2nd most common cause of otitis media (after Streptococcus pneumoniae)
Most common in children
212
Haemophilus influenzae (unencapsulated, nontypeable, nonsystemic): Gram stain
-
213
Haemophilus influenzae (unencapsulated, nontypeable, nonsystemic): Number of serotypes
Many
214
Haemophilus influenzae (unencapsulated, nontypeable, nonsystemic): Oxygen
fac. Anaerobe
215
Haemophilus influenzae (unencapsulated, nontypeable, nonsystemic): Pathogenesis (2)
3 invasion routes (extra- and intracellular)
Can also form biofilms
216
Haemophilus influenzae (unencapsulated, nontypeable, nonsystemic): Prevention (1)
Passive immunity from mother only lasts few months
217
Haemophilus influenzae (unencapsulated, nontypeable, nonsystemic): Reservoir
Carried by 75-80% of the population (5% are encapsulated)
218
Haemophilus influenzae (unencapsulated, nontypeable, nonsystemic): Shape
coccobacilli
219
Haemophilus influenzae (unencapsulated, nontypeable, nonsystemic): Special Features: Intra vs extracellular, presence of capsule, invasive or not (3)
No polysaccharide capsule
Both extracellular and intracellular
Non-systemic
220
Haemophilus influenzae (unencapsulated, nontypeable, nonsystemic): Special growth conditions (4)
FASTIDIOUS -> MUST use chocolate agar
2 growth factors required (X & V)
- -X (heat stable): hemin
- -V (heat labile): NAD or NADP
Susceptible to disinfectants and drying
221
Haemophilus influenzae (unencapsulated, nontypeable, nonsystemic): Symptoms (1)
Ear aches
222
Haemophilus influenzae (unencapsulated, nontypeable, nonsystemic): Transmission/vector/habitat
Aerosol
223
Haemophilus influenzae (unencapsulated, nontypeable, nonsystemic): Treatment (3)
Amoxicillin (otitis media & sinusitis)
Amox w/b-lactamase inhibitor for resistant strains
Can be persistent/recurrent due to biofilm formation and ability to invade cells
224
Haemophilus influenzae (unencapsulated, nontypeable, nonsystemic): Virulence Factors (2)
Adhesins -> colonization
| LPS
225
Helicobacter pylori: Diagnosis (6)
```
Radiolabled urea test (Breath test)
Stool culture (campy-BAP with cephalothin [special media])
Rapid urease test
Seroconversion
PCR
```
Endoscopy + histology (biopsy) -> definitive
226
Helicobacter pylori: Disease (3)
Peptic ulcer
Chronic Gastritis
Gastric cancer
227
Helicobacter pylori: Epidemiology (1)
Present in 50% of world's population (highest in developing countries - correlates with greater incidence of gastric cancer)
228
Helicobacter pylori: Gram stain
-
229
Helicobacter pylori: Infectious dose
ND in humans
| 10^4 in primates
230
Helicobacter pylori: Oxygen
Microaerophilic
231
Helicobacter pylori: Pathogenesis (3)
1. lives in stomach and duodenum mucus -> secretes urease (creates basic environment)
2. immune cells can't penetrate mucus -> release superoxide radical upon death => destroy stomach cells
3. gastritis (days), ulcer (later), metaplasia, cancer
232
Helicobacter pylori: Positive for: (1)
Urease (breath test or stool culture)
233
Helicobacter pylori: Shape
spiral
234
Helicobacter pylori: Symptoms (2)
Recurrent pain in upper abd., GI bleed
235
Helicobacter pylori: Transmission/vector/habitat (2)
Fecal matter present in tainted food/water
| Stomach-to-mouth by gastro-esophageal reflux (gastritis) => kissing
236
Helicobacter pylori: Treatment (2)
Antibiotic treatment [metronidazole, tetracycline] supplemented with bismuth salts (relapses require further treatment)
Contra-indicated for asymptomatic infected except in special circumstances
237
Helicobacter pylori: Virulence Factors (3)
--BabA (adhesin - binds to Lewis b Ag on surface of stomach epithelial cell)
--CagA (injected into stomach epithelial cell -> phosphorylated -> disrupts cytoskeleton, adherence to adjacent cells, intracellular signaling, cell polarity)
--VacA (injected - further damages epithelial cell lining)
238
Klebsiella pneumoniae: At Risk (3)
Alcoholic, diabetic, lung disease
239
Klebsiella pneumoniae: Diagnosis (1)
Capsule production causes mucoid colony morphology
240
Klebsiella pneumoniae: Disease (5)
```
OPPORTUNIST!
UTI
Bacteremia
Meningitis
Diarrhea
Pneumonia
```
241
Klebsiella pneumoniae: Gram stain
-
242
Klebsiella pneumoniae: Oxygen
fac. Anaerobe
243
Klebsiella pneumoniae: Positive for: (1)
Lactose
244
Klebsiella pneumoniae: Shape
rod
245
Klebsiella pneumoniae: Special Features: Intra vs extracellular, presence of capsule, invasive or not (1)
Red currant jelly sputum
246
Klebsiella pneumoniae: Virulence Factors (1)
Capsule toxins (reduced phagocytosis, reduced complement activity)
247
Legionella pneumoophila: At Risk (3)
Renal transplant, immunocompromised, and elderly
248
Legionella pneumoophila: Diagnosis (4)
Culture on charcoal yeast extract with Fe and cysteine
Direct fluorescent Ab test in sputum
Detection of Ag in urine
Analysis of Ab levels in blood samples obtained 3-6w apart (for epigenetics)
249
Legionella pneumoophila: Disease (2)
Legionnaires' disease
| Milder form called "Pontiac Fever"
250
Legionella pneumoophila: Epidemiology (3)
Significant mortality in original outbreak
Most infections clinically insignificant
Summer/fall outbreaks (increased AC use)
251
Legionella pneumoophila: Gram stain
-
252
Legionella pneumoophila: Incubation Period
2-10 days
253
Legionella pneumoophila: Oxygen
Aerobe
254
Legionella pneumoophila: Pathogenesis (3)
Early infection: apoptosis in macrophages/alveolar cells
Second phase: necrosis
--Both processes lead to cell deah in respiratory tract
Rare dissemination -> systemic disease
255
Legionella pneumoophila: Prevention
Proper water handling (heating, chlorine, cleanings)
256
Legionella pneumoophila: Reservoir
Water of cooling towers, in amoeba or as biofilms
257
Legionella pneumoophila: Shape
rod
| pleomorphic
258
Legionella pneumoophila: Special Features: Intra vs extracellular, presence of capsule, invasive or not (1)
Intracellular growth
259
Legionella pneumoophila: Special growth conditions (1)
Nutritionally "fastidious": grown on charcoal yeast extract with Fe and cysteine
260
Legionella pneumoophila: Symptoms (8)
Atypical (diffuse) pneumonia: fever, chills, cough (+/- sputum), muscle aches, headache, tiredness, loss of appetite, and occasionally diarrhea
261
Legionella pneumoophila: Transmission/vector/habitat
Airborne from environment
| NO human-to-human transmission
262
Legionella pneumoophila: Virulence Factors (1)
LPS
263
Mycoplasma pneumoniae: At Risk (4)
School-aged kids and teens through young adults
Childhood asthma, chronic lung disease, immunodeficiency
264
Mycoplasma pneumoniae: Diagnosis (4)
Sputum gram stain (+monocytes/PMNs) shows no organism
NO CULTURE generally attempted - Throat swab can take 3w (slow growth)
PCR (early results)
**Cold agglutination test (may be + in 50% of patients)
265
Mycoplasma pneumoniae: Disease (2)
Atypical (diffuse) pneumonia (gradual onset)
Extrapulmonary infections can occur (CNS, arthritis, autoimmunity) as complication
266
Mycoplasma pneumoniae: Epidemiology (5)
Causes 15-50% of pneumonias (50% of summer pneumonias)
Severity correlated with age
Epidemics every 4-8y
Close contact is a factor
Fatalities are rare
267
Mycoplasma pneumoniae: Gram stain
variable (no cell wall)
268
Mycoplasma pneumoniae: Number of serotypes
1 serotype, but NO lifelong immunity
269
Mycoplasma pneumoniae: Other
Have other mycoplasmas, often opportunists
270
Mycoplasma pneumoniae: Pathogenesis (2)
1. attaches to epithelium via adhesins (P1) inducing ciliostasis => necrosis
2. H2O2 production => oxidative damage and inflammation
271
Mycoplasma pneumoniae: Reservoir
NONE - only infects humans
272
Mycoplasma pneumoniae: Shape
pleomorphic (NO cell wall)
| Smallest replicating bacterium
273
Mycoplasma pneumoniae: Special growth conditions (2)
Colonies are small and grow slowly -> fried egg appearance
Needs cholesterol for membrane rigidity
274
Mycoplasma pneumoniae: Symptoms (4)
Cough (sputum), weakness, fever, headache
275
Mycoplasma pneumoniae: Transmission/vector/ habitat
Aerosol
276
Mycoplasma pneumoniae: Treatment (2)
***Resistant to cell wall inhibitors
Sensitive to antibiotics that interfere w/protein synthesis (erythromycin and tetracyclines)
277
Mycoplasma pneumoniae: Virulence Factors (4)
Lipoproteins (increase immune evasion and provide rigidity)
P1 adhesin: protein complex at tip of bacterium
H2O2, superoxide: damage host cell membranes, disrupt DNA synthesis & metabolism, -> CILIOSTASIS
278
Neisseria (general): Gram stain
-
279
Neisseria (general): Positive for: (2)
Oxidase
Glucose (and maltose for N.m.)
**Non-pathogenic Neisseria ferment ALL sugars except sucrose
280
Neisseria (general): Reservoir
Humans only
281
Neisseria (general): Shape
diplococci (adjacent sides slightly flattened)
THE ONLY Gm- coccus pathogen!
282
Neisseria (general): Special growth conditions (4)
FASTIDIOUS
Grow in 5-10% CO2
Need Thayer-Martin selective medium (modified chocolate agar)
Readily killed by drying, heat, disinfectants
283
Neisseria (general): Virulence Factors (4)
Pili and OMP (colonization)
IgA1 protease
LOS (LPS w/out O side chains) helps resist serum bactericidal activity
284
Neisseria gonorrhoeae: Diagnosis (4)
Gm- stain of purulent exudate (pus)
Present in phagocytic cells
History of exposure
Oxidase-positive Gm- diplococci cultured
285
Neisseria gonorrhoeae: Disease (4)
Gonorrhea
Opthalmia neonatorum
Disseminated complications:
1. Arthritis-dematitis syndrome
2. Chronic pelvic inflammatory disease (PID; females)
286
Neisseria gonorrhoeae: Epidemiology (4)
Most prevalent communicable bacterial disease of humans (along w/C. trachomatis)
Worldwide pandemic
Asymptomatic carrier states are common
Opthalmia neonaturium was once the cause of 50% of blindness in children
287
Neisseria gonorrhoeae: Incubation Period
1 hour
288
Neisseria gonorrhoeae: Negative for: (3)
Maltose
Lactose
Sucrose
289
Neisseria gonorrhoeae: Number of serotypes
100+ serotypes based on antigenicity of pilus protein
Displays ANTIGENIC VARIATION: rearranges pilus genes to express different pili, evade immune system
290
Neisseria gonorrhoeae: Pathogenesis (4)
1. STD via genital contact
2. pili anchor to epithelium and impair phagocytosis by PMNs
3. penetrate through surface cells (intracellularly) to reach sub-epithelial CT
4. inflammation and yellow purulent urethral discharge
291
Neisseria gonorrhoeae: Positive for: (2)
```
Oxidase
Glucose (G = gonorrhoeae)
```
292
Neisseria gonorrhoeae: Symptoms (3)
Inflammation, yellow purulent urethral discharge (w/pain upon urination)
Males: 2-3 days post-exposure
Females: 10 days (high percentage remain asymptomatic)
293
Neisseria gonorrhoeae: Transmission/vector/habitat (4)
STD: direct genital contact, rectal and pharyngeal mucosa, conjunctiva of newborns
294
Neisseria gonorrhoeae: Treatment (3)
IM ceftriaxone + oral tetracycline
Silver nitrate or tet/erythromycin ointment to prevent blindness in newborns
High levels of drug resistance
295
Neisseria gonorrhoeae: Virulence Factors (4)
Pili, OMP
IgA protease
LOS (but not a major factor in disease state, unlike meningococcus)
NO capsule
296
Neisseria meningitidis: At Risk (3)
Crowded conditions: day care centers, military barracks, college dorms
Sub-Saharan meningitis belt (type A) during dry season (Dec-June)
Children 65
297
Neisseria meningitidis: Diagnosis (4)
History: URI -> meningitis
**PETECHIAE on skin
Culture/agglutination for capsule Ag in CSF
Blood, CSF (lumbar puncture), nasopharyngeal specimens cultured for G- diplococci
298
Neisseria meningitidis: Disease (4)
```
Meningitis (high mortality; usually type B)
Septicemia
Mild pharyngitis (in some)
```
Severe = Waterhouse-Friderichsen (adrenal failure, shock, death)
299
Neisseria meningitidis: Epidemiology (3)
Carrier rate varies (5% gen. pop but higher in households with history)
--Carrier state lasts from days to months
Cases usually sporadic
300
Neisseria meningitidis: Incubation Period
Days to 1 week
301
Neisseria meningitidis: Negative for: (2)
Lactose
| Sucrose
302
Neisseria meningitidis: Number of serotypes
Serogroups A, B, C, Y, W135 (most important) - based on capsule
303
Neisseria meningitidis: Pathogenesis (4)
Muliplies outside of cells, NOT inside
Endotoxin damages small vessels
Bacteria enter blood stream
Organotropism for meninges (but also skin, eyes and lungs)
304
Neisseria meningitidis: Positive for: (3)
Oxidase
Glucose
Maltose (M = meningitidis)
305
Neisseria meningitidis: Special Features: Intra vs extracellular, presence of capsule, invasive or not (2)
Encapsulated (antiphagocytic)
| Extracellular
306
Neisseria meningitidis: Symptoms (9)
Meningitis: high fever, vomiting, stiff neck, lethargy, petechial rash
Septicemia: fever, petechial rash, hypotension, WF syndrome
307
Neisseria meningitidis: Transmission/vector/ habitat
Lives in nasopharynx, person-to-person aerosol
308
Neisseria meningitidis: Treatment (2)
Prompt IV penicillin, 3G cephalosporin, ciprofloxacin
Prophylactic rifampicin or cipro for close contacts
309
Neisseria meningitidis: Vaccine
Military and Endemic:
Quadrivalent vaccine for serotypes A, C, Y, and W...(no component for B capsule - sialic acid in capsule)
Africa:
Conjugate vaccine, cheap
310
Neisseria meningitidis: Virulence Factors (5)
Capsule
LOS
pili, OMP
IgA protease
311
Proteus mirabilis, vulgaris: Diagnosis (1)
Dx with urease test -> alkaline products turn phenol red red (vs yellow with net acid)
312
Proteus mirabilis, vulgaris: Disease (1)
OPPORTUNIST!
| UTI
313
Proteus mirabilis, vulgaris: Epidemiology (1)
Frequent cause of UTI
314
Proteus mirabilis, vulgaris: Gram stain
-
315
Proteus mirabilis, vulgaris: Negative for: (1)
Lactose
316
Proteus mirabilis, vulgaris: Oxygen
fac. Anaerobe
317
Proteus mirabilis, vulgaris: Pathogenesis
Urea -[urease]-> NH3 + CO2 -> ALKALINE urine -> salt crystalization and stone formation -> chronic infection
318
Proteus mirabilis, vulgaris: Positive for: (1)
Urease
319
Proteus mirabilis, vulgaris: Shape
rod
320
Proteus mirabilis, vulgaris: Virulence Factors (2)
Flagella (swarming motility), urease
321
Pseudomonas aeruginosa: At Risk (3)
Immunocompromised (bacteremia)
| COPD and CF (chronic lung infection)
322
Pseudomonas aeruginosa: Diagnosis
**Obligate aerobe, no fermentation of sugar
323
Pseudomonas aeruginosa: Disease (5)
OPPORTUNIST!
Bacteremia
Pneumonia
Infections of burns, eyes, wounds
324
Pseudomonas aeruginosa: Epidemiology (1)
Associated with burns, catheters, implants, ventilator associated pneumonia, implants, eye wounds
325
Pseudomonas aeruginosa: Gram stain
-
326
Pseudomonas aeruginosa: Negative for: (1)
Sugar fermentation
327
Pseudomonas aeruginosa: Oxygen
obligate aerobe (because it does NOT ferment, but technically wrong)
328
Pseudomonas aeruginosa: Pathogenesis (2)
Elastase breaks down elastin (lung tissue damage)
Phospholipase breaks down phospholipids in host cell membranes and surfactant
329
Pseudomonas aeruginosa: Shape
rod
330
Pseudomonas aeruginosa: Virulence Factors (8)
Endotoxin
Exotoxins (elastase, phospholipase)
T3SS-secreted toxins (ExoA, S, T, U)
Pyocyanin (blue-green pigment, generates ROS)
331
Rickettsia (general): Diagnosis (3)
Clinical symptoms/history
PCR test
Specific immunohistologic detection of Rickettsiae
332
Rickettsia (general): Gram stain
-
333
Rickettsia (general): Life Cycle (3)
Growth cycle in human/arthropod cells
1. enter via phagocytosis (promoted by rickettsia and requires energy) even into non-phagocytic cells
2. multiply slowly (binary fission - 1x/day)
3. progeny released via lysis
334
Rickettsia (general): Shape
pleomorphic
335
Rickettsia (general): Special growth conditions (1)
OBLIGATE intracellular (unclear why: they're well adapted to intracellular environment but are able to make own ATP)
336
Rickettsia (general): Transmission/vector/habitat
Arthropods
337
Rickettsia (general): Treatment (1)
Tetracyclines
338
Rickettsia akari: At Risk (1)
Exposure to rodents
339
Rickettsia akari: Disease (1)
Rickettsial Pox
340
Rickettsia akari: Epidemiology (1)
Outbreaks usually confined to single, large apartment buildings
341
Rickettsia akari: Reservoir
Mouse
342
Rickettsia akari: Symptoms (3)
1. primary skin lesion (site of bite)
2. systemic disease 1 week later (fever, chills, headache, rash like chicken pox)
- -Benign, non-life-threatening
343
Rickettsia akari: Transmission/vector/ habitat
Mouse -> mouse mite -> human
344
Rickettsia prowazekii: At Risk (3)
Human misery, famine, and war
345
Rickettsia prowazekii: Diagnosis (4)
PCR detection
Various serological tests
Elevated LFT
Rise in antibody titers (compare acute and convalescent serum samples)
346
Rickettsia prowazekii: Disease (2)
Primary Epidemic Typhus
Endemic Typhus
Brill-Zinsser disease
347
Rickettsia prowazekii: Epidemiology (2)
Brill-Zinsser disease (reactivation of latent infection) may reintroduce rickettsia (Russia or eastern Europe)
Often fatal if untreated (except in children)
348
Rickettsia prowazekii: Incubation Period
10 days
349
Rickettsia prowazekii: Pathogenesis (6)
1. louse punctures skin to get blood meal - defacates
2. scratching drives feces (+rickettsia) into wound
3. multiply first in capillary endothelial cells
4. incubate
5. sudden onset of fever and headache
6. rash (4-7d later)
350
Rickettsia prowazekii: Prevention
Louse control (DDT or adequate bath and laundry facilities)
351
Rickettsia prowazekii: Reservoir
Flying squirrel and its lice
352
Rickettsia prowazekii: Symptoms (5)
Abrupt fever, severe intractable headache, rash, elevated liver enzymes
Frequently fatal
353
Rickettsia prowazekii: Transmission/vector/ habitat (2)
Primary Epidemic
Human "body" lice (NOT head/crab lice)
Endemic
Flying squirrel lice
354
Rickettsia rickettsii: At Risk (2)
Eastern USA
| Exposure to ticks
355
Rickettsia rickettsii: Disease
Rocky Mountain Spotted Fever
356
Rickettsia rickettsii: Epidemiology (2)
Untreated adult cases have 20% mortality
| Mostly cases from April to November
357
Rickettsia rickettsii: Incubation Period
<1 week
358
Rickettsia rickettsii: Prevention (1)
Avoid ticks (wear suitable clothing)
359
Rickettsia rickettsii: Reservoir (2)
Western USA: forest tick
Easten USA: dog tick
360
Rickettsia rickettsii: Symptoms (3)
1. Fever, headache, arthritic pains, abd. pain with nausea and vomiting
2. Rash from extremities spreads to trunk
3. Lesions on palm of hand and soles of feet
361
Rickettsia rickettsii: Transmission/vector/ habitat (2)
Transovarian -> tick -> human
| Mammal -> tick -> human
362
Rickettsia typhi: At Risk (2)
Exposure to rats and squirrels
363
Rickettsia typhi: Disease (1)
Endemic Murine Typhus
364
Rickettsia typhi: Reservoir (2)
Rats and ground squirrels
365
Rickettsia typhi: Symptoms (1)
Resembles primary epidemic typhus but milder and less fatal
366
Rickettsia typhi: Transmission/vector/ habitat
Rat/ground squirrel flea -> human
367
Salmonella (general): Diagnosis (3)
ID with MacConkey/EMB for lac -
Produces H2S - BLACK on Klinger Iron Agar
Serotyping and PCR tests w/ O & H antigens allows species identification
368
Salmonella (general): Gram stain
-
369
Salmonella (general): Infectious dose
10^3-10^5
370
Salmonella (general): Negative for: (5)
```
Lactose
Oxidase
Spores
Indole
Urease
```
371
Salmonella (general): Oxygen
fac. Anaerobe
372
Salmonella (general): Positive for: (5)
```
Glucose (+gas)
Motility (flagella)
H2S (black precipitate)
Nitrate reduction
O & H antigen
```
373
Salmonella (general): Shape
rod
374
Salmonella choleraesius: At Risk (6)
Young, malaria, immune dysfunction, steroid use, sickle cell, cancer
375
Salmonella choleraesius: Diagnosis (1)
Isolation in blood
376
Salmonella choleraesius: Disease (1)
Septicemia
377
Salmonella choleraesius: Epidemiology (1)
Rare
378
Salmonella choleraesius: Incubation Period
6-72 hours
379
Salmonella choleraesius: Infectious dose
10^3
380
Salmonella choleraesius: Number of serotypes
1 serotype
381
Salmonella choleraesius: Reservoir
Swine
382
Salmonella choleraesius: Symptoms (4)
High fever and bacteremia after onset of gastroenteritis
| Microabscesses can develop anywhere
383
Salmonella choleraesius: Transmission/vector/ habitat
Contaminated food
384
Salmonella choleraesius: Treatment
Appropriate antibiotics
385
Salmonella choleraesius: Virulence Factors (3)
SPI-1 (invasion, encodes T3SS)
SPI-2 (survival, encodes T3SS)
LPS (endotoxin)
386
Salmonella enteritidis and typhimurium: At Risk (1)
Both developed and developing countries
387
Salmonella enteritidis and typhimurium: Diagnosis (1)
Isolation in feces
388
Salmonella enteritidis and typhimurium: Disease (1)
Acute gastroenteritis
389
Salmonella enteritidis and typhimurium: Epidemiology (4)
Most common Salmonella infection in US
Self-limiting
Complications can arise
Death is uncommon
390
Salmonella enteritidis and typhimurium: Incubation Period
8-48 hours
391
Salmonella enteritidis and typhimurium: Infectious dose
10^3-10^5
392
Salmonella enteritidis and typhimurium: Number of serotypes
2200 serotypes
393
Salmonella enteritidis and typhimurium: Pathogenesis (3)
LPS release during epithelial cell (intestines) invasion - symptomatic
T3SS mediated invasion
Extracellular cells produce toxins (pertussis-like) - promote inflammation and secretion
394
Salmonella enteritidis and typhimurium: Reservoir
Reptiles and poultry
395
Salmonella enteritidis and typhimurium: Symptoms (6)
Lasts 1-4 days
| Headache, chills, abd. pain, vomiting, diarrhea w/fever
396
Salmonella enteritidis and typhimurium: Transmission/vector/ habitat (4)
Poultry, eggs (common), food, water
397
Salmonella enteritidis and typhimurium: Treatment (2)
Fluid and electrolyte replacement
Treat patients with predisposing conditions with antibiotics [amp, sulfa, 3G ceph, cipro; resistance is possible]
398
Salmonella enteritidis and typhimurium: Virulence Factors (3)
T3SS, LPS, pertussis-like toxin
399
Salmonella typhi: At Risk (1)
Developing world
400
Salmonella typhi: Diagnosis (3)
Wk1: subclinical, +stool
W2-3: +blood, symptomatic
W3: +stool, gall bladder colonized
401
Salmonella typhi: Disease (1)
Enteric (Typhoid) Fever
402
Salmonella typhi: Incubation Period
7-14 days
403
Salmonella typhi: Infectious dose
High (~10^5)
404
Salmonella typhi: Number of serotypes
1 serotype
405
Salmonella typhi: Pathogenesis (9)
1. survives stomach
2. adhesins attach to intestinal epithelium
3. endocytosis (invasion of Peyer's patches)
4. ingestion by macrophages (T3SS)
5. survive inside vacuoles (Vi)
6. kill macrophage and disseminate via thoracic duct to blood, liver, spleen, gall bladder
7. fever/shock via LPS
8. reinvade GI via gall bladder
9. GI bleed and sometimes diarrhea
406
Salmonella typhi: Prevention (4)
Control of water/sewage
Food safety
Pastuerization
Carrier screening
407
Salmonella typhi: Reservoir
NONE - only infects humans
408
Salmonella typhi: Special Features: Intra vs extracellular, presence of capsule, invasive or not (2)
Vi antigen, fac. intracellular pathogen
409
Salmonella typhi: Symptoms (6)
Early GI phase (incubation): may be subclinical w/+stool
Bacteremic: episodic fever, bradycardia, skin rash (Rose spot), leukopenia, enlarged liver/spleen
Late GI: intestinal hemorrhage or perforation
Chronic (3%): hide in gallbladder
410
Salmonella typhi: Transmission/vector/ habitat
Contaminated food/water
411
Salmonella typhi: Treatment (4)
Fluoroquinolones or 3G cephalosporins
--Should penetrate tissue --> macrophages
Chronic carrier states (3%) (gallbladder):
1. Ampicillin or Cipro
2. Cholecystectomy
412
Salmonella typhi: Vaccine
1. Ty21a - oral attenuated
| 2. ViCPS - Vi capsular polysaccharide
413
Salmonella typhi: Virulence Factors (3)
SPI-1 (invasion, encodes T3SS)
SPI-2 (survival, encodes T3SS)
LPS (endotoxin)
414
Serratia marcescens: At Risk (3)
Infection secondary to broad spectrum antibiotic treatment or instrumentation
Heroin addicts
415
Serratia marcescens: Disease (3)
OPPORTUNIST!
Pneumonia (after use of a contaminated respirator)
Joint/tissue infections
416
Serratia marcescens: Gram stain
-
417
Serratia marcescens: Negative for: (1)
Lactose
418
Serratia marcescens: Oxygen
fac. Anaerobe
419
Serratia marcescens: Shape
rod
420
Serratia marcescens: Special Features: Intra vs extracellular, presence of capsule, invasive or not (1)
Prodigiosins (red pigment)
421
Serratia marcescens: Transmission/vector/ habitat (2)
Loves to grow in water
| GI tract in neonates
422
Serratia marcescens: Virulence Factors (4)
MS-fimbriae
proteases
siderophores
swarming motility (colonization)
423
Shigella (dysenteriae*, flexneri, boydii**, sonnei***): At Risk
Children <10y
| Also infects adults
424
Shigella (dysenteriae*, flexneri, boydii**, sonnei***): Diagnosis (4)
Can detect organisms in feces up to 1-4w after recovery -> important for spread
Detect PMN (indicative of invasive process)
Immunochromatographic assay for Shiga toxin
Kliger Iron Agar (+ glucose fermentation)
425
Shigella (dysenteriae*, flexneri, boydii**, sonnei***): Disease (1)
Dysentery (shigellosis/bloody diarrhea)
426
Shigella (dysenteriae*, flexneri, boydii**, sonnei***): Epidemiology (5)
Self-limiting, rarely fatal
Dysenteriae: most common species in developing world
Flexneri: common (18%) in US and developing countries
Sonnei: most common species in US (75%)
Bodyii: common in Indian subcontinent
427
Shigella (dysenteriae*, flexneri, boydii**, sonnei***): Gram stain
-
428
Shigella (dysenteriae*, flexneri, boydii**, sonnei***): Incubation Period
1-4 days
429
Shigella (dysenteriae*, flexneri, boydii**, sonnei***): Infectious dose
Low inoculum (<100)
430
Shigella (dysenteriae*, flexneri, boydii**, sonnei***): Negative for: (6)
```
Lactose
H2S
Non-motile
Indole
Urease
H antigen
```
431
Shigella (dysenteriae*, flexneri, boydii**, sonnei***): Oxygen
fac. Anaerobe
432
Shigella (dysenteriae*, flexneri, boydii**, sonnei***): Pathogenesis (7)
1. acid tolerant
2. invade intestinal cells (lower ileum and colon)
3. uptake by macrophages into vacuoles (T3SS)
4. escape from vacuole into cytoplasm -> cell-to-cell spread (T3SS)
5. apoptosis of macrophage -> re-infection
6. IL-1 and TNF from macrophage leads to fever and systemic symptoms
7. bloody diarrhea + apoptosis of mucosal cells + ulceration (Shiga toxin)
433
Shigella (dysenteriae*, flexneri, boydii**, sonnei***): Positive for: (2)
Glucose (-gas)
| O antigen
434
Shigella (dysenteriae*, flexneri, boydii**, sonnei***): Prevention (1)
Sanitation
435
Shigella (dysenteriae*, flexneri, boydii**, sonnei***): Reservoir
NONE - only infects humans
436
Shigella (dysenteriae*, flexneri, boydii**, sonnei***): Shape
rod
437
Shigella (dysenteriae*, flexneri, boydii**, sonnei***): Similar to (2)
Salmonella, E coli (Enterobacteriaceae Family)
438
Shigella (dysenteriae*, flexneri, boydii**, sonnei***): Special Features: Intra vs extracellular, presence of capsule, invasive or not
Fac. intracellular pathogen
439
Shigella (dysenteriae*, flexneri, boydii**, sonnei***): Symptoms (6)
```
Fever (LPS)
Diarrhea, abd. cramps (Shiga toxin)
Bloody diarrhea w/mucus
Bacteremia (rare)
HUS (rare)
```
440
Shigella (dysenteriae*, flexneri, boydii**, sonnei***): Transmission/vector/ habitat
4F's: food, fingers, feces, flies
441
Shigella (dysenteriae*, flexneri, boydii**, sonnei***): Treatment (2)
Fluid and electrolyte replacement therapy (esp. young children)
Antibiotics in severe cases - increasing resistance
442
Shigella (dysenteriae*, flexneri, boydii**, sonnei***): Vaccine
Live attenuated vaccine not effective
Not-yet approved O-antigen conjugated to inactivated shiga toxin
443
Shigella (dysenteriae*, flexneri, boydii**, sonnei***): Virulence Factors (3)
T3SS (for uptake by/escape from MOs)
LPS
Shiga toxin (exotoxin)
--A subunit: interferes w/60S rRNA function
--B subunit: Binds to receptor on intestinal cells
444
Uropathogenic E. coli (UPEC): At Risk (2)
Women via sex (bacterial flora in short urethra) and catheters
445
Uropathogenic E. coli (UPEC): Diagnosis (3)
>10^5 bacteria/ml in urine
| Hemagglutination with sensitivity (Type I pili only, P are MR) to mannose testing
446
Uropathogenic E. coli (UPEC): Disease (3)
OPPORTUNIST!
UTI
Neonatal meningitis
Bacteremia
447
Uropathogenic E. coli (UPEC): Epidemiology (4)
Most common cause of UTIs (95%)
--Reoccurrence is common
Most common neonatal pathogen (K1 - neonatal meningitis)
Major cause of bacteremia, including leading cause of nosocomial bacteremia
448
Uropathogenic E. coli (UPEC): Gram stain
-
449
Uropathogenic E. coli (UPEC): Number of serotypes
Few are pathogenic
450
Uropathogenic E. coli (UPEC): Oxygen
fac. Anaerobe
451
Uropathogenic E. coli (UPEC): Pathogenesis (2)
Bacteria + urethra + ascension -> UTI
UTI + blockage -> bacteremia
452
Uropathogenic E. coli (UPEC): Positive for: (1)
Lactose
453
Uropathogenic E. coli (UPEC): Shape
rod
454
Uropathogenic E. coli (UPEC): Similar to
Neisseria meningitidis (K1)
455
Uropathogenic E. coli (UPEC): Special Features: Intra vs extracellular, presence of capsule, invasive or not (2)
Replicate intracellularly (epithelial cells)
Serum resistance (evade Complement, correlated w/K1 production) is a critical trait of bacteremia causing strains
456
Uropathogenic E. coli (UPEC): Symptoms (7)
Cystitis (dysuria, freqency, urgency, and suprapubic tenderness - typically lower UTI)
Acute pyelonephritis (UTI disseminated to kidney - flank pain, tenderness, fever, dysuria, frequency, urgency)
457
Uropathogenic E. coli (UPEC): Transmission/vector/ habitat (2)
```
Catheters
Sexual intercourse (spreads bacteria
```
458
Uropathogenic E. coli (UPEC): Treatment (2)
Self-limiting
| Treat pyelonephritis with Abx
459
Uropathogenic E. coli (UPEC): Virulence Factors (8)
```
BACTEREMIA/MENINGITIS:
LPS
K1 capsule (polysialic acid, non-immunogenic, in bacteremia)
motility
Siderophores
```
```
UTI:
Pili
--Mannose-binding type 1 (cystitis)
--P (pyelonephritis)
Adhesins -> colonization
Hemolysin
Biofilm formation
```
460
Vibrio cholerae: At Risk (4)
Refugee camps
Poverty
Inadequate sanitation
South-central/southeast Asia
461
Vibrio cholerae: Diagnosis (1)
Yellow opaque colonies on TCBS medium (selective and differential for V. cholerae)
462
Vibrio cholerae: Disease (1)
Cholera
463
Vibrio cholerae: Epidemiology (1)
John Snow + Broad Street Pump
464
Vibrio cholerae: Gram stain
-
465
Vibrio cholerae: Infectious dose
Infectious dose is source dependent (contaminated rice is highly infectious)
100 to 10^9
466
Vibrio cholerae: Number of serotypes
>250
O1 = epidemic cholera
- -Classical biotype = old cholera
- -El Tor biotype = current cholera
467
Vibrio cholerae: Oxygen
fac. Anaerobe
468
Vibrio cholerae: Pathogenesis (6)
1. Inactivated by gastric acid, but some survive (rice helps)
2. Enters small bowel, binds to epithelium
3. (VF) Toxin Coregulated Pilus -> microcolony formation in intestinal crypts
- > **Organism remains in intestine and DOES NOT invade
4. (VF) Cholera toxin: expressed & secreted
5. B subunit of CT binds ganglioside GM1 -> endocytosis
- -----(VF) Neuraminidase makes more GM1, increasing binding sites
6. A subunit is the TOXIN: ADP ribosylation of G protein on AC -> cAMP production -> PKA activation -> increased secretion of electrolytes and water, decreased NaCl absorption
469
Vibrio cholerae: Positive for: (1)
Motility (polar flagellum)
470
Vibrio cholerae: Prevention (3)
Water: bottle, carbonate, Cl, boil
Ice: beware
Food: dry, steaming hot, special attention to shellfish
471
Vibrio cholerae: Reservoir
NONE - only infects humans
472
Vibrio cholerae: Shape
comma with polar flagellum
473
Vibrio cholerae: Similar to (2)
Vibrio parahaemolyticus (invasive gastroenteritis - shellfish)
Vibrio vulnificus (wound infection - seawater/shellfish - underlying liver disorder)
474
Vibrio cholerae: Symptoms (4)
Painless, odorless profuse secretory diarrhea (rice water) -> rapid dehydration -> shock -> potential death
475
Vibrio cholerae: Transmission/vector/habitat
Contaminated H2O! shellfish, seafood
476
Vibrio cholerae: Treatment (3)
Oral/IV fluid replacement (electrolyte)
Antibiotics (reduce duration of diarrhea)
Doxycycline (adults) or azithromycin (children/pregnant)
477
Vibrio cholerae: Vaccine
NONE are highly effective
Inactivated: 2 oral doses (crude suspension, new killed whole cell)
70% effective, not recommended for travel, currently used in Haiti
Live-attenuated: effective in North American clinical trials but not in field
478
Vibrio cholerae: Virulence Factors (5)
```
O & H antigens
Endotoxin
Enterotoxin (cholera toxin)
Toxin coregulated pilus (TCP) - colonization
Neuraminidase
```
