Micro Flashcards
1
Q
Cryptococci
A
Can resolve on own in normal pts, PROBLEMATIC in immunocomp
2
Q
Cryptococci reservoir
A
Soil, bird poop
Not communicable person to person
3
Q
Cryptococci
A
Skin or pulm –> CNS Meningoencephalitis (fatal)
Inhalation of desiccated yeast cells
4
Q
Cryptococci
A
India ink on direct exam(yeast)
Sabaroud’s & Potato dextrose agar (SDA or PDA culture)
Growth on CGB medium
5
Q
Crypto most likely pathogen
A
Cryptococcus Neoformans
6
Q
Cryptococcus neoformans: Virulence Factors
A
Diphenol oxidase forms melanin from phenol containing subst
Ability to grow at 37C
Capsule evades phago
7
Q
Crypto clinical sx
A
Pulmonary: No sx, OR flu-like
Disseminated: Meningitis, Crypto skin lesions
(C. Gattii: more extensive infections)
8
Q
Toxoplasmosis Gondii
A
Foodborne illness
9
Q
Toxoplasmosis Gondii
A
Usually not a problem in normal pts, PROBLEMATIC in Immunocomp and Pregnant
10
Q
Triad of sx in Congenital Toxoplasmosis
A
Chorioretinitis (eye)
Hydrocephalus
Intracranial calcifications
11
Q
Toxoplasmosis has 2 forms
A
Trophozoite (Tachyzoite and Bradyzoite)
Cyst (INFECTIOUS)
12
Q
Toxoplasmosis subtypes of Trophozoites: Tachyzoite and Bradyzoite
A
Tachyzoite: acute dz, actively proliferating
Bradyzoite: chronic dz, slowly replicating
13
Q
Toxoplasmosis subtypes of Cysts: Zoitocyts and Oocyst
A
Zoitocyst: tissue type that contains bradyzoites
Oocyts: sexual stage in Cats
14
Q
How does Toxoplasmosis generally spread through Foodborne illness?
A
Via Zoitocyst (the tissue type containing bradyzoites)
15
Q
Toxoplasmosis Gondii dx
A
Difficult to get samples
ELISA: IgG, IgM in pregnant mother
PCR: detect parasite DNA in amniotic fluid
16
Q
Prevent Toxoplasmosis
A
Cook meat thoroughly
Wear gloves/ wash hands after gardening
Keep sandbox covered
Do not allow pregnant mothers to clean litter box- stay away from cats bc they are evil
17
Q
Naegleria Fowleri
A
Soil and Fresh water
Lake Havasu- rare brain infection
Amoeboid is the DANGEROUS form
18
Q
N. Fowleri
A
Cyst and
Trophozoite (flagellate and amoeboid*)
19
Q
N. Fowleri
A
Can cause PAM in HEALTHY pts
Travels olfactory nerves –> brain, eats RBC, WBC, olfactory bulbs, and brain tissue
20
Q
N. Fowleri
PAM!
A
1-14 d post exposure
Often death within 2 wks of sx onset
21
Q
N. Fowleri dx
A
Clearing zone on E.Coli agar (takes long)- Flagellated form is confirmation
Wet mount for motile Amoeba
CSF findings
PCR test in the making
22
Q
N. Fowleri, Trophozoite subtypes
- Flagellate
- Amoeboid
A
Flagellate: INFECTIOUS, enters nasal passage then transforms into–>
Amoeboid: DANGEROUS, DESTRUCTIVE, travels along olfactory bulb to brain
23
Q
Acanthamoeba spp
A
Enter through break in skin OR Lower respiratory tract
24
Q
Acanthamoeba spp
A
Soil and Contact lens
25
Acanthamoeba spp
Trophozoite (INFECTIVE, spiked pseudopodia) and
| Cyst (3 layered wall, resistant to environment)
26
3 clinical syndromes of Acanthamoeba spp
1. GAM/GAE- Granulomatous Amoebic Meningoencephalitis (100% mortality)
2. Ocular Acanth/ Keratitis and Uveitis
3. Disseminated dz
27
1. GAM/GAE of Acanthamoeba
Frm break in skin or inhaling cyst
| Sx: CNS, flu-like, Parenchymal (lung) edema, DEATH
28
2. Ocular Acanthamoebiasis
After trauma to eye
Ulcer and pain (might look like Herpes)
Blurred vision, FB sensation
29
Acanthamoebiasis
Most ppl are resistant
| Mostly PROBLEMATIC for Immunocompromised
30
Acanthamoeba dx
Both forms (Tropho and cytst) can be seen in tissue sections
Corneal scrapings
GAE-post mortem brain biopsy
NO POINT to examine CSF
31
Balamuthia Mandrillaris
Baboon dz
| AGGRESSIVE, both forms (Tropho and Cyst) are INFECTIOUS
32
Balamuthia Mandrillaris
Can infect healthy person
| Enters via Skin break or Respiratory
33
Balamuthia Mandrillaris infections
Healthy person: PAM
| Immunocompromised: GAE
34
Balamuthia Mandrillaris sx
Face paralysis, difficulty swallowing
Seizures
Double vision
35
Balamuthia Mandrillaris feeds on other Amoeba... co-infection
With Legionella, you are screwed
Allows Legionella to txr to be 1000x more virulens--> CNS and Respiratory complications
36
Forms of Balamuthia Mandrillaris (Both are infectious)
Trophozoite: flat pseudopodia for locomotion
Cyst: 3 layered wall
37
Balamuthia Mandrillaris
Soil organism
Southern states and Latin america
38
Balamuthia Mandrillaris dz
Cyst and Tropho can be seen in tissue sections
Culture only works as Co-culture with Primate liver cells or Human brain cells
39
Tetanus
"Lowjaw" and "Trismus"
| Death usually d/t Respiratory or Cardiac failure
40
Tetanus vaccine
Routine DTap and Td
41
Tetanus tx
Human tetanus immunoglobulin (HTIG) will neutralize toxin
42
Clostridial infections (2 subtypes)
C. Tetani-Tetanus
C. Botulinum- Botulism
Both are Neurotoxins and ANAEROBES
43
Clostridial infections: Tetanus and Botulinism
Gram (+) Bacilli
Environmentally resistant spores
Exotoxins: imp in dz progression
44
Tetanus spores
"tennis racket" appearance
45
Tetanus dz can arise from
Contaminated soil or Human/animal feces
46
Ppl at risk for Tetanus
Newborns, IVDU
47
Tetanus pathogenesis
Trauma to skin allows entry of spore
| Extent of dz depends on site of infection and infectious dose
48
Tetanus
Bacteria remains local but if multiplies and releases Tetanospasmin (potent exotoxin), this can be absorbed by local nerve endings and transported thru neurons, blood, and lymph
49
Clinical forms of Tetanus (3 subtypes)
Generalized (most common)
-includes neonatal infection of umbilical stump
-broken skin
Localized (uncommon)
-muscle spasm confined close to injured area, immunocompromised
Cephalic (rarest)
-assoc w/lesions to head/face/ear. only affects face, but can progress
50
Tetanus clinical sx
Severe dz, toxin --> cramping, twitching, spasm of muscles
51
Tetanus clinical sx
HA, trouble swallowing, fever, sweating, Clenched jaw: "Risus Sardonicus", arched back
52
Tetanus extremity sx
Flexed arms
| Extended legs
53
Dx of Tetanus (early is vital!)
Clinical findings more reliable than labs
54
Botulism
Bacillus has distended shape
Great heat resistance
Spores in soil, GI tract of birds, fish, mammals
Food poisoning assoc w/contaminated foods
55
Botulinim toxin (A-H)
A and B: Human dz
56
Botulinum toxin is Neurotoxic on chromosome
Prevents ACh from being released --> Flaccid paralysis
57
Botulinum toxin type H
Considered the most deadly substance ever
Inhaling only 13 ng or injecting ONLY 2 ng will kill adult
NO standard anti-toxin
(found in a strain that also produces type B)
58
3 Clinical forms of Botulism
Infant: ingest spores, 70% cases, colonize in intestine that has no established gut flora yet
Foodborne: ingested toxin, canned foods
Wound: spores reproduce in Anaerobic environment, IVDU
59
Botulism sx
| NO FEVER
Infant: lethal (sudden infant death)
Foodborne: Gi disturbance, Toxemia, Eventual neuroparalysis
Wound: Neuroparalysis
60
Do you have a fever with Botulism?
NO
61
Dx of Botulism
| diff bc similar presentation to many other dz
Confirmation related to toxin presence- stool sample
Tx: Antitoxin to neutralize
62
Dx of UTI
Microscopy: 2-5 WBC or 15 bacteria per high power
| Dipstick test
63
E. Coli
Most common cause of UTI
| Caused by UPEC: Uropathogenic E. Coli strains
64
E. Coli
Gram (-) bacillus, flagellated
65
UPEC E. Coli virulence factors
P. Fimbrae (pili) and Dr adhesins bind to uroepithelial cells and RBC
Produce a and b-hemolysins which lyse both types of cells
66
UPEC E.Coli
can produce K (capsular) antigen- typically in upper UTI and Chronic UTI d/t increased biofilms
67
Proteus spp (UTI)
Proteus vulgaris most common for UTI
68
Proteus Vulgaris cause of UTI
Nursing home/hospitals
(nare of hospital staff)
Can be part of normal flora
69
Proteus Vulgaris
| UTI
"Swarming" on culture agar
70
Proteus causing UTI
Organism spread --> Sepsis
| Produces UREASE and makes urine more Alkaline
71
Proteus causing UTI
Urease makes urine more alkaline --> Struvite Stones
72
Proteus UTI
Struvite stones
73
S. Saprophyticus causing UTI
Gram (+)
coag negative
Sexually active females
"Honeymoon cystitis"
74
S. Saphrophyticus causing UTI
2nd leading cause of UTI
sexually active Females
(normal flora of female genital tract)
75
S. Saphro causing UTI
Organism not very virulent
Has ADHESINS (lactosamine)
No exotoxins
Difficult to dx bc little number of bacteria present
76
How to differentiate S. Saphro causing UTI from other Coag negative organisms
Novobiocin resistance
77
S. Agalactae causing UTI
AKA Group B strep (GBS)
78
S. Agalactae (Group B Strep) causing UTI
Gram (+) coccus
79
S. Agalac (GBS) causing UTI
Gray-white colony w narrow zone of Beta-hemolysis
80
S. Agalac (GBS) causing UTI
infections in adults mostly only affects IMMUNODEFICIENT
81
S. Agalac (GBS) virulence factors
Capsular polysacch
Hyaluronidase
Collagenase
Hemolysin
82
Dx of S. Agalac (GBS)
Detection of CAMP factor
Definitive: isolation from blood, urine, CSF
83
Ulcerative STDs
Syphilis
Chancroid
Herpes
84
Non-ulcerative STDs
Gonorrhea
Trich
Chlamydia
85
Trepenoma pallidum causes:
Syphillis
86
Haemophilus Ducreyi causes:
Chancroid
87
Syphillis
Requires mammal host
| Spirochete with slow rotational motility
88
Syphillis virulence factors
Fibronectin coat
Lesions are result of Inflammatory Respone
89
Syphilis
Only a HUMAN pathogen
| Spread: usually STD, also needle sharing, lesion near mouth, MOTHER TO BABY
90
Clinical stages of syphillis
Primary: Chancre, if untreated heals in 3-8 wks w/ Fibrosis
Secondary: Maculopapular rash, Condyloma lata (warts)
LATENCY?? Or-->
Tertiary: NEURO, CARDIO, and Skin GUMMAS
91
Chancre (Primary Syphillis)
Thin, gray exudate
Base smooth
Border raised, firm, and indurated
92
Tertiary Syphillis
Neurosyph: cortical degeneration
Cardiovasc syph: aneurysm of ascending aorta
Gumma: skin, bones, joints
93
Congenital syphilis
Maculopap rash
Nasal obstruction w/mucoid discharge (infectious)
Osteitis of nasal bone
Neurosyphilis
+HUTCHINSONs TRIAD
94
Congenital syphilis
| "Hutchinson's Triad":
Notched incisors, interstitial keratitis, 8th nerve deafness
95
Hutchinsons triad of Congenital Syphilis
| Simple version
Incisors, Keratitis, Deaf
96
Dx of Syphillis
Darkfield microscopy
Most diagnosed w Serology: Trepenomal test- specific antibodies are confirmatory
97
Dx of Syphillis
Non-trep: used as screening. If (+), then move on to Trepenomal test... FTA-ABS, MHA-TP
98
N. Gonorrhea
Gram (-) diplococcus w kidney bean shaped cell
| PICKY (fastidious) growing requirements
99
N. Gonorrhea virulence factor
Plasmid and Chromosome mediated RESISTANCE to PCN, Tetracycline, Specto, and Fluoroq
100
More N. Gonorrhea virulence factors
Attachment via Pili
Surface proteins can dodge phagocytic activity
Bacteria alter surface property
Antigenic variation of pili
101
Gonorrhea epidemiology
Presence of b-lactamase positive strains (increasing #s of cases)
Major reservoir is Asymptomatic pt
102
Gonorrhea
Injury to cells d/t released Lipooligosacch and Peptidoglycan
Spread to other tissues via PILAR ATTACHMENT
103
Gonorrhea clinical spectrum
Can enter/exit any mucosal service
Female: endocervix, urethra
Male: anterior urethra with THICK mucopurulent d/c
104
Complications of Gonorrhea
Acute salpingitis
| PID
105
DGI- Disseminated Gonorrhea Infection
Fever, rash, Endocarditis, Meningitis
Purulent arthritis is MOST COMMON
106
Dx of Gonorrhea
Nucleic acid amplification (PCR): Gold standard
107
Non-gonn urethritis
Chlamydia
Ureaplasma
Mycoplasma
108
The Chlamydial diseases
STD
PNA
Conjunctivitis
109
Chlamydia characteristics
```
Infectious (elementary body) and
Fragile intracellular (reticulate body)
```
110
Chlamydia
Complication in female --> Salpingitis and PID
111
Cervicitis, Salpingitis, and PID in women probably caused by
Chlamydia
112
Dx of Chlamydia
Isolation in culture: Gold standard (detect Intracellular inclusions)
113
Dx of Chlamydia, non culture based test
NAAT preferred
114
Ureaplasma urealyticuum
NGU
Main reservoir: genital tract of sexally active
Responsible for 50% of non-gon, non-chlam urethritis in men
Cause of Chorioamnionitis and postpartum fever in women
115
Trich
Flagellated protozoan
Extracellular anaeroba
Trophozoite only
116
Life cycle of trich
Establishes on the mucosa and multiplies
117
Clinical sx of Trich
M: often no sx
F: Profuse vaginal d/c, frothy and malodorous
118
Trich often leads to
BV
119
Trich dz
Wet mount: most commonly used
| Culture: more sensitive
120
BV
Not STD
| Overgrowth of opportunistic pathogen in vagina d/t change in pH
121
Criteria for BV (any combo of 3)
```
Homogeneous secretions
Clue cells
Release of amine oder with addition of 10% KOH
pH >4.5
Curved gram (-) variable rods
```
122
Etiology of Vulvovaginitis Candidiasis "yeast infection"
Usually Candida Albicans
123
"yeast infection" Candidiasis
Thick, white, frothy d/c with NO odor
| Itching, irritation, vaginal pain, soreness
124
H. ducreyi
| Chancroid
Tropical country
Typical lesion: TENDER papule with sharp margins
Soft, ragged edge
125
Soft chancre of Chancroid
Develops quickly (3-5d)
Vesicle --> pustule/ulcer
Enlarges quickly, and multiple form
PAINFUL, bleeds readily, no induration
126
Dx of H. Ducreyi (chancroid)
ID from ulcer or swollen lymph node
PCR method commercially available
127
PID usually caused by
Gonorrhea or Chlamydia
128
Clinical sx of PID
```
Lower abd pain
Abnormal d/c
Painful sex
Increased menstrual pain/irregular menses
Scarring
```
129
Dx of PID
Clinical +
| Inflammation, fever, leukocytosis, elevated ESR
130
Cholera
gram (-)
sensitive to acid
LARGE NUMBERS must be ingested to cause infection
131
Cholera
A-B toxin
B(attachment)
A(enter cell)
132
Cholera
high CAMP causes cells to secrete Cl ions, Na, other ions, water follows, outpouring from cells
133
Cholera
rice water diarrhea
TONS of diarrhea- 20 L per day
(bacterial load in diarrhea is HUGE)
134
Cholera concern
Severe dehydration
135
Cholera most common source
Fecal contaminated water
136
Dx and Tx of Cholera
Dx: Culture stool specimen
Tx: Oral rehydration
Tetracycline, Erythromycin (severe cases)
137
Clostridium Difficile (C.Diff)
endospores
Severity ranges widely
Diarrhea, fever, abd pain, Colitis*
*pseudomembranous colitis, life threatening
138
C. Diff
endospores
Gram (+)
Anaerobic rod
DANGEROUS bc: Forms ENDOSPORES
139
Endospores of C.Diff are:
Highly RESISTANT to disinfectants, environment, abx
140
C. Diff toxins
A and B disrupt ACTIN and Cell signaling, cause pseudomembranes to form
141
C. Diff tx
Vancomycin, Metronidazole x 10d
142
Campylobacter
Most common cause of Bacterial gastroenteritis in US (mostly C. Jejuni)
143
Campylobacter
requires special gas concentrations
144
Campylobacter
Usually self-limiting
| PROBLEMATIC usually in HIV/immuncompromised
145
Campylobacter
contaminated chicken
146
Campylobacter
Low infectious dose! (not as low as E.Coli and Shigella)
147
Rare complication of Campylobacter
Guillain-Barre syndrome
(symm weakness)
d/t Campylobacter LOS resembles human neuronal ganglioside- infection creates antibodies to this
148
Dx of Campylobacter
Microscopy: S shaped antigen in stool sample
| Antigen detection
149
H. Pylori
Imp virulence factor: UREASE, allows it to colonize in stomach (one of the only that can do this) by making environment BASIC
150
H. Pylori
Gastric ulcer, Gastric CA
151
H. Pylori virulence factors
VacA- kills epithelial cell, forms pores, inflamm response
| CagA- cytoxin assoc
152
CagA (+) strains of H. Pylori show higher incidence of
Gastric CA
153
30% of strains of H.Pylori in Europe are
Cag A negative
154
Dx of H. Pylori
Tissue biopsy
| Antigen detection* stool sample
155
H. Pylori Tx
Omeprazole
Clarithromycin
Amoxicillin
7-10 d
156
C. perfringens
FOODBORNE
ingest toxins contaminated meat
Toxin short incubation period: SHORT dz, 24-48 hours
Abd cramps, nausea, diarrhea, no fever
157
C. Perfringens
24-48 hrs
| Potluck meals
158
Bacillus
SOIL, water, human microbio, everywhere
most are harmless, BUT B. Anthracis is very dangerous (ANTHRAX)
159
B. cereus more common
Gastroenteritis
Vomiting: heat stable enterotoxin
Diarrhea: heat labile enterotoxin
160
Bacillus
imp for creation of many Abx
161
Emetic dz of Bacillus Cereus
NO FEVER
Heat stable (cant be killed from heat)
Contaminated rice
162
Toxin bacillus stuff usually means
NO FEVER
| not infectious, just the toxin causing issue
163
Diarrheal Bacillus cereus
```
contaminated Veggies or meat
INFECTIOUS
fever
2-3 days
Heat labile
```
164
Bacillis cereus infections
No abx necessary
165
Staph
Non motile
Enterotoxin
FOOD POISONING
Heat labile, resistant to gastric enzymes
166
Staph GI food poisoning
Rapid onset, within 4 hrs of ingestion
| Deli meat, potato salad
167
Staph- food poisoning
Severe diarrhea, vomiting, abd pain
| NO FEVER
168
Giardia
Cross infectivity b/w animals and humans
More problematic in immunocomp
169
Giardia
Most common intestinal parasite in world
| Flagellate
170
Giardia simple llfestyle
Trophozoite: teardrop, feeds on mucous only (does not destroy tissue/RBC)
Cyst: Infectious, passed into environment, oval
171
Giardia lifestylee
Ingest cyst
Cysts escapes in stomach --> Trophozoite form in small intestine, replicate
Back to cyst in large intestine, passed to environment
172
Where is highest incidence of Giardia in US?
Western states (rocky mountains) contaminated water
173
Giardia
Can be STI
Diarrhea- no blood
Vit B12 deficiency dt malabsorption
174
Dx of Giardia
Stool sample
| ELISA detect Giardia antigen 65
175
Amoebiasis
Can --> Colitis and liver abscess
Most cases asympto
E. Histolytica is most common form
176
E. Histolytica
Ingest Cyst and then Trophozoite colonizes mucosa of colon- can pass in feces OR INVADE mucosal barrier and disseminate into bloodstream
177
Amoebiasis: E. Histolytica
Fecal contamination of food and water
| High risk: children, pregnant, malnourished, immunocompromised, oral-anal sex
178
E. Histolytic can be caused by a small number of cysts
BLOODY stools--> d/t ulcers in RUQ
Death: peritonitis, cardiac failure, exhaustion
179
Amobeba: E. Histolytica is pretty dangerous
Ulcers
Bloody stool
Death
180
Amoeba: E. Histolytica Virulence Factors
Lectin: adhesion
Phospholipase: disrupt membrane
Amoebapore: lysis
Cysteine protease: degrade everything
181
Crypto diarrhea
Mainly affects children
| Self limiting in normal healthy pts
182
Cryptosporidium diarrhea
Oocyts: infectious
Sporozoites: bind to intestinal cells
183
Crypto diarrhea
Thin walled oocyst: Asexual reinfeciton
| Thick walled ooccyst: Sexual, shed into environment
184
Crypto diarrhea
```
SERIOUS in immunocompromised
Highly infecitous
Severely wasted
~2 weeks
Bad prognosis
Watery diarrhea cardinal sx (dehydration, weight los, fever, abdominal ipain)
```
185
Dx of Crypto diarrhea
Oocyts in stool sample
186
Cyclosporiasis diarrhea
Autofluourescent Oocyts
LARGE
Contaminated foods and veggies
187
Cyclosporiasis clinical sx
EXPLOSIVE, NON-bloody diarrhea, rapid weight loss, profound fatigue
188
Dx of Cyclosporiasis
LARGE oocyst in stool sample
| Acid-fast, autofluorescent
189
Nematode (roundworm)
Elongated cylindrical, tapers at both ends
| Separate sexes
190
E. Vermicularis (pinworm)
Most common worm in US
| Small, whitich colored worm
191
E. Vermicularis (pinworm)
eggs become infectious very quickly!
life cycle direct and short
192
E. Vermicularis (pinworm)
Humans only host (children mostly affected)
Person to person, or frm environment
193
E. Vermicularis (pinworm) lifecycle
Eggs ingested and hatch in small intestine
Pregnant female MIGRATES AT NIGHT to peri-anal region to deposit eggs
194
E. Vermicularis (pinworm) clinical sx
Mostly no sx
Itching anal region at night
can --> Secondary Bacterial Infections, distrubed sleep, abd pain
195
E. Vermicularis (pinworm) dx
Scotch tape method
196
Soil transmitted worms- ingesting contaminated soil
```
Ascaris lumbricoides (roundworm)
Trichuris trichiura (whipworm)
```
197
Ascaris lumbricoides
| "Roundworm"
LARGEST intestinal roundworm
198
Ascaris lumbricoides "roundworm" life cycle
Ingested, travel via blood to LUNGS, then travel up trachea to OROPHARYNX, swallowed and then mature in SMALL INTESTINE (duodenum)
199
Ascaris Lumbricoides "roundworm" clinical sx
Worm burden
BLOCKAGE
"Pulmonary Loefflers sydnrome"
Abd pain
200
Pulmonary "Loefflers syndrome"
Ascaris Lumbricoides
| "roundworm"
201
Ascaris Lumbricoides "roundworm" dx
Stool sample (eggs)
202
Trichuris trichiura "Whipworm"
ingesting soil
Small worms whiplike morphology
| egg capsules
203
Trichuris trichuria "whipworm" life cycle
Eggs ingested, larvae released into duodenum
Mature in colon
204
Trichuris trichuria "whipworm" clinical sx
depends on worm burden
Heavy: painful passage of stool, Rectal PROLAPSE
Children: growth retardation, anemia
205
Hookworm
Small worm, Adult FEEDS ON BLOOD of intestinal mucosa
206
Hookworm, feeds on blood -->
ANEMIA
207
Hookworm get into body by
Can penetrate skin!!
208
Hookworm life cycle
Penetrate skin, travel to LUNG, up trachea to OROPHARYNX, swallowed and mature in SMALL INTESTINE (duodenum)
209
Worms that travel via blood to LUNGS, swallowed, then mature in DUODENUM
Hookworm
Roundworm (Ascaris lumbricoides)
Threadworms (Strongy)
210
Hookworm clinical sx
Blood filled pruritic lesions (penetrate skin)
"Ground itch"
Continuous blood loss
211
Strongyloides stercoralis "threadworms"
2 multiplication cycles (host or soil)
Poor sanitation
212
Strongyloides stercoralis "threadworms" lifecycle
LUNGS, swallow, SMALL INTESTINE (Duodenum)
213
Strongyloides "threadworm" clinical sx
Larval migration under skin
funny looking squiggly pattern
Intestinal diarrhea, pain, constipation, chronic infection
Life threatening in pts with defect in cell mediated immunity
214
Strongyloides "threadworm" dx
Stool sample, SPUTUM of hyperinfected pt, or duodenal aspirate
215
Trematude (fluke)
FLATTENED, leaflike
Suckers
Hemaphrodite (M and F)
216
Tapeworm
Large worms
SCOLEX face
Eggs are IMMEDIATELY INFECTIOUS once released
217
Tapeworm
"Taenia"
| Humans are only host
218
Tapeworm "Taenia"
Cattle, pigs
Larvae develop in muscle
UNDERCOOKED MEAT
219
Tapeworm "Taenia" clinical sx
Most pts no sx, only one worm
| Mild GI but if serious--> BLINDNESS, SEIZURE
220
Cystigercosis
seizures, bad form of Tapeworm "taenia"
221
Diphyllobothrium latum (fish tapeworm)
Worms VERY LONG
thousands of Proglottids
SERIES OF HOSTS required for life cycle completion
222
Diphyll (fish tapeworm)
Great lakes, Alaska
Humans and other fish eating mammals
Infectious larvae are in the MUSCLES OF FISH
223
Diphyll (fish tapeworm) clinical sx
Mostly asx
| BUT adult worm COMPETES FOR B12
224
Dx of Diphyll (fish tapeworm)
Anemia
stool sample
ID of worm
225
Two types of Viral Gastroenteritis (acute watery diarrhea, anorexia, vomiting)
Norovirus
| Rotavirus
226
Norovirus
TOP CAUSE in US of gastroenteritis (90% of viral)
227
Norovirus
Cruise ship
| out of both ends
228
Norovirus
Persistent in environment and very easily spread
| NAKED virus is more persistent (protein capsule)
229
Norovirus and Rotavirus dx
RT-qPCR (identify the RNA)
| sensitive and specific
230
Rotavirus
Common cause of Infant gastroenteritis- hospitalizations
231
Rotavirus
5-7d of Fever and Vomiting
232
Which one is more common: Norovirus or Rotavirus?
NOROVIRUS (cruiseship)
Rotavirus is assoc w/ infants
233
Enterobacteria
Gram (-) rods
```
Fimbrae
Flagella: H antigen
Capsule: K or Vi
LPS: O antigen
Peptidoglycan
```
234
Enterobacteria
Most ferment carbs --> lactid acid, how we differentiate b/w a wide array of organisms
235
Enterobacteria
70% of UTIs
| 1/3 Bacteremia
236
Subcategories of Enterobacteria
Salmonella
Shigella
E. Coli
(all gram negative)
237
Enterobacteria, most are motile EXCEPT
Yersinia
Klebsiella
Shigella
238
Enterobacteria
Fimbrae
Cell attachment
Horizonal sex gene transfer
239
Common virulence factors of Enterobacteria
| Salmonella, Shigella, E.Coli
Endotoxin (A component of LPS) --> septic shock
| Capsule (protect from phago)
240
Type 3 Secreteion System
Widely used by gram negative
241
Salmonella (a type of Enterobacteria)
Primary source: contaminated food/water
Chicken
Veggies
Honey smacks
242
Salmonella methods of transmission (secondary sources, after food)
Pet reptiles/birds
Pet chickens
Person to person
243
Serotyping Salmonella
Based on Flagellar (H) or LPS (O) antigens
244
Non-typhoidal salmonella
Foodborne gastroenteritis
245
Salmonella Typhimurium
Self limiting gastroenteritis in humans
246
Type 3 secretion system- Salmonella
How it gets in?
| Actin cytoskeleton changes, bacterium engulfed, thru epithelium layer and now access to systemic sites
247
Types of E.Coli
ETEC (entero-toxigenic)
EHEC (entero-hemorrhagic)
EIEC (entero-invasive)
UPEC (uro-pathogenic)
248
ETEC: Entero-toxigenic E.Coli
underdeveloped countries
children or travelers
Contaminated food/water
Watery diarrhea/cramps
lasts 3-5 days, then clears
249
ETEC: Entero-toxigenic E.Coli
Virulence
LT1- heat labile toxin
(increase cAMP)
STb- heat stable toxin
(increase cGMP)
250
EHEC: Entero-hemorrhagic E.Coli
Foodborne intestinal illness
Aka "STEC" Shiga-toxin producing E.Coli
O157:H7 (most common serotype)
251
Cattle are important reservoir for
EHEC, aka shiga toxin prducing E.Coli
| O157:H7
252
EHEC (shiga toxin producing E.Coli) virulence factor
Stx (shiga like toxin)
Intimin (binding)
Tir (type 3 secreted protein, inserts into cell membrane then acts as receptor for intimin)
253
EIEC: Entero-invasive E.Coli
basically same as shigella
PROFUSE BLOODY DIARRHEA
254
The Lactate (+) or (-) is what differentiates Shigella from other E.coli
Shigella is lac (-)
255
Shigella sx
Severe diarrhea with blood and mucus
256
Shigella spread
Leaves gut via M cells or dendritic cell engulfment
Replicate inside macrophage, killing cell
Invades membrane of epithelial cell
can also spread cell to cell
257
Shigella virulence factor
Shiga toxin 1 (identical to O157:H7)
| Shiga toxin 2
258
Shigella and EHEC strain
Low infectious dose
| ONLY takes 10 cells!!!
259
Shigella, Salmonella, E.Coli diagnosis
Isolate from fecal sample
| Mackonkey agar
260
Shigella and Salmonella
Lactate (-)
261
E.Coli
Lactate (+)
262
D+ HUS
| Diarrheal Hemolytic Uremic Syndrome
10% infections by shiga toxin producing Shigella and E.Coli
Abx use actually WORSENS infection
