Enteric Gram-Negatives Flashcards

1
Q

UTI and urosepsis in elderly nursing home resident

A

UPEC (E. coli leading cause of UTI)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Enteric infection with hemorrhagic colitis in child

A

EHEC O157:H7 (E. coli 4th leading cause of enteric infection in US)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Neonatal sepsis & meningitis

A

NMEC, K1 E. coli (#2 cause)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Normal commensal bowel microbiota

A

All E. coli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Laboratory workhorse

A

K12 E. coli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

G- Membrane

A

Inner membrane

Thin peptidoglycan membrane (periplasm w/LPS)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

O-antigen

A

Oligosacc side-chains (endotoxin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Traveller’s diarrhea

A

ETEC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

childhood diarrhea in underdeveloped places

A

EPEC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

2 ways of getting a UTI

A

Descending via hematogenous spread
Ascending via periurethral region (colon microbiota)

Ascending aka retrograde most common: Gut - urethra - bladder (bacteriuria) - ureter - kidney (pyelonephritis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Leading cause of UTI

A

E. coli
Type 1 fimbrae
PAP
Siderophores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Produces urease

A

Proteus

Can lead to stone production and obstruction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Diarrhea

A

Frequent stools
Painless, no fever
Infectious and non
Increased secretion/decreased absorption in SI or LI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Dysentery

A

Pus and blood in stool
Painful (cramps, tenesmus)
Fever
Invasion or cytotoxin destruction of LI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Enteric fever

A

systemic infection starting in GI tract

e.g. typhoid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Gastroenteritis characterisitcs

A

Catch-all for syndromes
NVD
Toxins or superficial inflammation
Infectious and non-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

High acid tolerance organism (2)

A

Shigella

EHEC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Top 4 bacterial causes of enteric infections

A

Campylobacter (1/2)
Salmonella
Shigella
E. coli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Traveller’s diarrhea

Similar to vibrio cholera (toxin)

A

ETEC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Infantile diarrhea

Similar: non-typhoid Salmonella

A

EPEC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Hemorrhagic colitis, HUS
O157:H7
Cow intestines
Similar: Shigella (Verotoxin “shiga-like”)

A

EHEC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

O, H, K antigens

A

O: part of LPS in the outer membrane
H: flagella (motility)
K: capsule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Sepsis bugs (PEEK)

A

Proteus
Escherichia
Enterobacter
Klebsiella

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Pneumonia bugs (SEEK)

A

Serratia
Enterobacter
Escherichia
Klebsiella

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Meningitidis bug

A

Escherichia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

UTI bugs (PEP)

A

Proteus
Escherichia
Providencia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Gastroenteritis bugs (YESS)

A

Yersinia
Escherichia
Salmonella
Shigella

Campylobacter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Intraabdominal infection

A

Escherichia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Enterobacter physiology (3)

A

Facultative anaerobes
Ferment glucose
Oxidase-negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Tracheobronchitis bug

A

Bordetella pertussis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

URI/OM/meningitis/sepsis bug

A

Haemophilus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Gastritis/ulcers/gastric cancer bug

A

Helicobacter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

URI/OM bug

A

Moraxella

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Genital infection/STI

Nasopharyngeal colonization/meningitis/sepsis

A

Neisseria gonorrhea

Neisseria meningitidis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Lung/skin/eye/burn/wound/blood

A

Pseudomonas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Gastroenteritis/skin lesion bug

A

Vibrio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

4 leading bacterial enteric pathogens in the US

A

Campy
Salmon
Shiggy
Escher

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Type 1 pili attach to what?

A

Mannose molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

P pili or “PAP” attach to what?

Host receptor? P1 blood phenotype assoc w/?

A

P for “pyelonephritis” attach to gal-gal
P blood group antigen on renal pelvis cells
P1 phenotype have predisp to recurrent upper-UTI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

MR of uropathogenic ecoli?

A

Biofilms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Capsules do 3, capsular agents e.g. (NESH)

A
Size, charge, concealment
Neisseria
Ecoli
Strep pneumo
H. flu type b
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Siderophores

A

secreted iron-chelating compounds that compete w/host iron-binding compounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

How does Neisseriae scavenge iron?

A

surface proteins bind host iron-containing transferrin and lactoferrin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

4 cytotoxins to know

A
Shiga toxin (shigella)
Verotoxin (EHEC)
Vacuolating toxin (H. pylori)
Exotoxin A (pseudomonas)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Hydrolytic enzyme bugs (2)

A

Pseudomonas (lots)

NeisseriAe, hAemophilus –> IgA protease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Acid tolerance:
Shigella, EHEC
Vibrio
Salmonella

A
Highly resistant (1-100)
Highly sensitive (+10^8)
Intermediate (10^6)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

UTI RF’s

A

catheter
abx
immunocomp
environment –> selective pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Most common source of bacteremia in the elderly?

A

urinary tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

How does E coli get in?

A

Principally via mouth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Important molecule for ascending UTI?

A

Adhesins –> stick to uroepithelium

Targets for vaccines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

providencia

A

Nosocomial UTI in catheterized pts

From animals/environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

normal intestinal microbiota
urease producer –> alkalization of urine
–> salt precipitation –> struvite stones
adhesive pili

A

proteus mirabilis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

K1 encapsulated NMEC

A

2nd in bacterial neonatal meningitis (GBS #1)

No opsonization –> sialic acid abundant in mammals, poorly immunogenic (mom doesn’t make antiB’s)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Do GNR’s cause CAP in healthy individuals?

A

No. Elderly, alcoholics, IV drug users, lung disease

Nosocomial pneumonial common in hospitalized pts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

4 Klebsiella spp that cause pneumonia (poor)

A

Pneumoniae
Oxytoca
Ozaenae
Rhinoscleromatis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Klebsiella characteristics

A
Facultative anaerobe
Nonmotile
Ferments lactose
Capsule
VISCOUS MUCOID COLONY ON SOLID MEDIUM
57
Q

Lobar pneumonia
Severe –> hemorrhagic necrotizing consolidation
“CURRANT JELLY” sputum
Abscess common

A

Pneumonia caused by Kleb

58
Q

Serratia

A

Nosocomial pneumonia

S. marcescens –> INTENSE RED PIGMENT in culture

59
Q

Pigmented or non pigmented serrata cause pneumonia, bacteremia, endocarditis in IV druggies and hosp pts?

A

Nonpigmented

60
Q

Serratia, E. coli, Enterobacter, Kleb share what features of pneumonia pathogenesis?

A

Opportunism (CA in immunocomp hosts: debilitated, elderly, alcoholics, IV) also nosocomial
Presentation (severe necrotic pneumonia w/purulent sputum, hemorrhagic, abcess)

61
Q

Factors influencing GI ecology

A

pH, osmolarity
age/diet
motility
host-microbe/microbe-microbe

62
Q

3 bugs of cholecystitis (complication of obstruction due to stones) Bile Can’t Empty

A

Bacteroides fragilis
Clostridium
Escherichia
LI –> SI –> ascend biliary tree

63
Q

Which bug’s resistance to bile salts allows it to colonize the gallbladder?

A

Salmonella

64
Q

Microbes that adhere and resist the cleansing effects of the upper SI (enterotoxin producers “Very Extreme Pathogens”)

A

Escherichia
Vibrio
c. Perfringens

65
Q

Terminal Ileitis bug?

A

Yersinia entercolitica

66
Q

First LI colonizers in the newborn?

A

E. coli, streptococci

Consume oxygen and encourage anaerobes

67
Q

Breast-fed infants are colonized with what?

A

Bifidobacterium (anaerobic G+ rods)

68
Q

Which G- obligate anaerobe ultimately dominates in the colon?

A

Bacteroides

69
Q

Intoxication (pre-formed): site, clinical, examples

A

small bowel
severe NVD
S. aureus, B. cereus

70
Q

Secretory toxin: S.C.E.

A

small bowel
profuse watery diarrhea
no/mild pain and fever
ETEC, Vibrio

71
Q

Cytotoxin: S.C.E.

A

large bowel
bloody diarrhea
painful cramps, +/- fever
EHEC 0157:H7, Shigella

72
Q

Mucosal colonization/destruction: S.C.E.

A

Small bowel
NVD, vomiting
EPEC, Salmonella, Campy

73
Q

Deep invasion: S.C.E.

A

Large bowel
Purulent bloody dysentery
Painful cramps, fever
EIEC, Shigella, Campy

74
Q

Systemic dissemination: S.C.E

A

GI –> blood –> liver –> GI
systemic sx
Salmonella typhi

75
Q

3 obligate human pathogens (primates)

Fecal/oral transmission

A

Salmonella typhi
Shigella
Helicobacter pylori

76
Q

3 zoonotic pathogens (animal reservoir)

A

E. coli (ground beef)
Non-typhoid Salmonella (poultry, eggs, reptiles)
Campylobacter (poultry, milk, puppies)
*once infected humans can transmit via feces

77
Q

E. coli

A

fecal/oral
ground beef, spinach irrigated w/wrong water
ETEC/EPEC –> humans
EHEC –> cows

78
Q

ETEC

A

Traveler’s diarrhea
ST/LT SECRETORY toxins (cholera-like; plasmid-mediated)
–> Hyper secretion of fluid
Watery diarrhea for 3-4 DAYS

79
Q

Watery diarrhea for 3-4 days

A

ETEC

80
Q

EPEC

A

infantile diarrhea
gastroenteritis –> invasion/destruction of SI epithelium
fever, NVD (non-bloody)

81
Q

zoonotic cow intestine or via infected humans

children during warm months

A
EHEC (O157:H7)
small inoculum
verotoxin (shiva-like)
hemorrhagic colitis w/severe abd pain, HUS
BLOODY diarrhea
82
Q

Complication of EHEC

A

HUS –> systemic disease via escape of the cytotoxin from the intestine into the blood

83
Q

Thrombotic microangiopathy
Hemolytic anemia
Thrombocytopenia
Renal lesions

A

=HUS
inflammatory/thrombotic effects
damage via inhibition of protein synthesis/induction of apoptosis

84
Q

HUS risk groups

A

children/elderly

85
Q

treatment for EHEC?

A

NO ANTIBIOTICS

86
Q

EIEC

A

invade LI mucosa

BLOODY/PURULENT dysentery

87
Q

eggs (inside and out), poultry, pets, amphibians, reptiles, chicks, ducks
children in warm months

A

Salmonella enterica
fecal/oral
LARGE INOCULUM

88
Q

“rotten egg” stools

A

Salmonella syndrome: Simple gastroenteritis (non-typhoid)
sulfhydryl compounds
organisms are resistant to bile salts

89
Q

phagocytosis, replication, transport in macrophages

A

salmonella systemic illness
reinvasion of SI via bile
blood culture + 1st week, stool + 2/3rd week

90
Q

Sequelae of salmonella systemic illness (3)

A
Enteric fever (typhoid w/systemic sx)
Metastatic foci: splenic abcess, osteomyelitis (sickle cell), endovascular (septic atherosclerotic plaques)
Carrier state (gallbladder: Typhoid Mary: asymptomatic: may shed bacteria)
91
Q

Vaccines effective for non-typhoid salmonella?

A

No

92
Q

Shigella

A
fecal/oral
daycare
ascending/descending route via ANAL SEX
no animal reservoir
SMALL INOCULUM
93
Q

Where does shigella invade?

Where does it not invade?

A
LI (invasion/destruction), DOES NOT invade blood
BACILLARY dysentery (~EIEC) >> gastroenteritis
fever, HEADACHE, SEIZURES
94
Q

Campylobacter jejuni

A

poultry, unpasteurized milk, contaminated water
fecal/oral
pets, domestic animals, rodents, fowl

95
Q
Early gastroenteritis (~EPEC) --> late dysentery (~EIEC) --> rare enteric fever
How to dx this bug?
A

Campy

Stool culture: DARTING motility w/polar flagella

96
Q

Yersinia

A

fecal/oral
pets, rodents, farm animals
COLD months/countries
not major in US

97
Q

Terminal ileitis –> mesenteric lymphadenitis –> abd pain –> “pseudoappendicitis”

A

Yersinia
also gastroenteritis, diarrhea
RARE bacteremia

98
Q

Y. pestis

A

DOES NOT CAUSE ENTERIC infection

humans-rodents via FLEAS, droplets

99
Q

Big disease of Y. pestis

A

BUBONIC PLAGUE:
systemic infection in lymphatic sys
painful/swollen nodes “buboes”

100
Q

Y. pestis infection spreading to lungs/blood

A

Pneumonic plague

Septicemic plague

101
Q

Vibrio cholerae

A

fecal/oral
Large inoculum (malnutrition increases risk)
Gulf coast during hurricans/floods
deadly for malnourished, children, debilitated

102
Q

Voluminous watery “rice water” diarrhea (~ETEC)

A

V. cholerae
good for bacterial spread
shock –> death of host
HYDRATION

103
Q

Antibiotics for cholera?

A

NO! Supportive care and electrolyte replacement

104
Q

What is the pathogenesis of V. cholerae?

A

No INVASION

gastroenteritis via mucosal colonization and secretory (A/B) toxin release

105
Q

Vibrio parahemolyticus

A

Salt water, shellfish/sushi
Gastroenteritis, rare enteric fever
NE/NW US

106
Q

Vibrio vulnificus
what makes this different from other 2 vibrios?
Risk groups? What’s the characteristic lesion?

A

Salt water - shellfish, skin abrasions
Risk: immunocomp, alcoholics
Bullous wound infection –> septicemia
NO GASTROENTERITIS (unlike other 2 vibrios)

107
Q

Helicobacter pylori

A
Fecal/oral
May be asymptomatic stomach colonization
Gastritis
Gastric and duodenal ulcers (PREDOMINANT)
Gastric malignancies
108
Q

H. pylori colonization mechanism

A

urease –> microenv pH
USED FOR DX
inc prevalence with age, but high in childhood

109
Q

Treatment for H. pylori

A

Amox + clarithro

PPI (only once syndrome is dx’d: may inhibit bacterial motility) diminishes inflammation, damage, and sx

110
Q

Which bug has propensity for bloodstream invasion? (aka enteric fever) NYCS

A
S. typhi
Rarely: other salmonella
Campy
Yersinia
Non-cholera Vibrio
111
Q

Syndrome 1-4 weeks post-GI infection

May also follow urogenital infection

A

Reactive arthritis (aseptic inflammatory)

112
Q

Antibiotics for reactive arthritis?

A

No

113
Q

When to use antibiotics?

A

Usually not needed unless…
Severe/protracted sx
At risk: infants, elderly, immunocomp
Quinolones (CIPRO)

114
Q

Obligate human bugs (SESH)

A

Salmonella typhi
Shigella
H. pylori
Entamoeba histolyca

115
Q

Zoonotic pathogens

A

E. coli
Non-typhoid salmonella (poultry, eggs, reptiles)
Campy (poultry, milk)

116
Q

Typhoid fever tx?

A

Antibiotics
Vaccine for high-risk travel or occupations
Capsular polysacch
No vaccine for non-typhoid enteric fever

117
Q

Enteric fever

A

Entry via GI tract (Peyer’s patches)
Fever and abd pain predominant
Bloodstream –> liver (replicate in MP’s here) –> gut via bile duct

118
Q

Colonization of gall bladder can lead to?

A

Asymptomatic shedding of bacteria

119
Q

Special tests

A

EHEC verotoxin ELISA in stool or serum
Rotazyme - stool ELISA for rotavirus
Stool ELISA for Entamoeba

120
Q

Meds for sx relief of NVD

A

Bismuth subsalicylate (antimicrobial?)
GI motility reducing: loperamide, diphenoxylate
Do NOT use stasis drugs if BLOOD OR PUS IN STOOL
Consider probiotics for abx-assoc-diarrhea

121
Q

Other vaccines of note

A

S. typhi
Rotavirus
Hepatitis A

122
Q

daycare

A

shigella

123
Q

4 sx of invasive shigella infection?

resembles?

A
Fever
headache
seizures
dysentery
EIEC
124
Q

rodents, fowl

A

campy

125
Q

pets, rodents, farm animals in COLD places/times

A

Yersinia

126
Q

how do you get a descending UTI?

A

hematogenous spread

127
Q

how does e. coli get iron?

A

siderophores

128
Q

intense red pigment on culture

A

Serratia marcescens

129
Q

spread humans-rodents via fleas

A

Y. pestis

130
Q

COD in cholera pts

A

septic shock

131
Q

A/B secretory toxin

A

V. cholerae (does not invade)

132
Q

Saltwater, shellfish/sushi

NE/NW US

A

V. parahemolyticus

133
Q

H. pylori infection dx by presence of what?

A

urease levels

134
Q

do not use stasis drugs when?

A

if blood or pus in stool

135
Q

anal sex

A

shigella

136
Q

reheated fried rice

A

B. cereus

137
Q

reheated meats/gravy

A

C. perfringens

138
Q

UTI bugs that infect via descending hematogenous spread

A

S. aureus

Candida

139
Q

asymptomatic bacteriuria is seen in 100% of these patients

A

long-term indwelling catheters