Exam 3: Gram Negative Bacilli Flashcards
1
Q
VFs of enteric E. coli species
A
enterotoxins, O antigen (LPS endotoxin), capsules
2
Q
Enterotoxins are
A
exotoxins that cause secretion and diarrhea
3
Q
O antigen
A
LPS endotoxin
4
Q
E. coli lab ID
A
anaerobic gram-negative rod
5
Q
do e.coli species form spores?
A
no
6
Q
Are E. coli species facultative anaerobes or aerobes?
A
anaerobes
7
Q
Which bacteria are part of the enterics group
A
E. coli, shigella, salmonella
8
Q
E. coli colonizes where
A
lower GI tract
9
Q
what is the most common aerobic and non-fastidious bacterium in the gut?
A
E. Coli
10
Q
Enterics reduce
A
nitrate to nitrite
11
Q
what would a positive nitrite on a dipstick mean?
A
you have an enteric pathogen causing the UTI
12
Q
enterics are ____ when introduced to ____ _____ ____
A
opportunistic, normally sterile sites
13
Q
what is the most common cause of UTIs? Accounts for up to 90% of cases of cystitis and pyelonephritis in healthy young women
A
E. Coli
14
Q
how are pathogenic strains of E. coli that cause diarrhea organized?
A
grouped by virulence properties (toxins and invasiveness)
15
Q
groups of e. coli
A
enterotoxigenic, enteroinvasive, enterohemorrhagic
16
Q
what bacteria accounts for 70% of traveler’s diarrhea?
A
enterotoxigenic e. coli
17
Q
enterotoxigenic e. coli is spread by
A
water and food that has been contaminated by feces
18
Q
enterotoxigenic e. coli presents with
A
severe watery diarrhea
19
Q
2 enterotoxins that cause severe watery diarrhea in enterotoxigenic e. coli
A
Shiga toxin, labile toxin
20
Q
shiga toxin
A
produced by both e. coli and shigella – inhibits synthesis, causing cell death
21
Q
which toxin causes cell death by inhibiting protein synthesis?
A
shiga toxin
22
Q
this toxin stimualtes Cl secretion out of the cell and blocks absorption of sodium
A
labile toxin
23
Q
true or false, enterotoxigenic e. coli invade and causes inflammation
A
false
24
Q
which strain of e. coli is the only to NOT cause inflammatory diarrhea
A
enterotoxigenic e. coli
25
causes inflammation and dysentery of the large intestine
enteroinvasive e. coli
26
what happens when enteroinvasive e. coli invades the mucosa of the large bowel
ulcerates it
27
what will be seen in the tool of someone with enteroinvasive e. coli?
blood and pus
28
what bacteria presents similar symptoms but in a milder form like shigellosis
enteroinvasive e. coli
29
uses invasion plasmid antigens and injects them into enterocytes --> enterocytes engulf bacteria in a phagosome which bacteria escape and then use cytoskeletal actin filaments to create "tails" for themselves --> propel to the next cell and invade, destroying enterocytes and creating FOCAL ULCERS
enteroinvasive e. coli
30
enteroinvasive e. coli is primarily seen in what population?
children younger than 5 in DEVELOPING NATIONS
31
bloody diarrhea in DEVELOPED NATIONS & can lead to HUS and permenant kidney damage
Enterohemorrhagic e. coli (O157:H7)
32
HUS
hemolytic uremic syndrome
33
hemolytic uremic syndrome
hemolytic anemia (RBC hemolysis), renal failure, thrombocytopenia
34
t/f antiobiotic treatment is effective against enterohemorrhagic e. coli
false
35
jack in the box
enterohemorrhagic e. coli
36
what is the main source of enterohemorrhagic e. coli
contaminated animal products
37
what is the infectious dose of enterohemorrhagic e. coli?
100 bacteria
38
what is the bacteria that is behind the reason you should not eat uncooked hamburger
enterohemorrhagic e. coli
39
where else is enterohemorrhagic e. coli found (other than undercooked hamburgers)
fruits, vegetables, ground water (due to contamination by animal waste)
40
VF of enterohemorrhagic e. coli
cell wall receptor that can fuse with the host cell membrane and shiga toxin
41
is enterohemorrhagic e. coli self limiting?
no
42
shiga toxin can get reabsorbed where?
into renal tissue
43
shiga toxin causes
capillary thrombosis and inflammation of the colonic mucosa
44
VF of pseudomonas aeruginosa
can survive and multiply in wide range of environments
exotoxin A
exoenzyme s
phagocytosis-resistant slime layer
45
Exotoxin A
pseudomonas aeruginosa
| shuts down protein synthesis and causes CELL DEATH
46
exoenzyme S
pseudomonas aeruginosa
| transported directly into host cells and induced apoptosis
47
what is present outside the cell wall in pseudomonas aeruginosa that helps resist phagocytosis?
mucoid polysaccharide slime layer
48
lab ID of pseudomonas aeruginosa
aerobic gram-negative rods with single polar flagellum; characteristic green pigmentation on culture and fruity odor
49
cultured a bacteria and it showed up green with a fruity odor... this is most like
pseudomonas aeruginosa
50
famous for hot tub folliculitis
pseudomoas aerugniosa
51
pt presents with red itchy rash all over body and said they went hot tubbing recently
pseudomonas aeruginosa
52
pseudomonas aeruginosa is a common inhabitant of
soil and water
53
pseudomonas aeruginosa isa an opportunistic pathogen therefore
there must be some sort of breakdown in the host defense
54
common cause of nosocomial infections esp. in immunocompromised
pseudomonas aeruginosa
55
what frequently contaminates ventilators, IV solutions, meds, anesthesia equipment
pseudomonas aeruginosa
56
what is the most common bacterial pathogen to colonize and infect patients with cystic fibrosis?
pseudomonas aeruginosa
57
otitis externa esp in diabetics is usually caused by
pseudomonas aeruginosa
58
why should you not sleep with contacts in?
pseudomonas aeruginosa can cause corneal ulcers
59
environmentally contaminated wounds by pseudomonas aeruginosa can cause ____ from an open fracture
osteomyelitis
60
which bacteria is notoriously multidrug resistant and always requires susceptibility testing?
pseudomonas aeruginosa
61
bordetella pertussis VF
surface protein: filamentous hemagglutinin (FHA)
Pertussis toxin
Tracheal cytotoxin (TC)
62
FHA
binds to and agglutinates red blood cells; bordetella pertussis VF
63
VF toxins of bordetella pertussis (PT and TC)
destroy ciliated respiratory epithelial cells
64
lab ID of bordetella pertussis
tiny aerobic gram-negative coccobacillus
65
Pertussis (whooping cough) is caused by
bordetella pertussis
66
which population carries largest mortality rate from bordetella pertussis?
infants less than 12 months
67
what percentage of deaths from bordetella pertussis occur in children under 1?
70%
68
What disease is being described?
one of the top 10 causes of death in children globally
follows a 7-10 incubation period
pertussis
69
first phase of pertussis last for
1-2 weeks with fever, malaise, rhinorrhea
70
prolonged course of pertussis lasts for
several weeks with coughing bouts
71
post-tussive gagging and/or vomitting
pertussis
72
true or false, bordetella pertussis is extremely contagious?
true, infects more than 90% exposed
73
how is bordetella pertussis spread?
airborne droplet nuclei --> transmitted usually via inhalation of aerosols during coughing phase of infection
74
where do the bacteria remain localized in bordetella pertussis?
tracheobronchial tree
75
since the bacteria remain localized in bordetella pertussis in the tracheobronchial tree is leads to
tracheobronchitis (WHICH IS A URI NOT PNEUMONIA)
76
Attach to the cilia of the bronchial epithelium with pili --> produce PT and TC which leaves a vulnerable mucosa --> bacteria does NOT directly invade or spread --> PT is absorbed into the bloodstream and interferes with the immune response --> can induce apoptosis
bordetella pertussis
77
dx of bordetella pertussis
nasopharyngeal secretions/wash or NP swab
78
TX of bordetella pertussis
azithromycin (Z pack)
79
DTap is given to
infants (2, 4, 6, months)
80
Tdap
booster given to adolescence and for all family members of a newborn
81
the DTap and Tdap are whole cellular vaccines or acellular and why?
acellular, the whole cell vaccine was causing febrile seizures in children
82
named for the 1976 outbreak at the American Legion convention
Legionella pneumophila
83
VF of legionella pneumophila
```
serogroup strains (16)
survives harsh environments by living and multiplying intracellularly
```
84
most common serogroup strain seen with legionella pneumophila
Philadephia strain = serogroup 1 (accounts for 90% of cases)
85
Lab ID of legionella pneumophila
aerobic, gram-negative rods
| thin, pleomorphic, motile, polar and lateral flagella
86
t/f legionella pneumophila are facultative intraceullar pathogens
true
87
where does legionella pneumophila like to live?
amoebas, protozoa, macrophages
88
how was legionella pneumophila spread at the American Legion Convention?
AC system via aerosols
89
Legionella pneumophila causes
necrotizing pneumonia aka Legionnarie's diseae
90
Legionella pneumophila is widely distributed where?
water (tap water, spas, ponds, fresh water, ac systems, cooling towers of hospitals, over vegetables in supermarkets)
91
Aerosol with water
legionella pneumophila
92
aerosols --> inhaled bacteria reach the alveoli --> adhere to alveolar macrophages --> BLOCKS FUSION OF THE ENDOCYTIC VACUOLE WITH THE LYSOSOME --> takes over the host machinery to create its own phagosome --> bacteria multiply to high numbers, kills the macrophage, release new cells --> repeat the cycle
legionella pneumophila
93
in re to legionella pneumophila when are the enzymes released? what does this lead to
when the macrophage is destroyed; leading to inflammation and DESTRUCTIVE LESIONS IN THE LUNG, and systemic toxicity related to immune response
94
destructive lesions in the lung
legionella pneumophila
95
Severe, destructive pneumonia that can lead to shock and/or respiratory failure within a week
Legionnaire's disease
96
initial s/sx of Legionnaire's disease
fever, chills, headaches, myalgias, dry cough, pleuritic chest pain
97
what is the infection rate of legionella pneumophila?
5%
98
t/f legionella pneumophila can be spread human to human?
false
99
Dx of legionella pneumophila
PCR for serogroup 1 in urine (if it is any other serogroup you will get a false negative)
100
lab id of pasteurella multocida
anaerobic gram-negative rods, small, coccobacillus
101
normal respiratory flora in animals --> transmitted to humans via BITE or SCRATCH
pasteurella multocida
102
when does the local infection associated with pasteurella multocida usually present?
within 24 hours
103
what does the infection of pasteurella multocida usually look like?
cellulitis with well-defined borders; can also cause an abscess than can spread to joints, bones, and lymph nodes
104
all patients with animal bites should be given
prophylactic antibodies (augmentin)
105
VF of shigella species
O antigens in LPS layer
Able to invade and multiply in variety of epithelial cells including enterocytes
shiga toxin
endotoxin
106
4 species of shigella
s. dysenteriae s. sonnei, s. flexneri, s. boydii
107
shiga toxin causes
cell death
108
endotoxin causes
fever
109
lab id of shigella species
anaerobic gram-negative rods, non-motile, lack flagella
110
shigella species is famous for
shigellosis
111
incapacitating dysentery with crippling abdominal pain and watery stool filled with mucus and blood
shigellosis caused by shigella species
112
shigellosis spreads
person to person under poor sanitary conditions
113
t/f shigellosis infection does not spread outside the GI tract
true
114
erosion of the lining of the large bowel
shigella dysentery
115
shigella species initial transmission route
fecal- oral route --> the four F's
116
the four F's of shigella transmission
feces, flies, fingers, food
117
shigella species invades
villi of large intestine
118
does the shigella species perforate the intestine to invade the bloodstream?q
no
119
invasion plasmid antigens and shiga toxin damage the mucosa and villi leading to
mucus secretion, focal ulcers, and bleeding
120
shiga toxin in shigella can cause damage to the
kidneys by same MOA as E. coli 0157:H7
121
lab id of salmonella species
anaerobic gram-negative rods
122
salmonella is spart of the
enterics group
123
shigella is part of the
enterics gruops
124
responsible for typhoid fever
salmonella typhi
125
salmonella typhi transmission route
fecal-oral
126
t/f typhoid fever still runs rampant throughout the rest of the world outside of the US?
true
127
infectious dose of salmonella typhi
1,000-10,000
128
VF of salmonella typhi
secretion systems that allow it to invade, multiply in, and kill macrophages
Vi surface polysaccharide that inhibits neutrophil phagocytosis
endotoxin
129
ingested bacilli adhere to small intestine, cause diarrhea, invade and ULCERATE INTESTINAL LINING --> ingested by macrophages and other cells of the immune system --> bacilli then travel within macrophages to infiltrate the lymph nodes, liver, and spleen, where abscesses can form --> can also invade the blood stream either at this point or by perofrating intestine --> fever produced by endotoxin
salmonella typhi
130
chronic carriers of salmonella typhi have bacteria in there
gallbladder (chronic infection of the biliary tract when gallstones present)
131
less severe than typhoid fever but more prevalent
salmonella gastroentertitis
132
what is a very common source of salmonella gastroenteritis?
poultry
133
kid doesn't watch hands before eating dinner after he was playing with his pet turtle, he has been puking for 2 days, what is he most likely infected by right now?
salmonella gastroenteritis
134
sx's of salmonella gastroenteritis
v/d, fluid loss, lasting 3-4 days
135
vf of haemophilus species
polysaccharide capsule
136
lab id of haemophilus s.
anaerobic gram-negative rods, coccobacilli, tiny; require culture media with blood or blood products (prefer chocolate agar)
137
Haemophilus influenzae capsulated strains cause
acute life-threatening infection of CNS and soft tissues (i.e. bacteria meningitis, epiglottitis, septic arthritis, sepsis, pneumonia)
138
capsulated strains of haemophilus influenzae occur primarily in
children
139
non-capsulated strains of h. influenzae cause
otitis media, bronchitis, sinusitis, conjunctivitis
140
H. influenzae is a strict
pathogen of humans
141
H. influenzae is found in ______ _____ of up to 80% of normal people (usually noncapsulated form)
nasopharyngeal flora
142
how is h. influenzae spread?
respiratory droplets
143
t/f h. influenzae causes the flu
false
144
vf of h. influenzae
polysaccharide capsule
antiphagocytic
allows invasion past respiratory epithelium to deep tissues
145
H. influenzae is subtyped ast ___ strains based on
6, polysaccharide antigens
146
which strain of h. influenzae is associated with 95% of the invasive diseases? which disease accounts for 50% of these cases?
Tybe b (aka Hib); Hib meningitis
147
chiefly responsible for infections at the mucosal surface (i.e. otitis media, bronchitis, sinusitis, conjunctivitis)
non-capsulated or non-typeable h. influenzae
148
t/f immunization with conjugated Hib vaccine does not confer protection against the non-typeable strains
true
149
what remains a major cause of otitis media in children?
non-typeable H. influenzae
150
sexually transmitted infection found in africa, southeast asia, india, latin america
H. ducreyi
151
tender papule on the genitalia that develops into a soft, PAINFUL ulcer called CHANCROID; often associated with unilateral tender inguinal lymphadenitis
h. ducreyi
152
vaccines for haemophilus s.
Hib vaccine (uses the Hib capsule conjugated to the other bacterial proteins); administered to infants 2 mo and up)
153
Most common cause of UTIs are
enterics
