Stoeckel- Haemophilus, Pseudomonas, Listeria Flashcards
Haemophilus species are small, gram-_____ bacteria that colonize what part of humans?
gram-negative
colonize upper reps track of almost everyone
T/F: influenza is caused by H. influenzae
False: influenza is caused by a virus
what 2 things does H. influenzae require for growth?
Hemin (x factor)
NAD+ (V factor)
what makes H. influenzae different from other Haemophilus species?
it requires Hemin to grow
-requires lysed blood
(others just need NAD+)
H. influenzae type ____ is most virulent. it causes what diseases in children?
Type b (Hib) -causes bacteremia (bloodstream) and meningitis in children
___-_____ strains of H. influenzae are frequently causes of respiratory tract diseases in humans
Non-typeable
Haemophilus virulence factors: what is the PRP capsule? its role in virulence?
Polyribosyl Ribitol Phosphate
resists phagocytosis
basis for Hib vaccine
The endotoxin of Haemophilus causes what?
pathogen-directed endocytosis
Haemophilus can produce IgA1 protease, similar to what other microbe?
gonococci
The pili and outer membrane proteins of Haemophilus are similar to those in gonococci, which are used for what?
attachment to columnar epithelia
T/F: pure Hib PRP polysaccharide vaccines are not used in infants because they cause too strong of an immunological reaction.
False. Pure PRP polysacch is not immunogenic in infants
Many H. influenzae and non-typeabable species produce B-lactamase, meaning which antibiotics should/can’t be used?
Cannot use penicillin
use chloramphenicol or third-generation cephalosporins
Pseudomonas aeruginosa: its basic characteristics (gram stain, environment, oxygen tolerance)
A) Gram-negative rods (bacilli)
B) found in soil/water
C) motile (flagella & pili)
D) aerobic
colonies of Pseudomonas aeruginosa produce water-soluble pigment that acts as what?
antibacterials
can be shades of blue, green and fluorescent yellow
P. aeruginosa, when cultured, often smells like ______
fruit/grapes
T/F: P aeruginosa will only grow rapidly when large amounts of nutrients are available
false: they are very robust and grow rapidly
- do not ferment
- only need acetate and ammonia
the virulence factors for P. aeruginosa are split between 2 categories: ______ and _______
Persistence and Dissemination
Persistence of P. aeruginosa: _______, also called iron binding compounds, compete with transferrin
siderophores
Phospholipase C is used by P. aeruginosa in what way?
It uses phospholipase C to hydrolyze phospholipids in the eukaryotic membrane, releasing usable phosphate
Swimmers ear (otitis externa) and hot tub rash (dermatitis) are both caused by what?
encountering Pseudomonas in water
Pseudomonas is a _____ pathogen
opportunistic pathogen
T/F: Pseudomonas can only enter a host through an abrasion/cut/damage to the epithelium
true
the ability for Pseudomonas to spread through its host depends on what?
A) avoiding phagocytosis
B) successful adherence to a surface
adherence of Pseudomonas to epithelia is mediated by _____ and ____
flagella and pili
the pili and flagella of Pseudomonas interact with which 2 parts of the host cells?
Interact with:
- glycolipids
- toll-like receptor (TLR5)
The Polysaccharide capsule of Pseudomonas
- mucoid type
- major adhesin of biofilm in CF patients
- its production is highly regulated
Pseudomonas can produce numerous ______ ______
cytolytic exotoxins
what components of the Pseudomonas’s LPS layer cause damage?
A) adhesins
B) Lipid A (an exotoxin)
C) core oligosaccharide
D) long o-antigen side chains
Lipid A from Pseudomonas interacts with what host receptor?
TLR4
-initiates inflammatory response
in Pseudomonas, the long _-_____ side chains are responsible for what?
O-antingen side chains
-resistance to human serum, antibiotics
the ______ released by Pseudomonas cause local inflammation
Exotoxins
Name the 2 proteases produced by Pseudomonas
A) elastase
B) LasA
______ will cleave elastin, collagen, immune system components
elastase
LasA is a _____ protease which works with elastase to degrade elastin
Serine protease
The type 3 secretion system of Pseudomonas does what?
1) delivers virulence factors directly into host cell
2) similar to flagella
3) target specific host proteins
what genetic disease is P. aeruginosa closely related to?
Cystic fibrosis
what is CFTR? what does a loss of this lead to?
Cystic fibrosis transmembrane conductance regulator
- Loss of Cl- transport
CFTR may cause decreased _______ of surface glycolipids. why is this important?
sialylation of surface glycolipids
allows P. aeruginosa to bind
Sepsis due to Pseudomonas is mediated by ______
LPS (endotoxin)
which endotoxin of Pseudomonas is responsible for sepsis?
Lipid A
-triggers TNF release
what does “MODS” stand for? (think sepsis)
Multi-Organ Dysfunction syndrome
symptoms of MODS
- high cardiac output
- low blood pressure
- distributive shock
what are the 3 requirements for sepsis?
1) Large population of infecting/colonizing organisms
2) Presence of bacterial products that stimulate release of host cytokines
3) Widespread dissemination of microbial products to host’s reticuloendothelial system
the mortality rate for sepsis depends on what?
1) nature and severity of infection
2) host defense state
3) promptness and efficacy of treatment
Pseudomonas endocarditis induced shock has up to a __% mortality rate
50%
T/F: Pseudomonas is easily cultured and identified
true
Pseudomonas infections often require ______ _______ to treat
antibiotic synergism
Listeria monocytogens: gram stain, environment, motility
A) gram-positive rod
B) found in intestinal tracts, sewage, soil and water
C) Food-borne pathogen
-heat and cold resistant
D) flagella and actin polymerizationListeriosis infections of _____ are of special concern
a fetus
Listeriosis can result in:
Bacteremia and meningitis
Listeriosis is a concern in which population groups?
Immunocompromised, elderly, and pregnant people more susceptible
Listeria uses ______, a virulence factors, which mediates adherence/invasion of cells
Internalins
Listerolysin O enables what?
enables Listeria to escape vacuoles
along with Listerolysin O, ______ also aid in escape from vacuoles
Phospholipases
what molecules allow Listeria to cross the placenta?
Phospholipases
what is the best way to prevent Listeria infections?
control growth in the food supply
why are pregnant women told to avoid deli foods, raw meats, and soft cheeses?
they can harbor Listeria which can cause stillbirths
