Respiratory Bacteria Flashcards
Bordetella pertussis- Gram, o2, what deos it cause
Gram neg
Obligate aerobe
-causes pertussis (whooping cough)
what structures does B pertussis use to colonize lung epithelial cells (3)
Filmentous haemagglutinin adhesion
Fimbriae
Pertactin
Main pathogenesis of pertussis (4 toxins it produces)
Tetracheal cytotoxin- stops cilia beating (causes coughing fits
Pertussis toxin/ Adenylate cylase- increases cAMP which causes cellular signaling disfunction
LPS- local inflammation
What are the 2 stages of Pertussis
Catarral stage
Paroxysmal stage
What happens in the catarhal stage of pertussis + how long does it last
1-2 weeks
-Upper respiratory tract symptoms- rhinorrhea, conjunctivitis, cough, fever
What occurs in the paroxysmal stage of pertussis + how long does it last
2-8 w
- Paroxysmas of coughing typically in single expiration with whoop sound after
- Post tussive vomiting common
transmission of pertussis and who is commonly affected
Highly contagious spread thru respiratory droplets
-children under 1/ those with faded immunity
in what stage are antibiotics usefull in pertussis
Most useful if started during the catarrhal stage
Haemophilus influenza- gram, shape, what is their endotoxin
gram neg
Coccobacilli
Produce LOS (instead of LPS)
Howw is Haemophilus influenza transmitted and 2 types
Respiratory droplets
- Strains w no capsul (Nontypable)
- Encapsulated (Type B)
Nontypable haemophilus influenza- invasive?, Symptoms/causes
not typically invasive
- associated w otis media
- exacerbations of COPD disease
- Sinus infections/conjunctivitis
- pneumia
What does the capsul of type b H. Influenzae have that allows it to evade
Capsul made of polyribosylribitol phosphate which allows the organsim to evade phagocytosis
What does H influenzae cause/symptoms
Upper respiratory infections (sinitus/epiglottitis)
-bactermia (pneunomia, meningitis)
What is epiglottis and what is a medical emeregency it causes
Swelling of the epiglotis and aryepiglottic fods that may obstruct air flow (med emergency)
What type of vacine do we have for h. influenzae
Just for encapsulated strands
Legionella pneumophilia- gram, o2, intra/extracellular
Gram neg obligate anerobe (most resp bac are) Faculatative intracellular bac
How does legionella pneumophilia transmit
Inhalation of water droplets from a contaminated source (stagnant water; accidental exposure)
Pathogensis of legionella (how does it enter cell)
Bac infect alveolar macrophages in lungs
- Entry via coilded phagocytosis (avoids immune system)
- virulent strains impair function of phagosome
- results in macrophage death (causing inflammation etc)
mc symptoms of legionella
Almost all experience fever w/ productive cough (not many serious complications)
What is the more mild form of legionnairs disease And symptoms
Pontiac fever (by legionella pneumophila) symptoms- neusa, fever, cough headache, BUT NO PNEUMIA
Pseduomonas spp- gram, shape, mc species
gram neg
Rod shapped
mc- Pseudomonas aeruginosa
Pseudomonas aeruginosa- capsul, o2, what color does it turn in media
Encapsulated
- Aerobic
- characteristic blue-green color in media
Where is Pseudomonas aeruginosa found and what special feature does it have to sense surroundings
Thrives on moist surfaces
Quorum sensing- Produce autoinducers which sense surroundings for high microbial density
Why is Pseudomonas aeruginosa multidrug resistent
-Actively pump antimicrobial agents out of bacterial cell thru eflux pumps
What are the virulence factors of Pseudomonas aeruginosa (4)
LPS
Exotoxin A- inhibits translation
Flagella to embed themselves
Biofilms- triggers potent inflammatory response to protect bacteria from antibiotics
Who are Pseudomonas aeruginosa mc in/ who is likely to get it
Primarily associated with nosocomial infections, primarily in those in ICU
Moraxella caterrhalis- gram, o2, shape, what does it produce
gram neg
Aerobic
diplococcs
All strains produce B lactamases
What does moraxella caterrhalis produce on its surface that allow it to adere to tissues
Trimeric autotransporter adhesions
What symptoms can moraxella caterrhalis produce in children and and adults and immune compromised elderly
children- otis media
Adults- bronchitis, sinitus and larygitis
Elderly- pneumonia in elderly (+ those w copd)
Is pseudomonas spp vaccine preventable
no
