Pseudomonas spp. (2)

Gram negative bacillus

gram type and shape of pseudomonas aeruginosa

Facultative aerobe

oxygen type of pseudomonas aeruginosa

Nonfermentive

is pseudomonas aeruginosa is fermentative or non fermentative

Soil, water, vegetation

where is pseudomonas aeruginosa found

4-42 C

temp range of pseudomonas aeruginosa

Iridescent pigmented colonies

colony morphology of pseudomonas aeruginosa

Pyocyanin

blue green pigment of pseudomonas aeruginosa

Pyoverdine

yellow green pigment of pseudomonas aeruginosa

Grape/sweet

smell of pseudomonas aeruginosa

Respiratory tract, skin/soft tissue, urinary tract and blood

locations of pseudomonas aeruginosa infections

Opportunistic pathogen

pseudomonas aeruginosa is an _____ which is not normally a pathogen for an immunocompetent host

Severe burns, CF, immunocomprised, corneal scrath, ICU catheters and IVs, antibiotic treatments

situations which pseudomonas aeruginosa take advantage of as an opportunistic pathogen

Nosocomial pathogen

related to the healthcare setting and pseudomonas aeruginosa is 10% of all ___ infections

Acute pneumonia

this type of pseudomonas aeruginosa infection can be modeled in mice and rabbits

Burned mouse model

this is a pseudomonas aeruginosa model for burn victums

Arabidopsis and amoeba

plant model and other odd model for pseudomonas aeruginosa

Drosophila and butterfly

insect model for pseudomonas aeruginosa

C elegans

nematode model for pseudomonas aeruginosa

Single polar flagella

flagella type for pseudomonas aeruginosa used in swimming motility

Type 4 pili

this is used for twitching of pseudomonas aeruginosa

Swarming

differentiated ___ allow for ____ in pseudomonas aeruginosa

Iron uptake and metabolism

hemolysisn, iron targeting proteases, heme uptake systems, siderophores are used by pseudomonas aeruginosa for ______

Hemolysins

phospholipases (PlcH and PlcN) are used as ___ in pseudomonas aeruginosa for iron uptake and metabolism

Rhamnolipid

heat stable hemolysin used in pseudomonas aeruginosa for iron uptake and metabolism

Iron targeting proteases

degrade hemoglobin to release heme in pseudomonas aeruginosa for iron uptake and metabolism

Pyochelin and pyoverdine

siderophores used in pseudomonas aeruginosa for iron uptake and metabolism

Proteases

elastases and alkaline ____ are used by pseudomonas aeruginosa to release energy stores and in tissue destruction and invasion of underlying tissues

Elastases

LasA and LasB are ____ and degrade a wide range of host proteins to DESTROY tight junctions by degrading elastin, collagen, immunoglobulins, fibronection in pseudomonas aeruginosa

Pigments

toxic and capable of generating ROS , includes pyrocycanin, pyochelin and pyoverdine in pseudomonas aeruginosa

Pyocyanin

results in ROS damage and kills neutrophils by pseudomonas aeruginosa

Pyochelin

has iron chelating ability (low affinity) and forms OH- radical and damages mitochondria and kills neutrophils in pseudomonas aeruginosa

Pyoverdine

fluorescent and has iron chelating ability (high affinity) and plays a major role in pseudomonas aeruginosa iron acquisition

Exotoxin a

major toxin of pseudomonas aeruginosa which inhibits translation in eurkaryotic cells

Effectors

secreted virulence factors are often called …

Type 3 SS

toxin/effector secretion system into host by pseudomonas aeruginosa which needs intimate contact between bacterium and host cell to inject toxins and effectors

ExsA

high level transcriptional regulator for T3SS genes, turned on based on calcium levels in pseudomonas aeruginosa and controls expression of other effectors

ExsE

secreted under low calcium conditions and frees ExsC to bind to ExsD in pseudomonas aeruginosa

ExsC

resembles chaperones that maintain T3S proteins in an export competent state in pseudomonas aeruginosa

ExsD

binds ExsA to inhibit transcription under non inducing conditions, bound to ExsC in low Ca2+ conditions

High calcium

ExsE binds to ExsC, allowing ExsD to bind ExsA in _____ conditions

Low calcium

ExsE is secreted freeing ExsC to bind ExsD in ____ conditions

T3SS expression

free ExsA activates…

ExoS, ExoT, ExoU, ExoY

four major T3S effectors which have the goal of killing the host cell

ExoS

has GAP activity for Rho GTPases and ADP ribosyl transferase activity for ERM and promiscuous targets

ERM

link the plasma membrane to the cortical actin cytoskeleton

ExoS

alters cell cytoskeleton, causes cell rounding, inhibits autophagy and mTOR which are key process in innate immunity, inhibits vacuole acidification and promotes vacuolar escape, blocks ROS burst in neutrophils and can be cytotoxic and/or antiphagocytic in pseudomonas aeruginosa

ExoT

has GAP activity for Rho GTPases for Rho, Rac, Cdc42, cytoskeletal regulation and ADP ribosyltransferase for Crk1, Crk2

ExoT

overall function is to stimulate actin reorganization and induce mitochondrial apoptosis, including loss of focal adhesion and disruption of integrin mediated survival signaling and cytochrome c release

ExoY

adenylate cyclase activity ATP which makes cAMP as it binds actin filaments, initates cAMP production and promotes microtubule breakdown

ExoY

overall host effect is rounding of mammalian cells due to microtubule breakdown, tissue edema and alters actin cytoskeleton dynamics and increases endothelial tau phosphorylation and permeability

ExoU

phospholipase activity that needs ubiquitin which destroys eukaryotic membranes and it is an acute cytotoxin

Ecthyma gangrenosum

infection caused by pseudomonas aeruginosa that causes necrotic skin lesions and is almost always preceded by bacteremia

Folliculitis

infection caused by pseudomonas aeruginosa infection of the hair follicle and is self limiting aka hot tub rash

Endocarditis

infection caused by pseudomonas aeruginosa infection of heart valves and prosthetic heart valves, iv drug users and provides direct access to the bloodstream

Corneal infections (keratitis)

infection caused by corneal scratches in contact wearers in pseudomonas aeruginosa

Swimmers ear

external otitis and ear infections caused by pseudomonas aeruginosa

Burned epithelial

pseudomonas aeruginosa infections often leads to bacteremia with a high mortality rate

Acute respiratory infections

potentially treatable with antibiotics, infection may be clearable and may spread to the bloodstream seen mostly in immunocompromised individuals pseudomonas aeruginosa

VAP

ventilator associated pneumonia which has a 70% mortality rate

Chronic respiratory infections

seen exclusively in patients with CF

Alginate

exopolysaccharide responsible for the mucoid phenotype in CF airways composed of 2 repeating subunits of mannuronic acid and guluronic acid, aids in colonization of lung, evasion of host immune response and biofilm formation

High osmolarity, low nitrogen or phosphate

alginate is induced by these conditions

Beta lactam + aminoglycoside

combination therapy of antibiotics for treatment of pseudomonas aeruginosa infections