PSEUDOMONAS AND NON-FERMENTING GRAM NEGATIVE BACILLI Flashcards
Pseudomas and related genera
Complex mixture of opportunistic pathogens of plants, animals and humans
Many genera, but relatively few commonly isolated
- P.aeru
- Burho…. cep…
- strenotroph….. maltop..
- acine…. baumna….
- Morax…. catar….
- Bordete…. pertu…
- Legio…..
Complex mixture of opportunistic pathogens of plants, animals and humans. Many genera, but relatively few commonly isolated: P.aeruginosa, Burkholderia cepacia, Stenotrophomonas maltophilia, Acinetobacter baumannii Moraxella catarrhalis. Bordetella pertussis, Legionella.
Pseudomonads
- Ubiquitous - found in …., decaying ….. …., …. and water
Hospital environment in most reservoirs
- F
- S…. T
- Fl….
- Dis….
carried as normal flora in im….. and …… patients
Ubiquitous – found in soil, decaying organic matter, vegetation and water.
Hospital environment in moist reservoirs
Flowers,
Sinks toilets,
Floor mops equipment
Disinfectants.
Carried as normal flora in immunocompromised and hospitalised patients.
Pseudomonads
Simple growth requirements
- can use many organic … as source of ….. and nitrogen
Respiratory metabolism
- Non-fermentative and use relatively few carbohydrates during……. ………
Oxygen is the terminal …… acceptor
Presence of cytochrome ….. differentiates them from enterobacteriaciae
Simple growth requirements.
Can use many organic compounds as source of carbon and nitrogen.
Respiratory metabolism.
Non-fermentative and use relatively few carbohydrates during oxidative metabolism.
Oxygen is the terminal electron acceptor.
Presence of cytochrome oxidase differentiates them from Enterobacteriaciae.
pesudomonads
Obligate aerobes but may grow …… using …. as an alternative …. acceptor
Grow over a wide range of temperatures 4-42
Motile by means of polar flagella
Gram negative Bacilli, straight or slightly curved
size 0.50-1 x 1.5 -5 um
Obligate aerobes but may grow anaerobically using nitrate as an alternative electron acceptor.
Grow over a wide temperature range.
4-42°c.
Motile by means of polar flagella.
Gram negative bacilli, straight or slightly curved.
0.5-1.0 x 1.5 – 5m.
Pseudomonads
Map appear ,,, because of polysaccharide ….
Some produce diffusible pigments
- Poly……(blue)
- Fluro…. (yellow)
- Py (red-brown)
Resistant to salts. …. , ….. and many ant…..
May appear mucoid because of polysaccharide capsule.
Some produce diffusible pigments
Polycyanin (blue)
Fluorescein (yellow)
Pyorubin (red-brown).
Resistant to salts, dyes, chemical disinfectants and many antib
Pseudomonas aeruginosa
Many subspecies identified by ….. and … differences
p.aer…. most common
Possess many structural factors and toxins enhance ……..
Resistant to most ….
Grow in ……
Many subspecies identified by biochemical and genetic differences.
P.aeruginosa most common.
Possess many structural factors and toxins that enhance virulence
Resistant to most common antibiotics
Grow in most environments.
Pseudomonas aeruginosa
Opportunistic pathogen of ……. patients
- chronic l….j
- B…..
- Ope….
- Patients expose to …
- dia….
- the e
- IV d….
Causes range of clinical symptoms
Opportunistic pathogen of immunocompromised patients Chronic lung disease, Burns, Open wounds, Patients exposed to contaminated water, Diabetics, The elderly IV drug abusers. Causes range of clinical syndromes.
Pseudomonas aeruginosa
Virulence factors
Adhesins
- … used to bind to epithelial cells
- Also produce …..
Polysaccaride capsule
- Muciod ….. layer
- Alginate protects from … and enhances …..
- Complex …..regulation
Virulence factors. Adhesins. Pili used to bind to epithelial cells. Also produce neuraminidase. Polysaccharide capsule. Mucoid alginate layer. Alginate protects from phagocytosis and enhances adherence. Complex genetic regulation.
Pseudomonas aeruginosa
endotoxin
- ….. in cell wall
- Lipid A mediates ….
Exotoxin A
- Produces by ……. ……
- Blocks protein synthesis like diphtheria …. but less potent and different receptor
- mediates ….
Exoenzymne S
- Inhibits protein synthesis
- Heat stable
Endotoxin. LPS in cell wall. Lipid A mediates septic shock. Exotoxin A. Produced by pathogenic strains. Blocks protein synthesis like diphtheria toxin but less potent and different receptor. Mediates tissue damage. Exoenzymne S. Inhibits proteins synthesis. Heat stable.
pseudomonas aeruginosa
Elastase. two enzymes
- Las A (ser,,,,, ,,,,,)
- ….. (zinc metallo…) act synergistically to degrade elastin
Damage lung tissue and also …… complement components and inhibit white cell ……
Phospholipase C
- tissue destruction breaks down lipids and …..
Elastase. Two enzymes,
LasA (serine protease)
LasB (zinc metalloprotease) act synergistically to degrade elastin.
Damage lung tissue and also degrade complement components and inhibit white cell proteases.
Phospholipase C
tissue destruction breaks down lipids and lecithin.
Pseudomonas aeruginosa
Pyocyanin - blue pigment
- Catalyses the production of superoxide and ,,,,,,,,
- Hydroxyl radical formed in presence of …..
- Causes tissue damage
Antibiotic resistance
- Mutation of porin proteins gives inherent resistance to many …….
…….. mutates during therapy
Pyocyanin – blue pigment
Catalyses the production of superoxide and hydrogen peroxide.
Hydroxyl radical formed in the presence of pyochelin.
Causes tissue damage.
Antibiotic resistance.
Mutation of porin proteins gives inherent resistance to many antibiotics.
Further mutates during therapy
Pseudomonas aeruginosa
clinical syndromes
- lower respiratory tract infection in susceptible patients,
- Range from colonisation to severe bronchopneumonia.
- Chronic lung disease in ………… …..
Urinary tract infections
- Associated with …… and ……. antibiotic treatment
Clinical syndromes.
Lower respiratory tract infection in susceptible patients.
Range from colonisation to severe bronchopneumonia.
Chronic lung disease in cystic fibrosis.
Urinary tract infections.
Associated with catheters and prolonged antibiotic treatment.
Pseudomonas aeruginosa
Ear infections
- Otitis …… associated with swimming
Eye infections
- following damage t o….. and …. to contaminated water
Skin infections.
- …… and infection of burns
- Ulc…..
bacteriaemia and ……. resulting from initial focus of infection
Ear infections. Otitis externa associated with swimming. Eye infections Following damage to cornea and exposure to contaminated water. Skin infections. Colonisation and infection of burns. Ulcers. Bacteriaemia and endocarditis resulting from initial focus of infection
Burkholdreia
B,cepacia becoming makor problem in ……. …… patients
Nosocomial infection causing . …. symptoms
otherwise low ……
Susceptible to tr…… but resistant to many antibiotics
B.pseudomallei prevalent in the far east cause ……
B.cepacia becoming major problem in cystic fibrosis patients.
Nosocomial infection causing respiratory symptoms.
Otherwise low virulence.
Susceptible to trimethoprim but resistant to many antibiotics.
B.pseudomallei prevalent in the far east – causes melioidosis.
stenotrophomonas maltophilia
Opportunistic infection
Resistant to most beta lactam and …… antibodies
Broad spectrum of noso,,,, infection:
- Bacte….
- P….
- W
- Urinary … …..
Sources of infection include hospital equipment
Opportunistic infection. Resistant to most beta lactam and aminoglycoside antibiotics. Broad spectrum of nosocomial infection Bacteriaemia Pneumonia, Wound Urinary tract infections. Sources of infection include hospital equipment.
