4.2 Flashcards
nonfermentative GNR
- Don’t utilise glucose by fermentative biochemical pathways
4 genus of non fermentative gram negative rods
pseudomonas
stentrophomonas
burkholderia
acinetobacter
1 species of pseudomonas
pseudomonas aeruginosa (most commonly encountered)
pseudomonas aeruginosa found in
□ Most commonly encountered
□ Favours aquatic and moist environments
pseudomonas aeruginosa infection
hospital acquired
swimmers ear
pseudomonas aeruginosa resistance
□ Inherently resistant to antibiotics, more so than strains found in hospitals
hospital acquired infection with pseudomonas aeruginoa may lead to
septicaemia
□ Hospital acquired infections with pseudomonas auruginosa may include
® UTI, particularly associated with indwelling urinary catheters
® Pneumonia, particularly in the intensive care setting
infection of burns wounds
coloniser of other wounds
pseudomonas auruginosa pneumonia
hospital acquired
◊ May be complicated by septicaemia and systemic infection
® Infection of burns wounds with pseudomonas auruginosa
◊ Most common bacterium infecting burns
◊ Delays healing, increases scarring
◊ May lead to septicaemia and systemic infection
◊ Pus may be green tinged due to pigments produced by this bacterium
pus of burns wounds infected with pseudomonas auruginosa
may be green tinged due to pigments produced by this bacterium
pseudomonas auruginosa colonising wounds
◊ Leg and foot ulcers from where It may become invasive
□ Swimmers ear caused by
pseudomonas auruginosa
swimmers ear
® Otitis externa
® External ear canal
□ Oxidase positive result means
® Not enterobacteriaceae
® May be pseudomonas aeruginosa
the oxidase test detects the presence of
cytochrome oxidase
cytochrome oxidase is
◊ An enzyme in the electron transport chain of some bacteria but not others
oxidase test process
◊ In the test, a colourless compound takes place of oxygen in the real chemical reaction, and when this is reduced it becomes blue
◊ A piece of filter paper is impregnanted with an aqueous solution of the colourless compound
◊ A small portion of the bacterial colony is lifted from the agar with a wooden toothpcik and smeared onto the filter paper
positive oxidase test result appearance
◊ If cytochrome oxidase is present in the bacteria, the filter paper turns blue in this area and the test is positive
most commonly encountered pathogen of stenotrophomonas
stenotrophomonas maltophilia
stenotrophomonas maltophilia behaves similar to
pseudomonas auruginosa
strenotrophomoas maltophilia colonises
may colonise hospital patients
hospital infection in debilitated patients with stenotrphomonas maltophilia
® Lower respiratory tract infections
® UTIs
® Surgical infections
® Septicaemia (particularly in neutropaenic camcer patients
stenotrophomonas maltophilia
resistant to many antibiotics
