Pseudomonadaceae Flashcards
General characteristics
GN rods
- motile via polar flagella
- oxidase positive
- obligate aerobes
- some produce soluble pigments
Where are psuedomonas found?
Water, soil, and vegetation
What is the ultimate opportunist of the pseudomonas family?
P. aeruginosa
- transient colonizer of skin and mucosa
- is a major nosocomial pathogen of people
- commonly resistant to antibiotics
- produces pyocyanin –> green pigment that reacts with O2 = toxic radials
What is P. aeruginosa susceptible to?
Ciprofloxacin and genamicin
What do burn patients typically die from?
Pseudomonas infections
Disease
Wound abscesses and UTI infections in ALL species
- may replace bacteria that have been eliminated by antimicrobial therapy
Dog and cat
Prostatitis, cystitis, dermatitis, chronic purulent otitis externa, ulcerative keratitis
Cattle
Mastitis = infertility and abortion
- spread by coitus
- ulcerative keratitis, conjunctivitis
Poultry/fowl
Septicemia, keratitis
Sheep
Dermatitis (fleece rot)
Mink and chinchillas
Hemorrhagic pneumonia and septicemia
Pathogenesis
Complex due to invasiveness, toxinogenic, and virulence factors of P. aeruginosa
Virulence factors
- surface slime: inhibits complement and phagocytosis
- type 3 secretion system
- proteases
- fimbriae
- antimicrobial resistance: permeability barrier, R plasmids, efflux pumps
Exotoxins of the type 3 secretion system
- A: inhibits protein synthesis
- S and T: interrupt actin cytoskeleton functions
- U: cytotoxin
- Y: adenlyate cyclase
Control
Proper disinfection and drying of hospital surgical suite and instruments
- proper use of antimicrobial therapy
