Module 14 Flashcards
What is the cellular morphology of Pseudomonas aeruginosa?
Thing gram neg rods, slightly curved
One polar flagellum
Capsules
What are the growth requirements for Pseudomonas aeruginosa?
Obligate aerobe
Optimum temp is 35°C but can grow up to 42°C and at low temps as well
Growth in BAP, MAC and nutrient agar
What pigment do 90% of Pseudomonas aeruginosa produce?
Pyocyanin (blue-green)
What kind of growth does Pseudomonas aeruginosa show?
BAP- large, beta hemolysis, irregular edges, metallic sheen (if infected with bacteriophage), blue-green pigment
MAC- NLF
Strong grape odour
Growth on moderately selective media for Enterobacteriaceae
What are the ID tests for Pseudomonas aeruginosa?
Ox pos
Glc OF +/-
Darting motility
K/K
Cit pos
Urea pos
ADH pos
Growth at 42°C
What is the clinical significance of Pseudomonas aeruginosa?
Moist environments
Normal/transient stool flora
Swimmer’s ear, pneumonia, UTI, folliculitis
Colonization of cystic fibrosis patients early in life
What is the antimicrobial susceptibility of Pseudomonas aeruginosa?
Very resistant
Combo of B lactam antibiotic and aminoglycoside
Testing always required
How does cation concentration affect the testing of Pseudomonas antimicrobials?
Low- falsely resistant
High- falsely sensitive
What is the cellular morphology of Stenotrophomonas maltophilia?
Gram neg rods
Lophotrichous flagella
What kind of grow does Stenotrophomonas maltophilia show?
BAP- 2-4mm colonies, lavender green
MAC- NLF
Ammonia odour
What are the ID tests for Stenotrophomonas maltophilia?
Ox neg
Glc OF +/-
Malt OF +/-
Lac OF +/-
Motile with rapid directional movement
K/K
Cit variable
Urease usually pos
ADH neg
Lys pos
DNase pos
What is the clinical significance of Stenotrophomonas maltophilia?
Moist environment
Colonize moist body sites
Serious infections in debilitated patients
Pneumonia, septicaemia, endocarditis, UTI, meningitis, wound infections
What is the antimicrobial susceptibility of Stenotrophomonas maltophilia?
Trimethoprim-sulfamethoxazole (SXT)
What is the cellular morphology of Acinetobacter baumannii?
Gram neg coccoid rods
No flagella
May resemble Neisseria or Moraxella
What are the growth requirements for Acinetobacter baumannii?
Aerobes
Variable temp
What kind of growth does Acinetobacter baumannii show?
BAP- small grey colonies, no hemolysis or pigment
MAC- NLF (pink tint after 48hrs)
What is the ID for Acinetobacter baumannii?
Ox neg
Glc OF +/-
Lac OF +/-
Malt OF variable
Nonmotile
Cit usually pos
Urease variable
K/K
Lys neg
ADH neg
What is the clinical significance of Acinetobacter baumannii?
Important nosocomial pathogen
Debilitated patients
Pneumonia, wound infections, UTI
What is the antimicrobial susceptibility of Acinetobacter baumannii?
Testing always required
Imipenem
Meropenem
Amikacin
Polymixin B
Some tetracyclines
What family does Pseudomonas aeruginosa belong to?
Pseudomonadineae
