Units 6-7: Nonfermentative GNB And Curved GNB/Oxidase Positive Fermenters Flashcards
What are 2 characteristics of Nonfermenters?
- Oxidase testing is required
- Oxidation of sugars used for ID as opposed to fermentation of sugars
What is the number one isolated non-fermenter in clinical specimens?
Pseudomonas aeruginosa
Pseudomonas aeruginosa: Colony morphology
Blood Agar: shiny “mermaid scales” beta hemolytic
Mac-non-lactose fermenter, green pigment
Smalls like grapes or tortilla chips
4 pigments of pseudomonas and what causes them?
- Pyocyanin- blue green; unique to P. Aeruginosa
- Pyoverdin- green fluorescent
- Pyorubin- reddish brown
- Pyomelanin- brown/black
Linked to virulence factors
What KIA/TSI is expected with nonfermenters?
K/K
Pseudomonas fluoresens and Pseudomonas putida: colony morphology
Blood Agar- no distinct appearance
Produce pyoverdin
What is sometime found in baby formula or cosmetics?
Pseudomonas stutzeri
Pseudomonas stutzeri: colony morphology
Blood Agar: Wrinkled, light yellow or brown
Non-fluorescent pseudomonad
What is the causative agent of glanders in horses?
Burkholderia mallei
What was used as a biowarfare agent in WWI?
Burkholderia mallei
Burkholderia mallei: colony morphology
Blood: Smooth gray translucent
Variable growth on MAC
Habitat and transmission of Burkholderia pseudomallei
Habitat: soil and stagnant water in SE Asia (“rice patty infection”
Transmission: inhalation of dust and direct contact through breaks in skin
What is a potential bioterrorist agent?
Burkholderia pseudomallei
Burkholderia pseudomallei: colony morphology
Blood: round wrinkled bright orange to cream
Grows well on MAC
What causes foot rot?
Burkholderia cepacia complex
Why can Burkholderia cepacia complex be life threatening ?
Intrinsic resistance to multiple anti microbial agents
Burkholderia cepacia complex: colony morphology
Yellow non-fluorescing pigment
Mac: Some can be pink to red due to oxidation of lactose
What are the two types of selective media for Burkholderia cepacia complex?
PC Agar
OFPBL Agar
What does PC Agar do?
Selects for Burkholderia cepacia complex
Inhibits PSA
Colonies look bright pink to red
What does OFPBL Agar do?
Selects for Burkholderia cepacia complex
Inhibits most microorganisms
Oxidation of lactose
Not routinely used, only in hospitals with CF patients
What opportunistic infections are CF populations specifically at risk for?
Burkholderia cepacia complex
Pseudomonas aeruginosa
What microorganism is often a contaminant?
Alcaligenes faecalis
Alcaligenes faecalis: colony morphology
Blood: Greenish
Fruity green apple odor
Achromobacter xylosoxidans: colony morphology
Blood: nonpigmented
What causes meningitis and septicemia in newborns?
Elizabethkingia meningoseptica
Elizabethkingia meningoseptica: colony morphology
Yellow pigment
Blood: Lavender-green discoloration
May produce a fruity
Grow poorly on MAC
Which nonfermentative GNBs are DNase POS?
Elizabethkingia meningoseptica
Stenotrophomonas maltiophilia
Which nonfermentative GNBs have Intrinsic resistance to multiple anti microbial agents
Burkholderia cepacia complex
Stenotrophomonas maltiophilia
Why can Stenotrophomonas maltiophilia be dangerous?
Instrinsic resistance to most commonly used antibiotics
Stenotrophomonas maltiophilia: reservoir
Salads
Tap water
colonization of hospital patients
Stenotrophomonas maltiophilia: colony morphology
Blood: greenish discoloration of agar
- Pale yellow, avenger green
- Strong ammonia smell