Nonfermtatentive Gram Negative Bacilli Flashcards
What do all of these organisms have in common?
They do not ferment glucose or lactose
How are these organisms ID’d?
By testing their ability to oxidize different sugars
In the O/F Carbohydrate test what do the colors indicate?
Yellow indicates acid production and green indicates no acid production
What indicates a positive result for LDC/ADH test?
Deeper purple color than starting color
What is the number one isolated non-fermenter in clinical specimens?
Pseudomonas aeruginosa
What is the habitat for Pseudomonas aeruginosa?
Widely distributed; Can be found in environment, hospitals, hot tubs, etc.
How is Pseudomonas aeruginosa tranmitted
Exposure to contaminated food/water, medical devices/solutions and penetrating wounds
What is the clinical significance of Pseudomonas aeruginosa?
Nosocomial infections (patient to patient via staff or medical devices) and community acquired (cystic fibrosis patients at high risk)
What is the colony morphology of Pseudomonas aeruginosa?
Shiny “mermaid scales” and beta hemolytic on blood agar; Green on MacConkey; Has grape or old tortilla chip smell
What is the pigment called that is unique to Pseudomonas aeruginosa?
Pyocyanin
What is the pigment called that is green fluorescent?
Pyoverdin
What is the pigment called that is reddish brown?
Pyorubin
What is the pigment called that is brown/black?
Pyomelanin
What is the habitat of Pseudomonas fluorescens and Pseudomonas putida?
Environmental; Associated with HA infections
What is the route of transmission of Pseudomonas fluorescens and Pseudomonas putida?
Exposure to medical devices and solutions
What is the clinical significance of Pseudomonas fluorescens and Pseudomonas putida?
Rare opportunistic pathogen, bacteremia from transfused blood, UTIs and wound infections
What is the colony morphology of Pseudomonas fluorescens and Pseudomonas putida?
No distinct appearance on BAP, Produces pyoverdin (fluorescent green pigment)
What is the key reactions used to distinguish between Pseudomonas fluorescens and Pseudomonas putida? What are the results?
Gelatin (Pseudomonas fluorescens is positive for gelatinase)
What is the habitat of Pseudomonas stutzeri?
It is found commonly in baby formula, hospital equipment and cosmetics.
How is Pseudomonas stutzeri transmitted?
Exposure to contaminated devices/solutions
What is the clinical significance of Pseudomonas stutzeri?
Uncommon cause of infection, rarely associated with otitis media, conjunctivitis, pneumonia, and wounds
What is the colony morphology for Pseudomonas stutzeri?
Wrinkled, light yellow or brown on BAP, Non-fluorescent Psuedomonad
What is the habitat of Burkholderia mallei?
It is the causative agent of GLANDERS in horses, mules and donkeys - results in septicemia and death of the animal
How is Burkholderia mallei transmitted?
It is zoonotic and is transmitted through close contact with infected animals/ mucous membranes or breaks in skin
What is the clinical significance of Burkholderia mallei?
It can cause supperative skin infections, pulmonary infections, septicemia and was used for biowarfare in WWI
What is the colony morphology of Burkholderia mallei?
Smooth, grey and translucent on BAP, variable growth on MAC
What is the gram stain of Burkholderia mallei?
Small, straight or slightly curved GNCB with rounded ends
What is the habitat of Burkholderia pseudomallei?
Soul and stagnant water primarily in Thailand, Vietnam, Cambodia, Malaysia, and Northern Australia
How is Burkholderia pseudomallei transmitted?
Through inhalation of dust and direct contact through breaks in the skin
What is the clinical significance of Burkholderia pseudomallei?
Meliodosis - septicemia, metastatic lesions, TB-like pneumonia, chronic cellulitis; Can be used as bioterrorism agent
What is the colony morphology of Burkholderia pseudomallei?
Round, wrinkled, bright orange to cream on BAP
What is Burkholderia cepacia complex?
A complex of 10 genomovars
What is the habitat of Burkholderia cepacia complex?
Water sources - detergent solutions and IV fluids
How is Burkholderia cepacia complex transmitted?
It is an opportunistic pathogen, cystic fibrosis patients are at risk, also a nosocomial infection
What is the clinical significance of Burkholderia cepacia complex?
Foot rot, septicemia, meningitis, endocarditis, UTI, respiratory infections - can be life threatening and may have intrinsic resistance to multiple antimicrobial agents
What is the colony morphology of Burkholderia cepacia complex?
Yellow, non-fluorescing pigment
- some isolates can be dark pink to red on MAC due to oxidation of lactose
What is the selective media for Burkholderia cepacia complex?
PC (Ps. cepacia) agar - inhibits PSA and colonies look bright pink to red
OFPBL - inhibits most microbes, shows oxidation of lactose
What is the habitat of Alcaligenes faecalis?
Environment - water or soil
Hospital - respirators, hemodialysis systems, IV solutions
What is the mode of transmission for Alcaligenes faecalis?
Contaminated medical devices
What is the clinical significance of Alcaligenes faecalis?
Opportunistic pathogen, often a contaminant
What is the key test used to ID Alcaligenes faecalis?
It is asaccharolytic
What is the habitat of Achromobacter xylosoxidans?
Nosocomial infections and found in water
What is the mode of transmission for Achromobacter xylosoxidans?
Exposure to contaminated fluids, soaps, and disinfectants
What is the clinical significance of Achromobacter xylosoxidans?
It may cause opportunistic infections, could be serious for patients with underlying disease
What is the colony morphology of Achromobacter xylosoxidans?
Non-pigmented on BAP
What is the key test to ID Achromobacter xylosoxidans?
Xylose oxidation
What is the habitat of Elizabethkingia meningoseptica?
Environment, food and water sources
What is the mode of transmission for Elizabethkingia meningoseptica?
Exposure to contaminated medical devices/solutions, can colonize URT
What is the clinical significance of Elizabethkingia meningoseptica?
Meningitis and septicemia in newborns; Pneumonia, endocarditis, bacteremia, and meningitis in adults
What is the colony morphology of Elizabethkingia meningoseptica?
Yellow pigment, lavender green discoloration in BAP, may have fruity/ green apple scent, grows poorly on MAC
What is the habitat for Stenotrophomonas maltophila?
Tap water, salads, and colonization of hospitalized patients
What is the mode of transmission for Stenotrophomonas maltophila?
Use of medical devices - IV or urinary catheters
What is the clinical significance of Stenotrophomonas maltophila?
Can be recovered from every body site, primary pneumonia and opportunistic infection, intrinsic resistance to most commonly used antibiotics
What is the colony morphology of Stenotrophomonas maltophila?
Greenish discoloration of agar on BAP, pale yellow, lavender-green, has strong ammonia odor
What is the key test used to ID Stenotrophomonas maltophila?
Maltose oxidation
What is the habitat of Acinetobacter sp?
Widely dispersed, can live in inanimate objects for extended periods of time, able to survive most dry and moist surfaces
What is the mode of transmission for Acinetobacter sp?
Colonization of hospitalized patients through medical devices
What is the clinical significance of Acinetobacter sp?
HA pneumonia, genitourinary infections, wound/soft tissue infections, and bacteremia
What are the two species of Acinetobacter?
A. baumannii and A. lwoffi
What is the colony morphology of Acinetobacter sp?
Smells like rotten pumpkins, has mauve colonies at 24-48 hours, A baumannii oxidizes lactose on MAC, Grey to white on BAP
What is the key test to differentiate A. baumannii and A. lwoffi?
A. lwoffi is asaccharolytic
What is the habitat of Pseudomonas oryzihabitans?
Found in water, specifically Japanese rice paddies, hospital drains and respiratory therapy equipment
What is the mode of transmission of Pseudomonas oryzihabitans?
Exposure to contaminated fluids and medical equipment
What is the clinical significance of Pseudomonas oryzihabitans?
Catheter-associated infections, bacteremia, wound infection, pneumonia, and UTIs
What is the colony morphology of Pseudomonas oryzihabitans?
Rough, wrinkled, yellow colonies, non-fluorescent pseudomonad
What is the habitat of Moraxella spp.?
Mucous membranes of humans and animals. specifically URT
What is the mode of transmission of Moraxella spp.?
Opportunistic infections and dog bites
What is the clinical significance of Moraxella spp.?
Conjunctivitis/keratitis, sinusitis, bronchitis, endocarditis, and septicemia
What is the colony morphology of Moraxella spp.?
Pinpoint, may grow slowly on MAC
What is the gram stain of Moraxella spp.?
Tiny, plump, GNCB
What is the clinical significance of Oligella species?
They may cause UTIs and septicemia in women
What is the test used to differentiate the two Oligella species?
Urea (ureolytical is positive and urethralis is negative)