Exam 6 Flashcards
What is the primary habitat for vibrio?
aeromonas?
C. violaceum
vibrio-brackish, salt water
Aeromonas- freshwater
C. violaceum- soil or water
What biochemicals for aeromonas
oxidase +
glucose fermenter
motile
indole +
Biochemicals for A. hydrophila
Arg +
orn -
TCBS-
What diseases do Aeromonas hydrophila cause
gastrointestinal
cellulitis
septicemia, meningitis,
What are Aeromonas species usually resistant to and S?
penicillin, ampicillin, carbenicillin cefazolin
S to 3rd gen cephalosporins, SXT, aminoglycosides
Oxidase +, GN, glucose fermenting
curved, motile, purple pigment
Chromobacterium violaceum
What biochemical test does not help ID chromobacterium and why
oxidase, because it is pigmented
Organism in soil and water
immunocompromised with low WBCs
C. violaceum
Almond Smell
C. violaceum
What biochemicals distinguish chromobacterium from other organisms
if pigmented, enough to ID it
if non pigmented, +indole, - Lys and orni
non maltose or mannitol fermentation
What is chromobacterium violaceum often resistant to
beta lactams and colistin
What do vibrio need for growth
need sodium, salt lovers
What do all vibrio species have in common in biochemicals
glucose fermenters mostly
all motile, catalase -, oxidase +
nitrate +
What temperature do Vibrio grow in
can be in water if more than 20C
Best way to differentiate Vibrio from aeromonas
String test
DNA
vibrio +
Aeromonas -
halophilic
vibrio
What special agars are used to culture Vibrio
How to interpret
stool- TCBS
yellow sucrose +
What does vibrio look like on MAC
all NLF except V.vulnificus
What agar is not very helpful for Vibrio
HE and XLD, shows as yellow, non selective to Vibrio
What special agar is used to find vibrio parahaemolyticus from seafood and what does it look like
chromogenic vibrio agar
mauve/ violet
What distinguishes vibrio from enterbacteriales in a stool culture
what species is it probably
oxidase +
probably cholera
How does Vibrio cholera spread and what does it cause
contaminated water or seafood, rapid flux and electrolyte loss
cholera toxin
Rice water stool
vibrio cholerae
What does Vibrio vulnificus cause and how is it transmitted
*** Fatal septicemia and especially + liver disease
can become cellulitis and necrotizing fasciitis, multiple organ failure
What does vibrio parahaemolyticus cause and how is it acquired
raw seafood, watery diarrhea
self limiting
24-48 hrs
What environment almost always has V. parahaemolyticus
in coastal environments
What does V alginolyticus cause
least pathogenic, eye and ear infection, wound and burn
Vibrio species that is oxidase -
Vibrio metschnikovii
Only vibrio species that is lactose fermenting/ MAC pink
Vibrio vulnificus
Which Vibrio species nearly always comes from extraintestinal sources
Vibrio algunolyticus
How are Vibrio species distinguished in the lab
sucrose fermentation
TCBS is selective for all Vibrios
What Vibrio species is Bright Yellow on TCBS
and black?
yellow cholerae
black parahaemolyticus
What subgroups are withing V. cholera
antigen groups
worst- O1- cholera toxin-fatal
O139- makes toxin also
others non O1/ non O139- no toxin
All NLF GNR are oxidase positive except
S maltophilia
Acinetobacter
V. metschnikovii
All GNR that are NLF are motile except
Burkholderia mallei
TSI restults for Burkholderia and Pseudomonas
gas + bubbles
H2S + black butt - yellow underneath
red slant
O/F results for Pseudomonas aeruginosa
Glucose
Open tube - yellow- pos-oxidizer
closed tube- green- neg fermenter
Best way to distinguish pseudomonas and burkholderia
pseudomonas is catalase +
burkholderia catalase -
What organisms are BCSA agar for
how to read
Burkholderia
if translucent colony, red-orange agar then
B cepacia
non wrinkled, rough, serrated edges on MAC
B. cepacia
What is the best way to ID pseudomonas and Burkholderia vs enterobacteriales
API 20NE
What do E.coli, Psuedomonas and Staph look like on MAC
E. coli- pink growth
Pseudomonas- yellow growth
Staph- no growth
What do B mallei and B. pseudomallei look like on a gram stain
mallei- coccobacillus on GNR
pseudomallei - GNR small bipolar staining
Organism in eye drops and spas
Burkholdeereia cepacia
What major diseases do B. cepacia cause
cystic fibrosis pts
Organism that grows on onions
Burkholderia cepacia
What biochemicals Burkholderia cepacia
Looo
oxidase slow weak +
lysine +
ornithine +
ONPG +
What is Burkholderia cepacia resistant to
Pac
Best treatment?
aminoglycosides, polymyxin B, colistin
lot of R, no good antibiotic treatment
Oxidizes lots of sugars
glucose, lactose, maltose, mannitol
B. cepacia
Organism that is NLF, GNR, decarboxylates lysine in cerebral spinal fluid is probably
B. cepacia
What immunocompromised patients are at most risk of B cepacia infection
CGD chronic granuloma disease,
How does B cepacia affect immunocompetent people
infection of blood, UT, and respiratory tract
rarely fatal
Rice paddies
B. pseudomallei
What organism is Ashdown medium for
B pseudomallei
appears violet purple color
What do B. pseudomallei look like on a gram stain
and BA?
gram- bipolar staining, safety pins
wrinkled metallic varied hemolysis
organism that has an earthy odor
B. pseudomallei
Biochemicals for Burkholderia pseudomallei
oxidase +
Arg +
lactose oxidizer
cetrimide neg
How to distinguish B. pseudomallei from pseudomonas?
B. pseudo cetrimide -
Pseudomonas cetrimide +
What makes B pseudomallei look different from P. aeroginosa on a plate
no pyrverdin pigment on pseudo
What disease does B. pseudomallei cause
meliodosis- pulmonary disease very fatal
Causes disease amoung Vietnam vets and SE Asian immigrants
B. pseudomallei
Organism that causes infections in horses called Glanders
B. mallei
Organism that is a potential bioterrorist agent
B. mallei
strictly aerobic
motile
polar flagella with tufts
Pseudomonas
Organism that smells like grapes
P. aeroginosa
What diseases are P. aeruginosa associated with
Cystic fibrosis
What virulence factors do P. aeruginosa have***** practice matching
exotoxin A
Exoenzymes S and T
phospholipase C
pilli
alginate
pyocyanin
Organism involved in quorum sensing
What do they produce
P. aeroginosa
allow it to produce a biofilm with alginate
swimmers or divers ear infection
P. aeruginosa
Hot tubs
P. aeroginosa
artificial nail infection
P aeruginosa
What organism is the most related to cystic fibrosis
P. aeroginosa
What does P aeruginosa look like on BAP and MAC
blue- pyocyanin
green- pyoverdin
flat, shiny, spready, metallic
Beta
What is the only Pseudomonas species that grows at 42C
P. aeruginosa
Biochemicals for P. aeroginosa
Arg +
citrate +
gelatinase +
cetrimide +
What is the only Pseudomonas species that produces Pyocyanin and what color is it
green-blue aeroginosa
What diseases do P. fluorescens and P. putida cause
rarely anything
UTI, post-surgical abcesses
septic arthritis
What Pseudomonas species produce pyoverdin only
fluorescens and putida
What are P. fluorescens and putida resistant to
carbenicillin and ticarcillin
What test is used to distinguish P. fluorescens from P putida
gelatin hydrolysis
fluorescens +
putida -
What does P. stutzeri look like on BA
tree root, wrinkled, leathery, bright yellow/ brown
What biochemical test distinguishes P. stutzeri
Arg neg
What environments are P orzyhabitans and luteola from
water and soil
sticky eye
P. oryzihabitans
What do orzyhabitans and luteola colonies look like
wrinkly yellow
Distinguishing biochemicals for P. luteola and oryzihabitans
oxidase -
What antimicrobial therapy is used to treat pseudomonas infections
beta lactam and aminoglycoside
How are Pseudomonas, Stenotrophomonas and Burkholderia distinguished
antimicrobial testing
Only organism mentioned to be non motile
B. mallei
On TCBS agar, why are organisms yellow
ability to oxidize sucrose
What is the most commonly encountered GNR genera outside of enterobacterales
Pseudomonas
What are the 3 organisms that are associated with cystic fibrosis, which is the most associated
Most- P. aeruginosa
B. cepacia
S. maltophilia
Vibrio body sites
Cholerae
alginolyticus
vulnificus
cholerae-stool
alginolyticus- skin, wound, ear
vulnificus- blood