Exam 5 Flashcards
What is true of all enterobacteriales
usually in GI tracts
GNR coccobacilli or straight rods
usually transmitted by food or water
all ferment glucose
oxidase negative except one
All reduce nitrate to nitrate
All motile except 2
All Enterobacteriales are motile except for
Klebsiella and Shigella
All enterobacteriales are oxidase negative except for
Pleseomonas
What diseases do Salmonella and Shigella cause
typhoid fever and dysentery
What pathogens in enterobacterials are in stool?
E. coli
P. shigelloides
Salmonella sp
Shigella sp
What pathogens of enterbacteriales are in blood, wounds or respiratory
Y. pestis
Y. enterocolitica
Y. pseudotuberculosis
Which organism is the most common cause of a UTI and kidney infections
E.coli
What virulence factors can E. coli have
capsular antigen K1
adheres to epethelial cells
O antigen can cross react with Shigella
What hemolysis and MAC results do E. coli give
Beta mostly
sometimes gamma
lactose fermenter- pink on MAC
What does E. coli look like on EMB agar? and XLD?
EMB- shiny green
yellow- XLD
Bloody watery diarrhea
E. coli O157:H7
E. coli has a ___ infectious dose required for infection
low
What genes did E.coli give to Shigella, which Shigella?
Stx1 and Stx2 created shiga toxin
What other symptoms can E. coli O157:H7 cause
HUS hemolytic uremic syndrome
low plts, hemolytic anemia and kidney failure
What other name does E. coli O157:H7 have
enterohemorrhagic E. coli
EHEC
How can we distinguish O157 from other less harmful E. coli
MacConkey sorbitol- if clear, means O157 is present
if pink, normal E. coli
Also rapid test cards that look for Stx1 and 2
What is ETEC
enterotoxigenic E. coli
What virulence factors do ETEC have
toxins
heat stabile toxin (ST)
heat labile toxin (LT)
Traveler’s Diarrhea
ETEC- non bloody
ETEC- non bloody
Travelers diarrhea
What is EIEC
enteroinvasive E.coli
What does EIEC cause
dysentery, direct penetration of intestinal mucosa
Watery diarrhea and scant stool with pus, mucous and blood
EIEC
What are the unique biochemical features of EIEC
lactose -
non-motile
What is EPEC
P for pediatrics
infantile diarrhea
enteropathogenic E. coli
Stool with large amounts of mucus but no blood
EPEC
What is EAEC
enteroaggregative E.coli
a for adherence
adheres to mucosal surface, D, V, dehydration
What organism is normally not much of a problem but really bad for AIDS patients
EAEC
What organism has slow reactions to biochemical testing
Edwardsiella tarda
How is Edwardsiella tarda transmitted
person to person
fish or water
liver absesses
Edwardsiella Tarda
What do all citrobacter species have in common
all can use citrate as sole carbon source
What special virulence factors do citrobacter have and what resistance does it give them
Ampc plasmids
make them carbopenamase
resistance to B lactase antibiotics
Citrobacter can be confused for ____ in stool because it is H2S ___ on HE and XLD
Samonella
positive
Organisms that is slowly urea positive
Citrobacter
Organism that is a late lactose fermenter
citrobacter
What are the 2 distinguishing tests for Klebsiella
indole negative, non motile
very mucoid on BA
Klebsiella
What does Klebsiella cause?
pneumonia mostly
also UTI, bacteremia, infections in wounds
Which Klebsiella species is an exception with the indole test?
Oxytoca- indole positive
Klebsiella sp that is mostly Urinary infections
K. oxytoca
Organism that was formally known as Calymmatobacterium granulomatis
K. granulomatis
Kleb species found in scrapings of skin lesions
K. granulomatis
What term can be used to describe K. granulomatis if intracellular in epithelial cells
Donovan body
What are the biochemical test results for K. granulomatis
Citrate +
ONPG +
What biochemical testing do enterobacter species have
citate, VP, ornithine +
What body sites are enterobacter species found in
wounds, urine, blood, CSF
What are the most commonly isolated enterobacter species
E. aerogenes
E. cloacae
Mostly hospital acquired infection
Enterobacter
What does Serratia look like on BA and MAC
red on both
What is the main pathogen in the Serratia group
maracescens- healthcare issue
What biochemicals do Serratia have
motile, slow lactose fermente
ONPG+
Dnase +
What body sites can Serratia be found in
Urinary tracts, respiratory tracts, wounds
Organism that can survive under harsh environmental conditions
Serratia
Organism that made the Mary statue look like she was crying
Serratia marcescens
What antibiotics are Serratia resistant to
ampicillin and 1st gen cephalosporins because of AmpC beta lactamase
What special media is used to ID Serratia and what does it look like on it
DNAse
enriched agar
breaks down DNA and creates a clearing zone
What does Serratia look like on MacConkey
clear on MAC, eventually will become pink
Organism that is swarming, like waves on a beach
Proteus
What are the biochemical tests for proteus species
non lactose fermenter
GNR, Phe deaminase +
What body sites are proteus species in
urine, wounds, ears, blood infection
What are the 2 main species of interest in proteus
P. vulgaris
P. mirabilis
Biochemicals for P. mirabilis
indole neg
ornithine pos
H2S pos
If an organism is black on XLD and HE it could also be
could also be proteus
organism that makes dogs paws smell like frito/ corn chip smell
proteus
Biochemicals P. vulgaris
indole pos
ornithine pos
H2S pos
Which species is not technically enterobacteriales anymore
Morganella morganii
Emerging pathogen, for skin, soft tissue, UTIs as an HAI
Morganella morganii
What biochemicals Morganella morganii
ornithine, lysine, phe deaminase pos
urease pos
non lactose
What antibiotic resistance do Morganella have
AmpC genes sometimes
Biochemicals for providencia
motile, non lactose
phe pos
Orni neg
organism that is phe pos but not swarming
providencia
What are the 2 main providencia species
stuartii and alcalifaciens
motile GNR that lives in freshwater environments and causes infection through ingestion or direst contact
Plesiomonas shigelloides
Biochemicals for Plesiomonas
oxidase pos
DNAse neg
lysine, ornithine arginine pos
uncooked seafood
plesiomonas shigelloides
zookeepers often get it
Plesiomonas shigelloides
What antibiotics can be given to more severe cases of Plesiomonas
SXT sulfamethoxaole trimethorpim
non lactose GNR safety pin appearance
Yersinia
What are the 3 most important Yersinia species in order of most to least important
Y. pestis
Y. enterocolitica
Y. pseudotubersulosis
Organism that caused the black plague
Yersinia pestis
How is Yersinia pestis transmitted
rat fleas
survives cold temps
survives pRBC manufacturing processes
mimics acute appendicitis
Yersinia enterocolitica
Motility of Yersinia enterocolitica?
motile at 25C
non motile at 35C
Red bulls eye in CIN
Yersinia enterocolitica
What organisms are never motile
Kleb and Shigella
What natural reservoir does Yersinia pseudotuberculosis
GI flora for rodents, birds and rabbits
abdominal pain
What organism is never normal to see in any body part
Salmonella
What salmonella species are in warm blooded animals whereas all of the rest are in cold blooded animals
enterica enterica
What subspecies are in Salmonella enterica enterica
typhi and paratyphi
What virulence factors do Salmonella species have
O antigen
K or Bi antigen that hides O antigen
What color on HE and XLD for Salmonella
XLD- black
HE- black
Selenite
What color is the XLD plate and HE
XLD- pink
HE- green
Organism that does vertical invasion
Organism that does horizontal invasion
vertical- Salmonella
horizontal- Shigella
Salmonella has needs to be in ___ quantities to cause illness
large quantities
Some strains of Salmonella can be extra virulent and gain access into the bloodstream and cause
Typhoid fever
high fever, headache, loss of appetite, bloody stool, occasional rach
Typhoid fever
GI symptoms 8 to 36 hrs after ingestion
Salmonella
Why can’t we use antibiotics on Salmonella
causes a carrier state that is prolonged and causes relapse, could need gall bladder removed
What organism is never normal flora and does not have an animal reservior
Shigella
Organism that can be transmitted through reptiles
Salmonella enterica enterica
How is Shigella spread
spread person to person due to poor hygiene
Causes bacillary dysentery
shigella
What species has to be sent to the state lab for tracing
Shigella
What does Shigella look like on XLD and HE agar
clear
How can we distinguish Shigella from E. coli
lysine neg
What organisms are in the 4 Shigella O antigen groups
A, B, C, D
flexneri
boydii
dysenteriae
sonnei
A- dysenteriae
B- flexneri- boys flex
C- boydii Chef Boyardee
D-sonnei Sunny D
What Shigella species is the most common
sonnei- Group D
Shigella needs to be in ____ quantities
small, very contagious
___ rarely invades the bloodstream
Shigella
Fever and chills, bloody diarrhea, blood, mucus, pus in stool
in 2-4 days, self limiting
Shigellosis
bacteremia, meningitis, necrotizing colitis in neonates, mucoid on routine culture
Raoutella, Erwinia, Pantoea, Hafnia, chronobacter
oddball chronobacter
Meant and dairy, not pathogenic
Raoutella, Erwinia, Pantoea, Hafnia, chronobacter
Hafnia alvei
Yellow on BAP, neg for all sugars, trauma contaminated with soil
Raoutella, Erwinia, Pantoea, Hafnia, chronobacter
Pantoea
Plant pathogen
Raoutella, Erwinia, Pantoea, Hafnia, chronobacter
Erwinia
utilizes sorbose,
Raoutella, Erwinia, Pantoea, Hafnia, chronobacter
Raautella
What to do if Enteric pathogen is delayed in growth
Cary-Blair transport medium
What are the requirements of all enterobacteriaceae
grown on routine media
24hrs at 35C in CO2 or ambient air
Routine stool cultures are orders to look for mostly
Salmonella and Shigella
Physicians can order additional tests if they suspect pathogens like
E. Coli O157:H7
campy
pleseomonas
yersinia
aeromonas
viruses or parasites
What organism could have a yellow halo around it on HE agar
Salmonella
must be isolated
What are the 3 antigens that can be found on Salmonella and what do they each do
O- somatic on cell wall, heat stable
H- flagellar on flagella, heat labile
K- capsular, heat labile in some species could be Vi
How can we test for the O antigen specifically on Salmonella
boil it to leave only the O antigen
What organisms need to be serogrouped and tested on WellColex
Salmonella and Shigella
What 3 organisms come to mind that are citrate and VP pos
What rules out one of them?
What else distinguishes the remaining 2
entero motile
Kleb non motile
Serratia slow/ NLF
How to distinguish 2 main Kleb species
indole negative: pneumonia
indole positive: oxytoca
What should come to mind when there are 2 positives in ornithine and arginine
E. cloacae arg and orni +
E. aerogenes lys and orni +
What should come to mind if Phe is pos, what helps further distinguish them?
proteus- H2S pos
morganella- ornithine pos
providencia- orni, lys and arg pos
How to distinguish 2 main proteus species
mirabilis- indole neg
vulgaris indole pos
Biochemicals of E. coli
indole pos
motile
beta
lactose fermenter
dark flat
lysine pos
H2S. citrate, lysine neg
How to distinguish Citrobacter from E. coli
indole, H2S, motile, citrate pos
lysine neg
Late lactose fermenter
IMViC for
E. coli
Kleb pneumo
Citrobacter freundii
enterobacter
proteus mirabilis
proteus vulgaris
serratia marcescens
E. coli ++–
proteus vulgaris ++–
Kleb Oxytoca +-++
enterobacter –++
serratia marcescens –++
Kleb pneumo–++
Citrobacter freundii-+-+
proteus mirabilis -+- or +-
Is it necessary to do antimicrobial susceptibility on enterobacteriales?
allways
What are ESBL
extended spectrum beta lactamases
can hydrolize penicillins and cephalosporins
possible in Kleb, E. coli and P mirabilis
Pink disk +
ESBL
What special media is used to grow ESBL
Chromagar ESBL
What are CRE
carbapenem resistant enterobacteriales
What organisms can be CRE
Kleb pneumoniae
neutralizes meropenem, imipenem, ertapenem, doripenem
CRE kleb
What antigen allows for CRE
AmpC
What organisms can be CRE
K aerogenes and E cloacae
E. coli, Kleb pneumoniae, P. mirabilis
• Which members of Enterobacterales are lactose fermenters?
E. coli
Citro
Klebs
Enterobacter
• Which members of Enterobacterales are lactose non-fermenters?
Edwardsiella
Providencia
Morganella
salmonella
Shigella
Yersinia
• Which members of Enterobacterales are motile?
all except Klebsiella and Shigella
• Which members of Enterobacterales are phenylalanine positive?
Proteus
Morganella
Providencia
• Which members of Enterobacterales are H2S positive?
proteus
Citrobacter
Salmonella
• Which members of Enterobacterales swarm on BAP
proteus
• Which members of Enterobacterales are oxidase +?
pleseomonas
• Which members of Enterobacterales are indole positive?
citro
P. vulgaris
E. coli
Enterobacter
Klebsiella oxytoca