ENTEROBACTERIACEAE PT.1 Flashcards
nm at 37 and rt
klebsiella
shigella
nm at 37 but m at rt
yersinia
used in the presumptive identification of enteric organisms in the laboratory.
Primary culture media
what bacteria has polar flagella
tatumella ptyseos
what type of flagella does motile members have
peritrichous flagella
what are antigens
substances (proteins) that react with specific antibodies
what are antibodies
proteins that react to antigens
what is serotyping
a serologic test that determines species/subtypes of bacteria based on the antigens present on its surface.
what is antigenic variations
refers to the variations in the antigenic structures of antigens.
- Used in the serotyping between species of Salmonella and other motile bacteria.
- flagellar antigen
- Heat labile
H antigen
- somatic antigen
- Heat stable, located in the cell wall
O antigen
how to remove k antigen
must be boiled for 30 minutes
- capsular antigen/envelope antigen
- Heat labile polysaccharide found in
encapsulated strains.
K antigen
species that have k antigen
klebsiella
salmonella
e. coli
what antigen for Salmonella is categorized as K antigens.
vi antigen
Common types of infections in enterobac
uti
gastroentreritis
septicemia
diff opportunistic pathogen from primary pathogen
opportunistic pathogen is a harmless bacteria that can be harmful if an opportunity arise;
primary pathogen is a harmful bacteria that cause disease to a healthy individual
- Previously considered as a harmless member of the colon biota
- Primary marker of fecal contamination in water
Escherichia coli
what cho does e. coli ferments
glucose
lactose
trehalose
xylose
what is Enterotoxigenic E.coli (ETEC)
Associated with diarrhea of infants (major cause!) and
adults in tropical and subtropical areas
ETEC infective dose of organisms in immunocompetent individuals.
10^6-10^10
Serves as a protective mechanism against colonization and disease initiation
stomach acidity
lack of hcl; – higher risk compared to normal persons.
achlorhydria
Colonization of ETEC in the small intestine mediated by
fimbriae
how many a and b subunits in etec
1 a subunit
5 b subunits
B subunit binds to the … , the same receptor used by cholera toxin to bind on the epithelial cells in the small intestine.
GM1 ganglioside receptor
Associated with dysentery
Enteroinvasive E.coli (EIEC)
mediate the colonization of EIC into the colonic
epithelium
plasmid encoded invasive genes
Movement within the cytoplasm and into the adjacent
cells is regulated by
actin filaments
carbon source of eiec
acetate
mucate utilization
what is sereny test
test of invasiveness
characteristic of enteropathogenic e. coli
watery diarrhea with large amount of mucous with no blood
results in polymerization of actin
Binding of intimin to Tir
mediates the initial aggregation of EPEC that leads to the formation of micro-colonies on the epithelial cell surface.
Bundle-forming pili
– inserted into the host’s epithelial cell membrane and functions as a receptor
Translocated intimin receptor
function of Escherichia coliI secreted protein F (EspF)
causes loss of intestinal barrier
Causes hemorrhagic diarrhea and colitis
Enterohemorrhagic E.coli (EHEC)
associated with hemorrhagic diarrhea, colitis, and hemolytic uremic syndrome (HUS)
EHEC STRAIN 0157:H7
what is verotoxin 1
phage encoded toxin identical to shiga toxin
Shiga-toxin binding to proteins on the surface of glomerular endothelium and inactivating a metalloproteinase called
von Willebrand factor-cleaving protease (VWFCP)
what is verotoxin 2
it lacks antigenic similarities
specific glycolipid that is expressed on host cells particularly on the intestinal villi and renal endothelial cells.
globotriaosylceramide
triad symptoms of HUS
thrombocytopenia
microangiopathic hemolytic anemia
kidney failure
Due to reduced blood flow leading to Ischemia and alson due to the direct damage caused by the toxin to the renal endothelial cells
Kidney Failure
- On of the few bacteria associated with chronic
diarrhea and growth retardation in children - Implicated in persistent watery diarrhea in infants in
developing countries and in travelers to these countries
Enteroaggregative E.coli (EAEC)
function of thick biofilm
protects the aggregated bacteria from antibiotics and phagocytic cells
2 toxins produced by Enteroaggregative E.coli
Enteroaggregative heat stable toxin
Plasmid encoded toxin
Most common cause of UTI, mostly occurring among females
Uropathogenic E.coli
function of cytolysin
it is a hemolysin that lyses wbcs and inhibits phagocytosis and chemotaxis
function of Aerobactin
allows uropathogenic strains to chelate iron
Formerly called E.coli atypical or enteric group II
E. hermannii
Isolated from humans with infected wounds
E. vulneris
Associated with diarrheal disease in children
E. albertii
aka friedlander’s bacilli
Klebsiella pneumoniae
Absence of motility, possess a polysaccharide capsule
klebsiella
distinct feature of kp
polysaccharide capsule
carbapenemase
ventilator-associated pneumonia
what test is kp positive
capsular swelling test
what culture media is used in the diagnosis of kp
emb
mac
xld
causative agent of antibiotic associated hemorrhagic colitis
klebsiella oxytoca
function of potassium cyanide
it is used to differentiate organisms based on their ability to grow with the presence of cyanide
treatments in klebsiella oxytoca
amoxicillin-clavulanate
amoxicillin
penicillin
ampicillin
tilivallin
causes mitotic arrest of host cells and induces apoptosis
names before of klebsiella granulomatis
donovania granulomatis
calymmatobacterium granulomatis
are rod-shaped, oval organisms that can be seen in
the cytoplasm of mononuclear phagocytes or histiocytes in tissue samples from patients with
granuloma inguinale.
donovan bodies
It commonly affects the nasal cavity and nasopharynx, but it can also involve the larynx, trachea, bronchi,
middle ear, and orbit.
klebsiella rhinoscleromatis
foamy macrophages with numerous cytoplasmic vacuoles containing viable and nonviable Klebsiella bacilli
mickulicz cells
Causative agent of chronic atrophic rhinitis called
ozena.
klebsiella ozanae
Inhabits soil and water and, to a lesser extent, the large bowels of man and animals
enterobacter
is a disease of the nose in which the bony ridges and mucous membranes of the nose waste away
ozena
characteristic of enterobacter colonies
fish eye colonies
produces a yellow pigment and has been documented asa pathogen in neonates causing meningitis and bacteremia often coming from powdered infant
formula.
Cronobacter (Enterobacter) sakazakii
found in respiratory samples and is rarely isolated from blood cultures
Enterobacter gergoviae
gained notoriety with a nationwide (U.S) outbreak of septicemia resulting from contaminated IV fluids
Pantoea (Enterobacter) agglomerans
–isolated from human sources such as blood, wound, and sputum.
Enterobacter hormaechei
similar biochemically to Enterobacter cloacae and has been isolated from blood, urine, feces, sputum, and wounds.
Enterobacter asburiae
emits a dirty, musty odor resembling “rotten potatoes”
serratia odorifera
serratia species Pigment production at room temperature
s. marcesens
s. rubidea
s. plymuthica
formerly Enterobacter taylorae has been associated with osteomyelitis after traumatic wounds.
Enterobacter cancerogenus
pigment produced by serratia species
prodigiosin (pink-red color)
diff s. odorifera biogroup 1 and biogroup 2
biogroup 1 - isolated from the respiratory tract
biogroup 2 - isolated from the blood and csf
tribe proteeae generas
proteus
providencia
morganella
Resembles Enterobacter but differentiated by its inability to ferment lactose, sucrose, sorbitol, and raffinose
hafnia alvei
does tribe proteeae ferments lactose?
no
are widely recognized human pathogens in genus proteus
p. mirabilis
p. vulgaris
it forms the kidney stones
struvite crystals
results form a tightly regulated cycle of differentiation
from standard vegetative cells (swimmers) to hyper-flagellated, elongated, polypoid cells (swarmers) capable of coordinated movement.
swarming
what is diene’s phenomenon
a line of inhibited growth results where strains meet.
what kind of odor does swarmers produce
burnt chocolate
Proteus antigens are used in the diagnosis of
rickettsial disease
the only urease positive under genus providencia
Providencia rettgeri
proteus antigens
OXK, OK19, OX2
weil-felix test
an agglutination test to differentiate rickettsial disease
associated with UTI in those with indwelling catheters
p. stuartii
associated with human infections
p. rettgeri
p. stuartii
– only species within the genus Morganella
morganella morganii
Considered as inhabitants of the GIT tract and are associated with hospital-acquired infections, most
frequently UTI.
citrobacter
– associated with infectious diseases in hospital settings such as UTIs, pneumonias, and intra-abdominal abscess. It is also associated with endocarditis in IV drug abusers.
c. freundii
Isolated from cold blooded animals including reptiles, freshwater and aquarium fish, frogs, and turtles.
E. tarda
E. hoshinae
E. ictaluri
- Phylogenetically closely related to Enterobacteriaceae, but it does not have the ability to produce gas from glucose
- Only oxidase-positive member of the family Enterobacteriaceae
pleisiomonas
the only species in genus pleisiomonas
pleisiomonas shigelloides
It has emerged as a potential cause of
enteric disease in humans, most often after consumption of undercooked seafood or untreated water.
pleisiomonas shigelloides
