Enteric Bac 2 Flashcards
What is the gram stain for Salmonella?
Gram neg rod
What causes the salmonella-shigella agar medium to turn black with salmonella?
Production of H2S by salmonella
What things are caused by salmonella?
Enterocolitis
Enteric fever–typhoid fever
Septicemia
Risk of reactive arthritis–Reiter’s syndrome
What strains of salmonella usually cause enterocolitis?
S. typhimurium
S. enteritidis
S. Heidelberg
What increases the risk of developing enterocolitis caused by salmonella?
Use of antacids
What cells do the salmonellae selectively attach to in order to enter the intestinal cells?
M cell of the Peyer patches –loads into macrophages
What does the Ipf operon virulence factor of salmonella enhance?
Adhesion to M cells
What virulence factor does salmonella have the enhances bacterial translocation?
type 3 secretion system
What virulence factor is present in S. typhi that allows remodeling of phagosomes for systemic spread?
Spi2 type 3 system
What virulence factor of S. typhi allows for immune invasion?
Vi antigen
The Vi capsule protects it from humoral immunity
What predisposition allows septicemia from salmonella?
Sickle cell anemia
Causes osteomyelitis
What abx are used for enteric fevers and septicemia caused by salmonella?
Ceftriaxone or cirofloxacin
What is the gram stain for yersinia enterocolitica and pseudo tuberculosis?
Gram neg oval rods
Urease +
Where does yersinia enterocolitica and pseudo tuberculosis grow?
Grows in cold–motile at 25c and nonmotile at 37c
Where may yersinia enterocolitica spread causing “false appendicitis”?
Local lymph nodes–mesenteric lymphadenitis
What virulence factors of yersinia enterocolitica enhance binding to M cells?
Pili and Inv
What virulence factor of yersinia enterocolitica is a dermonecrotic toxin that destroys tissue?
CNF
What virulence factor of yersinia enterocolitica injects proteins into macrophages–no phagocytosis–reduced inflammatory response?
Yop–type 3 secretion system
Pt with yersinia enterocolitica or pseudo tuberculosis are at an increased risk of developing what?
Reactive arthritis–Reiter’s syndrome
What is Y. pseudo tuberculosis associated with in children?
Izumi fever–generalized vasculitis with symptoms of fever, rash, conjunctival injection, cervical lymphadenitis, inflammation of the lips and oral cavity, and arrhythmia and edema of the hands and feet
What is seen on exam of pt with Y. enterocolitica?
Diarrhea
Dehyrdation
False appendicitis
What agar is used to grow Y. enterocolitica and pseudo tuberculosis?
Cefsulodin-irgasan-novobiocin (CIN)
What is the gram stain of listeria?
Gram + rod
What is the appearance of listeria on non-blood agar?
Blue-green sheen
What type of motility is seen with listeria?
Tumbling motility
What virulence factor is present in listeria that binds host E-cadherin and mediates invasion of cells in GI tract, placenta, meninges?
Internalin
How does the listeria escape into the cytosol
Listeriolysin–opens phagosome
What virulence does listeria have allowing it to spread cell-cell?
ActA
