L5: Enterobacter II Flashcards
- What tribe is Shigella a part of?
- Lactose + or -?
- Indole + or -?
- Motile?
- Co2 + or -
- What is its habitat?
- Tribe I - Escherichieae
- Lactose NEGATIVE
(E.Coli is positive) - Indole negative
- NOT MOTILE
- CO2 negative
- Habitat = intestines of humans
How does Shigellavary from E.COli in terms of:
- Lactose fermentation
- Gas production
- Motility
- NON LACTOSE FERMENTER
- Non gas producer
- Non - motile
SHigella:
- Transmission via _____
- 5f’s
- Highest risk individuals?
- Person to person via fecal oral route
- Contaminated WATER, food, flies, fingers, fomites, feces (5f’s)
- Young children in day care center/nurseries
- siblings/parents of these children
- MALE HOMOSEXUALS
PATHOGENESIS of Shigella:
- Virulent strains carry ____ for attachment and entry
- Enters cells by _____
- Organism escapes in _____
- Intracellular _____ (in cytoplasm)
- _____ drives organism in cytoplasm
- Organisms enter adjacent cells - Shigella phagocytosed into new cell and released into ____
- Shigella can KILL _____
- plasmid
- phagocytic vacuole
- cytoplasm
- replication
- Actin “tail”
- cytoplasm
- PHAGOCYTIC MACROPHAGES
Shigella infection does not extend where?
Unlike Salmonella, does it require a low or high inocolum?
Lamina propria!
LOW inoculum to cause disease for shigella!
What is the major clinical syndrome of shigella?
What are symptoms of this syndrome?
What is tissue invasion limited to?
How long is the incubation period? How long does it last?
- Bacillary Dysentry
- Abdominal cramps, tenesmus, pus and BLOOD in stool
- Tissue invasion limited to EPITHELIAL. cells and SUBMUCOSA
Fecal leukocytes present
- Incubation 1-3 days lasting 48 hrs.
HUMAN SERVES AS NATURAL HOST
Edwardseilla tarda is found in what habitat?
What tribe is this?
- Cold blooded vertebrates, fresh water, catfish
Tribe II - Edwardsielleae
Genus Edwardsiella
What are the clinical symptoms of E. Tarda?
(2)
Is the diarrhea bloody?
What is it often mistaken for? (2)
- Gastroenteritis
- Septicemia (rare)
- acute, self-limiting w/ watery diarrhea
Typhoid like illness with BLOODY diarrhea & possible fever, nausea, vomiting, colonic ulcerations & terminal ileum modularity
- Mistaken for:
- Salmonellosis
- IBD (Crohn’s)
What is the habitat for Salmonella (Tribe III)?
a) non-typhoid
b) S.typhi
- INTESTINEs of Lower animals (poultry, cows, pigs, pets) for non-typhoid strains
- Humans for S. typhi
Salmonella:
- Lactose fermenter?
- Produces ____ (black)
- Trasmission via____
- Found where? (2)
- Secondary transmission ____
- NON - LACTOSE fermenter
- H2S positive
(grows black colonies on Nekton Agar plates) - transmission via Improper food handling
- Found in humans and livestock
- Secondary transmission person-to-person***
Salmonella is Encapsulated. T/F
Samonella is acid STABILE T/F
- TRUE
- FALSE - Salmonella is acid LABILE (think of lemon on salmon = acidic)
- Need HIGH DOSE to cause infection
Almost half of salmonella epidemics are a result of contaminated_____
contaminated poultry and poultry products
- Also associated with reptiles (lizards, snakes, turtles)
What are the 5 clinical syndromes of Salmonella?
- Asymptomatic (carrier state)
- Febrile Gastroenteritis
- Enteric fever
- Septicemia
- Focal Infections
- The asymptomatic (carrier) state is mostly seen with S. Typhi (T/F)
- TRUE
- limited with non-S.Typhi
What clinical syndrome of salmonella does the following describe:
- Most common
- Incubation of 12-48 hours
- Symptoms: malaise, nausea, sometimes with vomiting, followed by abdominal pain and diarrhea.
- Self-limited.
- Duration 3-5 days.
T/F: Not treated with antibiotics
FEBRILE GASTROENTERITIS
TRUE: Do NOT treat with antibiotics.
WHY???
Can destroy normal flora
Create antibiotic resistant Salmonella strain
Enteric Fever:
- ____ is best example
- Caused by ___ and ____
- Incubation period?
- Length of illness?
- What are the 2 stages of Enteric Fever?
- What is the only known reservoir of S. Typhi?
BIMODAL DISEASE
- Typhoid fever
- S. Tyhphi & S. Paratyphi A & B
- Incubation 1-2 weeks
- Length is 4 weeks
a) fever for 2 weeks (bacteremic stage)
b) GI symptoms for 2 weeks
6. Only known reservoir of S. typhi is man
The following describes what syndromes of Salmonela?
1.Osteomyelitis, meningitis, brain abscess, endocarditis *
- -found in patients with
underlying leukemia, lymphoma, AIDS, SLE, sickle cell crisis, and alcoholic hepatitis.
- Found frequently in infections due to S. choleraesuis, S. dublin, and S. oranienburg.
Relapses are common
- Focal Infections
2. Septicemia (w.o major GI involvement)
Pathogenesis of Gastroenteritis:
- Salmonella produces
produces an _____»_space; stimulates rearrangement of plasma cell membrane to form ruffles. - Bacteria enter cell by ______
- Organisms invade what 3 areas?
- What is the result?
- adhesin
- by pinocytosis associated with ruffles
- Organisms invade large and small bowel and lamina propria
- Large inflammatory response induced