Micro Test 3: Salmonella,Shigella
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How do you contract salmonella?
Contaminated food (chicken, eggs, etc.)
Salmonella invades and replicates in the _____ of the _________ in the small intestine
Salmonella's Pathogenesis includes initial invasion of the intestinal mucosa via a __________ encoded on a _________
- Type III SS
- Pathogenicity Island (SPI-1)
What Salmonella apparatus secretes invasion proteins (Sips or Ssps) into M cells? What does this cause?
SPI-1, causes host membrane ruffling and engulfment of bacteria
Salmonella are resistant to acidic pH due to?
Acid Tolerance Response gene
What type of bacteria has an ATR gene?
Subsequent systemic Salmonella disease occurs by a _____ encoded on a ________
Type III secretion system, Salmonella pathogenicity island 2 (SPI-2)
What replicates within the vacuole and what replicates once its escaped the vacuole?
- Inside vacuole: Salmonella
- After they escape vacuole: Shigella
Serovars of Salmonella that cause typhoid and paratyphoid fever pass through the cells lining the _____ and are _____.
Serovars replicate after transport to the ____, ____, and ____
- intestinal mucosa
- engulfed by macrophages
- liver, spleen, and bone marrow
Fever, headache, malaise, and anorexia set in ____ days after ingestion of Salmonella.
One week or longer after symptom onset: GI symptoms, bacteremic phase, colonization of the gallbladder and reinfection of the intestines occurs.
S. typhi and S. paratyphi are ____
strict human pathogens
Asymptomatic colonization (usually by S. typhi or S. paratyphi) occurs in 1-5% of patients. These patients harbor it in the _____ and shed it in the feces.
Name the 3 things that cause paratyphoid fever.
S. parathyphi A, S. schottmuelleri, and S. hirschfeldii
Most common form of salmonellosis.
- S. typhimurium
- S. eteritidis
Symptoms in 6-48 hrs: nauseau, vomiting, non-bloody diarrhea
Serovars of Salmonella that are more commonly associated with bacteremia.
S. choleraesuis, S. paratyphi, S. typhi
Salmonella on TSI
- Red slant
- black line
- yellow butt
2) S. typhi, S. paratyphi
- 1) Antibiotics NOT recommended
- 2)Choose an antibiotic based on susceptibility testing (fluoroquinolones, chloramphenicol, sulfa-trimethoprim, broad-spectrum cephalosporin)
1) How many species?
2) All species contain?
- 1) 4 species: S. dysenteriae, S. flexneri, S. boydii, S. sonnei
- 2) 45 O-antigen-based serogroup
What type of Shigella is most common in developed countries?
What type of Shigella is most common in underdeveloped countries?
Shigella invades and replicates in the
Shigella virulence factor genes are carried on a _____ but are regulated by _______
- large plasmid
- chromosomal genes
What type of flagella:
- E. coli= peritrichous
- Shigella= none
Like Salmonella, Shigella first attaches to the ____ on ____
M Cells on Peyer's Patches
1) Shigella Type III Secretion System allows secretion of _____ into epithelial cells and macrophages.
2) Host membrane ruffling occurs and the bacteria are engulfed within the cell in a phagocytic-like vacuole
3)Bacteria lyse the vacuole, escape into the cytoplasm, and replicate.
four invasion plasmid antigens (IpaA, IpaB, IpaC, and IpaD)
Since Shigella don't have a flagella and are nonmotile, they induce _____ in the host and use the ______ to move within the cell and to adjacent cells.
- Actin polymerization
- actin tails
Shigella survive phagocytosis by
- 1) Residing intracellularly
- 2) Inducing apoptosis of macrophages
When Shigella induces macrophage apoptosis, ____ is released. This attracts _____, which destabilizes the intestinal wall.
Which Shigella produces Shiga toxin? Which E.coli produces Shiga toxin?
- Shigella dystenteriae
Shigella primarily affects?
Shigellosis is characterized by what symptoms?
Symptoms start ____ after ingestion
- Abdominal cramps, diarrhea, high fever, bloody stools
- 1-3 days
- Profuse watery diarrhea
Shigella Diagnosis is made by:
- Isolation from stool
- Selective media
Shigella on TSI
- Yellow butt, red slant (doesn't ferment lactose, doesn't produce H2S)
- Urea -
Treat Shigella by
Antibiotic therapy (fluroquinolones, sulfa-trimethoprim)
Gram-N enteric that causes the plague and gastroenteritis.
Prominent characteristic virulence factor of Klebsiella:
Copious mucoid capsule
Which enterobacteriaceae has a copious mucoid capsule?
What people are at higher risks for Klebsiella?
- People w/ compromised pulmonary function
Name 2 common types of Klebsiella.
- K. pneumoniae
- K. oxytoca (CA-primary lobar pneumonia)
NDM-1 (metallo-beta-lactamase-1) was first detected in?
- Pneumonia (what it is most known for)
- Liver abscesses in alcoholics
- Granulomatous disease of nose or genitals
Necrotic destruction of ____
Formation of ____
Production of _________
- alveolar spaces
- blood-tinged sputum
What bacteria causes liver abscesses in alcoholics?
1) What disease is transmitted after repeated exposure through sexual intercourse or nonsexual trauma to the genitalia.
2) How long is incubation?
3) Presents as?
- 1) K. granulomatis (granuloma inguinale or donovanosis)
- 2) weeks or months
- 3) Subcutaneous nodules which break down into granulomatous lesions
Which bacteria does not grow outside of cells in vitro, and therefore requires tissues or scrapings?
What do you stain these with?
What do you see?
- K. granulomatis (K. pneumonia can be grown on culture media)
- Giemsa or Wright's stains
- Appearance of small rods in the cytoplasms of histiocytes, PMNs, and plasma cells (Donovan Bodies)
What disease are Donovan bodies present in? What do they look like?
- Klebsiella graulomatis
- Appearance of small rods inthe cytoplasms of histiocytes, PMNs or plasma cells
K. pneumoniae on MacConkey:
Lactose fermenting: + or -
Positive for fermenting lactose (pink)
Tetracycline, erythromycin, sulfa-trimethoprim (antibiotic prophylaxis is useless)
2 Forms of Proteus:
- 1) Swimmers (8-10 flagella)
- 2) Swarmers (Peritrichous flagella), form concentric patern on semi-solid agar surface, big problem for people with catheters
Most common Proteus disease
Name the 3 most common types of Proteus.
- P. mirabilis
- P. vulgaris
- P. penneri
Which bacteria has urease that splits urea into CO2 and ammonia, thus raising urine pH and causing renal stones?
Which bacteria is urease +?
Which 2 bacteria have phase variation?
E. coli, Proteus
Nitrofurantoin (commonly given for UTIs) is not effective for what common cause of UTI?
Tigecycline is not effective for Proteus alone. It must be combined with?
Enterobacter is multiple antibiotic resistant. Name 2 types and what they cause.
- E. cloaceae: HA neonatal sepsis
- E. sakazakii: Food-borne in powdered baby formula --> necrotizing enterocolitis, meningitis, and sepsis in neonates
What bacteria causes splenic abscess and neonatal meningitis?
What bacteria causes sepsis, meningitis, and brain abscesses in neonates?
Name 2 ways citrobacter can be transmitted.
Nosocomial or vertically
Causes bacteremia in hospital patients, UtIs, wound infections, and is resistant to B-lactams
What bacteria can cause Contact lens induced acute red eye (CLARE)?
In room temp=
- Incubator = white
- Room= red
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