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26 Cards in this Set
- Front
- Back
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Name the main characteristics of Salmonella
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Gram -, nonsporulating, facultative anaerobic rod, most have flagella, mesophilic (but some can survive at low and high temps)
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What are the main subspecies and serovars of Salmonella?
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Subspecies: enterica & bongori
Serovars: Typhimurium, Enteritidis, Typhi, Paratyphi |
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What are the diseases caused by Salmonella, Serovars associated, and Symptoms?
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Typhoid Fever: Typhi or Paratyphi. Acute or Chronic. Acute (When org. does not enter organs): High prolonged spiking fever, abdominal pain, diarrhea. Chronic (when org enters organs): recurring fever, anorexia, slow heart rate, malaise.
Salmonellosis (Non Typhoid Fever): Typhimurium, Enteritidis, most symptoms are acute (org does not typically get into organs), abdominal cramps, diarrhea, nausea, vomiting, chills |
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How does Salmonella invade its host? What does it invade?
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It Attaches, Invades, and Grows and Survives within cells (intracellular pathogen). It invades enterocytes and M cells.
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Name 4 out of the 6 Virulence factors for Salmonella.
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Invasion appendage protiens
chaperone proteins type III secretion systems outer membrane secretion channels outer membrane secretion channels enterotoxin siderophobes (for iron uptake) |
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What is the greatest concern food for salmonella, why?
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Eggs (enteritidis), because chickens can harbor it in their ovary and the bacteria can be inside the shell.
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What are the foods that have Salmonella most often?
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Poultry, Turkey, Eggs
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How can you detect salmonella in a lab setting?
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Production of H2S, Fermentation of xylose and glucose (not lactose)
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What are the main characteristics of Campylobacter?
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Gram negative, nonsporeforming, spirally shaped bacterium, microaerophilic (prefers atmosphere of 5% O2/ >10% CO2), Motile, Catalase positive, Fastidious, Sensitive to environmental factors (grows at 32-45C, dies at low pH), can survive refrigeration and freezing.
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Name the main pathogenic species of Campylobacter
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C. jejuni, C. coli
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What are the main disease characteristics for Campylobacter?
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Gastroenteritis (fever, PROFUSE diarrhea, nausea, cramps)
Self Limitation 2-3 days Systemic Complications (Bacteremia, Meningitis, Acute Paralysis) INCUBATION TIME 2-5 Days INFECTIVE DOSE 500CFU |
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How is Campylobacter pathogenic? (What does it do to cause disease)
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Intracellular pathogen
1. Binds to Cell Surface 2. Internalization 3. Induction of Apoptosis (Cell Death) |
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Name 2 of 3 Virulence Factors for Campylobacter
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Flagella genes (flaA, flaB) that allow for motility
Cholera-like enterotoxin Cytolethal distending toxin |
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Where does Campylobacter come from?
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Wild Birds, Rodents, Sheep, Horses, Cattle, Pigs, Domestic Pets (PIERRE AND LUCY)
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What foods is Campylobacter most present?
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Chiken, Turkey, Unpasteurized Milk
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How do you detect for campylobacter?
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Motility, Hippurate hydrolysis, Catalase +
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What is one major concern regarding Campylobacter?
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Antimicrobial resistance that is thought to originate from overuse of antibiotics in animal husbandry
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Name characteristics of E.Coli
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Gm-, nonsporeforming facultative anerobe, ferments lactose, coliform bacteria, produces
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Why is E.Coli O157:H7 considered an emerging pathogen?
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Because it was not present before 1982 and is a relatively new pathogen onto the scene.
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Why is E.Coli O157:H7's acid tolerance of particular concern?
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Because it can survive well and tolerate exposure to low pH for short periods of time. Particularly concerning for fermentation and acidic foods.
Also the infectious dose is 10 cells, which is very low most acid resistant microbe in general pathogen group |
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Name symptoms of E.Coli O157:H7
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Bloody Diarrhea, Cramps, Vomiting.
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What is the incubation time of E.Coli O157:H7
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1-8 days
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What are complications of E.Coli O157:H7 infections? What are char. of those complications?
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HUS in Children
acute kidney falure effect of shiga toxins (toxicoinfection) TTP in elderly |
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Name the virulence factors of E.Coli O157:H7
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Shiga Toxins:
(Three subunits B, A1 & A2) B Binds to GF3 receptor A1 inhibits protein synthesis by cleaving the 60S ribosomal subunit Pathogenecity Island: Intimin (facilitates attachment to cell) EHEC Plasmid pO157 |
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How can you detect E.Coli O157:H7
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Lack of sorbitol fermenting ability
Lack of B-glucuronidase O157 Antibody Affinity |
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Where did E.Coli O157:H7 come from?
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Thought is that E. Coli picked up virulence factors from other e.coli and bacteria through evolution. Encoded possibly by dormant phages
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