Foodborne Ilnesses Flashcards
How many cases are food borne illnesses per year?
48,000,000
15% of americans
How does food poisoning occur?
Ingestion of pre-existing enterotoxins
The pathogen may no longer _____
Be present
2 examples of non present pathogens
Botulism and staphylococcus aureus
Types of Foodborne pathogens (3)
- Salmonella enteriditis (eggs, poultry, produce, pets)
- Salmonella typhi (typhoid fever, 4–500 cases annually in USA, mainly from travelers)
- Campylobacter jejuni (poultry, cattle, drinking water, sexual activity, causes more diarrhea than salmonella and shigella)
How can Listeria occur?
Bacteria could be in packaged food
Shigellosis is a _____ bacterium
Gram-negative
Shigellosis symptoms
Usual gastroenteritis symptoms, plus dysentery
What can you contract Shigellosis from?
Eggs, shellfish, dairy, vegetables, water
What are the two types of shiga toxins?
Active (A) and Binding (B)
What is Active Subnit?
An N-glycosides which cleaves a single adenine residue from 28S rRNA, halting protein synthesis
What do shiga toxins lead to?
Death of vascular endothelial cells, causing bloody diarrhea
Where are shiga toxins most effective?
In small blood vessels, such as the gut and kidney
Where are many of the genes that are needed for Shigella virulence?
On the invasion plasmid
What does the virulence plasmid contain?
Many pathogenicity island clusters
- toxin genes stxA and stxB are NOT on this
-contained in a viral prophage embedded in the bacteria genome
Two ways of transfer for genes
Vertical and horizontal
Lateral gene transfer types
Transformation, phase transduction, bacterial conjugation, transposition
- all can occur within or between species and strains
E.coli is a _______
Natural gut bacterium