Food Borne Pathogens Flashcards
(20 cards)
What is a foodborne illness?
A disease caused by ingesting contaminated food with infectious or toxic agents.
What defines a foodborne outbreak?
Two or more cases of the same disease linked to the same source.
Name the most common foodborne bacterial pathogens in Scotland.
Campylobacter, Salmonella, E. coli O157, Listeria.
How do pathogenic bacteria cause disease in foodborne illness?
Through infection and growth in the GI tract, or by pre-formed toxins in food.
Which bacterium is associated with ready-to-eat foods and has high fatality in elderly?
Listeria monocytogenes.
What are the two forms of illness caused by Bacillus cereus?
Emetic (vomiting) and diarrhoeal.
What bacterium causes botulism, and how?
Clostridium botulinum, by producing a potent neurotoxin in anaerobic conditions.
Which bacterial pathogen is most associated with undercooked beef and petting farms?
E. coli O157:H7.
What are the symptoms of infection with E. coli O157:H7?
Bloody diarrhoea, haemolytic uraemic syndrome, kidney failure.
What is phenotyping in bacterial strain typing?
Identification based on observable traits like morphology, staining, disease symptoms.
What is genotyping in bacterial strain typing?
Identification based on DNA sequences, e.g., PCR, MLST, WGS.
What is serotyping?
Identification based on specific surface antigens like O and H antigens.
What is MLVA?
Multiple-locus variable number of tandem repeats analysis to determine strain relatedness.
What is MLST?
Multilocus sequence typing using housekeeping genes to identify sequence types.
What is WGS and its advantage in strain typing?
Whole genome sequencing; provides complete sequence for precise comparison.
What outbreak was caused by E. coli O104:H4?
The 2011 Germany outbreak linked to contaminated fenugreek seeds.
What methods are used to identify foodborne pathogen strains in epidemiology?
PCR, phage typing, PFGE, serotyping.
What are the key virulence genes in E. coli O157?
stx1, stx2 (shiga toxins), eae (adherence), rfbE (O157 antigen synthesis).
What is immunomagnetic separation (IMS)?
A method to isolate specific bacteria using magnetic beads coated with antibodies.
What are four strategies to determine infection routes?
Epidemiological studies, case-control studies, spatial mapping, quantitative microbial risk assessment.
