Food Borne Pathogens Flashcards
List Gram negative bacteria
Neg sal crok sleeps yvv Salmonella spp. Campylobacter spp. Verocytotoxigenic Escherichia coli Shigella spp. Yersinia enterocolitica Vibrio spp.
List Gram positive bacteria
POS lee shorr became Carter cartered Listeria monocytogenes Staphylococcus aureus Clostridium perfringens Clostridium botulinum Bacillus cereus
What are the ways we can get disease from food borne routes?
- through eating and/ or drinking
1. INFECTION
2. INTOXICATION
What are the different types of category of food borne infections?
Summaries each
- Toxico infection
Usually short incubation
TOXINS
a) Enterotoxin - produce toxins in the GUT. Pathogenic potential is local to gut and CS associated with gastrointestinal vom or diarr
b) neurotoxin - more dangerous than enteric, associated neurological signs - Invasive Infection: Usually long incubation period
Not toxins but bacteria
a) enteric - local
b) systemic - spreads systemically, more severe as can lead to bacteraemia and septicaemia
What are the different categories of food borne intoxications? (3)
- chemical
- Poisonous plants/ animals
- Microbial
Talk about microbial intoxication
- fungi
- bacteria (mycotoxins): diarrhoeic, enterotoxins or neurotoxins
- Algal (biotoxins)
Food borne intoxication vs foodborne infection
FB intoxication - organism produced specific toxins or toxic metabolites in the food that is INGESTED. TOXIN is ingested.
FB infection is either INVASIVE ( Bacteria ingested through food consumption, the organism invades and penetrates intestinal mucosa, NO TOXIN) or TOXICO infection (bacteria ingested through food consumption, the organism produces toxin while in the INTESTINAL tract)
examples of food borne intoxication
REmember when the organism produces specific toxins or toxic metabolite(s) in the food that is ingested
• Cl. botulinum intoxication in adults;
• Staph. aureus heat stable enterotoxin, - typical intoxication
• B. cereus (emetic syndrome)
Examples of food borne infection
- invasive - • Bacteria ingested through food consumption, the organism invades and penetrates intestinal mucosa: NO TOXINS
– Local enteric infection (non-typhoid Salmonella, Shigella, Campylobacter, Yersinia)
– Systematic infection (typhoid Salmonella, Listeria monocytogenes) - Toxico infection - • Bacteria ingested through food consumption, the organism produces toxin while in the intestinal tract:
– E. coli
Definition of facultative anaerobe
and examples gram neg ones?
grow in anaerobic conditions with a little oxygen e.g. • Salmonella spp. • Yersinia enterocolitica • E. coli O157 (and other VTEC) • Shigella spp. • Vibrio spp
NOT
• Campylobacter spp. (micro-aerophilic) – needs v low presence oxygen (5-7%) high presence CO2
Which bacteria causes YERNINIOSIS?
Main one
Yersinia
mainly Yersinia enterocolitica
List the 3 main species yersinia
- Yersinia enterocolitica - most common, more than 90% FB diseases caused by this
b. Y. pseudotuberculosis foodborne pathogens
c. Yersinia pestis – Bubonic plague (“black death”) NOT food borne. Not talk today
Growth characteristics Yersinia
- Gram negative,
- non-sporogenic,
- curved shaped rods
- Enterobacteriaceae = primary source guts, get into environment from gut and infect other animals
- Facultatively anaerobic rods (partial anaerobic atmosphere conditions)
- usually motile at 22-25 С° non motile higher
• PSYCHROPHILIC bacteria - grow Temp. range 1o – 44oC (28-29oC optimal)
• Salt: can grow 5-7% NaCl (high)
• Sustain v low pH 4
How common is Yerniniosis in the UK and EU??
• 3rd most common FB disease eu
- less common in UK due to main meat source being tongue and head muscles which aren’t preferred in UK meat market. And if meat is fully cooked then hard to get FB disease. High prevalence in pork in abattoir but we cook it a lot!
What are the diff parts to a hazard risk assessment?
hazard identification, incidence and exposure assessment
