Food bourne pathogens Flashcards
Campylobacter examples
C. jejuni
C. coli
Campylobacter foods
Poultry and raw milk
Pros of Campylobacter
Grows at >30C
Responds to O2, drying, freezing and heating
Cons of Campylobacter
Very low infection dose
Salmonella examples
S. typhimurium
S. enteritidis
S. typhi
Salmonella foods
Eggs and poultry
Pros of Salmonella
Responds to temperature, H+ and low Aw
Controlled with lactic acid bacteria
Cons of Salmonella
High prevalence in food chains
Listeria examples
L. monocytogenes
Listeria foods
Dairy
Processed meats
Pros of Listeria
Low heat resistance
Cons of Listeria
Psychrotrophic (resistant to low temp)
Resistant to low Aw
High mortality rate
Staphylococcus examples
S. aureus
Staphylococcus foods
Any (handler contamination)
Pros of Staphylococcus
Large number needed for toxicity
Low heat resistance
Cons of Staphylococcus
Produces toxins
Resistant to low Aw and salt
Vibrio examples
V. cholerae
V, parahaemolyticus
Vibrio foods
Fish
Pros of Vibrio
Low heat resistance
Cons of Vibrio
High salt (NaCl) tolerance
Yersinia examples
Y. enterocolitica
Yersinia foods
Pork and raw milk
Pros of Yersinia
Low heat resistance
Cons of Yersinia
Psychrotrophic
Escherichia examples
E. coli (O157:H7)
Escherichia foods
Wide range
Pros of Escherichia
Low heat resistance
Cons of Escherichia
Can be H+ tolerant
Bacillus examples
B. cereus
B. subtilis
Bacillus foods
Grains
Cereals
Dairy
Pros of Bacillus
Vegetative cells respond to heat
Cons of Bacillus
Spore forming
High heat resistance
Pre-formed toxins
Clostridium examples
C. perfringens
C. botulinum
Clostridium foods
Meat and poultry
Pros of Clostridium
Responds to O2
Large dose required for illness
Cons of Clostridium
Some strains are psychrotrophic
Yeasts examples
Saccharomyces
Candida
Zygosaccharomyces
Yeast foods
Low Aw foods (jam, dried meats)
Low pH foods
Pros of Yeasts
Responds to thermal treatment
Cons of Yeasts
Resistant to H+, low Aw
Grow with or without O2
Resistant to weak acids
Moulds examples
Penicillium
Aspergillus
Botrytis
Moulds foods
Low Aw and pH foods
Pros of Moulds
Responds to thermal treatment and reduced O2
Cons of Moulds
Resistant to H+ and low Aw