Pathogens

Cards (24)

  • Pathogen is a disease-causing microbe - all viruses are pathogenic
  • Pathogen Bacteria: Food poisoning, strep throat, whooping cough
  • Pathogens Fungi: Athletes foots, ringworm, thrush
  • Pathogens Viruses: Covid, influenza, chicken pox
  • Pathogens spread by
    • In contaminated food or water
    • Through air
    • By contact with a directly contaminated person to indirect surface/objects.
    • By bodily fluids
    • By vector animals e.g. mosquitos
    • By transfer by animals to humans
  • Food can turn into food poisoning if it is left in a warm place, not stored in at low temperatures, or if it is not cooked thoroughly through
  • Food poisoning is a slow process - and takes a long time for bacteria to multiply in the body
  • Food Safety: microbes that cause food poisoning
    1. Before food preparation or eating hars should be washed thoroughly with soup to get rid of microbes and cross-contamination
    2. Food should be stored below 4 to slow the development of microbes
    3. Food must be in sealed containers so cross-contamination can't occur e.g. meat juice
    4. Different cutting boards should be used on raw meats and other foods to prevent food contamination
    5. Cooked thoroughly at high temperatures to kill microbes
  • Biotic factors are living - competition, predation, availability of food
  • Abiotic are non-living - pH, temp, levels on O2
  • Abiotic Temp:
    • Low temp: Slow development of microbes
    • Warm temp: optium growth
    • High temp: Kill microbes
  • Oxygen: presence of oxygen can prevent anerobic respiration which causes bad microbes to form
  • High or low pH can kill microbes - some microbes have adapted to survive in acidic or alkaline conditions
  • Food preservation: Temperature
    1. High temp will kill of pathogens
    2. Pasteurizing is the process of heating at 72 celsisu then rapidly cooling in 15 seconds to kill microbes e.g. milk, wine
    3. Low temp will result in slow production of pathogens (freezer) e.g. cheese, deli, meats
  • Food preservation: Water
    1. Dehydration removes water from food - slow growth (moisture is needed for the growth of microbes) e.g. apricots, raisins, sweetcorn
    2. Salt/Sugaring foods also prevents growth of microbes e.g. Jam, anchovies
  • Food preservation: pH
    1. Pickles are stored in vinegar (low pH) environment which prevents growth.
  • Food preservation: Oxygen
    1. Removing oxygen by vacuuming or canning will inhibit growth
  • Food preservation: Irradiation
    1. Radioactive ways to kill microbes e.g. fruits and vegetables
  • Food preservation: Chemicals
    1. smoking kill microbes off on meats
  • Salmonella and listeria: when food is left in a warm place this bacteria develops and releases toxins within the food, causing harm to the individual who is eating it.
  • Campylobacter and Salmonella: when food is not cooked through properly the heat kills these bacterias. - Raw milk also may have these bacteria, so it is important to pasteurise milk. 
  • Pasteurisation 72 C for 15s followed by rapid cooling
  • Dehydrate: drying, sugaring and salting
  • The symptoms of a bacterial disease are not seen immediately because it needs a certain amount of bacteria to build up before a person experiences an illness.