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
Before food preparation or eating hars should be washed thoroughly with soup to get rid of microbes and cross-contamination
Food should be stored below 4 to slow the development of microbes
Food must be in sealed containers so cross-contamination can't occur e.g. meat juice
Different cutting boards should be used on raw meats and other foods to prevent food contamination
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
High temp will kill of pathogens
Pasteurizing is the process of heating at 72 celsisu then rapidly cooling in 15 seconds to kill microbes e.g. milk, wine
Low temp will result in slow production of pathogens (freezer) e.g. cheese, deli, meats
Food preservation: Water
Dehydration removes water from food - slow growth (moisture is needed for the growth of microbes) e.g. apricots, raisins, sweetcorn
Salt/Sugaring foods also prevents growth of microbes e.g. Jam, anchovies
Food preservation: pH
Pickles are stored in vinegar (low pH) environment which prevents growth.
Food preservation: Oxygen
Removing oxygen by vacuuming or canning will inhibit growth
Food preservation: Irradiation
Radioactive ways to kill microbes e.g. fruits and vegetables
Food preservation: Chemicals
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.
Pasteurisation72 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.