To start with, raw meat may be contaminated with spores of certain pathogenic bacteria (e.g. Clostridium perfringens) and spores are not readily destroyed by normal cooking temperature.
Cooking food will kill some bacteria, but it won't destroy all of it. Many bacteria have an adaptable cell wall that can become resistant to a particular attack mode. This means that if you apply heat or a chemical to kill bacteria more than once, you're going to get less benefit from it each time.
If food is contaminated with Staph, the bacteria can multiply in the food and produce toxins that can make people ill. Staph bacteria are killed by cooking, but the toxins are not destroyed and will still be able to cause illness.
The toxin produced by staph bacteria is very heat-stable—it is not easily destroyed by heat at normal cooking temperatures. The bacteria themselves may be killed, but the toxin remains. Re-heating foods, even at high temperatures, that have been contaminated with toxins will NOT make them safe to eat!
It's a basic fact that every cook should know: bacteria that cause illness inevitably end up on nearly every ingredient we cook with, and even boiling won't kill all of them. Boiling does kill any bacteria active at the time, including E. coli and salmonella.
Cooking also causes the proteins in bacteria to break up so they no longer function and the bacteria die. This is why cooking removes the risk from harmful bacteria that are in some food. Bacteria usually grow in the 'Danger Zone' between 8°C and 60°C.
Although, some bacterial spores not typically associated with water borne disease are capable of surviving boiling conditions (e.g. clostridium and bacillus spores), research shows that water borne pathogens are inactivated or killed at temperatures below boiling (212°F or 100°C).
The short answer: Yes, cooking can kill Salmonella. Depending on the type of food, the Centers for Disease Control and Prevention recommend cooking food to a temperature between 145 degrees F and 165 degrees F to kill Salmonella.
Listeria can contaminate foods we don't usually cook, such deli meats, sprouts, and soft cheeses. In 1985, Listeria-contaminated queso fresco sickened 142 people, killed 10 newborns and 18 adults, and caused 20 miscarriages.
160°F/70°C -- Temperature needed to kill E. coli and Salmonella. While Salmonella is killed instantly at temperatures above 160F keeping the temperature for longer periods of time at lower temperatures will also be effective. See the chart below.
Regarding the most and least resistant pathogens to heat, S. senftenberg 775W, L. monocytogenes and some strains of S. aureus would be the most heat resistant, whereas Campylobacter would be even the least heat-resistant one (Sagarzazu et al., 2010b).
Thermophiles are the most heat resistant, followed by mesophils and psychrophils. Sporeforming bacteria are more heat resistant than non-sporeforming bacteria.
Some bacteria can survive at very high temperatures. These types of bacteria are called thermopiles, which means “heat loving.” Thermophiles are harmless to humans and grow best at temperatures between 113 to 176°F (45 to 80°C). They're often found in hot springs and in hydrothermal vents deep in the ocean.
Complete answer: The bacteria which spoil the cooked food is clostridium. It spoils food which causes food poisoning and is faster in warmer weather so that the food can spoil more quickly and possibly cause severe illnesses.
Bacteria multiply rapidly between 40 and 140 degrees. Bacteria will not multiply but may start to die between 140 and 165 degrees. Bacteria will die at temperatures above 212 degrees.
Even though cooking will destroy most of the harmful micro-organisms that may be on fish, cooked products (and any other foods) can be re- contaminated through poor handling or storage practices.
Raw foods of animal origin are the most likely to be contaminated, specifically raw or undercooked meat and poultry, raw or lightly cooked eggs, unpasteurized (raw) milk, and raw shellfish. Fruits and vegetables also may get contaminated.
Every year, an estimated 1 in 6 Americans (or 48 million people) get sick, 128,000 are hospitalized, and 3,000 die from foodborne diseases.
Thorough cooking of food kills Listeria bacteria. Ensure food is cooked thoroughly. If you plan to eat previously cooked and refrigerated leftovers, only keep them in the refrigerator for a day and reheat them thoroughly to steaming hot. This will kill Listeria bacteria.
The good news is, E. coli and many other harmful bacteria can be killed by cooking food properly. Food safety tip: Because ground beef can turn brown before disease-causing bacteria are killed, use a digital food thermometer to make sure you cook hamburger to an internal temperature of at least 71°C (160°F).
Cooking of Ground Beef
But CDC and USDA say that consumers should cook ground beef to 160°F. The guidance for consumers is different because it is simpler to meet one standard (temperature) than two (temperature and time). Cooking ground beef to 160°F kills E. coli germs rapidly.
Chicken is a good source of protein – but if it is not handled, cooked and stored correctly, it can carry bacteria that cause food poisoning. However, preventing food poisoning from chicken is simple if a few behaviours are followed at home.
Boiling water can only remove solids and bacteria, meaning it will not remove harmful substances such as chlorine and lead from tap water.
Heat your meat
Poultry naturally contains Salmonella, which you can kill by cooking the meat to an internal temperature of 165°F or higher. Cook all raw ground beef, pork, lamb, and veal to an internal temperature of 160 °F – and don't rely on guesswork. Measure the temperature with a food thermometer to be sure.
Never drink water from a natural source that you haven't purified, even if the water looks clean. Water in a stream, river or lake may look clean, but it can still be filled with bacteria, viruses, and parasites that can result in waterborne diseases, such as cryptosporidiosis or giardiasis.