Your commercial kitchen is a potential breeding ground of harmful bacteria. Commonly these harmful bacteria can cause outbreaks of colds, flus, and foodborne illnesses, affecting both your staff and customers. They tend to develop as a result of poor handling of food and then spread via hand-to-hand and hand-to-food contact.
Knowing what to watch out for can be really valuable in tackling outbreaks and will give you the knowledge you need to support any procedures you put in place. So we’ve pulled together a list of the most widespread types of bacteria that you as a food handler should be aware of:
The campylobacter bacteria is the most common cause of food poisoning in the UK. Living in the intestinal tract of animals and humans, the bacteria can be spread through the poor handling of contaminated foods, in particular raw food or water that has been exposed to faecal matter of animals or humans infected by the bacteria. It is estimated that at least 50% of all raw chicken is contaminated with the bacteria during mass production.
The campylobacter bacteria can be transmitted to humans through the consumption and processing of raw or undercooked meat (especially chicken, turkey and fowl), unpasteurised milk, untreated water and occasionally mushrooms and shellfish.
Once infected with the bacteria it can take 3 to 5 days before symptoms become evident and it can lead to diarrhoea, fever and vomiting that lasts several days. It can in fact leave more lasting health issues such as irritable bowel syndrome (IBS), reactive arthritis and Guillain-Barré syndrome, which is a very rare but serious condition of the nervous system. At its worst, it can kill.
Food handler tips: Cooking food through properly (70°C for 2 minutes or higher; 82°C and rising in Scotland) is the only way to kill the bacteria. It can survive refrigeration temperatures but storing food chilled will ensure that the bacteria does not multiply. Care with food preparation and thorough hand washing are vital to ensuring that the bacteria does not spread to others through your kitchen. If you’re a food handler and have symptoms of campylobacter infection you should not return to work for the next 48 hours after your symptoms have stopped.
Salmonella is probably the most well-known bacteria in the foodservice industry, especially because of the amount of media coverage it receives every year. It is the second most common cause of food poisoning in the UK. The bacteria, which lives in the intestinal tract of animals and humans, can be spread through the exposure of raw food or water to faecal matter and the subsequent poor handling of contaminated foods.
Meat (chicken, turkey, and fowl in particular), eggs, milk and seafood can all be contaminated with the bacteria. Food contaminated by salmonella is not identifiable through smell or taste.
Handling or consuming raw contaminated food, or processing this contaminated food in raw form with cooked foods, can pass the bacteria on. Fruit and vegetables can be contaminated too and can be a source of concern when unwashed if they have been in contact with manure in the soil or sewage in the water.
Once exposed to the bacteria it can take 12 to 72 hours to begin to experience symptoms such as diarrhoea, headaches, cramping, sickness and fever. Salmonella poisoning can be very serious, especially for vulnerable people such as the very young and the very old. In very rare cases, Typhoid fever can result from a severe Salmonella infection. At worst, this bacteria too has caused deaths.
Food handler tips: If you’re a food handler and have symptoms of salmonella infection you should not return to work for the next 48 hours after your symptoms have stopped. Disturbingly, a salmonella infection can last as long as a year even if symptoms cease to be evident. This means that humans can continue to excrete the bacteria and subsequently spread it through poor handwashing and un-hygienic processing of food. Cooking food through properly (70°C for 2 minutes or higher; 82°C and rising in Scotland) is the only way to kill the bacteria.
3. Staphylococcus Aureus
Staphylococcus is a fast growing bacteria that can also produce toxins which can cause sickness. The bacteria is so common that about 25% of people carry it on their skin and hair and in their noses and throats. It becomes dangerous once the bacteria is passed to food and others through contact with the skin – in particular of those who have skin, nose or eye infections or breakages in the skin.
The bacteria is spread in particular through uncooked and handled food, such as sandwiches, salads, puddings and pastries. Unpasteurised milk and cheese products are also common sources of contamination. The most dangerous thing about this bacteria is that it is tolerant of both salt and a wide range of temperatures, from approximately 4 to 46°C. Although the cooking process can kill the bacteria relatively easily, the toxins it releases are far more resistant to cooking.
The illness is common but short-lived. Symptoms usually develop between 1 to 6 hours and can include vomiting, pain and diarrhoea.
Food handler tips: Food handlers can avoid the spread of this bacteria through adequate handwashing, observation of good personal hygiene, kitchen sanitation, strict storing procedures and protecting displayed food with sneeze screens.
4. Clostridium perfringens
Clostridium is commonly found in soil and in the intestinal tract of animals and humans. Uncooked meats, gravy, cured or pre-cooked foods can be contaminated with the bacteria, whose spores are harder to get rid of with high temperatures than the bacteria itself. The bacteria prefers to grow in conditions with little or no oxygen.
Once passed on the bacteria produce a toxin in the gut which can within 8 to 24 hours result in symptoms including nausea, pain and diarrhoea. It rarely causes vomiting or fever. The majority of outbreaks are associated with undercooked meats.
Food handler tips: Cooking and storing food at the right temperature is vital (below 5°C and above 63°C is acceptable), but spores can survive cooking and multiply if the food is inadequately chilled. So to avoid cases of this bacteria multiplying in your kitchen, temperature is the biggest thing to watch. Be especially vigilant with the cooking and simmering of stocks and gravies – follow the cook/chill rules and do not simmer overnight or for prolonged periods.
5. Clostridium Botulinum
This is a much rarer but also much more severe strand of the Clostridium bacteria which can contaminate and grow on food. Although more common in the home than in the commercial kitchen, there have been outbreaks in the past. The most common source of this bacteria is processed canned meat and vegetables, meat and fish.
Although rare, it is important to be aware of this bacteria. Once humans are infected with the bacteria it can produce nerve affecting toxins that can impact vision, cause paralysis and even be fatal.
Food handler tips: The most important thing to watch is use-by dates on your canned foods and to discard all swollen, gassy, or spoiled canned foods using a tightly closed double plastic bag.
Listeria is a bacteria that is carried by most animals and humans without harm if they are healthy. Similar to campylobacter and salmonella it is spread through the exposure of raw food or water to faecal matter and through the subsequent poor handling of contaminated food.
Listeria can be rapidly destroyed by heat at 75°C during cooking, but is most commonly transferred through soft cheeses, uncooked eggs, and some types of processed meats (eg cooked or sliced meats), smoked fish, cooked shellfish, soft mould-ripened cheeses, pate and pre-prepared sandwiches.
Although it is relatively uncommon to contract the bacteria, it can be extremely dangerous for pregnant women, those with weaker immune systems and the elderly. Contracting the bacteria can have varying results and can take approximately 30 days to develop. Some symptoms include fever, headaches, septicaemia, meningitis and miscarriage or damage to the foetus in pregnant women.
Food handler tips: Unlike most other bacteria, listeria continues to grow well (although slowly) in the 1-3°C temperature of a refrigerator. Ensuring food past their use by date is thrown away is one of the best ways to avoid the bacteria from becoming harmful although individuals at higher risk should avoid contact with these types of foods altogether.
7. E-Coli (Escherichia coli)
E-Coli is another bacteria that resides in human and animal intestinal tracts and spreads during the slaughter of infected animals when intestines and/or its contents are mixed with the rest of the meat that is processed. In particular this includes ground or mechanically tenderised meats (especially from cattle) but also unpasteurized milk, soft cheeses, and fruit and vegetables and unpasteurized juices that have been affected through contaminated water.
Most strains of E-Coli are harmless for humans but some strains, in particular E-Coli 0157:H7, can be extremely harmful. Just a few cells of the bacteria are necessary to infect someone. The worst strand could cause fever, bloody diarrhoea, kidney damage and even death. Other strands of e-coli can cause inflammation of the intestines, sickness and diarrhoea between 1 to 10 days after consuming contaminated food.
Food handler tips: The cooking process is the most important factor in ensuring the destruction of these bacteria – undercooked food leave you susceptible. In addition, the risk of cross-contamination must be minimised, which can be achieved by separate preparation and storage areas for raw product.
8. Bacillus Cereus
Bacillus Cereus is a bacteria which, although not as well-known as salmonella and campylobacter, can in fact dominate both of these bacteria. For this reason some strains actually are included in probiotic animal feed to reduce the number of salmonella bacteria in their digestive system and boost growth.
There are two strains of the Bacillus Cereus bacteria which can be harmful for humans. The vomiting version strikes within a few hours (1 to 5), whereas the diarrhoeal version’s symptoms tend to appear between 6 to 15 hours after consumption. On the whole this type of food poisoning is milder and short-lived.
Commonly this particular bacteria is found in foods in contact with soil (eg. cereals) as well as of vegetable origin. Rabbits, pigs, fowl, fish, unpasteurised milk, cheese, desserts, cooked rice, pasta and potatoes are also all possible sources of contamination.
Food handler tips: The bacteria’s toxins in particular are heat and salt resistant, meaning that they survive tough cooking conditions and quickly multiply when food is left to cool slowly for long numbers of hours. Besides cooking food to the required temperature, reheating rapidly and ensuring cross-contamination is prevented, storing cooked food in a wide and shallow container in the refrigerator is another way to prevent the bacteria from multiplying.
Shigella is a family of bacteria that, although less common, requires relatively fewer cells to be transferred for it to cause food poisoning. Similar to most other bacteria related to food poisoning, it is most easily transferred through food that has been in contact with faecal matter.
Most associated with the bacteria are foods that require handling but no further cooking (such as salads and sandwiches) as well as unwashed vegetables.
It usually takes 1 to 3 days before symptoms occur which can include cramping, fever, nausea, vomiting and diarrhoea containing blood or mucus. This usually lasts no more than a week, although bowl movements can continue to be affected for up to a month after. For those who fall in the high risk category Reiter’s Syndrome could be contracted which results in painful eyes, swelling of the joints and pain during urination.
Food handler tips: Proper sanitisation in the kitchen and personal hygiene, particularly through regular handwashing are the most important factors in avoiding the spreading of this bacteria.
10. Vibrio parahaemolyticus
Vibrio is another type of bacteria that is less well-known when it comes to food poisoning. It can be contracted through consumption but also through contact with open wounds or through swimming in contaminated water.
The most significant difference for this type of bacteria is that it is most commonly found in seafood, in particular oysters, clams and other shellfish, but also tuna, sardines, mackerel, squid and crab. It is also found in seawater contaminated by the faeces of infected sea creatures.
Although this type of food poisoning is rare, for those with stronger immune systems the symptoms usually occur 24 hours after the initial exposure to the bacteria and tend to be typical to food poisoning, explosive diarrhoea being the most noticeable symptom, and can last between 2 to 8 days. For those with weaker immune systems the symptoms can be far more severe and might include fever, septic shock and blistering skin wounds.
Food handler tips: Cooking fish well, avoiding cross contamination between cooked and raw fish and shellfish. Frying shucked shellfish at high temperatures is another important way to avoid this type of food poisoning (minimum of 191°C), boiling them for at least 5 minutes after opening or steaming them for 9 minutes after opening.
With this many types of bacteria threatening your kitchen it is really important to introduce overarching rules and procedures for cooking, storing and handling food. Training your staff in best practices is an obvious next step too. Violations could have serious consequences and for this reason alone food safety considerations should be at the forefront of every food handler’s mind. Due diligence to legal requirements is another huge reason to maintain appropriate food safety standards.
If you require any food hygiene and safety industry advice to, then our Food Safety experts can help guide you through this process. Get in touch today to book a free, no obligation consultation by calling 01279 620 866 or hitting the Get a Quote Now button at the top right of your screen!