First of all, to summarize simply, if a food is detected to have an excessive coliform flora, it basically proves that it is contaminated with feces. manure! Whether it's human or animal dung, in short... You know! So, whether or not it ends up with a pathogenic outcome, it's an unqualified food.
Coliform bacteria
Today first understand the coliform, coliform is not a bacteriological classification name, but a term in the field of hygienic bacteria, it does not represent a certain or a genus of bacteria, it is generally believed that the bacteria can include Escherichia coli, citric acid bacillus, klebsiella aerogenes and enterobacter gusouli and the like.
1. The coliform flora is widely distributed and widely present in the feces of warm-blooded animals and in nature. Survey studies have shown that coliform bacteria are mostly found in the feces of warm-blooded animals, places where humans are often active, and places where fecal contamination is present.
2. Coliform bacteria are proposed as fecal pollution indicator bacteria, mainly based on the detection of the microflora to indicate whether there is fecal pollution in food. The number of coliform bacteria indicates the degree of fecal contamination and also reflects the size of the harm to human health. In addition to the general normal bacteria in the feces, there will also be some intestinal pathogenic bacteria (such as Salmonella, Shigella, etc.), so there is fecal contamination in the food, consumers eat food with excessive microorganisms, it is easy to suffer from intestinal diseases such as dysentery, which may cause vomiting, diarrhea and other symptoms, endangering human health and safety. The coliform bacteria exceeding the standard will also cause diarrhea, gastrointestinal infections and so on.
colibacillus
The E. coli we are mainly discussing today is only a small class within the coli flora, Escherichia coli, also known as Escherichia coli, which is a normal hermit bacterium in the intestines of animals, most of which are harmless in the normal state, and a small part of which may cause disease under certain conditions.
Enterohemorrhagic E. coli (EHEC) is a subtype of E. coli, classified as an O antigen, the main pathogenic strain is O157:H7, which can cause infectious diarrhea, named after the hemorrhagic enteritis that can cause human hemorrhagic enteritis. (The most pathogenic also includes O104:H4, O26:H11, etc.).
Today we give an example of two of these "bad deeds":
1、O157：H7（Enterohemorrhagic E. coli, EHEC）
2、O104：H4(Shiga toxin-producing E.coli）
1
O157：H7
In 2018, there was an outbreak of E. coli O157:H7 in many states in the United States, and 121 people in at least 25 states were infected, of which 52 were hospitalized, 14 had hemolytic uremic syndrome, and 1 died. The U.S. Centers for Disease Control and Prevention (CDC) issued a statement saying the outbreak may have been caused by romaine Lettuce.
In 1982, O157:H7 contaminated beef burgers in the United States, "creating" the famous "beef burger poisoning incident";
In 1996, O157:H7 was in Japan, causing more than 9,000 infections;
2
O104：H4
E. coli O104:H4 can be counted as a "sibling" of the aforementioned enterohaemorrhagic E. coli O157:H7, which causes disease and is similar to the mode of transmission.
In May 2011, E. coli O104:H4 "manufactured" the epidemic through sprouts in Germany, which spread to 13 other countries in the European Union, the United States, Canada and other places, causing more than 4,000 infections. The results of experimental studies showed that this outbreak was caused by Shiga toxin-producing E. coli O104:H4 type E. coli. Subsequently, German authorities tested the same strain of sprouts obtained from the infected patient's home. A follow-up survey by the European Centre for Disease Control and Prevention and the European Food Safety Authority suggests that fenugreek seeds from Egypt may be the source of intestinal haemorrhagic E. coli outbreaks in Germany and France.
disseminate
- Enterohaemorrhagic E. coli is mainly transmitted through contaminated food.
- Enterohaemorrhagic E. coli is commonly found in the intestines and excrement of ruminants such as cattle and sheep. That is, food or water is directly or indirectly contaminated with ruminant faeces, and then infected by eating undercooked food, drinking contaminated water, handling contaminated food or contact with infected animals, a very small amount of enterohaemorrhagic E. coli is enough to cause human infection.
- In past outbreaks of foodborne illness caused by the consumption of food contaminated with enterohaemorrhagic E. coli, the foods involved included uncooked beef and other meats, unpasteurized milk, a variety of fresh vegetables (such as yellow, sprouts, spinach and lettuce), unpasteurized juices and cheeses.
- According to the European Food Safety Agency, there has been an increase in the scientific literature documenting outbreaks of Shiga toxin-producing Escherichia coli related to vegetables, particularly contaminated germinated seeds and leafy green vegetable salads.
- In addition to the above-mentioned sources related to food or food animals, water from lakes, ponds, paddling pools and swimming pools, as well as direct contact with goats, sheep or other ruminants in zoos, has been reported to have been the source of previous outbreaks of E. coli.
- If an infected person does not pay attention to hygiene, such as not washing their hands after going to the toilet and/or before handling food, they may pass on the germs to others.
characteristic
1. The toxins produced by Intestinal Hemorrhagic Escherichia coli are called Shiga-like toxins or Shiga-like toxins because they are similar to the toxins produced by Shigella dysentery.
2. Temperature Intestinal hemorrhagic Escherichia coli can grow at a temperature of 7 °C-50 °C, and its optimal growth temperature is 37 °C. Low temperature resistance, can survive in the refrigerator for a long time; in the water of nature can survive for weeks to months, not heat-resistant, 75 ° C 1 minute to be inactivated;
3. pH Some hemorrhagic E. coli can be grown in foods with a pH of 4.4 and a minimum water activity (Aw) of 0.95. O157:H7 has strong acid resistance, pH 2.5-3.0, 37 °C can withstand 5 hours;
4. Sensitive to chlorine can be killed by the residual chlorine concentration of 1mg/L.
Pathogenic
1. Toxin (VT), also known as Shiga-like toxin (SLT), is the main pathogenic factor of intestinal hemorrhagic E. coli.
2. The infection dose of E. coli O157:H7 is extremely low. The incubation period is 3-10 days and the course of the disease is 2-9 days. Usually sudden onset of severe abdominal pain and watery diarrhea, bleeding diarrhea after a few days, fever or no fever, some patients may develop hemolytic uremic syndrome, thrombotic thrombocytopenic purpura, etc., severe cases can lead to death.
What should a baker do?
Because the body itself is heat-processed, it is easier to prevent E. coli in the bakery, but if the bread set is made with vegetable salad, and the secondary processing products such as sandwiches and hamburgers are still not taken lightly.
1. Wash your hands with soap before handling food and after going to the toilet.
2. Ground beef and burger meat should be thoroughly cooked until the temperature of the central part reaches 70 degrees Celsius or above for at least 2 minutes.
3. Ready-to-eat fresh fruits and vegetables, especially pre-cut fruits and fresh leafy vegetables for salads, should be stored at a temperature of 4 degrees Celsius or below.
4. If you have or suspect infection with infectious diseases or signs, such as diarrhea, vomiting and fever, you should stop handling food.
5. Thoroughly wash the fruits and vegetables that make salads, sandwiches, and burger ingredients.
6. Clean the countertop with chlorine-containing disinfectant every day, and soak the chlorine-containing disinfectant in boiling water and boil the towel.
7, do not contact the baked bread with bare hands, package the bread in time after it is cooled, pay attention to the use of food-grade packaging materials when packaging, wear food-grade gloves when packaging, disinfect hands with alcohol and tools and packaging tables that touch bread.
The above content is thrown out of bricks, there may be incomplete accuracy, or there will be more good food safety operation methods and processes, welcome to leave a message, welcome to discuss together.