Presentation of the bacterium
The Clostridium perfringens it is a bacterium protagonist of numerous food poisonings; to speak more specifically, the enterotoxins produced by Clostridium perfringens can trigger a food poisoning - normally not dangerous - after ingestion of contaminated food. The pathogen, after an incubation time ranging from 8 to 16 hours from the intake of the infected food, triggers typically gastrointestinal symptoms (diarrhea and abdominal cramps ): for this reason, we speak of enteritis from Clostridium perfringens, an intestinal inflammation that tends to resolve itself in a few hours. Before analyzing the details of the infection triggered by this pathogen, let's examine its general microbiological characteristics.
Microbiological description
The Clostridium perfringens, like all the other bacteria belonging to the same category, it has a rod shape, it is a flagellated microorganism, therefore mobile, and only rarely capsulated; to complete the general description, the bacterium is sporogenous and anaerobic (it lives in the absence of oxygen). Bacteria of the species Clostridium perfringens they are able to reduce sulphites to sulphides, and produce spores stable in the environment and heat resistant.
Some strains of Clostridium perfringens (NOT spores) are particularly sensitive to temperatures, unlike others, which tend to withstand the action of heat; the spores - let us remember again - are almost always thermostable (heat resistant).
Clostridium perfringens in nature
Clostridium perfringens it is almost ubiquitous in nature; it is found in decaying plants, in the intestines of mammals and vertebrates, in insects and in the vast majority of soil. It is estimated that in human feces the bacillus is present in concentrations ranging between 102 and 107 CFU / g (where UFC stands for Colony Forming Units); high levels of Clostridium perfringens they are also found in the faeces of pigs and dogs, while in other warm-blooded animals the presence of the bacterium is minimal or even absent. It is estimated that the concentrations of this bacterium in the wastewater are around 105 UFC / ml; however, modern water purification systems make it possible to reduce the bacterial load by 95-98%.
For the qualitative evaluation of foods, the determination of Clostridium perfringens it is certainly a parameter not to be underestimated. The detection of the bacterial load in water intended for consumption, for example, indicates both the organoleptic / microbiological quality of the food and the efficiency of the purification treatment to which the water has been subjected.
Food poisoning
As previously mentioned, Clostridium perfringens it is one of the major causes of food poisoning, therefore of food poisoning. With heat treatment, Clostridium perfringens and many other bacteria succumb, but not their enterotoxins which, remaining unaltered, create gastrointestinal damage in humans.
METHOD OF TRANSMISSION: Infection with Clostridium perfringens it is transmitted to humans through the ingestion of contaminated food, especially meat, poultry and processed fish. Following preparation, if the food remains at room temperature for a long time, the spores, producing toxins, can give rise to new vegetative forms: precisely, immediately after ingestion, the spores germinate in the digestive tract of the host, synthesizing a new toxin. The effects of the toxin originating inside the organism, added to those of the preformed toxin (inside the food) trigger the toxic infection from Clostridium perfringens.
Please Note:
- Cooking the food → the heat-resistant spores survive and are in a status of anaerobiosis (consequence of the thermal action)
- Subsequent storage of the food at a temperature of 106 clostridia / gram) → manifestation of symptoms of Clostridium perfringens
Symptoms of Toxic Infection
8-16 hours after ingestion of food contaminated with Clostridium perfringens, the subject begins to complain of typically gastrointestinal symptoms, such as abdominal cramps and profuse diarrhea, sometimes associated with fever and vomiting. The prodromes usually resolve without the need for treatment within 24 hours.
The prognosis is good in the vast majority of cases, and the treatment is purely symptomatic; many patients do not need any medication, since pathogens and toxins are easily eradicated in a few hours.
Only rarely does the Clostridium perfringens causes serious complications in humans; however, it appears that a strain of this bacterium (Clostridium perfringens of type C ) is responsible for a severe form of intestinal inflammation, known as necrotizing enteritis. Complications are an expression of the production of beta-toxin, produced exclusively by Clostridium perfringens type C, potentially capable of developing ulcers, fulminant toxemia, dehydration, shock and death.
Prevent food poisoning
NOT negligible risk factors: the slow cooling of the food, after cooking, is a critical element that promotes the disease → The heat reduction, immediately after cooking (or pre-cooking) of the food to be preserved, is a fundamental preventive form for avoid food contamination. This very important preventive practice must always be respected, especially in canteens, as these are places where food is often prepared many hours before actual consumption.
The scrupulous compliance with the rules of food handling and storage - therefore the development of what is described in detail in the HACCP model - minimizes the risk of developing food poisoning, including that triggered by Clostridium perfringens.
