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Several months ago, I published a couple of posts that dealt with the path of water during its cycles, trying to explain what were the rules that were exploited by man or the earth we live in during precise atmospheric conditions. More than one year later, I'm going back to talking about water - and what I creatively defined under the tag #waterlovers - taking a particular case as a reference. I decided to take the opportunity of a very recent event that affected me and my council roommates.
A few days ago, in the municipality where I live, an ordinance was issued which recommended a ban on the use of drinking water distributed in homes. This is because some analyzes had found the presence of a bacterium, Clostridium Perfrigens, inside a cistern from which drinking water reaches our homes. Just to get an idea of what lies behind this phenomenon and to avoid future scaremongering, I decided to sift through the web here and there and collect information to try to give an explanation on why the presence of this bacterium is not a humanitarian tragedy but just an alarm bell. Let's start with an overview of this nice and smelly little animated thing.
C.Perfrigens is a gram-positive, anaerobic and sporogenous rod-shaped bacterium.
It is ubiquitous in nature and can be found as a normal component of decaying plants, in marine soils, in the intestinal tract of humans and other living beings (vertebrates, mainly, then insects), in water and soil. Relying on Wikipedia, only the desert soil is devoid of C.Perfrigens, unlike any other soil sample a person might want to examine.
It is defined as sporogenous because it is able to release spores, which is an inactive form of the bacterium that is very resistant to atmospheric conditions. This is the reason why large quantities of bacteria can reach the digestive tract of ordinary people: cooked contaminated foods - where the spores can resist - which are not consumed completely but left for hours/days at room temperature or not in the refrigerator; the spores are activated and the bacterium begins to reproduce; in doing so, the food subsequently ingested will be contaminated by a large dose of pathogens.
C.Perfrigens is one of the main responsible for the rotting processes of corpses, where it leads to the deterioration and production of elements in gaseous form.
A Clostridium Perfrigens infection works by releasing several main elements, all of which are categorized as EXOTOXINs. First, we see its type-II exotoxins, so classified because they act at the level of the cell membrane.
Molecule characterized as C phospholipase and as lecithinase; in fact, it degrades lecithin, component of the cell membrane. Precisely for this reason it completely destroys platelets, elements of the blood formed almost entirely by the cell membrane. Furthermore, the α-toxin leads to an increase in the permeability of capillaries and muscle cells - with the onset of edema in the affected areas;
A collagenase that degrades collagen, a fundamental component in the construction of muscle or connective tissues in general;
A hyaluronidase, which degrades part of those bonds that allow the cells to remain united to form a tissue.
Exotoxins are so-called because they are released from a starting element (in this case clostridium) to the outside, without being an integral part of it. They are distinguished from ENDOTOXINs because the latter represent structural components of the starting element (such as a virus or a microorganism) and are released following the destruction or modification of the element itself.
Clostridium Perfrigens acts - in second place - through type-III exotoxins (exotoxins that act by interfering with the functions of the host cell), in particular ENTEROTOXINs. Perfrigens enterotoxins bind to intestinal cells, setting in motion a chain of events that results in the loss of water and electrolytes that will end up in the intestinal tube.
Following the list of toxins listed above, we can identify 2 types of main manifestations of Clostridium Perfrigens infections:
1) Wound infections
which can then lead to different patterns and sustained by the first 3 exotoxins seen previously. Some diseases may involve internal organs following bacteremia (spread of the bacterium in the blood), others remain limited to the tissue surrounding the wound, even if of high severity. An example is GAS GANGRENE, also known as clostridium myonecrosis: this condition involves the necrosis of the cells and muscle tissues, associated with the formation of gas for which C.Perfrigens is responsible, through the massive fermentation of carbohydrates in which it stands out (in general, variable quantities of gas are produced in each fermentation process). This type of infection manages to reach the deep layers of the tissues, thanks to the characteristic of C.Perfrigens of being ANAEROBE: we define anaerobic microorganism as any microorganism that is able to survive in conditions of absence of oxygen. The deeper layers of our tissues, where oxygen is scarce if not absent, thus become a fertile ground for our little friend;
2) FOOD TOXINFECTION
The bacterium reaches the cells of the intestinal lumen and acts there by means of enterotoxins. This results in bouts of diarrhea and any resulting signs, symptoms or pathological findings associated with repeated bouts of diarrhea.
However, this type of enterotoxin can be broken down through the production of antibodies. Thanks to some studies, it has been noted how widespread antibodies against this toxin are actually, which is why infections are often subclinical, that is, unable to cause important symptoms such as to suggest a pathological finding of the disease. In short, many can meet C.Perfrigens, but few could actually get sick in the case of toxic infections.
Specifically, C.Perfrigens Gastroenteritis is a pathology that arises due to food contaminated with one of the variants of the bacterium, the A one. The first symptoms, sudden cramps, and diarrhea, appear 7-15 hours after ingestion of contaminated food (rarely, even 24-30 hours later). Resolution occurs spontaneously within 6-12-24 hours. Important to keep an eye on people already weakened. A severe form is instead caused by C-type C.Perfrigens. C-type causes a real gas gangrene operating on intestinal tissues: fortunately, these cases are very rare.
The therapy for simple cases is almost useless, if not supportive for excessive fluid loss. On the other hand, prophylaxis is more suitable: in the consumption of meat leftovers, these must be kept in the fridge and subsequently well heated (reaching the temperature you reached in the first cooking), so as to eliminate any bacteria that may have multiplied in the period between first cooking and last consumption.
image from the web, all rights reserved
Serious? Very serious? Terrible? Irremediable? No, none of this. So why a ban on the use of drinking water? Let's see the reasoning.
In our current water management system we have purification plants that take care of filtering the water that arrives in our homes, depriving them of all those elements that can represent a threat. Normally, the presence of C.Perfrigens may not be a problem, since a very large portion of the population is protected by specific antibodies against the toxins responsible for food poisoning: the danger of the presence of C.Perfrigens in the waters is not in fact that of incurring the infection of wounds, but rather to ingest it, to make it possible to bind to our intestinal cells and to get to the classic diarrhea attacks.
As we have said, C.Perfrigens is commonly found in the soil we step on, in various decaying organisms and in our intestines (therefore, even from everything that comes out of there .......). Finding C.Perfrigens in a tank dedicated to water that has already passed through the purification system could be a sign of an inefficient purification or of a system with connections that should not exist (for example, infiltrations from the outside due to small breakages in the cage containment of the cistern where the water rests).
In this perspective, the danger becomes evident: inside the tank from which the distribution starts, there could be MUCH MORE than we think. And I don't want to fall into the vulgar, but I assure you that on this occasion it would be appropriate to do so.
In these cases, just as happened in the municipality where I live, the consumption of water is reported as allowed only after boiling treatment, at 100°C and for 15 minutes. This leads to the cleaning of the water from bacteria and their possible toxins. However, it is strongly recommended to obtain supplies from other water distribution sources, at least for needs that require its ingestion.
You have understood? In most cases, the bacterium is not dangerous. Those who have been sourcing regularly from natural sources for some time will certainly have the antibodies necessary to protect themselves from enterotoxins. In the remaining cases, where it is not natural sources that lead the water to its final consumer but man-made sources of distribution, it is always good to avoid the use of water pending subsequent checks, without however falling into unjustified scaremongering resulting in imaginative theories and generators of unjustified anxieties.
I hope I was clear, even if the article went on quite a bit - it must be said -. With this one, I greet you and make an appointment for a new future post, hoping it will be not too far away.
Medicine Course Notes, G. di Bonaventura, Università Chieti-Pescara
Clostridium perfrigens: gastroenteriti da Clostridium, Dipartimento federale dell'interno DFI, Ufficio federale di veterinaria UFV, Confederazione Svizzera