THE ENVIRONMENTAL DISINFECTION


MEN AND MICROBES
What was the first contact? The illness or the taste a food product of a microbial transformation, eg. of wine or leavened bread. One thing is certain: when the first men began to inhabit the earth microbes were already there. Indeed, many think that they were the first inhabitants of the earth. We believe that even for the more conscious microbiologist to think to your body as the result of a symbiosis between him and a few billion of microbes it leads him to a "moment" of loss. Yet this is true. To talk about DISINFECTION we must
accept that the air that we breathe it is a mixture of gases and microbes, that the hand shake between two people it involves an exchange of microbes, as well as tap your phone or a computer keyboard. But also eating means to accept the fact of including in our body an elevated number of microbial entity. Why don’t we fall ill? Because most of the microbes are either useful or indifferent for us. Only few microbial species are potentially dangerous. So we must defend ourselves from them and only remember that our objective is not the infertility but a coherent hygienic level with the environment in which we operate: it is different to talk about a hospital ward, an office or a production structure part of the food chain.

WE LEARN TO KNOW THEM
Bacteria, protozoan, fungus and moulds, algae, viruses. It is very difficult to deal with this great universe to the point that their study is divided into specialized areas: eg. the protozoology (protozoan), the fitology (algae), the bacteriology (bacteria), the mycology (fungi) and virology (viruses), but from the functional point of view there is a medical, industrial, food, etc.. microbiology that the study of all the microorganisms that positively or negatively interact in the context of health, or in an industrial process, or in the food chain.
The man has always lived surrounded by microbes, but a little over 2 centuries he has direct consciousness of this situation. Since then he has started to classify them using more sophisticated techniques: in one extreme accuracy microbiologist begins his work growing bacteria collected in a certain environment. For example you put a jelly sterile on a surface: that gelatine contains all the elements to enhance growth of the great part of the microorganisms. The gelatine is present in a plate with a lid and, after inoculation, it is
placed in an environment where the temperature favours the growth of microbes. After 2 or 3 days on surface of the this you will notice the colonies mainly circular in shape.
The colour, the smell, the shape and the type of growth indicate to the eye of our trained biologist the membership of that colony to a group: "macroscopic" assessment possible with the naked eye. If the investigation requires further study, our expert collects a small fraction of any colony and proceeds to the growing of pure cultures: this technique is called "ISOLATION", after that he would proceed to microscopic observation, and through the identification of certain characteristics, he would take the appropriate considerations: a bit as the botanist with the flowers of a plant. In general, however, microscopic observation can not be separated from the assessment of physiological characteristics that allow to
investigate some biological characteristics mainly metabolic that enable the specialists examination of the case. Obviously the investigation can go far beyond and today they involve sophisticated techniques of bioengineering, but the details are beyond our current needs.

AN EXAMPLE OF COLOR
We believe interesting detail, although to a first approximation, a popular coloration technique that our readers have probably seen in the instructions for use of common antibiotics that provide: "it’s effective on bacteria both Gram negative and Gram positive." That phrase is generally found on data sheets of disinfectants. However, starting from our microbial colonies, the result of the reproduction of bacteria present on the surface and collected from our technical partnership with a sterile gelatine and "raised" in a special
thermostat for 48 hours at 27 ° C.
We collect our microbial materials with a metal tip made sterile on a flame and then cooled and let on a slide (a heat-resistant glass of about 2 cm to 5 thickness of 1.5 mm). We dilute the microbial mass in a drop of water and we let dry all on a flow of air lukewarm, then move the slide over a flame trying not to burn .... moreover, it is said that to become good microbiologists must burn at least 100 times.
a) We treat the preparation with crystal violet, that dyes the cells of blue and we rinse with water to remove excess of colour and then we let a drop of iodine solution length on a slide to make the colour insoluble in water;
b) If at this point we wash 2 or 3 times with the alcohol our preparation the cells of some bacterial species will be bleached;
c) observing with the microscope we see colourised cells in blue: the GRAM + or Gram-positive;
d) by adding on a slide the safranin the bacteria, that have not kept iodine, will colour of red, or at least pink: GRAM or Gram-negative;
e) at this point in the visual field of microscope you will have blue cells and red cells, which facilitates our job as apprentices or microbiologists such.

MORPHOLOGY
Mould with colonies of uniform grainy appearance of usually white colour, sometimes beige;the exudation are colourless. It’s a biserial aspergillum with conical mature spherical heads of diameter up to 200-300 microns. The conidiophores, high up to 500 microns, have a diameter of about 5 microns. I Conidiums are globy, not pigmented and they present a smooth, thin wall; their diameter is about 2.5 microns.

DIFFUSION
Are very common in nature, on vegetables in the final phase of deterioration. They are located frequently on mouldy grains and ensiled grain. They were also found on the surfaces of seasoned ham, salami, dried fish, dried fruit and bread and corn bran.

PATHOGENICITY
This species produces an active antibiotic against bacteria, the candidulina low toxicity for animals (LD50 subcutaneously for the rat: 250mg/kg) but also coic acid that plays an important role in certain food poisoning.

KEY CHARACTERISTICS
They can grow in the presence of low values of humidity and up to 550C of temperature.

CONTAMINATION’S METHOD
The development of the mould depends on the state of freshness of food and on the optimum temperature and humidity conditions.

PROPHILAXIS
The use of correct techniques of conservation does not allow the development of this mould.

HOW TO DEVELOP
The microbes, like any other living being, need a favouring environment to develop and
necessary nutrients. So temperature, pH, presence or absence of oxygen and humidity are the most important environmental parameters to facilitate or not the growth of "our friends / enemies microbes (see later because friends / enemies). The availability of a food substrate of protein rather than lipid kind with abundance or absence of simple or complex sugars promotes or less the growth of that microbial rather than another.

WHY FRIENDS?
Because without microbes, or at least not without some microbes we could live because they act positively on the great cycles of mineralization of organic matter and on the number of minerals substances. Because they allow us to digest some foods (think of the intestinal flora), because they put off to major food processing.

WHY ENEMIES?
Because certain species can cause disease, because they interact negatively on the processes of food processing and other vileness of this kind.

HOW TO POSITIVELY COHABIT WITH MICROBES
The answer is apparently simple: facilitating the growth of microbes "good" and trying to eliminate or at least disadvantage the development of those "bad". From a health point of view this is achieved through the creation of healthy environments, healthy lifestyles that enhance our defensive capabilities and, if necessary, with the use of antiseptics in the disinfections of wounds and of sulphonamides and antibiotics for "internal" infections; the topic deserves further study, but for us it may be sufficient. From the "industrial" point of view, in the larger sense of the word, the guidelines are similar: to create a hygienic environment coherent with what is done in that structure, to avoid the contact of the substances that are produced or processed with microbial pathogenic strains or that favour non-conforming transformations and, importantly and not easy, to prevent not desirable pollution of microbes that are "working for us" , see the delicate fermentation of wine or
bakery or dairy processing. Leaving the medical treatment or process to medical specialists, or technologists we put in shoes of environmental hygienists.

THE DISINFECTANTS
The vinegar used by "Good Samaritan" was in fact an antiseptic, in an era closer to our days the first phenolic compounds represented the first answer that the "chemical friends" put at the disposal of hygienists.
Nowadays the pharmacopoeia is very large and, in this respect, we allege summary table.
In general terms, to evaluate disinfectant you should read carefully the text of the label that remains in fact the official reference, but it is also important to investigate:
• the spectrum of action.
• the. concentration necessary to obtain the desired level of disinfection
• the. contact time
• the stage of contact, meaning by "stage" if the. disinfectant works in a gas phase or liquid (aqueous, hydro alcoholic or more) or dried, when the liquid film is dried.

Other important variables are represented by the temperature, the pH, the presence of organic substances and / or other chemicals such as detergents. Of course we should not forget the substrate on which it operates: some formulations are corrosive. We must also add that the disinfectant (similar to insecticides) can have a residual demolishing action, of course this involves different areas of applicability.

THE EQUIPMENT
The facilities are aerosolizators application, the ultra low volume (ULV), nebulizators, the atomizators, the micro sprayers and the sprayers. In addition, humectants instruments are used as fringes brooms, disposable rags and dusters. The distribution equipment depart from those indicated in the degree of chopping droplets in very high way until the sprayers that contrary they have a high wetting ability. As we will see below each system has specific use.

SYSTEMS OF INDIVIDUAL PROTECTION (SPI)
The operator must protect themselves from contact with the products used and to this end, depending on the type of application can be used suitable working clothes, footwear, headgear, goggles, gloves and masks that may be nose mouth with filters or even face masks or face helmets (such as astronaut) in case of micronization thrust (ULV) or, in contrast, can be sufficient good mask 'for powders, preferably activated carbon when a sprayer fitted with a fan nozzle is used.
Of course these are general guidelines and they should be "personalized" in relation to specific use and the disinfectant used.

THE APPLICATION TECHNIQUES
The application techniques need to optimize integration product / equipment in relation to purpose of carrying out the disinfection.

MORPHOLOGY
It’s a Gram positive stick, sporulated without cychromes and catalase. it’s a obliged anaerobic, or he develops only when there is no air: only the vegetative forms are sensitive to oxygen, while the spores survive.

DIFFUSION
It 's almost present everywhere, from sea to land and even in polar glaciers. Some, instead, consider it index of faecal contamination. It was found on various foods such as milk boiled and meat let cook for a long time to cool to room temperature.

PATHOGENICITY
From a medical point of view, this species is cause of gassy gangrene due to damage or tissue damage left; from food point of view it is known by the possibility of some types of C. perfrigens to lead intoxications that manifest with diarrhoea (fever and vomiting are absent).

KEY CHARACTERISTICS
Predominantly it has an saccaris and slightly proteic action.

METHOD OF CONTAMINATION
Mainly by thermal management and handling of food not properly executed.

PROPHILAXIS
Appropriate techniques for handling, cooling and storage of foods preserved by the contamination of this microbial species.

SURFACE AND AIR DISINFECTION
In this case you need an equipment capable of delivering very small particles that "float" for a long time in the air and that larger particles, that settling on the surfaces, disinfect them. The experts, choosing the right mix of droplets, can give more or less weight to the disinfection of surfaces and air as needed.

DISINFECTION OF THE AIR
For made this the droplets must be very small, in some cases less than 5 microns.
It’s important to emphasize that in this case we are dealing with a liquid so crumbled that it behaves as a gas with all the attention that this entails: protection of the respiratory tract, closure of locals, aeration before reuse, choice of disinfectant and vehicle to be used for the delivery, eg. glycols.

OTHER TYPES OF DISINFECTION
At these applications we can add, without details, gaseous ones, those of the pipes of liquid food, those of large areas with suitable equipment (eg. scrubber) and those with descaling effect with high pressure water jet for example for rubbish bins.

CONCLUSIONS
In the practice of disinfection is important to assess why you make it and what is the goal. Depending on this you choose product, the appropriate equipment, security and appropriate application techniques aimed at the needs. We would like to point out the opportunity to rotate the active ingredients to the scope not to select species or strains resistant or induce resistance in normally sensitive species. This practice is even less useful as you proceed to the quality-quantitative determination of results through the analysis of bacterial posts before and after.
It seems consistent to conclude by underline the fact that microbes are not seen, but they are everywhere with their cousins virus and that not all microbes are "bad." Hence the fact that before it is necessary to evaluate critically protocols enable speech that maybe asking an expert or our supplier of confidence.
At the disinfection’s origin it exists not only a necessity for survival of the species, often attacked violently, but also and above all, gradually with the social development of each civilization, the desire to live in a hygienically healthy environment. It is now beyond dispute that the techniques of disinfection carried out with chemicals, if used correctly and rationally, they represent a valuable and indispensable aid, able to effectively counter the spread of fierce and disguised enemies, but they also all agree that chemical disinfection is not the only possibility of "environmental sanitation". We need a real synergy between the cleaning and maintenance (even manic) of the environment and the use of appropriate chemical disinfectants because the sanitation of any environment is not a sporadic and
episodic fact, but represents a way of life. Ultimately, it is a matter of sensibility, of will, mentality and if you like, even of culture.

Precautions during disinfecting:
• to remove or storage in cabinets of paper materials, personal effects, tools, kitchenware
• to leave the disinfectant for about 1 hours.
• to rinse and thoroughly to clean. all surfaces
• to air environment (about 30 min.) before re-entry of persons.

Precautions during disinfecting:
• to move away all the animals.
• to clean. the stables and the environments
• treatment equipment.
• return of animals, after the disinfection of the clogs.