Bacterias, definition


What are bacteria? They are microscopic living cells with a relatively simple structure; they are unicellular. Bacterial infections are contracted by respiratory and digestive tract or by inoculation by sting, scratch and cut. Bacteria in the ambient air come from two sources: aerosols generated by water such as humidifiers, air conditioners, cooling towers and dirty water, etc., and aerosols generated by humans or animals. Saprophytic and pathogenic bacteria are dispersed in the air by humans when sneezing, coughing and talking. These bacteria can survive for varying periods of time, depending on the size of the droplets, the temperature of the air, its relative humidity, and the presence of a substrate that allows it to travel.

It is usually accepted that the transmission of diseases from person to person can be done by exposure to an aerosol, but few people know that the bacteria carried by water, which are present in the outdoor environment, can multiply. These same bacteria can be hidden inside buildings and cause disease. Some types of bacteria are found in humidifiers of ventilation systems. They would then cause the syndrome called "humidifier fever". This syndrome is a response to airborne allergens that include endotoxins from a number of Gram-negative bacteria. Endotoxins can cause fever, leukocytosis, or leukopenia (a decrease in white blood cells) in humans. In addition, exposure of the epidermis to certain bacteria can cause skin diseases (dermatitis), etc.

Bacterias, sampling methods

Depending on the nature of the specific needs of each situation and the time available to obtain the results provided by the laboratory, here are the different sampling methods used by AIRTESTS in the search for indoor environmental contaminants:


Method 1 Bacteria in the air sampling by Bio Impaction Andersen. Bacteria suspended in the air The parameters obtained by these samples are the enumeration, the Gram stain with the advanced search option and the species identification. Bacteria and microbiological readings of the air are taken after sampling with an Andersen impactor. Through the impaction process, the air enters the impactor from above the unit and the microorganisms are separated and stored in appropriate culture medium by the impaction force. For the bacteria, two petri culture media are used simultaneously, namely MacConkey and TSA 100. The samples are stored at 4 °C. The results of the laboratory analyzes are given in CFU/m3 (colony forming unit/cubic meter of air). The interpretation of the data is done by comparing volumetric results between indoor and outdoor air. Bacterial concentration should be lower indoors than outdoors for enumeration or have similar profiles when the indoor environment is healthy. The sampling techniques apply to viable bacteria only (relative to growth in incubator).

AIRTESTS has adopted a research protocol which by default consists of a combination of Gram staining count and classification. In principle, the enumeration will indicate whether or not the area being tested is contaminated, Gram stain will indicate whether the family of bacteria belongs to either the Gram + or Gram - family. Example of bacteria of the Gram (+) family such as Staphylococcus, Streptococcus, Enterococcus ... Example of bacteria of the Gram (-) family such as Escherichia Coli, Enterobacter, Salmonella ... If it is relevant in the process for further investigation, we will choose to push the search to identify 2 to 3 dominant colonies that have been cultured on the agar that has been previously incubated.

Air - Bacteria (BHAA) Our basic research protocol will include the following steps: Enumeration of BHAA (Gram Negative) on MacConkey Agar Enumeration of BHAA on TSA Agar 100 Gram Stain Classification Our Search Option Protocol Advanced will include this additional step: Identification of 2 to 3 dominant bacterial species per culture medium

Method 2 Surface Bacteria from Swab-Type Matrix sampling

Viable Surface Bacteria - The parameters that can be obtained by these samples are enumeration, Gram staining and species identification. A sample of surface contaminants for microbiological analyzes is collected using a swab specifically designed for the collection and transport of microorganisms. This method of sampling is defined by the term "smear-contact". An area of 100 cm2 (10cmx10cm) or 25 cm2 (5cmx5cm) will be selected according to the most appropriate situation, will be sampled with a swab to obtain the results in CFU/cm2. Sampling applies to viable bacteria only. These samples are usually taken inside the ducts or on the ventilation grills and on any other surfaces of suspect appearance. The enumeration is the basic step, it will indicate if the evaluated area is contaminated or not. The Gram stain, the next research step, will indicate the family of bacteria belonging to either Gram-positive or Gram-negative bacteria. Example of bacteria of the Gram (+) family such as Staphylococcus, Streptococcus, Enterococcus ... Example of bacteria of the Gram (-) family such as Escherichia Coli, Enterobacter, Salmonella ... The third and last stage of research consists in retaining 1 , 2 or 3 dominant colonies observed during selection for Gram staining and identification. One of the advantages of species identification is that the knowledge provided will make it easier to choose the appropriate biocide for eradication.

Bacteria, sewer backflow


Regardless of the source of water infiltration, it must be taking seriously and quickly. It is important to quickly clean and dry materials after infiltration. Sometimes, it is necessary to proceed to the removal of the damaged materials. This is even more important when it comes to sewer backup since the water can contain feces and therefore bacteria. Contaminated wood and gypsum must be discarded. Other surfaces must be disinfected. It is also necessary to repair the problem to prevent the water continues to seep into the home. Air and surface quality tests will help to better understand the environmental impact of the problem.

There are three (3) categories (status classification) of water and the extent of the problem depends on it.

Clear water: This is a called clean water that can come from a broken supply pipe, a bath or a sink that overflows.
Gray water: This water may contain bacteria. It comes from the return of the washer, a toilet where there is urine or a dishwasher.
Black water: it is a water contaminated by micro-organisms (viruses, bacteria and molds). It is unhealthy and can cause significant health problems. It comes, among other things, from sewer backups.

Bacterias, seasonal flood


Every spring, some homes are at risk of seasonal flooding. Flood waters can be contaminated by sewage or other pollutants. They can therefore be harmful to the health of the occupants. Before proceeding with the major cleaning, it is necessary to avoid all risks of infection which can represent the dirty water, the microbes, the particles of the soil, the residues of the chemicals ... To do this, it will be necessary that the individuals carry the recommended protection material.

If the house has a well, it is important to have the water tested before consumption. Ideally, all household items that have been damaged by the flood should be discarded.

As for the house, you have to ventilate it and/or dehumidify it to dry completely. The speed with which water will be removed most quickly will limit the formation of mold. It will rinse and clean all floors as quickly as possible. Floor coverings must be discarded and replaced. Carpets should be discarded or dry and cleaned by a professional. If the furniture has mud and is simply damp, cleaning once dried may be sufficient. If not, throw them away. All insulation materials, particle board furniture, mattresses, box springs, fabric toys, ears, cushions, furniture coverings ... It will be necessary to be attentive to the characteristic odor which demonstrates the presence of microbes.

Bacteria in the air from air conditioners


Air conditioning devices can harbor viruses, bacteria or molds. When this is the case, respiratory infections can occur in the occupants. Legionellosis is a serious, rare lung disease that can be life-threatening. Legionella pneumophila is responsible for this infection. This bacteria proliferates easily in the presence of slightly heated and stagnant water. Some air conditioners use a circuit system cooled with water. The bacterium multiplies and found in the air. Individuals can become infected by breathing droplets of contaminated water. This disease is called the "legionnaire's disease". His name comes from the circumstances of his discovery. In 1976, 200 delegates attending an American Legion convention in Philadelphia fell ill. Health authorities concluded that the respiratory infection came from the hotel's air-conditioning system, which was contaminated with the bacteria.

The bacteria can grow when all conditions are met. They can colonize poorly maintained or defective wetlands. In systems with stagnant water that does not exceed 50 degrees Celsius. The most vulnerable facilities are water distribution systems, hot water tanks, cooling towers, humidifiers, air conditioning systems, whirlpools, spas, shower heads, swimming pools, fountains, etc. The bacterium is found in the water droplets generated by the devices. They can then find themselves in the air and get into the ventilation system. The bacteria is then found all around the building.

The proper maintenance of circuits and facilities is important to prevent the proliferation of the bacteria. Regular cleaning and disinfection of air conditioning and humidification systems is important.

Bacteria from domestic animals


Some diseases can be transmitted by our pets. Infection is transmitted by a bite, scratch or skin contact with mucous membranes, saliva or excrement from a contaminated animal. The risk of infection varies from pet, age and general health. Adult dogs and cats are generally less parasitized than young ones. Reptiles and amphibians can indirectly contaminate you when you touch an area contaminated with faeces.

More than 70 sources of diseases can be transmitted by all domestic animals (cats, dogs, guinea pigs, parakeets ...): Bacterial (salmonella, campylobacter, etc.) Fungal (ringworm, dermatophytes, etc.) Parasitic (fleas, worms, etc.) Viral pathogen (rabies, etc.)

Animal-borne infections (zoonosis) are low, especially in healthy individuals. However, caution should be exercised and special precautions should be taken by certain individuals (pregnant women, children under 5 years of age, adults over 65 or immune suppressed).

Here are the main tips to prevent the transmission of disease from animals to humans:

  • Wash hands after contact with an animal;
  • Pay more attention with young animals and with exotic species (reptiles, rodents, hedgehogs, birds ...) since they are more at risk of transmitting diseases;
  • Clean the environment of exotic species regularly;
  • Regularly clean the cage, toys and bed of an animal;
  • Collect faeces and urine from cats in bedding daily;
  • Immediately pick up the stool from your dog;
  • Cover the sandbox outside;
  • Protect your garden, wash your hands well after gardening and wash your fruits and vegetables well before consuming them;
  • Watch out for Easter farms in shopping centers;
  • Avoid raw meat in the diet of your dog or cat (otherwise be careful in the daily management of their diet);
  • Do not let your pet drink in a puddle outside or in your bowl;
  • Avoid contact with unknown animals;
  • Regularly cut the claws of your pet;
  • Quickly clean up any wounds by an animal;
  • Ensure good dental health of your pet;
  • Wear gloves to collect urine, stool or vomit from your pet;
  • Carry out tests for your pet when a suppressed immune person lives with an animal;
  • Ideally adopt an adult animal when a person at risk is present in the family;
  • Choose an animal suitable for your family (exotic animals are not recommended for children under 5);
  • Never leave a child under 3 years of age in contact with a reptile;
  • Never leave a young child unattended with an exotic animal;
  • To teach the hygiene rules in children;
  • Vacuum regularly and wash regularly floors.
  • Cases of pet-borne disease are few and generally not serious for healthy people.

Bacteria from undesirable animals and insects


The rat. The rat, like the mouse, can transmit diseases to humans. It can also cause many problems in a home. Like the mouse, his teeth grow constantly and he must gnaw to reduce the length. Rats dig burrows that can destabilize the foundation of a building and even cause a collapse of the structure. When they enter a house, they can attack furniture, cables, ceilings ... By their presence, they can contaminate certain surfaces with their urine and stool that are contaminated. The rat has been associated with the plague in the past, today it is also known for the transmission of certain diseases:

  • Salmonellosis;
  • Leptospirosis;
  • Rabies;
  • The solitary worm;
  • Typhus;
  • E. Coli;

The rat can also carry fleas, mites and ticks.

The mice. The mouse carries bacteria, viruses and parasites. They can affect the health of humans and pets by transmitting diseases through their urine, saliva and excrement.

The teeth of the mice grow continuously, they must gnaw to shorten them. When they find themselves in a house, they can eat furniture, insulation materials and electrical cables. Cable gouging can cause short circuits and in the worst case fires.

Roaches (cockroaches)

Cockroaches (cockroaches) are harmful insects and can be dangerous for human health. They are found mainly in kitchens. They defile worktops, appliances, spaces around ovens and dishwashers, dishes and foodstuffs by direct contact with their excrement. Feces, molts and saliva can cause allergies, eczema and asthma in the occupants. Young children, old people or those who are sick are more at risk.

Here is the list of the main diseases transmitted by cockroaches:

  • Salmonellosis;
  • Diphtheria;
  • Typhoid fever;
  • Tuberculosis;
  • Hepatitis;