Legionella is a major health problem in facilities with large/aging water
heating systems or cooling towers.
When bacterial cells are exposed to a sanitizers or disinfectant, various physical structures within the cell may sustain irreversible damage. The permanent loss of a bacterial cell’s capability to reproduce is commonly referred to microbial death. In the presence of germicides, some bacteria, may only be partially damaged. A surface which is swabbed immediately after sanitization can often provide false or negative results, indicating that effective sanitization had occurred. However, depending on the degree, partially inactivated bacteria have the capacity to “heal” or regenerate within 18 to 24 hours and become viable. Such an “apparently” clean and bacteria free surface will show the presence of high levels of bacterial contamination the following day and if left unchecked, can contaminate food products which may come into contact with the surface during the normal course of food processing.
The effectiveness of a specific germicide is a function of several factors, including the number and type of microorganisms which are present on the surface being sanitized.
Some of the factors requiring consideration are whether they are the easy to kill bacteria in their vegetative state or whether they are present on the surface as highly resistant spores. A major consideration that also needs to be addressed is whether other materials such as blood, feces or organic matter are are present within the bacterial environment. These contaminants reflecting an unclean surface, can rapidly inactivate some germicides, such as hypochlorites, rendering them ineffective for their intended use.
In general however, germicides exert their effect by either attacking a specific part of the bacterial cell, or causing damage to some of its components. Germicides can fall into three classifications, based on the their method ot bacterial attack.
- CELL MEMBRANE DESTRUCTION
Germicides such as sodium hypochlorite of peroxyacetic acid (PAA), are strong oxidizing agents and can cause total destruction of the cells membrane, resulting in vital bacterial components leaking out into their surrounding environment. This process results in a true microbial death.
- INHIBITION OF FOOD UPTAKE AND WASTE EXCRETION
Some germicides, such as the quaternary ammonium compounds (quats), have the capacity to attach themselves onto specific sites on the bacterial cell membrane. They do this by virtue of the fact that the quats carry a positive electrical charge in solution and are attracted to the negatively charged portions of the bacterial membrane. The end result is that quats block the uptake of nutrients into the cell and prevent the excretion of waste products which accumulate within their structure.
In effect, the cell is both starved and internally poisoned from the accumulated wastes.
- INACTIVATION OF CRITICAL ENZYMES
Biocides, such as phenolics, which exert their activity in this manner actually enter the cell and chemically react with certain key enzymes which support either cell growth or metabolic activities which supplies the bacteria with the energy needed for growth and multiplication. If inactivation is incomplete the injured bacteria can regenerate several hours later and recontaminate the surface.
ELECTROLYZED WATER: METHOD OF ACTION
It is presumed that viral infectivity is supressed, due to the denaturing and break down of the viral protein necessary for infection, though a reaction of that protein with two types of active oxygen present in the Water:
1.Electrolyzed Hypochlorous Acid (HOCL)
2.Hydroxyl radicals (OH)
It is widely believed that the bactericidal effect of Electrolyzed Water (HOCL-solution) against various strains of bacteria is due to the combined action of hydrogen ion concentration, oxidation-reduction-potential (ORP-reactions) and dissolved chlorine (HOCL).
First, ORP-reactions at the cell membrane damage the outer and inner membrane and inactivate the microbes defense mechanism. Then HOCL can penetrate the cell and oxidize it.
Hypochlorous Acid (HOCl, which is electrically neutral) and Hypochlorite Ions (OCl–, electrically negative) will form Free Available Chlorine (FAC) when bound together. This results in disinfection. Both substances have very distinctive behavior.
The cell wall of pathogenic microorganisms is negatively charged by nature. As such, the negatively charged Hypochlorite Ion (OCL-) can only penetrate it by the neutral Hypochlorous Acid (HOCL), rather than.
HOCL itself can penetrate slime layers, cell walls and protective layers of microorganisms and effectively kills pathogens as a result. With the aid of ORP-reaction, HOCL can even easier penetrate cell membranes. The microorganisms will either die or suffer from reproductive failures.
According to Dr. Cloete, the advantages of onsite generated HOCL has been confirmed, wherein the biocidal activity of HOCL generated onsite, is 300 times more active than Sodium Hypochlorite at the same concentration of free available chlorine. Additionally, a concentration of 2% HOCL achieved same results than 0,05% Gluterhaldehyde. Similarly, it has been shown that a 5% solution of Sodium Hypochlorite (only to be used as disinfectant) has equal results than 0.03% HOCL (which can be used as disinfectant and as sporicidal agent).
Thus, Electrolyzed Water (HOCL-Solutions) have been conclusively shown to exceed chemically derived equivalents both in low dosage effectiveness as well as physico-chemical purity.
Note: Ecasafe is not responsible for the content of external articles or content