bactericidal Activity Benchmarks

Bactericidal Activity Tests
Bactericidal Activity Tests

Disinfectants are surfaces that contain pathogenic microorganisms, or surfaces that are suspected of being present, or a number of chemical substances used for the means of transmission. The choice of disinfectant to be used depends on a number of factors, such as the type of microorganisms, the pollution of the environment, the structure of surfaces and tools, materials and materials, the chemical structure of the disinfectant, and of course the cost.

The first stage of the disinfectant tests is a pre-screening test whereby the concentration of the disinfectant and the minimum contact time with the microorganism are determined. In the second stage, an artificial environment is prepared in the laboratory and the disinfectant is brought into contact with the environment for a certain period of time. At the end of this period, live microorganisms are counted and the effect of the disinfectant is determined.

Tests used to measure disinfectant effectiveness are classified according to different criteria. For example, the classification according to test organisms is bactericidal tests, tuberculocidal tests, sporocidal tests, fungicidal tests and antiviral tests.

The classification according to the type of activity is as follows: bacteriostatic-bactericidal tests, tuberculostatic-tuberculocidal tests, sporistatic-sporicidal tests, fungustatic-fungicidal tests and virustatic-virusidal tests.

The strains recommended for antibacterial activity tests are:

  • Pseudomonas aeruginosa ATCC 15442 (a type of bacteria found in soil and water that breaks down glucose by oxidation but does not ferment)
  • Escherichia coli ATCC 10536 (shortly known as E. coli, a species of bacteria living in the large intestine of mammals)
  • Staphylococcus aureus ATCC 6538 (a type of bacterium that usually causes nosocomial infections)
  • Enterococcus hirae ATCC 10541 (usually bacterial species responsible for many infections)
  • Salmonella typhimurium ATCC 13311 (type of bacteria causing typhoid)

Strains are different subtypes of a bacterium or virus with genetic differences between them. Different strains may exhibit differences in resistance to external influences, drug resistance, and the like.

Bactericidal activity tests are also performed in accredited laboratories within the scope of disinfectant analyzes. These tests use standards published by various national and international organizations.

The main tests performed in this context are as follows:

  • Basic bactericidal activity test of disinfectants and antiseptics
  • Bactericidal activity test of disinfectants and antiseptics used in food, home and industry
  • Bactericidal activity test of disinfectants and antiseptics used in medicine
  • Bactericidal activity test of hygienic hand washing disinfectants and antiseptics
  • Bactericidal activity test of hygienic hand scrub disinfectants and antiseptics
  • Antimicrobial activity tests in disinfectants

Disinfectants and antiseptics are antimicrobial agents that are mainly used in hospitals and health care facilities, but also in households and in various industries, to maintain and maintain standard hygiene conditions and to eliminate harmful microorganisms that may present an infection. There are many factors affecting the microbial activity of these chemicals. For example, concentrations of active substances, pH values, bacteria, viruses, fungi or which microorganisms are more effective, recommended contact times and storage conditions are among these factors. Therefore, it is necessary to know their microbicidal activity before using these substances.

Quarterner ammonium compounds (QACs) exhibit bactericidal effect by acting on the cell membrane of bacteria. It can only have a preventive effect on mycobacteria and bacterial spores. The concentration of hydrogen peroxide is effective at different rates depending on the disinfection, sterilization or antisepsis process. This substance has a bactericidal effect but is used for disinfection as well as for sterilization purposes. Ethanol and isopropyl alcohol are the most widely used and fast acting antimicrobial substances in the world today. The potency of alcohols ranges from 60 to 90. These agents are effective against bacteria, viruses and fungi, including mycobacteria, but their effects against spores are discussed.

As can be seen, it is not correct to use disinfectants and antiseptics without knowing the effects and the compounds they contain.