Inhibition and killing of micro organisms

Sterilization is a process by which an article, surface or medium is made free of all microorganisms either in vegetative or spore form. It is also defined as killing  all forms of life, including the most heat resistant  forms, i.e, bacterial spores. Sterilization was introduced and developed by renowned scientist Louis Pasteur (1822-1895). He is responsible for development of steam heat sterilization, hot air oven, autoclave, Pasteurization, etc.  Sterilization is essential in preparation of sterile pharmaceutical products. The aim of sterilization is to provide a product that is safe and eliminate the possibility of introducing microorganisms. It prevents the growth of diseases, spread of diseases and double surgeries. sterilization can be done by physical methods, chemical and physio-chemical methods.

                         Inhibition and killing of micro organisms

Definition of terms

Sterilization

This is the process by which all living cell, viable spres, viruses and viroids are either destroyed or removed from an object or habitat. A sterile object is totally free of viable micro-organisms, spores and other infectious agent. It can be physical, chemical or physio-chemial.

Disinfection

This is the killing, inhibition or removal of micreo-organism that may cause disease. The primary goal is to destroy potential pathogens and also reduces the total microbial population.

Disinfectant 

These are agents, usually chemical used to carry out disinfection and are normally used only on inanimate object. A disinfectant does not sterilize and object because spores and a few micro-organism may remain.

Sanitization

This is closely related to disinfection. In sanitization, the microbial population is reduced to levels that are considered safe by public health standard. The inanimate object is usually cleared as well partially disinfectors. For example, sanitizers are used to clean the kitchen utensils in the restaurant.

Antiseptics

These are chemical agents applied to tissues to prevent infections by killing or inhibition pathogen growth. They also reduce the total microbial population.

Properties of antiseptic or disinfectant

• Should be non toxic, non-allergenic, non irritative and non-corrosive
• Should not have bad odour
• Should not leave non-volatile residue or stain
• Efficacy should not be lost on reasonable dilution
• Should not be expensive and must be available easily

Germicides

This kills pathogen but not necessarily endospores.

Bactericide, fungicide, Algicide or Virucide kill pathogen

Bacterio Static

This do not kill, but do prevent growth, if this agent are removed, growth will resume