Microbiology, Sterilization & Sanitization PDF

 Microbiology  Science that deals with the study of micro- organisms.  Different forms of micro- organisms are:  Bacteria  Virus  Fungi  Bacteria  Study is known as Bacteriology  Minute, single celled micro- organisms...

 Microbiology  Science that deals with the study of micro- organisms.  Different forms of micro- organisms are:  Bacteria  Virus  Fungi  Bacteria  Study is known as Bacteriology  Minute, single celled micro- organisms  Can be seen with the help of microscope  Also known as germs or microbes.  Exist almost everywhere, particularly on the skin of the body, in water, air, and decayed matter.  Two types of bacteria:  Pathogenic Bacteria (Harmful)  Non – pathogenic bacteria (Harmless)  Bacteria  Non- pathogenic  Constitute the majority of all bacteria  Perform many useful functions - decomposing and improving the fertility of the soil.  Saprophytes belongs to this group  They live on deal matter but don not produce disease. Pathogenic  Organisms in the minority  Cause considerable damage when they invade plant or animal tissues.  Harmful because they produce disease.  Parasites belongs to this group which require living matter for their growth.  Main Groups of Microorganism  Saprophytes: Lives on dead material  Parasites: Lives on living material  Host: Person or animal on whom the micro-organism live  Commensals: Organisms live in harmony with their host and do not cause any problems.  Pathogenic micro-organisms: Responsible for causing diseases.  True pathogens: Causes diseases  Opportunistic pathogens: Do not cause disease but only in certain circumstances. Classification of Pathogenic Bacteria  Have distinct shapes that help to identify them.  Classified as follows:  Cocci - Round-shaped bacteria  Bacilli – Rod shaped bacteria  Spirilla - Spiral or corkscrew-shaped bacteria  Cocci  Round-shaped bacteria that appear singly or in the following groups. Staphylococci  Pus-forming bacteria that grow in clusters  They cause abscesses, pustules, and boils. Diplococci  Grow in pairs  Causes diseases such as pneumonia Streptococci  Singular - Streptococcus  Grow in chains and are found in blood poisoning.  Bacilli  Short rod-shaped bacteria.  Most common bacteria  Produce diseases such as tetanus, typhoid fever , tuberculosis (growth of nodules in the tissues, especially the lungs)  Spirilla  Spiral or corkscrew-shaped bacteria.  Subdivided into subgroups  Treponema papillida - causes syphilis, a sexually transmitted disease (STD)  Borrelia burgdorferi - causes Lyme disease.(an illness that is spread by bites from ticks infected by the bacterium. Can affect the skin, joints, heart, and the nervous system). Defence Mechanism against Micro- organisms  Ability to cause disease is based on the host Defence mechanism.  Skin is the first line of defense.  Acid Mantle acts as a hindrance to micro-organisms  Below the skin surface is second line of defence i.e. the immune system. Conditions reducing Host Defence  Breaks in the skin surface  Excessively dry skin  Very moist skin  Prolonged change of skin pH from acid to alkaline.  Reduced immune system  Basic Structure of Bacteria  Cell wall surrounding cytoplasmic membrane.  Membrane encloses cytoplasm which doesn't contain most organelles and a nucleus.  DNA forms a coiled structure called Nucleoid.  Many bacteria have a tail like structure called flagilum which assist with movement.  Different Forms of Bacteria  Active form (vegetative form)  Dormant form (spore form)  Spore forms are very important from the point of view of sterilization  In this form the bacteria can survive through long periods of starvation, heat, draught and other adverse environmental condition.  More difficult to destroy and are resistant to drying, heating and chemical disinfectants.  Not all bacteria are capable of producing spores  Few of bacteria that cause skin diseases produce spore. Eg- Tetanus and Gangrene Factors affecting Bacterial Survival Oxygen and Carbon-dioxide  Aerobic bacteria require the oxygen to survive.  Anaerobic bacteria do not require oxygen for their survival.  Presence of O2 very often destroys anaerobic bacteria.  Small amount of CO2 is essential for survival of all bacteria. Temperature  The optimum temperature is at which growth is most rapid.  Parasitic bacteria have an optimum temperature of 37°c.  That live on soil & water grow temperature between 20°c & -7°c.  Third group thrives between temperature of 55°c and 80°c.  Use of heat and cold below the range of specific organism is an important method of bacterial destruction. Factors affecting Bacterial Survival Moisture and desiccation  Desiccation is the state or process of extreme drying.  Bulk of bacteria consist of water  Drying is injurious to many bacteria while some bacteria are very susceptible to drying,  Staphylococcus can survive drying for weeks.  Spore form survives for months or year.  Susceptibility to drying from the process of sterilization called LYO-FILIZATION (freeze drying).  Product is maintained in a sealed glass at room temperature. Factors affecting Bacterial Survival pH – Potential of Hydrogen  Bacteria’s are neutral or slightly alkaline.  Strong acids or alkalis thus destroy them. Light  Most bacteria favour darkness for growth.  Sunlight and ultra-violet rays are used to destroy bacteria. Nutrition  Bacteria require nutrient to survive.  Some uses inorganic matter, others dead organic matter and still other on living organic matter.  Spore forms can survive in dormant state without nutrients for many months.  Viruses  Smallest organisms  Study is known as virology  Not visual under micro-scope , compared with nucleus of a cell.  Can’t carry on a free life of its own only exist within another cell.  True parasites, living and growing within the living cells of an host.  Host may be plant, animal or bacteria.  Focus on only one particular kind of host & particular kind of tissue.  Fungi  Study is called Mycology  Part of the plant world.  Different from plant as they do not contain chlorophyll & are not capable of photosynthesis.  Depend on the tissue on which they exist for growth.  The fungi consist of 2 parts :-  Vegetative part consisting of filaments. Part of the fungus that acquires foods.  Reproductive part (spore) is a mass of protoplasm enclosed in a wall.  Animal Parasites  Organism that live or feed on living tissue.  Belongs to animal kingdom which lives on human skin.  Not truly micro-organism as they are fairly large and can often be seen by the naked eye.  Parasitic diseases commonly produce skin rashes.  Associated with poor public hygiene and health. Hygiene, Sterilization & Sanitization Difference between Sanitization and Sterilization Sanitization Sterilization Attempt to keep the area germ Process of destroying any micro- free organisms May not kill all the micro- 100% destruction of micro- organisms organisms Uses antimicrobial agents to Uses chemicals, temperature, reduce the number of disease- gas and/or pressure to kill all causing organisms disease-causing organism Does not affect some spores and Affects bacteria, spores, fungi viruses and viruses  Sanitization Sterilization Methods of Sterilization & Sanitization  There are different methods of sterilization and sanitization  Main categories are:  Heat  UV Light and Gamma Rays  Chemical  Fumigation Cabinet  Methods of Sterilization Heat - Moist (steam) heat or DRY heat Moist heat  Implements are placed in boiling water for up to 20 minutes.  Not very suitable for salons as temperature of 100C may damage many items. Steam heat  Steam under pressure is used as sterilization.  Autoclave has ability to kill all harmful bacteria and viruses, especially AIDS and HEPATITIS B.  Autoclave  Considered to be the most ideal method of sterilization  Has the ability to destroy all microorganisms including the spores.  Boiling point of water is increased above normal atmospheric pressure.  The pressure increase can be obtained by preventing steam escape from Autoclave  Having weight over the steam outlet controls the pressure build-up.  Recommended time and temperature to use autoclave for sterilization:  121C - 15 mins  126C - 10 mins  134 C – 3 mins  Methods of Sterilization Dry Heat  Baking in hot air oven.  One of the earliest forms of sterilization practiced. Utilizes hot air that is either free from water vapor, or has very little of it.  Instruments should be dry before sterilization  Destroys microorganisms by causing coagulation of proteins.  Dry Heat- minimum time and temperature for sterilization:  160C – 45 mins  170 C – 18 mins  180 c – 7 min 30 sec  190 C – 1 min 30 sec  170C – 18 mins  Glass Bead Sterilizer  Small glass crystal beads are heated to temperature of 230 C – 300C.  Tips of metal instruments are inserted between the glass beads.  Suitable for tweezers and cuticle cutters and knives.  They are put into beads for 30- 60 seconds.  Methods of Sterilization UV Light and Gamma Rays  Used especially for sterilization of electrolysis needles. Gamma rays  Mainly used for the sterilization of pharmaceuticals.  Delivers a certain dose that can take time from minutes to hours depending on the thickness & volume of the product. Ultraviolet rays (UVR)  Uses UV rays to sterilize any objects.  Glass tubes contain Mercury.  When the current flows the Mercury vaporizes ad emits UV rays into small cabinet.  Gamma Radiation Sterilization UV sterilizer  Methods of Sterilization Chemical  Most widely used in salons.  May involve diluting a disinfectant with water – immersing implements in solution. Fumigation Cabinet  Formalin (bacterol) when heated by light vaporizes and fumigates items.  Generally used in pest control. Sanitization chemical  Definitions  Sanitary: Products relating to promoting health & cleanliness.  Sanitation: Application of measures to promote public health and prevent the spread of infectious diseases.  Insanitary: Injurious to health or unclean.  Sterile: Completely free from microorganisms  Sterilization: Process of making an object germ free, by 100% destruction of all micro-organisms  Micro-organism: Smallest organism which can’t be seen with naked eyes. Include bacteria, fungi and viruses.  Definitions  Bacteria – Minute single celled organism which live in organic matter.  Virus -Smallest microorganism capable of replication within living cells.  Vaccination: Means of producing immunity to disease by introducing special preparation (antigens)  Fungi: A vegetable parasite that do not contain chlorophyll  Parasite: Any living thing, vegetable or animal that lives in on another organism.  Insect: Member of large group of mainly land dwelling animals, which possess a hard external skeleton and jointed legs.  Definitions  Immunity: Resistance to or freedom or protected from disease by natural means.  Pathogenic: Harmful, causes disease.  Non Pathogenic: Harmfulness, does not cause any disease.  Sepsis: A life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs.  Inflammation: Reaction of the body to irritation or injury which may be acute or chronic.  Definitions  Organic: Contains the element carbon.  Inorganic: Do not contain carbon, therefore they will not burn e.g. Iron and calcium.  Antiseptic: Chemical agent that destroys or inhibits the growth of disease causing bacteria and other micro-organisms  Disinfectant: Strong agent that destroys or removed bacteria. Thank You!!!