Module 3 and 4 Revision PDF

Microbiology Microbiology is the study of microscopic organisms, also known as micro-organisms, microbes or germs. Microorganisms Can be pathogenic agents of infectious diseases Normal flora which found normally in Human body Its measure only two or three microns in size and the smallest are al...

Microbiology Microbiology is the study of microscopic organisms, also known as micro-organisms, microbes or germs. Microorganisms Can be pathogenic agents of infectious diseases Normal flora which found normally in Human body Its measure only two or three microns in size and the smallest are almost 100 times smaller than that. Microbes are invisible to the naked eye —we can see things only as small 90 microns, about the thickness of a human hair. Microbes can be shown as different shape according each type of microorganisms Spores, and biofilms in bacteria Cysts in protozoa Survival strategies Mutations in the viruses Spores and altered metabolism in fungi Scientists are becoming better at finding and recognizing them New varieties of microorganisms are discovered Mutations and genetic exchange regularly create new forms from existing microbes Every year Bacteria, under optimal growth conditions, can multiply very rapidly Doubling in number every 20-30 minutes It is so important to clean reusable medical devices as soon as possible after use All microorganisms grow and reproduce in an optimal range of conditions Their basic requirements are food, temperature and moisture Changes these conditions to a range that is not tolerable will inhibit or kill the microorganisms Microbes or pieces of biofilm in blood or soil can form more biofilms on reusable medical devices if left on them for any length of time Their degree of attachment becomes stronger with time so by the time they get to the decontamination zone in the CSSD, they are more difficult to detach in the cleaning process It is best practice to avoid delays before starting decontamination of used reusable medical devices. When this is not possible, keep the reusable medical devices moist and treat them with a neutral detergent and cleaning enzymes until they can be properly decontaminated Cleaning of Bacteria Heat killed spores that resist to disinfections Most can be killed by disinfectants Cleaning area • Smallest infectious agents. • Require living cell for reproduction. • Human, animal, plant or bacteria. • Consist of either DNA or RNA and a protein coat. • Viruses are obligate intracellular parasites • Only demonstrate characteristics of life while “inside” a host cell. • They are only visible under electron microscopes. Biofilm develops by microbes (usually bacteria) either sticking to each other or to a nearby surface They secrete a matrix of slime which covers them like a tent This protection from disinfectants and various other stressful situations allows them to continue multiplying, and resist removal •By using validated procedures and processes proven to clean and decontaminate to ensuring the safety and sterility of their reusable medical devices. Very small proteinaceous units that cause Transmissible Spongiform Encephalopathies (TSEs) when folded in an abnormal way Abnormally folded prions can cause disease (particularly in the brain) by converting normally folded prions into abnormal ones These then aggregate and disrupt tissue structure and function Reusable medical devices used on prioninfected patient tissues are not used on other patients due to difficulty in decontaminating them Difficult for inactive by heat Difficult to disinfection Difficult to remove by cleaning Cleaning of Prions There are millions of different microbial species it is estimated that less than 10% of these have been identified or studied The best studied microbes are the ones that cause disease — these microbes are referred to as pathogens Plants, animal and humans are all dependent on microbes for their normal function and survival Personal microbiome help protect from disease and stimulate immune system and vitamins Helpful microbes are known as commensals whereas disease causing microbes are known as pathogens In a hospital or healthcare setting where patients are vulnerable to infection, we undertake many methods of infection control to prevent the transfer of pathogens or commensals. A human can therefore add a large number of microbes to their surrounding environment in a number of different ways Coughing, sneezing and bodily secretions can spread microbes or touch by hand to body parts and contaminated material So, decontamination methods and hand hygiene must be always performed Skin covering our bodies is The top layer of skin multilayered; the top layer is composed of dead cells contains a large amount of Our body discards this commensals of our own, entire top layer of dead together with transient populations picked up from skin cells and associated clothing, contact with microbial biofilm over a others, and our period of five or six weeks environment We try to contain our dead skin cells and microbes by using hygiene procedures and appropriate PPE to prevent us from recontamination the reusable medical devices or their environment Very high levels of contamination prevention and PPE are used in clean rooms and sterile areas of pharmaceutical and microelectronics factories, and when assembling spacecraft Often, two layers of clothing are worn, one to enter semi critical areas and then another on top of that to enter the critical areas Human body Reusable medical devices Water Microorganisms may be present in the: Working environment Air •By using validated procedures and processes proven to clean and decontaminate to ensuring the safety and sterility of their reusable medical devices. Scientists are becoming better at finding and recognizing them New varieties of microorganisms are discovered Mutations and genetic exchange regularly create new forms from existing microbes Every year What is the mutations? Examples: • Influenza virus, have a high rate of mutation. • Bacteria, fungi and yeasts can develop or pick up antibiotic resistance genes from other microbes Mutation is a change in the DNA or RNA sequence of the microbes This change leading to avoid being recognized by our immune system and create an outbreak risk and no longer treatable using antibiotics By changes in microbe gene or producing enzymes against antibiotics Microbes doesn't treat with previous effective antibiotic Antibiotic Resistance Develop to resistance to all available antibiotics Example: Methicillin Resistant Staphylococcus aureus (MRSA) Multi-drug Resistant Tubercle Bacillus (MDR-TB) Carbapenem-Resistant Enterobacteriaceae (CRE). • Injection — deliberate or accidental penetration of the skin or mucous membrane, for example, a needlestick, or an open wound • Ingestion — swallowing into the digestive tract via a splash or droplet • Inhalation — enter the respiratory tract via a droplet or aerosol • Contact — transfer from a contaminated object to the skin, eye, mucous membrane via a hand, glove, mask, droplet, or splash • The role of PPE, Standard Precautions and infection control is to prevent transmission, reduce risk and break the chain of infection. Accidental Needlestick or Sharps Injury Many reusable medical devices are designed to puncture or cut skin or tissues (sharps). After use, these may be contaminated by pathogenic microbes Some of these are designed for single use and will be discarded into the infectious waste stream these items may enter the CSSD mixed in with other reusable medical devices and can accidentally cause injury to the person handling them The main risks are from bloodborne viruses. Because of this, CSSD staff are usually vaccinated against these risks when they start work in the CSSD. An aerosol is defined as being a suspension of tiny particles or droplets in the air The size of the droplet, initial velocity and environmental conditions generally determine how long it will remain in the air and how far it will travel An aerosol becomes a means of infection-transmission if the droplets or particles contain microbes An aerosol may form in the CSSD when handling liquids, operating an ultrasonic bath, running a tap, brushing or blowing on a wet surface or when ventilation/humidification units release contaminating microbes. While large droplets do not travel very far, tiny droplets (5–10 microns, true aerosol) can remain airborne for many minutes The size of aerosol droplets or particles also affects the extent of lung penetration if you inhale them The smaller they are, the further they penetrate and this usually creates a higher risk of becoming infected Standard Precautions are operating procedures that apply in healthcare to minimizing the risk of infection regardless of the perceived infectious risk The approach is based on the understanding that all blood and body substances should be considered potentially infectious Therefore, all surgical instruments could be potentially contaminated with microorganisms Use of PPE Aseptic technique Vaccination Education and training Precautions include elements Safe systems for handling blood and body fluid Sharps awareness Handwashing Medical condition management Gown with Sleeves • Protect from splashes of blood or body fluids, or during activities that may contaminate it with infectious material. Gloves • Use gloves for environmental cleaning activities, and handling contaminated reusable medical devices and waste Plastic Bib or Apron • Extra protection from splashes during manual cleaning processes Mask & Eye Protection • Reduce the risk of microbes being transferred to the eyes, nose and mouth. These must be fitted properly and worn to cover eyes, mouth and nose Shoes or Shoe Covers • Worn only in the decontamination zone and used to protect regular shoes from becoming wet and contaminated during cleaning procedures Head/Hair cover • Wear a clean, single use, low lint surgical hat or hood that fully covers and confines your hair Uniform/Scrub • Wear a freshly laundered or new, disposable, that minimizes bacterial shedding and is comfortable for you and changed daily Footwear • protect from injury or contact with accidently dropped sharp objects Make-up/Jewelry • Do not wear make-up or jewelry (except a plain wedding band) in CSSD. You may wear stud earrings that are confined within the head cover in case they come loose Patients who become infected by microbes while in hospital are said to have a healthcare-acquired infection (HAI). This is also known as a nosocomial infection Staff working in the healthcare environment are also at risk from infection Protects them and helps prevent them from being a reservoir of infection or a means of transmission