* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Commensalism • Benefits both the host and the commensal
Globalization and disease wikipedia , lookup
Neonatal infection wikipedia , lookup
Cancer immunotherapy wikipedia , lookup
Psychoneuroimmunology wikipedia , lookup
Immune system wikipedia , lookup
Adoptive cell transfer wikipedia , lookup
Adaptive immune system wikipedia , lookup
Rheumatic fever wikipedia , lookup
Antimicrobial peptides wikipedia , lookup
Sarcocystis wikipedia , lookup
Polyclonal B cell response wikipedia , lookup
Plant disease resistance wikipedia , lookup
Germ theory of disease wikipedia , lookup
Hospital-acquired infection wikipedia , lookup
Hygiene hypothesis wikipedia , lookup
Molecular mimicry wikipedia , lookup
Schistosoma mansoni wikipedia , lookup
Infection control wikipedia , lookup
Transmission (medicine) wikipedia , lookup
Commensalism Benefits both the host and the commensal. Commensal- gets ready supply of nutrients and sanctuary Host- commensal competes with other pathogens for nutrients Produces antimicrobial components Produces compound needed by host e.g. HCL Human body commensal is MICROFLORA Human microflora is mainly BACTERIA Pathogen Disease causing organism e.g parasites cannot live without the host Pathogenesis Ability for a pathogen to cause disease Virulence factors 1. Overcoming or evading host defences 2. Structures that help attachment to surfaces so that pathogens can resist removal 3. Tissue degrading enzymes= tissue injury 4. Resistance to adverse condition s 5. Produce toxins First Line of defences Second line of defences Third line of defences 1. Non-specific line of defence 2. Non-specific line of Defences 3. Adaptive line of defence Skin Natural killer cells Lymphocytes B & T Cells Mucous membrane Phagocytic WBC Antibodies Microbiota Inflammation Fever Antimicrobial substances Barriers to Infection SKIN MUCOUS MEMBRANE Physical barrier, stratified Mucus prevents attachment Low moisture & increased salt In resp tract mucous and ciliated epithelium helps removal of foreign materials Surface secretions of antimicrobial substances e.g. lysozyme, sebum Secretes antimicrobials e.g. lysozyme, acid Systemic line of defence 1. FEVER Rise in temp creates an undesirable environment for bacteria. 2. PLASMA PROTEINS Immunoglobins, complement proteins and clotting factors 3. CELLS OF IMMUNE SYSTEM neutrophils- phagocytosis Opportunism Body’s own microflora causes disease by: 1. Displacement of organism to a new environment 2. Change in environment favours overgrowth of a particular commensal 3. Failure or weakness in host defences Transmission of Infection CONTACT AIRBORNE WARTERBORNE Transfer from one region to Particles in air > 1m Faecal-oral transmission another e.g. person to E.g legionella pneumophillia E.g. diarrhoeal diseases person or animals to fomites Control of Microbial Growth 1. Sterilisation- total eradication of all living cells and spores and infective materials 2. Disinfection- killing/ inactivation of a large number of organisms PHYSICAL CHEMICAL Antimicrobial therapies 1. Heat – incineration, dry heat sterilisation, boiling, -Reactions between the 1. Drugs with wet heat (autoclaving) 2. Radiation- ionising radiation (disrupt DNA), Ultraviolet (disinfect) 3. Filtration- physical barrier agent and components of infection agent e.g. alcohol swabs, bleach - Dosages basis selective toxicity 2. Target chemical/metaboli c pathways specific to the pathogen