Control of Microbial Diseases

Vocabulary terms and guiding questions on control of microbial diseases

Disinfection

Killing or inactivating microbes that cause disease (chemical or physical)

Sterilization

Destroying all microbes, spores, and viruses

Pasteurization

Food process reducing pathogenic microbes

Oligodynamic effect

Takes few molecules of heavy metal to kill or be toxic to microbes

Disinfectant

Used on inanimate objects and surfaces; toxic to the body

Antiseptic

Can be used on living body and tissue

Antibiotic

Compounds produced by microbes (bacteria or fungi) to combat other microbes

Antibiotic resistance

Germs (bacteria, fungi) develop the ability to defeat the antibiotics designed to kill them

Selective toxicity

Causes greater harm to microbe than host

Bacteriostatic

Inhibits growth of bacterial cells

Bactericidal

Kills the bacterial cells

Broad-spectrum

Inhibits/kills a wide variety of bacteria

Narrow spectrum

Targets one specific class of bacteria

Antagonistic

Interfere with each other

Synergistic

One medication enhances another

Additive

Medications are neither antagonistic nor synergistic

Therapeutic index

Comparison of agent amount that causes therapeutic effect vs the amount that causes toxicity

primary role of immune system

recognize and destroy foreign molecules, invading microbes and their products, and mutant or damaged cells.all considerd antigens

also internal survailance-elimination of tumor, and old/worn out/damaged cells

Innate Immune System:

• nonspecific, inherent, present before infection

Adaptive Immune System

• specific, develops over time as a response to infections

self vs non self

The ability to recognize anything that is foreign, you need to be able to eliminate foreign pathogens(invadic microbes,secretions, toxins,enzymes)

can also exist on non normal self cells-cancerous or virus infected 

Self vs non self-examine a cell and spesifisize if it is healthy or bacteria/virus 

Name four factors that can influence the function of the immune system.

ge, sex, race, nutrition, health status, genetics, physical and mental stress

detrimental roles of the immune system and explain how they are a malfunction of the immune response.

• Hypersensitivity reaction - AKA allergic reaction when immune system goes into overdrive

• Allergies - adverse immune response to protein molecules associated with allergens

• Autoimmune diseases - failure of immune system to distinguish self from nonself

• Reaction to organ transplantation

how does the innate immune system recognize self vs non self

• Pathogen-associated molecular patterns (PAMPs) - innate immune cells rely on PAMPs to identify and respond to an infection

  • Exs. cell wall components, flagella, certain carbohydrate structures

Pattern Recognition Receptors (PRRs) - innate immune cells (most notably white blood cells/leukocytes) have PRRs that recognize PAMPs

how does the adaptive immune system recognize self vs non self

• Rely on lymphocytes (T cells and B cells) and their associated receptors bind antigens

• Due to vast array of lymphocyte receptors, theoretically possible to develop B cells and T cells that can recognize virtually any antigen you encounter

Explain the role(s) of the following types of immune cells:

• (Lymphocytes-25-25%antibody formation,cell mediated immunity 

  • B CELLS-antibody response 

  • T CELLS-adaptive immunity 

  • NATURAL KILLER-inate response to viral infection

• B cells-produce antibody response 

• T cells-nessasary for adaptive immunity 

• Natural Killer cells-innate response to viral innfection 

• (granuolocytes)Neutrophils- 60-70% of the total bloood leukocites phagocytosis(ingestion/distruction of foriegn materials)

• (granuolocytes)Eosinophils 2-4% inflamitory response, limited pjhagocytosis also parasitic worm 

• (granuolocytes)Basophils-.5-1% rich in histamine- allergic responses 

Explain the role of cytokines in immune cell communication?

Allows for coordinaited response between cells of immune system-produced By immune cells-voices cells-tells other cells they need to start growth and division,movement can lead to cell death

What type of cytokine is primarily responsible for the antiviral immune response?

interferons-

What is a differential count and what is the purpose of performing one?

• Reflects the ratio of the white blood cells and is an important tool in the diagnosis of infection(granulocytes vs agranulocytes)

  • Bacterial infections frequently yield elevated neutrophil count

  • Viral diseases can sometimes yield elevated lymphocytes

blood plasma

Noncellular fluid part of blood consisting of water and proteins

Define the three components of blood plasma and explain their role in the immune response.

• Globulin fraction

  • Gamma globulin → contains antibodies

    • Recognize and bind to specific foreign antigens (adaptive response)

• Complement proteins

  • Series of proteins that act as significant defense mechanism

• Interferon

  • Group of proteins that act to interfere with viral replication

  • Released from virus-infected cells

  • Act to alert other cells of impending attack → triggers them to produce virus-blocking enzymes

1. What is the purpose of the lymphatic system in immune function?

Contribute to the innate and adaptive immune system-swollen lymph nodes=active immune response to an infection

• Vast majority of lymphocytes located in specialized tissues known as lymphoid tissues of lymphoid organs.

• Lymphatic system is anatomically connected to blood circulatory

1. How do lymph nodes contribute to innate and adaptive immunity?

Contribute to the innate and adaptive immune system-swollen lymph nodes=active immune response to an infection

Contain both B and T cells and are the site of antibody production

• Also contain phagocytic cells → destroy microbes and stimulate adaptive immune response

What are the two primary immune structures? Explain each of their contributions to the immune system.

Primary-lymphocytes develop and mature to where they can respond to a specific pathogen divided into-bone marrow and thymus 

Bone marrow-hematopesis in adults- the process in which all blood cells are formed also the location of hematopoetic stem cells(initial stem cell that gives rise to the different types of white blood cells)

From there 

Myeloid-platelits and red blood cells-leucosites: monocytes, neutrophils, eosinophils, basophils 

Lymphoid-b cells mature into bone marrow T lymphocytes careated in bone marrow but mature in the thymus 

• Thymus

  • Organ located behind the sternum and just above the heart

  • T cells leave bone marrow in an immature state and migrate to the thymus

    • In thymus T cells build their genes that encode for their antigen-specific receptors and learn what is self

    • Once mature they leave the thymus and migrate to secondary lymphoid tissues & are ready to respond to infections

What is the role of the secondary immune structures in immune function?

Secondary/peripheral lymphoid tissues are where all important parts of the immune system come together with lymphocytes to initiate adaptive immunity

Name the four structures/organs of the secondary immune structures and explain how each functions in the immune system.

• Lymph nodes

  • Contain phagocytic cells and mature T and B cells

  • Almost all antigens end up in lymph or blood → then carried to lymph nodes, site of antibody production

• Spleen

  • Spongy, fist-sized organ

  • Contains phagocytic cells and mature T and B cells

• Tonsils and Adenoids

  • Located at the back of the throat

  • Protect against microbes entering the nose and throat

• Peyer’s patches

  • Located in lining of the gastrointestinal, respiratory, and urinary tracts

  • Protect against microbes entering through mucosal surfaces 

1. What are the two main goals of the physical/chemical barriers of the innate immune system?

• Nonspecific branch of the immune system

• Present from moment of birth and do not require any previous exposure to microbes

• Characterized by physiological defenses that operate to:

  • Prevent microbes the external environment from gaining access into the body

  • Quickly eliminate any microbes that do gain access

1. Explain how each of the following components acts to prevent or eliminate microbial infections:

• Skin

  • First line of defence against microbial infection

  • Physical barrier that block entry of microorganisms into the body

    • External surface not very hospitable for most microbes (repels water, dry environment)

    • Very few microbes can penetrate intact skin

    • Outer layer continually sloughs off along with any attached microbes

      Mucous Membranes

      • Digestive, respiratory, genitourinary tracts

      • Constantly bathed in scretions (ex. mucous)

      • Peristalsis of intestines, mucociliary escalator of respiratory tract removes microbes

      • Acidity of stomach acid

Antimicrobial substance (also name at least three examples of these and how they work)-

• Protect skin-mucousus mem

• Salt-skin-micronal growth 

• lysozome -degrades pepdicoglycan-tears sliva mucosis, blood 

• peroxidase -breaks down hydrogen perozide-saliva milk body tissue

• Antimicrobial peptides AMP’S-chain of aa that have antimicrobial activity promite direct immune responses -epithelal cells,phagocytes

Normal microbiota-

• Skin and mucous membrane-innate immunity 

• Compete with pathogens for space and nutyrients

• Immune stimulation 

• Nutritional support 

• Potential secretion of toxins toward pathogens

What is the role of the complement system and what are the three potential outcomes of complement activation?

• Complement proteins are made in an inactive form

  • Can be activated in a cascade-like manner as part of innate immunity or be triggered by antibodies as part of adaptive immunity

• System of biological amplification that enhances the immune response

  • Complement activation leads to chemotaxis of phagocytes and initiates inflammation

  • Complement enhances phagocytosis

  • Complement can bring about lysis of the target cell via building a pore through the cell

What is the role of phagocytosis in the immune response and what cells are able to perform phagocytosis?

Significant innate defense mechanism by which monocytes, macrophages, and neutrophils engulf and destroy foreign substances (including microbes)

1. Explain the process of phagocytosis.

• Chemotaxis: phagocytes recruited by chemoattractants to invader

• Recognition/Attachment: phagocytes recognize and bind to invader

• Engulfment: pseudopods surround invader and form phagosome

• Phagosome Maturation/Phagolysosome Formation: lysosomes fuse with phagosome forming phagolysosome

• Destruction/Digestion: Within phagolysosome invader is killed and digested via enzymes and production of toxic products

Exocytosis: release of degraded products

What is the purpose of inflammation?

•  contain site of damage, localize response, eliminate invader, restore tissue function-good leads to tissue damage

What are the four cardinal signs of inflammation?

Redness heat swelling pain -due to activity in b lood veseslf-capilarys engorged with blood-vasodilation-redness heat and fluid from blood leaks into surrounding tissue-swelling and pain is result of incresed pressure and products released 

Explain the cascade of events that occurs during the process of inflammation.

Dilation of small blood vesseld 

Migration of leukoctes fromthe bloodtreal to tissies

Clottting factors to eall off site of infection 

Dead netrophils-debris accumulate as pus

1. What is the role of fever in the immune response and what does it help to enhance?

• ever is important host defense mechanism

  • Strong indicator of infectious disease, especially bacterial

  • Temperature-regulation center in brain normally holds at 37 °C but raises during infection

  • Moderate temperature rise increases rates of enzymes

    • Enhances: inflammatory response, phagocytosis, multiplication of lymphocytes, production of interferons and antibodies, release of leukocytes from bone marrow