Question | Answer |
Pathogenicity | The ability to cause disease |
Virulence | The extent of pathogenicity. |
What are the portals of entry? | 1.) Mucous membranes (respiratory, gastrointestinal, genitourinary, conjunctiva) 2.) Skin 3.) Parenteral route (cuts, bites,injections). |
What are the portals of exit? | Respiratory tract (coughing & sneezing), Gastrointestinal tract (feces & saliva), Genitourinary tract (urine, vaginal secretions), skin, & blood (biting arthropods & needles/syringes). |
What is ID50? | Infectious dose for 50% of the test population. |
What is LD50? | Lethal dose (of toxin) for 50% of the test population. |
What is adherence? | When adhesion's/ligands bind to receptors on host cells. Can be glycoproteins or lipoproteins & are frequently associated with fimbriae. Biofilms provide attachment & resistance to antimicrobial agents. |
What is coagulase? | The coagulation of blood. |
What is antigenic variation? | Alters the surface of proteins. |
Toxin | Substances that contribute to pathogenicity. They can be endotoxins or exotoxins. |
Toxigenicity | The ability to produce toxins. |
Toxemia | The presence of toxin in the host's blood. |
Toxoid | An inactivated toxin used in a vaccine. |
Antitoxin | Antibodies against a specific toxin. |
Endotoxin | Source: Gram (-) bacteria, Chemistry: Lipid, & Can it be Neutralized by an antitoxin? NO. |
Exotoxin | Source: Mostly Gram (+) bacteria, Chemistry: Protein, & Can it be Neutralized by an antitoxin? YES |
Cytopathic effects of Viruses? | Stopping mitosis, lysis, formation, of inclusion bodies, cell fusion, antigenic changes, chromosomal changes, & transformation. |
Pathogenic properties of Fungi? | Fungal waste products may cause symptoms. Chronic infections provoke an allergic response. Tichothecane toxins inhibit protein synthesis. Capsules prevent phagocytosis. Ergot toxin. |
Pathogenic properties of Protozoa? | Some change their surface antigens while growing in a host, thus avoiding destruction by the host's antibodies. |
Pathogenic properties of Algae? | Neurotoxins produced by dinoflagellates. Produce neurotoxins that cause paralysis when ingested by humans, shellfish paralysis. |
What are the symptoms of Helminths and Protozoa diseases? | Diseases can be caused by damage to host tissue or by the metabolic waste products of the parasite. |
Innate Immunity (Non-specific immunity) | Refers to all body defenses that protects the body against any kind of pathogen. |
Adaptive Immunity (Specific immunity) | Refers to defenses (antibodies) against specific microorgansisms. |
What is susceptibility? | The lack of resistance to a disease. |
What is resistance? | Ability to ward of diseases. |
What is Non-specific resistance? | Defenses against any pathogen. |
What is specific resistance? | Immunity, resistance to a specific pathogen. |
Innate Immunity (Non-specific immunity) | Refers to all body defenses that protects the body against any kind of pathogen. |
Adaptive Immunity (Specific immunity) | Refers to defenses (antibodies) against specific microorgansisms. |
What is susceptibility? | The lack of resistance to a disease. |
What is resistance? | Ability to ward of diseases. |
What is Non-specific resistance? | Defenses against any pathogen. |
What is specific resistance? | Immunity, resistance to a specific pathogen. |
First line of defense (non-specific) | Intact skin, mucous membranes and their secretions, & normal microbiota. |
Second line of defense (non-specific) | Phagocytic white blood cells, inflammation, fever, & antimicrobial substances. |
Third line of defense (specific) | Specialized lymphocytes: B cells & T cells, antibodies. |
Mechanical factors | Skin & mucous membranes. Ciliary escalator: microbes trapped in mucous are transported away from the lungs, Lacrimal apparatus: washes eye, Saliva: washes microbes off, Urine: flows out, & Vaginal secretions: flow out. |
Chemical factors | Sebum, low pH (3-5) of skin, Lysozyme in perspiration, tears, saliva, & tissue fluids, low pH (1.2-3.0) of gastric juice, Transferrins in blood find iron & make it unavailable to bacteria. |
What are the types of white blood cells? | Neutrophils: phagocytic, Basophils: produce histamine, Eosinophils: toxic to parasites, some phagocytosis, Monocytes: phagocytic as mature macrophages, Lymphocytes: involved in specific immunity ( B & T cells). |
What is inflammation? | A bodily response to cell damage; it is characterized by redness, pain, heat, swelling, & sometimes the loss of function. |
What is edema? | An abnormal accumulation of interstitial fluid in body parts or tissues, causing swelling. |
What is vasodilation? | Vasodilation or enlargement of blood vessels. The release of histamine, kinks, & prostaglandins cause vasodilation & increased permeability of blood vessels. |
What is margination? | Phagocytes have the ability to stick to the lining of the blood vessels. |
What is emigration? | |
Fever | An abnormally high body temperature produced in response to a bacterial or viral infection. A chill indicates a rising body temperature; crisis ( sweating) indicates that the body's temperature is falling. |
The Compliment system | Consist of a group of serum proteins that activate in a cascade that work with one another to destroy invading microorgansisms. Activated via the classical pathway, the alternative pathway, & the lectin pathway. |
What is the classical pathway (1)? | Antibodies attach |
What is the alternative pathway (2)? | Complement factors attach. |
What is the lectin pathway (3)? | Macrophages stimulate liver to release lectin which can attach & start cascade. |
Complement system & cascade? | The complement system is not adaptable & does not change over the course of a lifetime; so it belongs to the innate immune system. Complement proteins act in a cascade; that is one reaction triggers another, which in turn triggers another, & so on. |
What is an Interferon ( IFN)? | Antiviral proteins produced in response to a viral infection. Alpha IFN & Beta IFN cause cells to produce antiviral proteins that inhibit viral replication. Gamma IFN: causes neutrophils and macrophages top phagocytize bacteria. |
What is a Differnetial white blood cell count? | The number of each kind of leukocyte in a sample of 100 leukocytes. A "typical" healthy patient would have; Neutophils: 60-70%, Basophils: 0.5-1%, Esinophils: 2-4%, Monocytes: 3-8% & Lymphocytes: 20-25%. |
What are antimicrobial peptides (APM's)? | Inhibit cell wall synthesis; form pores in plasma membranes, resulting in lysis; & destroy DNA & RNA. Produced by nearly all plants & animals, & bacterial resistance to AMP's has not yet been seen. |
Adaptive/aquired Immunity | Specific antibody & lymphocyte response to an antigen (aquired). |
What is an Antigen (Ag)? | A substance that causes the body to produce specific antibodies or sensitized T cells. |
What is a Antibody (Ab)? | Proteins made in response to an antigen. |
What is Serology? | The study of reactions between antibodies and antigens. |
Humoral Immunity | Involves antibodies, which are found in serum & lymph & are produced by B cells. |
Cell-mediated Immunity | Involves T cells. |
Aquired Immunity | Developed during an individual's lifetime (not born with it). |
What is Naturally aquired active immunity? | Resulting from infection. |
What is Naturally aquired passive immunity? | Aquired via transplacental or via colostrum (from breast milk). |
What is Artifically aquired active immunity? | An injection of Ag (antigen) vaccination. |
What is Artifically aquired passive immunity? | An injection of Ab (antibody). |
What is self-tolerance? | The body doesn't normally make Antibodies against itself. |
What is Clonal deletion? | The process of destroying B & T cells that react to self antigens. |
What is Clonal selection? | Bone marrow gives rise to B cells. Mature B cells migrate to Lymphoid organs. Mature B cells recognize epitopes (from antigens). |