test 2

Describe the cause, signs and symptoms, and prevention of strep throat

• Back of pharynx red • Swollen lymph nodes • Purulent abscesses over tonsils • Pain during swallowing• Fever • Malaise • Headache • Bacteria can spread from throat to larynx and bronchi to cause laryngitis and bronchitis if untreated Glomerulonephritis (kidneys swell due to complement activation) or Rheumatic fever (damage to heart valves and muscle) can occur

Identify two effects of cord factor of M. tuberculosis

• Cord factor prevents fusion of phagosomes with lysosomes, thus preventing phagocytosis • Cell wall glycolipid that causes daughter cells to remain attached to one another in parallel alignments

Describe antimicrobial peptides as part of the body's defenses

Present in skin, mucous membranes, and neutrophils, act against a variety of microbes. Some punch holes in cytoplasmic membranes, others interfere with enzymes, and some attract leukocytes.

Explain how mucous membranes protect the body both physically and chemically

-secrete mucous -thin layer of live cells -sheds and replacement of cells carries attached microorganisms away -cilia, pushes microbes out and traps particles (and because it is sticky) -lysozyme and antimicrobial peptides found in mucus

Contrast symptoms, signs, and syndromes

- Symptoms: subjective characteristics of disease felt only by the patient - Signs: objective manifestations of disease that can be observed or measured by others - Syndrome: group of symptoms and signs that characterize a disease or abnormal condition

Describe the roles of hemagglutinin and neuraminidase in the replication cycle of influenza viruses and in the origin of new influenza viruses

--Glycoprotein spike variation <Neuraminidase - hydrolyzes mucus in lungs, allowing virus to spread <Hemagglutinin - binds to pulmonary epithelial cells and triggers endocytosis < e.g., H1N1 variant

Explain the roles of APCs and MHC molecules in antigen processing and presentation

-APCs are phagocytic cells that phagocytize antigens and MHC II molecules will bind with antigen and "present" it on the cell membrane, where it can interact with B or T cells - Once the MHC II or I complex is loaded with antigen T cells with the proper antigen binding site can bind and destroy that cell - If an epitope cannot bind to a MHC molecule, it typically does not trigger an immune response

Describe the cause and signs and symptoms of Mycobacterium tuberculosis

-Gram-positive rod -Mycolic acid (acid fastpositive) • Unique characteristics -VERY slow growth -Protected from destruction following phagocytosis -Intracellular growth -Cord factor

Explain the function of immune system cytokines

-cytokines are soluble regulatory proteins that act as intercellular messages when released by certain body cells -immune system cytokines are secreted by various leukocytes and affect diverse cells When released by certain body cells, these soluble regulatory proteins act as intracellular messages. The signaling proteins are secreted by leukocytes and affect diverse cells. They are crucial because they control growth and activity of other immune systems cells.

List six mechanisms by which antimicrobial drugs affect pathogens

1. Inhibition of pathogen's attachment or entry into host cell (Arildone, Pleconaril, Enfuvirtide) 2. Inhibition of DNA or RNA synthesis (Actinomycin, Nucleotide analogs, Quinolones, Rifampin) 3. Inhibition of general metabolic pathway 4. Inhibition of cell wall synthesis (Penicillins, Carbapenems, Cephalosporins, Vancomycin, Bacitracin, Isoniazid, Ethambutol, Echinocandins-antifungal) 5. Inhibition of protein synthesis (Aminoglycosides, Tetracyclines, Chloramphenicol, Macrolides, Antisense nucleic acids) 6. Disruption of cytoplasmic membrane (Polymyxins, Polyenes-antifungal)

Describe the importance, advantages and disadvantages, and use of the six types of physical methods of microbial control

1. Heat-Related Methods •***Look at heat-related methods slides • Moist Heat = -can sterilize, disinfect, and pasteurize with moist heat -kills by denaturing proteins and destroying cytoplasmic membranes • Methods of microbial control using moist heat -Boiling, Autoclaving, Pasteurization, Ultrahigh-temperature sterilization • Dry Heat= Used for materials that cannot be sterilized with or are damaged by moist heat -Denatures proteins and oxidizes metabolic and structural chemicals -Requires higher temperatures for longer time than moist heat because dry heat penetrates more slowly 2. Refrigeration and Freezing •***look at fridge and freezing slide • Cold= -ice crystals can puncture cell membranes -cold temperature slow enzyme reactions 3. Desiccation and Lyophilization •Desiccation -drying inhibits growth because metabolism requires liquid water -Inhibits the spread of most pathogens -Some molds can grow on dried fruits -Desiccation (drying) inhibits growth because metabolism requires liquid water. •Lyophilization -lyophilization used for long-term preservation of microbes and othercells -Prevents formation of large damaging ice crystals -Lyophilization (freeze-drying) preserves microbes by preventing ice crystal formation 4. Filtration • The passage of a fluid through a sieve designed to trap particles and separate them from the fluid • Traps microbes larger than the pore size • Examples include surgical masks and HEPA filters 5. Osmotic Pressure • High concentrations of salt or sugar inhibits microbial growth • Cells in a hypertonic solution of salt or sugar lose water; cell desiccates 6. Radiation (look more in slide) - particulate radiation -electromagnetic radiation -Ionizing - wavelengths shorter than 1 nm - electron beams, gammarays, and X rays Nonionizing - wavelengths gr

Describe the three conditions that create opportunities for normal microbiota to cause disease

1. introduction of a member of the normal microbiota into an unusual site in the body --> leads to organism becoming an opportunistic pathogen 2. immune suppression --> anything that suppresses the body's immune system can enable opportunistic pathogens 3. changes in the normal microbiota --> normally there is an abundance of normal microbiota which cause microbial antagonism, preventing other pathogens from surviving, BUT if there is less normal microbiota, a member may become an opp. pathogen

Contrast contact, vehicle, and vector transmission

Contact is transmission from people transferring microorganisms to other people. Vector transmission occurs when a living organism carries an infectious agent on its body (mechanical) or as an infection host itself (biological), to a new host. Vehicle transmission occurs when a substance, such as soil, water, or air, carries an infectious agent to a new host.

Contrast the structure and function of the five classes of antibodies

A blood protein that neutralizes a foreign matter by binding to it. 1. the IgM antibody activates the complement pathway by binding to a complement protein. 2. neutralizes pathogens by preventing it from changing its structure or shape so that it can replicate in the cell. 3. opsonization, which means the antibody can tag foreign substances from elimination through phagocytes. 4. agglutination, where they bind to pathogens and make them clump together in order to decrease the number of infectious particles circulating in the body. 5. antibody-dependent cytotoxicity, where an antibody targets a cell and rounds up effector cells to induce target cell death.

Explain the benefits of fever in fighting infection

A fever is the body's response to fighting off an infection and ultimately stimulates bodily defenses. It is known to help the stimulation of interferons and enhances the effects of phagocytes, and tissue repair.

Describe the relationship between contamination and infection

Contamination refers to the non-intended introduction of infectious microorganisms such as bacteria, yeast, fungi, and protozoans as well as viruses and prions. Infection refers to an invasion of body tissues by microbes.

Describe the formation and functions of plasma cells and memory B cells

Activated, immunoglobulin-secreting B cells are called plasma cells -B cells generate plasma cells, whichsecrete antibodies

Contrast active versus passive acquired immunity and naturally acquired versus artificially acquired immunity

Active immunity = antigens are given to a person -natural immunity: exposure to antigens -artificial immunity: vaccines, antigens are injected to promote active response Passive immunity= antibodies are given to a person -natural immunity: fetus from mother -artificial immunity: antibody therapy, covid patient receiving antibodies from a patient who had recovered

Describe the inducement and action of a T-independent antibody immune response

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Describe the basic structure of an immunoglobulin molecule

An antibody, also known as an immunoglobulin, is a Y-shaped structure which consists of four polypeptides — two heavy chains and two light chains. This structure allows antibody molecules to carry out their dual functions: antigen binding and biological activity mediation.

Describe three types of reservoirs of infection of humans

Animal reservoirs: spread from animal to humans→ zoonoses (yellow fever, anthrax bubonic plague, and rabies) Human carriers: Direct- congenital/ mother via placenta (syphilis, gonorrhea) , touching (herpes), kissing (Epstein Barr virus, sexual (HIV HPV, Herpes) Indirect body fluids (blood, urine, saliva, sweat, rectal fluid) Nonliving reservoirs:(indirect transmission) - water, body fluids, food, airborne

Identify the characteristics of antigens that stimulate effective immune responses

Antigen's shape, size, and complexity • Larger molecules are more easily recognized than smaller ones • Most effective are large foreign macromolecules such as proteins and glycoproteins (carbohydrates and lipids can also be antigenic) • Complex molecules have more epitopes to detect

Contrast antigenic shift with antigenic drift with respect to influenza virus variants

Antigenic shift occurs when a virus undergoes a sudden change in genetic makeup, creating a new strain. Antigenic drift occurs when a virus undergoes a gradual change in genetic makeup, causing a different, but somewhat similar genetic makeup to the parent virus. Antigenic drift: -Mutations and recombinations in the genes coding for HA and NA spikes are responsible for the production of new strains of influenza A and B viruses via this process 1. influenzavirus A or B enters host cell 2. mutation occurs during replication within host cell's nucleus 3. New strain of influenzavirus, differing slightly from original virus, exits cell Antigenic shift: -Antigenic shift by influenza A virus occurs about once a decade. Influenza B virus does not undergo this process 1. two different strains of influenza A viruses enter the same host cell 2. genes and antigens from both viral types are combines in new virons 3. a new influenzavirus A, which can be very different from the original two viruses, exits cell

Contrast endogenous antigen processing with exogenous antigen processing

Antigens processed via the exogenous pathway are presented on MHC class II and activate CD4+ Th cells. Antigens processed via the endogenous pathway are presented on MHC class I and activate CD8+ Tc cells.

Compare and contrast the terms in Table 9.1 and describe their practical uses: (Antisepsis, aseptic, -cide and -cidal, degerming, disinfection, pasteurization, sanitization, -stasis and -static, sterilization)

Antisepsis: reduction in the number of microorganisms and viruses, particularly potential pathogens, on living tissue (ex: use of iodine or alcohol to prepare skin for an injection) Aseptic: refers to an environment or procedure free of pathogenic contaminants (ex: preparation of surgical field, handwashing, flame sterilization of laboratory equipment) -cide + -cidal: suffixes indicating destruction of a type of microbe (ex: bactericide, fungide, germicide, virucide) Degerming: removal of microbes by mechanical means (ex: handwashing, alcohol swabbing at the site of injection) Disinfection: destruction of most microorganisms and viruses on nonliving tissue (ex: use of phenolics, alcohols, aldehydes, or soaps on equipment surfaces) Pasteurization: use of heat to destroy pathogens and reduce the number of spoilage microorganisms in foods and beverages (ex: pasteurized milk and fruit juices) Sanitization: removal of pathogens from objects to meet public health standards (ex: washing tableware in scalding water in restaurants) -stasis and -static: suffixes indicating inhibition but not complete destruction of a type of microbe (ex: bacteriostatic, fungistatic, virustatic) Sterilization: destruction of all microorganisms and viruses in or on an object (ex: preparation of microbiological culture media and canned food)

Describe the characteristic of B cells that provides them specificity

B cells contribute to immune response by generating plasma cells that secrete antibodies. Antibodies bind to pathogens to neutralize them so they can't harm the body. The B cell receptor interacts with these foreign substances to stimulate B cell activation so it can start the antibody creating process.

Explain how a biofilm may facilitate contamination and infection

Biofilm is a way of bacteria attaching to host cells indirectly. They interact with each other to forma sticky web of bacteria and polysaccharides and adheres to the surface within a host.*EX: Dental plaque is a biofilm that contains bacteria that causes dental carries.*

List two basic divisions of adaptive immunity and describe their targets

Cell mediated immune responses and antibody immune responses. Cell mediated immune responses are controlled and carried out by t cells and often act against intracellular pathogens. Antibody immune responses are often directed against extracellular pathogens and toxins. Both are powerful defensive reactions that have the potential to severely and fatally attack the body's own cells. B-cells carry out antibody immune responses, though T cells play roles in regulating and fulfilling such immune responses.

Describe a cell-mediated immune response

Cell-mediated immune responses involve the destruction of infected cells by cytotoxic T cells, or the destruction of intracellular pathogens by macrophages the activation of naive T cells in response to antigen, and their subsequent proliferation and differentiation, constitutes a primary immune response

Discuss the process and benefits of inflammation

Inflammation is a nonspecific reaction to tissue damage and in response helps with tissue repair and the migration of phagocytes. Thus, it provides long term adaptive immunity towards some pathogens and initiates the healing process.

Compare and contrast three types of T cells

Cytotoxic T Cells (Tc or CD8 Cell): These lymphocytes directly kill other cells - those infected with viruses and other intracellular pathogens, as well as abnormal cells, such as cancer cells. Helper T Cells (Th or CD4 Cells): Their function is to assist in regulating the activity of B cells and cytotoxic T cells during immune responses by providing necessary signals and growth factors. Type 1 Helper T Cells - assist cytotoxic T cells and innate macrophages. Type 2 Helper T Cells - function in conjunction with B cells. Regulatory T Cells (Tr Cells): suppressor T cells, repress adaptive immune responses and prevent autoimmune diseases. Tr cells express CD4 and CD25 glycoproteins.

Discuss the components of blood cells and their functions in the body's defense

Defensive Blood Cells: Leukocytes (T and B cells) • Formed elements -Erythrocytes = carry oxygen and carbon dioxide in the blood -Platelets = involved in blood clotting -Leukocytes (WBC) = involved in defending the body against invaders -Granulocytes = basophils, eosinophils, neutrophils] =Agranulocytes = lymphocytes , monocytes, macrophages

Discuss the diagnosis, treatment, and prevention of tuberculosis

Diagnosis: • Tuberculin skin test --Cell wall antigens injected into skin --Recheck at 24-72 h • Cell-mediated hypersensitivity reaction --Past infection --Immunized with M. bovis --Active disease --Chronic carriers • Chest X ray reveals presence of tubercles • Check sputum sample for acid fast cells and cords Treatment: • Common antimicrobials have little effect --Drug cleared from body before they have effect on organisms --Drugs have little impact of bacteria living within macrophages • Pyrazinamide with INH, rifampin and either streptomycin or ethambutol • MDR-TB strains (resistant to INH and rifampin) • XDR-TB strains (resistant to INH, rifampin and 3 or more other drugs) --Have emerged in populations with high incidence of HIV • Bedaquiline - first anti-TB drug in over 40 years used to treat MDR-TB and XDR-TB • Scientists are developing a subcutaneous implant Prevention: • Antibacterial drugs used prophylactically --IF patient recently converted from negative to positive TB skin test --OR IF they have significant exposure to active cases of TB • BCG vaccine (attenuated) --Not used for immunocompromised patients because it can cause disease --In the U.S. cost of mass immunization not warranted due to low prevalence of TB

Describe the actions of drugs that affect the cell walls of bacteria and fungi

Drugs that act against bacterial cell walls • Most common antibacterial agents act by preventing the cross-linkage ofNAM subunits • Another drug blocks transport of NAG and NAM from the cytoplasm out to the wall • Common features --- Prevent bacteria from increasing the amount of cell wall, but have no effect on existing peptidoglycan layer ---Effective only for growing cells; dormant cells are unaffected • Drugs effective against acid-fast positive organisms disrupt the formation of mycolic acid Inhibition of Synthesis of Fungal Walls • Fungal walls composed of various polysaccharides containing a sugar, 1,3-D-glucan, that is not found in mammalian cells • Drugs inhibit the enzyme that synthesizes glucan

Explain how microbial extracellular enzymes, toxins, adhesion factors, and antiphagocytic factors affect virulence

Enzymes: Secreted by the pathogen -Dissolve structural chemicals in the body -Help pathogen maintain infection, invade, and avoid body defenses -Important to virulence of the pathogen -Mutant species that do not secrete the enzymes are often avirulent Toxins: Chemicals that harm tissues or trigger host immune responses that cause damage -Toxemia refers to the presence of toxins in the bloodstream -The toxins are carried beyond the site of infection -Two types: Exotoxins (can cause damage to the host by destroying cells or disrupting normal cellular metabolism. They are highly potent and can cause major damage to the host) Endotoxins (initiates a host inflammatory response to Gram-negative bacterial infection. An adequate inflammatory response likely enhances host survival by mediating clearance of infection and bacterial toxins) Antiphagocytic: Factors that prevent phagocytosis by the host's phagocytic cells -Allow pathogens to remain in a host for longer time -Bacterial capsule -Composed of chemicals not recognized as foreign -Slippery and difficult for phagocytes to engulf Antiphagocytic chemicals -Prevent fusion of lysosome and phagocytic vesicles -Leukocidins directly destroy phagocytic white blood cells Adhesions: facilitate host colonization and enable bacteria to avoid clearance by mucosal secretions and peristalsis (Kline et al., 2009). Most commensal and pathogenic bacteria have adhesins on their surface that promote interactions with eukaryotic host cell receptors.

Explain the roles of interferons in innate immunity

Interferons are protein molecules that are produced by cells in response to a virus. They nonspecifically inhibit the virus by producing proteins that help stop the virus from replicating.

Distinguish among exogenous antigens, endogenous antigens, and autoantigens

Exogenous antigens- Include toxins and other secretions and components of microbial cell walls, membranes, flagella, and pili Endogenous antigens- Protozoa, fungi, bacteria, and viruses that reproduce inside a body's cells produce endogenous antigens. The immune system cannot assess the health of the body's cells; it responds to endogenous antigens only if the body's cells incorporate such antigens into their cytoplasmic membranes, leading to their external display. Autoantigens- Derived from normal cellular processes are autoantigens. Immune cells that treat autoantigens as if they were foreign are normally eliminated during the development of the immune system. This phenomenon, called self-tolerance prevents the body from mounting an immune response against itself.

List and briefly describe the three lines of defense in the human body

First line of defense: external physical barriers to pathogens - Skin -Mucous membranes of respiratory tract, reproductive tract, and digestive tract Second line of defense: internal and composed of protective cells, bloodborne chemicals, and processes that inactivate or kill invaders -Phagocytosis -Interferons -Complement -Inflammation -Fever third line of defense: responds against unique species or strains of pathogens

Describe the normal microbiota of the upper and lower respiratory tracts

Function of the Respiratory System• Exchange of gases between the atmosphere and the blood Respiratory system divided into two main parts: • Upper respiratory system -Collects air, filters contaminants from the air, and delivers it to the lower respiratory organs • Lower respiratory system

Describe the lacrimal apparatus and the role of tears in combating infection

Group of structures that produce and drain away tears Tears join the nasal mucus and flow into the pharynx, where they are swallowed Blinking- spread tears and washes the surfaces of the eye Tears contain lysozyme

Identify the locations of the body's mucous membranes

Nostrils, mouth, throat, ears, genitals, anus

Describe how populations of resistant microbes can arise

Not all pathogens are equally sensitive to a given therapeutic agent • A population may contain a few organisms that are either naturally partially or completely resistant

Compare and contrast the flow of lymph with the flow of blood

Lymph is colorless, it arises from fluid that has leaked out of blood vessels into the surrounding area. Unlike the cardiovascular system, the lymphatic system has no unique pump and is not circular, that is lymph flows only toward the heart as skeletal muscular activity squeezes the lymphatic vessels. Located at various points within the system there are about 1000 lymph nodes, which house white blood cells including B and T lymphocytes.

Describe the two classes of MHC proteins with regard to their location and function

MHC I is found on the cytoplasmic membrane of all nucleated cells. These molecules derive small portions of proteins from pathogens and bring it to the cell surface in order for T cells to recognize. Specifically, these pathogens are endogenous antigens. MHC II molecules are found only on antigen-presenting cells (B cells, Macrophages, and Dendritic cells). Even though they have a more specific location, they create an immune response similar to MHC I. However, they are known to be exogenous antigens.

Describe the transmission and pathogenesis of M. tuberculosis and its effects of the human body

Macrophages carry pathogen via blood and lymph to variety of sites • Bone marrow • Spleen • Kidneys • Spinal cord• Brain Signs and symptoms correspond to complications arising at the various sites involved Consumption • Minor cough and mild fever • As disease progresses patients develop: • breathing difficulties • fatigue • malaise • chest pain • wheezing • cough up blood • Inhalation of respiratory droplets

Define cross resistance, and distinguish it from multiple resistance

Multiple-drug-resistant pathogens (superbugs) resistant to three or more types of antimicrobial agents Cross resistance - resistance to one antimicrobial agent may confer resistance to similar drugs • Typically occurs when drugs are similar in structure

Distinguish among the types of symbiosis

Mutualism: both organisms benefit (bacteria in human colon) Commensalism: one organism is benefiting and the other is neither benefiting nor is harmed (mites in human hair follicles) Amensalism: one organism is harmed and the other is neither benefiting nor is harmed (fungus secreting an antibiotic, inhibiting nearby bacteria) Parasitism: one organism is benefitting and the other is harmed (tuberculosis bacteria in human lung)

Distinguish narrow-spectrum drugs from broad-spectrum drugs in terms of their targets and side effects

Narrow-spectrum antibiotics target a few types of bacteria. Broad-spectrum antibiotics target many types of bacteria. Broad-spectrum - killing of normal flora reduces microbial antagonism • May allow for secondary infections (transient pathogen) • May allow for superinfections(member of normal flora)

Describe the normal microbiota, including resident and transient members, and describe the sites where these are found in humans

Normal Microbiota- Microbes that colonize on the surface of the body without normally causing disease. **These Microbes can change from week to week** Resident Microbiota- They remain a part of the normal microbiota of a person throughout life. **These are found on skin, mucous membranes of digestive tract, upper respiratory tract, distal portion of the urethra and vagina.** Transient Microbiota-Colonizes the superficial layers of the skin, is more amenable to removal by routine hand hygiene. Transient microorganisms do not usually multiply on the skin, but they survive and sporadically multiply on skin surface.

Define resident microbiota, and explain how they help provide protection against disease

Normal microbiota help protect the body by competing with potential pathogens (microbial antagonism) Various activities of the normal microbiota make it hard for pathogens to compete • Consumption of nutrients makes them unavailable to pathogens • Create an environment unfavorable to other microorganisms by changing pH • Attach to all sites on human cells making it difficult for pathogens to attach • Help stimulate the body's second line of defense • Can produce antimicrobial compounds for defensive purposes • Promote overall health by providing vitamins (biotin, B5, folic acid, and a precursor to vitamin K) to host

Discuss the advantages and disadvantages of the different routes of administration of antimicrobial drugs

Oral pros= simple, patient can administer cons=lower concentration, patients don't follow directions Intramuscular and one time intravenous pros= fast acting cons= requires needle, concentration less than IV Continuous intravenous pros= fast acting, highest drug concentration cons=requires needles or catheter, liver and kidneys breakdown drug and remove from body

Identify the structures, enzymes, and toxins of Streptococcus pyogenes that enable this bacterium to survive against the body's defenses and cause disease

Pathogens: •Genus Streptococcus --Gram-positive, facultatively anaerobic cocci in chains or pairs --Streptococci differentiated by Lancefield grouping • Lancefield Group A - S. pyogenes --Major cause of bacterial pharyngitis and scarlet and rheumatic fevers --Causes a number of diseases, depending on the site of infection, the strain of bacteria, and the immune responses of the patient Virulence factors: • M protein - inhibition of C3b; interferes with opsonization and MAC formation • Hyaluronic acid capsule - acts as an immunologic disguise because humans have hyaluronic acids too • Streptokinases - lyse blood clots and allows for spreading • C5a peptidase - decreases movement of WBC to infection site • Pyrogenic (erythrogenic) toxins - stimulate leukocytes to release cytokines that stimulate fever, widespread rash, and shock ---toxic shock syndrome • Streptolysins - lyse erythrocytes, leukocytes, and platelets

Compare and contrast the nine major types of antimicrobial chemicals, and discuss the positive and negative aspects of each

Phenols: intermediate-low disinfectants- denature proteins and disrupt cell membranes in a wide variety of pathogens. remain active on surfaces; NEGATIVE: may smell bad, have side effects Alcohols: intermediate level- leave no residue, alcohol swabs help more in degerming. NEGATIVE: don't work against fungal spores or bacterial endospores, may not contact microbes long enough to be effective; they denature proteins and disrupting cytoplasmic membranes Halogens: intermediate level - effective against vegetative bacterial and fungal cells, fungal spores, some bacterial endospores and protozoan cysts, and many viruses; work by unfolding (denaturing) proteins (including enzymes) Oxidizing agents: high level and antiseptics- kill microbes by oxidizing their enzymes, preventing metabolism. release oxygen radicals against anaerobic microbes, used to kill anaerobes in deep puncture wounds Surfactants: low level- works on bacteria (-stain), fungi, and enveloped viruses; NOT on endospores. surface active chemicals; reduce the surface tension of solvents, decreasing attraction between molecules; act by disrupting cellular membranes so that the affected cells lose essential internal ions Heavy metals: low level- denatures proteins (inhibiting or eliminating their function): bacteriostatic and fungistatic agents:: silver may be used in surgical dressings, burn cream, and catheters; copper interferes with chlorophyll (algicide) Aldehydes: high level- cross-linking amino, hydroxyl, sulfhydryl, and carboxyl organic functional groups; denaturing proteins and inactivating nucleic acids Gaseous agents: denature proteins and DNA by cross-linking organic functional groups; leaving inanimate objects intact and unchanged; used to sterilize equipment Enzymes: high level- enzymes that act against microbes, denatures proteins.

Identify the physical and chemical aspects of skin that enable it to prevent the entrance of pathogens

Physical: - Epidermis ----multiple layers of tightly packed cells ----shedding of dead skin cells removed attached microbes ----dendritic cells are antigen presenting cells found in skin, phagocytize invaders -Dermis ----contains protein fibers called collagen ----given skin strength and pliability to resist abrasions could include microbes Chemical: - Sweat glands= ----sweat (salty) ----dermicidins- broad spectrum antimicrobial peptides ----lysozyme -Sebaceous glands= ----secrete sebum (oil) ----fatty acids lower the pH ----keep skin pliable

Describe the importance of red bone marrow, the thymus, lymph nodes, spleen, tonsils, and MALT to immunity

Primary lymphoid organs (have the most lymphoids): -Red bone marrow: releases blood cells into the bloodstream when they are mature and when required. Without bone marrow, our bodies could not produce the white cells we need to fight infection, the red blood cells we need to carry oxygen, and the platelets we need to stop bleeding. -Thymus: they make white blood cells Secondary lymphoid organs and tissues: -Lymph nodes: filter lymph (puts the toxins in the blood) -Spleen: filters blood and removes bacteria, viruses, toxins, and foreign matter -Tonsils: help filter out germs that enter through your nose or mouth to protect the rest of your body from infection -MALT: initiates immune responses to specific antigens encountered along all mucosal surfaces

Identify and describe the portals through which pathogens invade and exit the body

Skin: Outer layer of dead skin cells acts as a barrier to pathogens -Some pathogens can enter through openings or cuts -Others enter by burrowing into or digesting outer layers of skin Mucous membranes: Line the body cavities that are open to the environment -Provide a moist, warm environment hospitable to pathogens -Respiratory tract is the most common site of entry -Entry is through the nose, mouth, or eyes -Gastrointestinal tract may be route of entry -Microbe must survive the acidic pH of the stomach Placenta: Typically forms effective barrier to pathogens -Pathogens may cross the placenta and infect the fetus -Can cause spontaneous abortion, birth defects, premature birth

Describe the action of drugs that interfere with cytoplasmic membranes

Some drugs act by forming a channel through the membrane • Disruption of fungal membranes -Ergosterol is a lipid constituent in fungal membranes and is a target of several drugs ---Humans somewhat susceptible ---Most bacteria lack sterols; not susceptible • Disruption of bacterial membranes -Polymyxin effective against Gram-negatives; toxic to human kidneys ---Reserved for use against external pathogens Certain drugs disrupt transport across the cytoplasmic membrane Certain drugs change the permeability of cytoplasmic membranes of parasites

Describe the five distinctive attributes of adaptive immunity

Specificity- Any particular adaptive immune response acts against only one particular molecular shape and not against others. (Adaptive for specific tasks) Inducibility- Cells of adaptive immunity activate only in response to specific pathogens Clonality- Once induced, cells of adaptive immunity proliferate to form many generations of nearly identical cells, which are collectively called clones. (COPIES OF IDENTICAL CELLS) Unresponsiveness to self- As a rule, adaptive immunity does not act against normal body cells; in other words adaptive immune responses are self-tolerant. Several mechanisms help ensure that immune responses do not attack the body itself. Memory- Adaptive immune response has MEMORY for specific pathogens; that is, it adapts to respond faster and more effectively in subsequent encounters with a particular type of pathogen or toxin. (Don't want to have to do induction ceremony every time. It takes a long time!!)

Describe four respiratory diseases caused by Streptococcus idk if this is right-

Strep throat, tuberculosis, influenza, scarlet fever

List the two basic types of white blood cells involved in adaptive immunity

T cells and B cells both lymphocytes

Describe the basic process of T cell maturation and the interactions involving the T cell receptor

T cells are a type of lymphocyte that attack intracellular pathogens and toxins. T cell receptors detect antigens on Major Histocompatibility Complex Proteins.

Explain the process of clonal deletion in B and T cells

T cells: This process is located in the thymus and is used to eliminate or control self-reactive T cells. The goal and the intent of this system is that the surviving lymphocytes will only respond to foreign antigens B cells: This process occurs in the bone marrow and is similar to clonal deletion of T cells. However, the goal and intent of this system is for the self-reactive B cells to be removed from the active B cell repertoire.

Contrast T-dependent and T-independent antigens in terms of size and repetition of subunits

T-Independent Antibody Immunity (no assistance from Th cell) • Antigens consist of many identical, repeating epitopes (polysaccharides) • Like a cheese pizza, no complexity of epitopes • Weak immunity that disappears quickly and induces little memory • Does not produce memory cells • Stunted in children T-Dependent Antibody Immunity (requires assistance of Th2 cell) • Antigens lack numerous, repetitive, and identical epitopes • Involves a series of interactions among APCs, Th2 cells, and B cells, all of which are mediated and enhanced by cytokines (drawn on previous slide) • Like a multi-topping pizza, lots of epitopes• Make memory cells

Describe the complement system, including its three activation pathways

The complement system is made of plasma proteins that makes a hole in the plasma membrane. This process is triggered by the protein being stimulated by an antigen. This stimulation results in an inflammatory response by the protein because it breaks and recombines over and over again. Once the hole is made, a rush of water enters the cell, making it have no control of what enters or leaves the cell, and eventually the cell will undergo apoptosis and lysis. Can be activated in three ways: • Classical pathway - antibodies activate complement • Alternate pathway - occurs independently of antibodies • Lectin pathway - mannose attaches to activating molecules called lectins

Contrast primary and secondary immune responses

The primary immune response displays the first contact of the immune system with an infectious agent whereas all following contacts with the same pathogen are named secondary immune response. Maybe: Primary - IgM first, relatively small amounts of antibodies produced; takes longer Secondary - memory cells recognize and react, IgG spikes way earlier

Describe the importance of the thymus to the development of T lymphocytes

The thymus makes white blood cells called T lymphocytes. These are also called T cells. These are an important part of the body's immune system, which helps to fight infection.

Identify three main categories of side effects of antimicrobial therapy

Toxicity • Exact cause of many adverse reactions poorly understood • Drugs may be toxic to kidneys, liver, or nerves • Considerations needed when prescribing drugs to pregnant women Allergies • Although allergic reactions are rare, they may be life threatening • Anaphylactic shock Disruption of Normal Microbiota • May result in secondary infections • Overgrowth of normal flora - superinfections ---Of greatest concern for hospitalized patients

Contrast droplet transmission and airborne transmission

droplet transmission: droplets from sneezing within I meter (whooping cough, streptococcal pharyngitis-strep throat-) -transmission via droplet nuclei that travels <6 feet airborne transmission: come from coughing, sneezing, air conditioning systems, sweeping, mopping, changing clothes, or flaming inoculating loops -pathogens travel >6 feet to the respiratory mucous membranes of a new host

Differentiate among the terms endemic, sporadic, epidemic, and pandemic

endemic: (of a disease) regularly occurring within an area or community. sporadic: A disease that occurs infrequently and irregularly. epidemic: disease outbreak that is large but within a community and is somewhat controlled pandemic: disease outbreak that is international and out of control

Discuss the epidemiology of tuberculosis

epidemiology: •Someone in the world is infected with M. tuberculosis every second of every day • Kills an average of 4 people each minute, mostly in Asia and Africa • On the decline in the U.S. --More than 9 million Americans infected • Pandemic in other parts of the world --Over 1/3 of world's population infected and 10% of these develop a life-threatening case of TB --9 million new cases resulting in 1-3million deaths annually • Organism not particularly virulent --Only 5% infected develop disease --Kills 55% of untreated patients --Kills 15% of treated patients • Greatest risk of infection - those with lowered immunity; TB is the leading killer of HIV-infected patients • Other risk factors - diabetes, poor nutrition, stress, crowded living conditions, alcohol consumption, drug abuse, and smoking

Compare and contrast the terms infection, disease, morbidity, pathogenicity, and virulence

infection: Successful invasion of the body by a pathogenic microorganism disease: Any adverse internal condition severe enough to interfere with normal body functioning morbidity: any change from a state of health; condition of being diseased; the rate of disease in a population pathogenicity: A microorganism ability to cause disease virulence: a measure/ degree of pathogenicity -contributions adhesion factors, biofilms, extracellular toxins, toxins, antiphagocytic factors **Note: infection vs disease: bacteria enters the body-> infected; bacteria multiplies in body→ causes disease

Contrast mechanical vectors and biological vectors

mechanical vectors -passively carry pathogens to new hosts on their feet or other body parts -not required as hosts by pathogens they transmit biological vectors -transmit pathogens and serve as hosts for the multiplication of a pathogen during some stage of the pathogen's life cycle -pathogens replicate within a biological vector, then enter a new host through a bite -biting arthropods such as mosquitos, ticks, lice, fleas, bloodsucking flies, bloodsucking bugs, and mites

Describe the action of drugs that disrupt synthesis of folic acid

no clue

Explain the importance of adhesion in the establishment of an infection

required for successful establishment of infection by bacterial pathogens -only then the colonization of tissues can happen -otherwise immune system can eject bacteria (coughing, sneezing etc.)

Contrast incidence and prevalence

prevalence: sum of old and new cases incidence: total new cases in a specific time and specific place

Explain the principle of selective toxicity

to kill or inhibit the infecting organism without damaging the host; accomplished through the use of antimicrobial drugs.

Describe the antimicrobial action of nucleotide and nucleoside analogs, quinolones, drugs that bind to DNA or RNA, and reverse transcriptase inhibitors

• DNA and RNA are built from purine and pyrimidine nucleotides • Several drugs function by blocking DNA replication or mRNA transcription • Only slight differences between prokaryotic and eukaryotic DNA; drugs often affect both types of cells ---Not normally used to treat infections; used in research and perhaps to slow cancer cell replication • Quinolones act against prokaryotic DNA gyrase --These drugs typically have little effect on eukaryotes or viruses • Nucleotide/nucleoside analogs can distort shapes of nucleic acid molecules and prevent further replication, transcription, or translation --Most often used against viruses -----Viral DNA polymerases more likely to incorporate -----Viral nucleic acid synthesis more rapid than that in host cells --Also effective against rapidly dividing cancer cells Reverse transcriptase inhibitors act against reverse transcriptase, an enzyme HIV uses early in its replication cycle --Inhibitor does not harm people because humans lack reverse transcriptase

Describe four ways to retard development of resistance

• High concentration of drug maintained in patient long enough to killall sensitive cells and inhibit others so immune system can destroy --Finish entire antimicrobial prescription • Use antimicrobial agents in combination --Synergism - one drug enhances the effect of a second drug • Limit the use of antimicrobials to necessary cases --Many antimicrobial agents are used indiscriminately • Develop semisynthetic drugs, search for new antimicrobials, or synthetically design drugs

Describe the general characteristics of influenza and influenza viruses

• Influenza virus types A and B (orthomyxoviruses) • Structure --Eight different ssRNA molecules as genome --Glycoprotein spike variation <Neuraminidase - hydrolyzes mucus in lungs, allowing virus to spread <Hemagglutinin - binds to pulmonary epithelial cells and triggers endocytosis < e.g., H1N1 variant • Infects lung epithelial cells in the upper and lower respiratory tract • Genomes are extremely variable, especially with respect to genes that encode HA and NA • Mutations occur via two main processes --Antigenic drift < 1 single virus mutates within a cell < Accumulation of HA and NA mutations within single strain in a given geographical area < Relatively minor variations in spike glycoproteins < Results in localized increases in number of infections about every 2 years --Antigenic shift < 2 different viruses enter the same host cell at the same time < Reassortment of genomes from different influenza A strains infecting the same host cell < Occurs in influenza A every 10 years < Strains typically arise in Asia

List two ways that genes for drug resistance are spread between bacteria

• New mutations of chromosomal genes • Acquisition of resistance genes through horizontal gene transfer(transformation, transduction, or conjugation)

Describe the basic activities of drugs that interfere with protein synthesis

• Recall that prokaryotic ribosomes are 70S (30S and 50S subunits)while eukaryotic ribosomes are 80S (40S and 60S subunits) • Antimicrobial agents selectively target bacterial protein translation without significantly affecting eukaryotes • Mitochondria of animals and humans contain 70S ribosomes, so such drugscan be harmful to very active cells of the liver and bone marrow of humans and animals

List seven ways by which microbes can be resistant to antimicrobial drugs

• Resistant cells may produce an enzyme that destroys or deactivates the drug • Resistant microbes may slow or prevent the entry of the drug into the cell • Resistant cells may alter the target of the drug so that the drug either cannot attach to it or binds it less effectively • Resistant cells may alter their metabolic chemistry, or they may abandon the sensitive metabolic step altogether • Resistant cells may pump the antimicrobial out of the cell before the drug can act • Bacteria within biofilms resist antimicrobials more effectively than free-living cells • Protection of the target of an antimicrobial drug

Discuss environmental conditions that can influence the effectiveness of antimicrobial agents

• Warm disinfectants generally work better than cool ones • Acidic conditions enhance the antimicrobial effect of heat • Organic materials can interfere with penetration of heat, chemicals, and some forms of radiations, • Organic materials can deactivate chemical disinfectants

Define microbial death rate, and describe its significance in microbial control

•Microbial death - the permanent loss of reproductive ability under ideal environmental conditions •Microbial death rate - usually a constant rate over time that is species-specific and varies with environmental conditions

Describe the action of antimicrobial attachment antagonists

•Viruses must attach to their host's cells via the chemical interaction between attachment proteins on the virus and complementary receptor proteins on a host cell • Attachment can be blocked by peptide and sugar analogs of attachment or receptor proteins (attachment antagonists) • New area of antimicrobial drug development