microbiology theory final exam chapters 1-15

Explain herd immunity and describe how it protects non-immunized people

if there is a sufficient percentage of the rest of the population is vaccinated, non-vaccinated individuals still reap the protective benefits of immunization. the fewer disease-susceptible people in a community, the harder it is for a pathogen to be transmitted to a susceptible host who could then spread a disease.

Discuss the general immunology principles underlying vaccinations

immunity can be acquired by either natural or artificial means. vaccines are a tool for stimulating immunological memory without causing the disease they aim to prevent

Describe type 1 hypersensitivities and provide examples

include all allergies, atopic asthma (allergy based asthma), and atopic dermatitis- an inflamed and itchy skin condition also known as atopic eczema or allergy-based eczema

Contrast natural, semisynthetic, and synthetic antimicrobials and state the potential value of drug modifications

naturally occurring antimicrobials like penicillin from mold and streptomycin from bacteria. synthetic are wholly manufactured by chemical processes, represent one avenue for making drugs that can overcome antibiotic-resistance mechanisms that naturally evolve as pathogens. semisynthetic is when new antimicrobial drugs don't need to be built from scratch; instead, naturally occurring antibiotics can be chemically modified to improve their pharmacological actions and/or stability.

State what adjuvants are and describe their purpose

pharmacological additives that enhance the body's natural immune response to an antigen. they encourage antigen uptake and processing by antigen-presenting cells (especially dendritic cells), and they stimulate the release of certain cytokines that stimulate immune system activation.

Describe the hygiene hypothesis and its relevance to hypersensitivities

suggests that differential risk may relate to our microbiota profiles. It proposes that in developed countries, ultra-clean water and food combined with common antibiotic usage and decreased infection incidence has decreased the biodiversity of people's normal microbiota. This in turn may affect how our immune system develops and therefore increase our risk for developing autoimmune disorders and allergies.

Provide examples of autoimmune type III hypersensitivities

systemic lupus erythematosus, rheumatoid arthritis, scleroderma, Sjogren's syndrome, and post-streptococcal glomerulonephritis

Define the term valence electron and explain how valence electrons relate to bonding

valence electron, any of the fundamental negatively charged particles in the outermost region of atoms that enters into the formation of chemical bonds. Whatever the type of chemical bond (ionic, covalent, metallic) between atoms, changes in the atomic structure are restricted to the outermost, or valence, electrons.

Describe the various types of vaccine formulations

vaccines can be injected, inhaled, or ingested, and they come in a range of formulations

Explain what protein synthesis (gene expression) is, describe how it impacts phenotype, and state why it is essential to cell survival.

-Genetic information within a cell is read and used to create gene products (proteins) -Consists of genes in DNA being copied into RNA (i.e., transcription) and MRNA is used to build proteins (i.e., translation)-gene expression (phenotype)

Describe the key contributors to and consequences of viral genome evolution, and state why R N A viruses evolve faster than D N A viruses.

-The key contributors is their relatively quick replication time and the larger quantity of virions released within a host, viruses exhibit a faster rate of genomic change than do living infectious agents.-RNA viruses evolve faster than DNA viruses mainly because RNA polymerases, which copy RNA, do not have the proofreading capabilities of DNA polymerases.

Provide examples of how microbes impact industry and the environment.

1. Oil-spill cleanup crew 2. Fashionable fungi 3. Producing biofuel and bioproducts 4. Composting toilets - turning human waste into plant food 5. Plastic-eaters 6. Biocleaning wall painting with Pseudomonas

Identify the goals of aseptic technique, and explain why it is important in healthcare facilities and laboratories.

Aseptic technique, when performed correctly, maintains the sterility of equipment and key parts used during aseptic procedures. In turn, aseptic technique minimizes the risk of contamination of key sites, protects patients from their own pathogenic microorganisms, and ultimately, reduces the risk of infection transmission. Aseptic technique is a set of practices that healthcare professionals use to protect patients and themselves from infection.

Define the term buffer and state why buffers are important in biological systems.

A buffer is a chemical substance that helps maintain a relatively constant pH in a solution, even in the face of addition of acids or bases. Buffering is important in living systems as a means of maintaining a fairly constant internal environment, also known as homeostasis.

State why healthcare settings are hot zones for antibiotic-resistant pathogens and the role of epidemiology in managing such resistance

Abundance of susceptible, immunocompromised patients. Extensive use of antibiotics among patients. reduce transmission of infectious diseases in the healthcare setting through surveillance, prevention, and control programs.

Identify the types of passive and active transport mechanisms that exist in cells.

Active and passive transport are both methods by which a cell moves molecules or substances across the cell membrane or intracellular membranes. The main difference is that active transport requires energy, usually in the form of ATP, to move molecules against a concentration gradient (from lower to higher concentration). Passive transport does not require energy and moves molecules along a concentration gradient (from higher to lower concentration). Passive transport can occur through simple diffusion, facilitated diffusion, filtration, or osmosis

Name and describe the four categories of adaptive immunity and state which confer long-term protection and why

Adaptive immunity is natural or artificial and active or passive. Naturally acquired active immunity: contracting an infection that triggers the patient's immune system leads to memory cells and antibodies; it can be developed from either symptomatic or asymptomatic infections; confers long-term protection because of the production of memory cells. Artificially acquired active immunity: vaccines to trigger an immune response; confers long-term protection because of formation of memory cells and antibodies. Naturally acquired passive immunity: patient receives antibodies to an antigen through non-medical means (for example, maternal antibodies); temporary protection that does not confer long-term protection because memory cells or antibodies are not made. Artificially acquired passive immunity: patient receives protective antibodies from a medical treatment, antiserum is a preparation of antibodies developed to neutralize specific toxins or venoms; the post exposure rabies antiserum and snake anti-venom are two examples of antiserums that yield passive immunity; they offer temporary protection and do not confer long-term protection because no memory cells are made; the patient may have an immune response (serum sickness).

List the similarities and differences between aerobic and anaerobic respiration

Aerobic respiration is more efficient at releasing energy than anaerobic respiration, producing 19 times more ATP. Aerobic respiration requires oxygen, while anaerobic respiration does not. Lactic acid is produced as a by-product of anaerobic respiration. Aerobic respiration breaks down glucose and combines the broken down products with oxygen, making water and carbon dioxide. Anaerobic respiration occurs in conditions of low or no oxygen. Aerobic exercises are excellent at burning excess sugar in the body, while anaerobic processes are used for extreme and sustained efforts

Name the three main categories of contact precautions and explain what each entails

Airborne Precautions Some communicable diseases are spread by tiny airborne droplets. When an infected person coughs or sneezes, tiny droplets are released into the air. Because the droplets are so small, they can remain in the air for a long time and cause infection in people who inhale the droplets. Diseases that require airborne precautions include tuberculosis and chicken pox. Droplet Precautions For some types of communicable diseases, droplets that are released when a patient sneezes or coughs are large and do not stay in the air for a long period of time. Droplet precautions are required for these diseases. Diseases that require droplet precautions include pneumonia, influenza, and whooping cough. Contact Precautions Some communicable diseases can be spread through direct contact and indirect contact. Two examples are MRSA (methicillin-resistant staphylococcus aureus) and VRE (vancomycin-resistant enterococcus). These two infections are highly contagious and very dangerous.

Distinguish between an antibiotic and an antimicrobial drug

An antibiotic is a specific type of antimicrobial that fights bacterial infections. An antimicrobial is a broader term for any product that acts on microbes in general, including bacteria, fungi, viruses, helminths, and protozoa

Describe the differences between anabolism and catabolism. Describe how and why catabolic and anabolic reactions depend on each other

Anabolic pathways combine energy and molecules to build new substances; Anabolic reactions, also known as biosynthetic reactions, involve dehydration synthesis reactions and tend to be endergonic. Catabolic pathways break down substances and release energy; catabolic reactions are generally hydrolytic and exergonic. Catabolic and anabolic reactions are often coupled-- cells use catabolic reactions to harvest energy from complex molecules by breaking them down into simpler, lower energy molecules. Anabolic reactions use ATP generated in catabolic reactions to make building-block molecules and macromolecules.

Describe the basic structural and functional features of antibodies

Antibodies, also known as immunoglobulins (Ig) are secreted by plasma cells. Antibodies bind to the antigen that triggered the B cell's activations; they can activate complement cascades, neutralize antigens, and promote phagocytosis of targeted antigens. Structural features: an antibody's single-unit, monomeric structure consists of 2 heavy chains, 2 light chains, held together by covalent disulfide bonds, forming a Y-shaped molecule.

Define antibody titer and state how it differs in a primary versus secondary antigen exposure

Antibody titer is the number or amount of antibodies in a patient sample. In a primary exposure, IgM antibodies are generated first and then IgG. In secondary antigen exposure, the IgG titer will surge and be much higher than IgM, which may indicate immunity.

Explain the basic structure and function of endospores and discuss why they present challenges in healthcare settings.

Are metabolically inactive structures that allow certain cells to enter a dormant state. Once the endospore is released, it is simply called a spore. Bacterial spores are highly resistant to environmental stress such as starvation, heat, drying, freezing, radiation, or various chemicalsThe capacity to make endospores allows dangerous pathogens like Clostridium tetani (the causative agent of tetanus), Clostridium botulinum (the causative agent of botulism), Clostridium perfringens (the causative agent of gas gangrene), and Clostridium difficile (the causative agent of a severe diarrhea) to survive for extended periods on surfaces, even in healthcare facilities that work hard to eradicate them.

Define the term attenuated pathogen

Attenuated pathogen is the term applied to pathogens that lose virulence factors needed to cause disease; they are still infectious but weakened to the point that they do not cause disease in an immune competent host; may be used to formulate certain vaccines.

Describe how normal microbiota may impact immune responses and limit pathogens

Normal microbiota shape immune responses and confers protection to host; these microbes play a central role in inducing, training, and calibrating immune responses; immune system may become confused with normal microbiota change

Describe how a biofilm forms and discuss the healthcare implications of biofilms.

Bacteria that form biofilms by attaching to surfaces and secreting a polymeric matrix have an enormous impact in everyday life. In medicine, biofilms form on medical implants and within human tissue as in cystic fibrosis; in industry they cover equipment surfaces. Biofilms protect their inhabitants from various adverse environmental conditions including biocides and antibiotics.

Explain what a spontaneous mutation is and discuss the primary contributors to spontaneous mutations.

Spontaneous mutations occur naturally in the genome. They generally occur due to error during replication, mitosis, meiosis, etc. Mutations may also occur due to mobile genetic elements or transposons. The main causes of spontaneous mutations are: Replication errors Slipped strand mispairing Wobble base pairing Depurination or deamination

Compare the theories of biogenesis and spontaneous generation and summarize Louis Pasteur's role in proving biogenesis.

Biogenesis is the idea that life emerges from existing life spontaneous generation (abiogenesis = without) is the idea that life comes from nonliving items Louis Pasteur showed that biogenesis is responsible for the propagation of life and disproved the spontaneous generation by using the S-neck flask experiment

Define the terms decontamination, sterilization, disinfection, microbiostatic, microbiocidal, disinfectant, and antiseptic

Decontamination removes or reduces microbial populations to render an object safe for handling. Sterilization eliminates all bacteria, viruses, and endospores (required for drugs, objects used for medical procedures, and for lab media and glassware). Disinfection reduces microbial numbers (used for cosmetics, foods, surfaces, and external medical equipment). Bacteriostatic inhibit microbial growth are microbiostatic. Bactericidal kill microbes are classified and microbiocidal. Disinfectants are used to treat inanimate objects. Antiseptics are applied to living tissue.

Describe the features of chronic inflammation

Chronic inflammation describes an ongoing, long-term response to endogenous or exogenous inflammatory stimuli and is characterized by continued accumulation of mononuclear leukocytes (macrophages and lymphocytes), accompanied by tissue injury due to the prolonged inflammatory response.

Name and describe the five main classes of fungal spores.

Chytridiomycota (Chytrids), the Zygomycota (conjugated fungi), the Ascomycota (sac fungi), the Basidiomycota (club fungi) and the recently described Phylum Glomeromycota. An older classification scheme grouped fungi that strictly use asexual reproduction into Deuteromycota, a group that is no longer in use.

Describe the three general steps for producing a recombinant DNA (rDNA) vector, state how rDNA can be introduced into cells, and discuss the clinical applications of rDNA

Steps in rDNA technology Step 1: Identification and isolation of gene of interest or DNA fragment to be cloned. Step 2: Insertion of this isolated gene into a suitable vector. Step 3: Introduction of this vector into a suitable host the process is called as transformation. the host cell might contain particular metabolic pathways that limit production of desired protein. Alternatively, the protein may fail to correctly fold in the host cell, rendering it useless

Name the levels of germicide activity, and identify the types used for critical, semi critical, or noncritical equipment

Critical items (will enter tissue or vascular system or blood will flow through them) Disinfection High-level (semi critical items; [except dental] will come in contact with mucous membrane or non intact skin) Intermediate-level (some semi critical items and noncritical items) Low-level (noncritical items; will come in contact with intact skin)

Compare and contrast direct, indirect, and sandwich ELISA techniques

Direct ELISA In a direct ELISA, an antigen or sample is immobilized directly on the plate and a conjugated detection antibody binds to the target protein. Substrate is then added, producing a signal that is proportional to the amount of analyte in the sample. Since only one antibody is used in a direct ELISA, they are less specific than a sandwich ELISA. Indirect ELISA An indirect ELISA is similar to a direct ELISA in that an antigen is immobilized on a plate, but it includes an additional amplification detection step. First, an unconjugated primary detection antibody is added and binds to the specific antigen. A conjugated secondary antibody directed against the host species of the primary antibody is then added. Substrate then produces a signal proportional to the amount of antigen bound in the well. Sandwich ELISA Sandwich ELISAs are the most common type of ELISA. Two specific antibodies are used to sandwich the antigen, commonly referred to as matched antibody pairs. Capture antibody is coated on a microplate, sample is added, and the protein of interest binds and is immobilized on the plate. A conjugated-detection antibody is then added and binds to an additional epitope on the target protein. Substrate is added and produces a signal that is proportional to the amount of analyte present in the sample. Sandwich ELISAs are highly specific, since two antibodies are required to bind to the protein of interest.

Describe the various direct and indirect modes of transmission, and provide examples of each

Direct contact skin-to-skin or kissing Droplet transmission- when bacteria or viruses travel on respiratory droplets Airborne- a disease caused by pathogens that are transmitted through the air Vehicle borne- indirect transmission of an infectious agent that occurs when a vehicle (or fomite) touches a person's body or is ingested Vector borne- an illness caused by an infectious microbe that is transmitted to people by blood-sucking arthropods. The arthropods (insects or arachnids) that most commonly serve as vectors include

Compare horizontal and vertical gene transfer.

Horizontal gene transfer refers to the process in which genetic material is transferred between unrelated individuals. Vertical gene transfer refers to the process where genes are transferred from parent to their offspring. This is the key difference between vertical and horizontal gene transfer. Vertical gene transfer is common among organisms while horizontal gene transfer is less common.

Describe electrolytes and their importance in biological systems.

Electrolytes serve several purposes in the body, including conducting nervous impulses, contracting muscles, keeping you hydrated, regulating your body's pH levels, and maintaining the balance between fluids inside and outside your cells

Describe catalysts and their importance in biological systems.

Enzymes are life's great facilitators. They create the conditions needed for biochemical reactions to happen fast. The general name that chemists use for a chemical entity that increases the speed of a reaction is a "catalyst." Enzymes are biological catalysts--they catalyze the chemical reactions that happen inside living things.

Describe the function of prokaryotic ribosomes and discuss how their structural features support the endosymbiotic theory.

Essential organelles for making proteins; eukaryotic ribosomes, like prokaryotic ribosomes, are made up of protein and ribosomal RNA (rRNA); ribosomes build proteins by linking together amino acids. Prokaryotes have 70S ribosomes while eukaryotes have 80S ribosomes.Interestingly, the ribosomes of two eukaryotic organelles—chloroplasts and mitochondria—are 70S, just like prokaryotic ribosomes. This observation further supports endosymbiotic theory, which hypothesizes that eukaryotic cells developed from prokaryotic cells that lived symbiotically with an ancient shared ancestor.

.Discuss the basic structural and functional features of eukaryotic plasma membranes and how they differ among kingdoms.

Have a phospholipid bilayer that is filled with receptors and channels. They also contain sterols which are rare in prokaryotes.Sterols: Organic ring-structured compounds that have an alcohol functional group (OH group); the most common example of a sterol is cholesterol. Sterol compounds are hydrophobic, which means they do not like interacting with water. They are plentiful in eukaryotic membranes where they have central roles in maintaining membrane stability and fluidity.

Define the term mycosis and give examples of human mycoses

Fungal infections, or mycosis, are diseases caused by a fungus (yeast or mold). Fungal infections are most common on your skin or nails, but fungi (plural of fungus) can also cause infections in your mouth, throat, lungs, urinary tract and many other parts of your body.

Give example of eukaryotes with cell walls and discuss how cell walls differ among eukaryotic kingdoms

Fungi, plants, and certain protists have cell walls, but animal cells don't.In general, chitin (KITE-in) is a core compound in many fungal cell walls, while cellulose is abundant in plant cell walls. Protists have diverse cell walls that can include cellulose, calcium carbonate, xylan, silica, and a variety of other protein- and carbohydrate-based compounds.

Describe how Robert Koch helped shape the germ theory of disease and list his postulates of disease.

Germ theory of disease: infectious disease is caused by microbesKoch realized a bacterium caused anthrax, he isolated this bacterium and introduced a purified version to rats to establish an infection. Postulates of disease: Determining the causative agent of infectious disease 1. The same organism must be present in every case of the disease. 2. The organism must be isolated from the diseased host and grown as a pure culture. 3. The isolated organism should cause the disease in question when it is introduced (inoculated) into a susceptible host (a host that can develop the disease). 4. The organism must then be re-isolated from the inoculated, diseased animal.

Describe immunological memory and compare it to a primary response

Immunological memory is provided by memory cells residing in lymphoid tissues. Memory cells allow for a rapid reactivation of cellular and humoral adaptive responses if the same antigen is encountered again later.Secondary immune response requires the coordinated activity of memory B and T cells. Primary exposure to an antigen generates IgM isotype antibodies first, then IgG; in secondary response to the same antigen, activated memory cells quickly generate a high titer of high affinity IgG antibodies and only a small amount of IgM antibodies. In secondary exposure, the surge in antibodies is faster and greater than in primary exposure.

Discuss basic differences in features of microbial growth in a laboratory versus in nature.

In a lab, bacteria are usually isolated and grown in closed pure batch cultures.-bacteria deposited into flask of sterile growth medium and set amount of organic and inorganic nutrients-flask covered to prevent outside contamination-undergoes distinct growth phases that can be detected by counting the number of viable cellsIn industry, maintaining cells at specific growth phase is necessary for optimizing production of useful products like ethanol or pharmaceuticals; instead of closed batch culture, a chemostat is used. In chemostat:-fresh growth medium added at one end of culturing device-waste, nutrient-depleted medium, excess cells removed at another end of system-maintains constant culture volume for days or weeks-culture does not experience all four death phases In nature:-instead of four distinct growth phases, because of more diverse environments and mix of species, growth is not straightforward-instead of being grown as pure, single-species cultures, bacteria in nature intermingle and live side by side with archaea and eukaryotes-morphological property like cell shape can be altered by environmental factors-cells living communally, as in biofilms where they communicate and collaborate, are more realistic

Provide a basic description of a prokaryotic cell and explain why prokaryotes tend to be small.

In general, a prokaryotic cell is smaller because it has less DNA to create the proteins needed to make an ultra-efficient membrane. So, the cells reach a size where they can no longer import the number of nutrients they need for the volume of cytosol they contain

Explain the five stages of infectious disease, and summarize how these stages vary from one pathogen to another and the challenges that such variations present in epidemiology

Incubation Stage 1st stage From exposure to first signs of symptoms showing. Can be short or long Prodromal Stage (Initial stage of disease) 2nd stage First signs of symptoms to signs of fever. Pt will have feelings of malaise Acute stage 3rd stage At its peak Symptoms are fully developed Inflammatory response assists ( 2nd line of defense; is natural) Declining Stage Symptoms begin to reduce 4th Stage Pt is still sick, disease remains Medicine is often prematurely discontinued, makes microorganisms resistant to antibiotics Convalescent Stage Recovery and recuperation Patients regains strength and stamina Close to original state of health

Explain the relationship between symptoms and mode of transmission

Infection occurs in a cycle that depends on the presence of all of the following elements: infectious agent/pathogen• reservoir/source for pathogen growth• port of exit from the reservoir• mode of transmission• port of entry to a host• susceptible host TRANSMISSION- Infection can develop if this chain remains uninterrupted. *Preventing infections involves breaking the chain of infection. *The major route of transmission for pathogens identified in the health care setting is the unwashed hands of the health care worker. *Equipment used within the environment (stethoscope, blood pressure cuff, bedside commode) often becomes a source for the transmission of pathogens. *Organisms enter the body through the same routes they use for exiting. *Practicing infection prevention and control techniques (hand hygiene) interrupt the mode of transmission. Modes of Transmission: 1. Contact(Direct)•Person-to-person (fecal, oral) physical contact between source and susceptible host (ex: touching patient feces and then touching your inner mouth or consuming contaminated food)(Indirect)•Personal contact of susceptible host with contaminated inanimate object (needles/sharp objects, dressings, environment) 2. Droplet•Large particles that travel up to 3 feet during coughing, sneezing, or talking and come in contact with susceptible host 3. Airborne•Droplet nuclei/residue/evaporated droplets suspended in air during coughing or sneezing or carried on dust particles 4. Vehicles•Contaminated items•Water•Drugs, solutions•Blood•Food (improperly handled, stored, or cooked; fresh/thawed meats) 5. Vector•External mechanical transfer (flies)•Internal transmission: parasitic conditions between vector and host such as mosquito, louse, flea, and tick

Compare and contrast antigenic shift and antigenic drift, and state how they impact influenza virus evolution and outbreaks

Influenza strains are constantly mutating. A small change to the genetic makeup of influenza strains is referred to as antigenic drift, while a major change is called antigenic shift. While these designations are mainly relevant to scientists, they help explain why you can contract the flu more than once and why the influenza vaccine is changed annually (and may be less effective in some seasons than others).

Differentiate between organic and inorganic compounds and identify selected functional groups.

Inorganic compounds have no carbon except for a few exceptions. Organic compounds are made primarily from carbon. Functional groups are hydroxyl, carboxyl, amino and phosphate.

Correctly use clinical terminology to describe different fever patterns

Intermittent fever- This fever has a fluctuating baseline between normal temperatures and fever levels over the course of the day. Remittent fever- This type of fever may come and go, and the temperature fluctuates, but though it falls, it never falls all the way back to normal. Hectic fever- Either an intermittent or a remittent fever is considered hectic if the temperature range swings widely throughout the day, with a difference of at least 1.4 degrees Celsius between the highest and lowest temperatures. Continuous fever- Also called a "sustained" fever, this is a prolonged fever with little or no change in temperature over the course of a day. Relapsing- This is a type of intermittent fever that spikes up again after days or weeks of normal temperatures. This type of fever is common with animal bites and diseases like malaria.

Compare and contrast ionic and covalent bonds.

Ionic bonds occur between atoms with very different electronegativities, while covalent bonds occur between atoms with similar or low electronegativity differences. In ionic bonds, electrons are transferred from one atom to another, while in covalent bonds, electrons are shared between atoms.

Describe the difficulties of developing drugs against viruses and eukaryotic pathogens

It is difficult to develop drugs that specifically target viruses and eukaryotic pathogens without inflicting collateral damage on our own cells. Effective anti-protozoan and antihelminthic drugs are difficult to develop because these eukaryotes have complex life cycles; drugs that target one stage may be ineffective against other stages.

Outline the features of the four stages of bacterial growth in a closed pure batch system.

Lag phase: cells adjust to their environment. Log phase: exponential cell growth. Stationary phase: # of cells dying = # of cell dividing. Death phase: cells die as waste accumulates and nutrients are depleted.

Identify key mechanisms by which viruses can cause chronic or latent persistent infections.

Latent infection is the stage of the cell cycle that is defined as the time from the onset of the infection to the appearance of virus extracellularly. When the virus stays within the body of the host while continuously replicating and remaining infectious, that is termed as a persistent viral infection.

Describe how the two types of M H C s present antigens, and summarize how M H C s impact transplant rejection

MHC I is found on the surface of all body cells except red blood cells; acts like body's uniform; presents intracellular antigens to T cytotoxic cells; eliminated by killing host cell. MHC I presents antigens when viral proteins inside an infected cell are chopped up by a proteasome, the snippets are shipped to the cell's endoplasmic reticulum, where MHC I molecules bind to proteins to make MHC I-antigen complexes, and then the complex migrates to the cell surface, displaying the antigen. MHC I may bind to self-proteins and display them on the cell surface, where it is up to patrolling TC cells to decide if protein displaying is normal self-protein or not. Only T cytotoxic cells that have been trained by APCs to recognize the given antigen can effectively patrol the body an eliminate cells displaying suspicious antigens. MHC I interacts with CD8 on TC cells.MHC II is only made by antigen-presenting cells like macrophage, B-cells, and dendritic cells; presents extracellular antigens to T helper cells; can be directly attacked without need to kill host cells. APC's phagocytize dead self-cells and potential invaders, break down the ingested antigen, snippets associate with MHC II proteins to form MHC II-antigen complexes, and the migrate to the cell surface to display antigen. MHC II interacts with CD4 on T helper cells.MHCs—major histocompatibility complex proteins—are specialized "self-proteins" also known as human leukocyte antigens (HLAs). T cells must recognize "self" MHC so self-tissues are not attacked. If MHCs are not closely matched between a tissue donor and recipient, the recipient's immune system will recognize the transplanted tissue as foreign (allorecognition is the process that lymphocytes use to differentiate self from foreign MHCs).

Provide examples of how Mycobacteria, endospore, virus, protozoan, and prion levels are each controlled

Mycobacterium species cause tuberculosis and leprosy. Contain cell walls rich in waxy mycolic acids. Spread by airborne droplet, control measures target reducing airborne particles from infected individuals. Endospores are dormant structures that revert to growing (vegetative) cells once favorable growth conditions are restored. Endospores survive drying, radiation, boiling, chemicals, and heat treatments. Most effective way to ensure elimination of endospores is by autoclaving. Other methods include hydrogen peroxide vapor at high heat or sporicides. Viruses can be resistant to some measures. Lipids in the viral envelope are sensitive to heat, drying, and detergents. Glutaraldehyde-based detergents are effective at inactivating these viruses. Naked viruses are usually inactivated by chlorine-based agents. Protozoan control: Different stages of a protozoan's life cycle can resist certain control methods. Variety of treatments are used (e.g., filtration, carbon dioxide, UV, and ozone treatments). Prion control: proteinaceous infectious particles withstand autoclaving and chemical sterilization. Surgical devices are reused after autoclaving or chemical sterilization. Prions are eliminated through a combination of chemical treatments and increased temperature and pressure during autoclaving.

Name the various classes of microbes according to their oxygen use and tolerance

Obligate Aerobe: dependent on O2 for cellular purposes. Obligate Anaerobe: don't use O2 for metabolism Microaerophiles: uses small amounts of O2 in metabolism, lives in low O2 settings. Aerotolerant Anaerobe: tolerate O2 but don't use it. Facultative Anaerobe: prefer using O2 for metabolism but can survive without it

Compare the following sets of terms: opportunistic versus true pathogen; endemic versus sporadic disease; communicable versus noncommunicable disease; and acute versus chronic disease

Opportunistic pathogens only cause disease when host is weakened. True pathogen does not need a weakened host to cause disease. Communicable diseases transmit from humans. Noncommunicable do not spread from humans. Acute disease have a rapid onset and progression. Chronic diseases have a slow onset and progression Sporadic refers to a disease that occurs infrequently and irregularly. Endemic refers to the constant presence and/or usual prevalence of a disease or infectious agent in a population within a geographic area.

.Compare and contrast primary and secondary immunodeficiencies.

PRIMARY: basic development failure somewhere in the system, thymus, or antibody synthesis. This happens FROM BIRTH SECONDARY: loss of immune response that may occur ANY TIME DURING LIFESPAN.

State the four cardinal signs of inflammation and describe how they come about.

Pain: This may occur continuously or only when a person touches the affected area. Redness: This happens because of an increase in the blood supply to the capillaries in the area. Swelling: A condition call edema can develop if fluid builds up. Heat: Increased blood flow may leave the affected area warm to the touch.

State what fever is, list its potentially useful effects, and describe how it is generated and treated

Part of the acute phase response to inflammation that affects the thermoregulatory center 1. Limits microbe reproduction by diminishing the necessary concentrations of iron, zinc, and copper in blood plasma 2. Increases phagocytic leukocytes needed for healing 1. Release of prostaglanindins/fever-producing cytokines from inflammatory cells 2. Hypothalamus resets body temperature 3. Body responds with a variety of tactics to raise body temperature (eg, chills, etc.) 4. Fever develops 5. Body eventually tries to lower temperature back to normal with a variety of tactics (eg, flush, sweating, etc.) Fever reducing medicine

Discuss how shifts in normal microbiota levels or location may promote disease

Pathogens are usually crowded out by our normal microbiota but if our normal microbiota decreases or is disturbed, it can allow for pathogens to establish disease. E. coli lives harmlessly in the appendix but if it invades the abdominal cavity, as occurs when the appendix ruptures, then its attacked by the immune system.

Describe prions and the diseases they cause in humans.

Prion disease represents a group of conditions that affect the nervous system in humans and animals. In people, these conditions impair brain function, causing changes in memory, personality, and behavior; a decline in intellectual function (dementia); and abnormal movements, particularly difficulty with coordinating movements (ataxia)

Define the term phage conversion and discuss why it is medically important.

Phage conversion-- prophages are able to confer new pathogenic properties to bacterial cells Medical importance: can provide new pathogenicity factors to a bacterium (e.g. toxins)-Examples: Clostridium botulinum (creates botulism toxin)-Corynebacterium diphtheria

List the three primary functions of inflammation and describe its three phases

Phase 1: Inflammatory Response- Healing of acute injuries begins with the acute vascular inflammatory response. The purpose of vascular changes is to increase blood flow to the local area, mobilize and transport cells to the area to initiate healing. The damaged cells are removed and the body begins to put new collagen in the area of injury. This phase is initiated immediately after injury and lasts 3-5 days. Phase 2: Repair and Regeneration- The second phase is characterized by new collagen formation. New collagen fibers are laid down in a disorganized manner in the form of a scar and there are weak links between each fiber. Thus, the new tissue is weak and susceptible to disruption by overly aggressive activity. This phase lasts from 2 days to 8 weeks. Phase 3: Remodeling and Maturation- As healing progresses, the tissue continues to remodel, strengthen and improve its cellular organization. There is less new collagen formation, but increased organization of the collagen fibers, and stronger bonds between them. Tension becomes important because new collagen must orient along the lines of stress to best accommodate the loads required for function. The end of tissue remodeling is unknown and may take months to years for completion.

Explain why Protista is sometimes described as a catchall kingdom.

Scientists sometimes call kingdom Protista the "catch-all kingdom" because it is made up of organisms that don't really belong anywhere else. The organisms belong to Protista by virtue of not being animals, plants or fungi.

Explain transcription and translation and point out differences in the process in prokaryotes versus eukaryotes

Prokaryotic transcription and translation can occur simultaneously. This is impossible in eukaryotes, where transcription occurs in a membrane-bound nucleus while translation occurs outside the nucleus in the cytoplasm. In prokaryotes genetic material is not enclosed in a membrane-enclosed nucleus and has access to ribosomes in the cytoplasm.

Name and describe the four kingdoms of eukaryotes.

Protista Kingdom: Protista are simple, predominately unicellular eukaryotic organisms. Fungi Kingdom: Fungi are unicellular or multicellular organisms with eukaryotic cell types. Plantae Kingdom: Plants are multicellular organisms composed of eukaryotic cells. Animalia Kingdom: Animals are multicellular organisms composed of eukaryotic cells.

Define the term protozoan, list the four main groupings of protozoans, and state how they are classified.

ProtozoansMeans "first animal;" a term of convenience to describe animal-like protists that are unicellular, lack a true cell wall, exhibit asexual and sexual reproduction, and typically live by heterotrophic means.Amoebiod(Sarcodina): use false feet extensions of their cytoplasm called pseudopodsFlagellated(Mastigophora): Have one or more flagella for mobilityCiliated(Ciliophora): use hair like appendages called cilia for mobilitySpore-Forming(Apicomplexa): one of the largest phyla of protozoans. In their mature form, they have no flagella, cilia, or pseudopodia, and instead move by gliding

Describe the temperatures at which psychrophiles, psychrotrophs, mesophiles, thermophiles, and extreme thermophiles would thrive, and state the grouping for most pathogens.

Psychrophiles: between -20°C and 10°C Psychrotrophs: between 0°C and 30°C, associated with food borne illness. Mesophiles: between 10°C and 50°C, associated with most human body pathogens. Thermophiles: between 40°C and 75°C, associated with compost piles and hot springs. Extreme Thermophiles: Between 64°C and 120°C

Describe the various mechanisms that pathogens may use to avoid immune detection and elimination

Some pathogens avoid the immune system by hiding within the cells of the host, a process referred to as intracellular pathogenesis. The pathogen hides inside the host cell where it is protected from direct contact with the complement, antibodies, and immune cells. A lot of pathogens release compounds that misdirect or diminish the host's immune response. Some bacteria even form biofilms which protect them from the proteins and cells of the immune system. Many successful infections often involve biofilms. Some bacteria create surface proteins, such as Streptococcus, that will bind to antibodies making them ineffective.

Discuss how route of administration, drug interactions, and contraindications play into drug development

Route of administration- Oral: preferred because it is easiest but [the drug] must be stable in the acidic environment of the stomach and sufficiently absorbed in the intestines- parenteral (injection or infusion): may be intravenously, intramuscularly, or subcutaneously injected; downsides include that needles and/or intravenous lines must be used and patient may have "needle phobia" and injection discomfort (also breaking skin barrier) Nearly every drug has some sort of contraindication or warning listed-Rifampin for TB inactivates oral contraceptives- Digoxin shows higher toxicity when a macrolide is also prescribed- tetracyclines are not recommended during pregnancy or for nursing mothers

Compare silent, missense, and nonsense mutation effects.

Silent mutations - are caused by a point mutation & have no effect of the function because they code for the same amino acid Missense mutations - are caused by a point mutation & result in a different amino acid to be placed in the protein Nonsense mutations - a caused by a point mutation & cause a stop where there should not be one

Explain the flow of genetic material as it is presented by the "central dogma."

The central dogma of molecular biology describes the flow of genetic information in cells from DNA to messenger RNA (mRNA) to protein. It states that genes specify the sequence of mRNA molecules, which in turn specify the sequence of proteins. -DNA directs production of RNA-RNA directs assembly of proteins

.Compare bacteria and archaea plasma membranes and cell walls.

The chemical linkages in bacterial plasma membranes differs from those in archaea. This is actually one of the ways we distinguish bacteria from archaea. In bacteria, phospholipids are built from generally linear fatty acids, while archaea use long-branched lipids called isoprenoids instead of fatty acids. Certain archaea that live in extreme heat build lipid monolayers as opposed to lipid bilayers. These monolayer membranes contain unique lipids (called tetraether lipids) that are basically long lipid molecules capped on either end with a polar head group. These unique membrane adaptations help archaea thrive in harsh environments.

Describe the endosymbiotic theory as it relates to the evolution of eukaryotes.

The endosymbiotic theory is an evolutionary theory that describes how eukaryotic cells originated from prokaryotic cells. According to this theory, some prokaryotes lived inside larger cells in a symbiotic association and eventually became part of them. The endosymbiotic theory helps to explain the origin of mitochondria and chloroplasts, which are organelles in eukaryotic cells

State the general function of first-line defenses

The first line of defence (or outside defence system) includes physical and chemical barriers that are always ready and prepared to defend the body from infection.

Compare and contrast the ways eukaryotic and prokaryotic cells how genetic material organized their genomes.

The key difference between genetic material of prokaryotes and eukaryotes is that genetic material of prokaryotes floats in the cytoplasm since they do not have a nucleus while the genetic material of eukaryotes resides inside the nucleus. Another important difference between is that the prokaryotes have a small genome and contain plasmids. They also have a large coiled double-stranded circular chromosome whereas, eukaryotes have a larger genome and do not possess plasmids. Prokaryotes and eukaryotes are two types of organisms. Bacteria and Archaea are prokaryotes. Prokaryotes have a simple cellular organization. They do not have a nucleus and true organelles. On the other hand, eukaryotes have a complex cellular organization with a membrane-bound nucleus and true organelles. Fungi, protists, plants, and animals are eukaryotes.

Compare and contrast Gram-positive and Gram-negative cell walls

The key difference between gram positive and gram negative cell wall is that the gram positive cell wall has a thick peptidoglycan layer with teichoic acids while gram negative cell wall has a thin peptidoglycan layer surrounded by an outer membrane. Another major difference between gram positive and gram negative cell wall is that the gram positive cell wall stains in purple colour in grams staining while grams negative cell wall stains in pink colour.

Define osmosis and predict the outcome of placing a bacterial cell in hypertonic, hypotonic, or isotonic solutions.

The net movement of water across a selective membrane. Hypertonic will cause the cell to lose water to the environment. Hypotonic would rapidly take on water. Isotonic would have no net loss or gain of water from the cell because the solute concentrations are equal inside and outside the cell.

Identify the five tasks a pathogen must complete to successfully infect a host

The pathogen must gain entry into the host, attach to and invade specific cells/and or tissues within the host, evade host defenses, obtain nutrients from the host, and exit the host.

Compare and contrast T and B cells

While B-cells produce antibodies to fight infection, T-cells protect people from getting infected by destroying cancerous and infected cells. B-cells are also far more likely than T-cells to mutate into a liquid cancer such as chronic lymphocytic leukemia (CLL) or B-cell lymphoma. While both are critical to the body's defense against disease and infection, T-cells and B-cells play very different roles. CAR T-cell therapy and checkpoint inhibitors are examples of how researchers are using what they've learned about T-cells specifically in developing new cancer treatments. But as their differences and similarities show, both types of immune cells employ important natural defenses in helping the body fight cancer.

Explain several roles of molecular second-line defenses in innate immunity

The second line of defense of the innate system includes chemical signals that produce inflammation and fever responses as well as mobilizing protective cells and other chemical defenses.

Define the term strain.

The term strain is used to distinguish a genetically distinct lineage separated from another strain by one or more mutations.

Explain why virulence is best viewed as an evolving property

Through interacting with us, our pathogen enemies evolve new virulence factors. Pathogen virulence factors also develop and evolve in response to the selective pressures that we impose on various agents. Evolution of antibiotic resistance is a classic example of this process.

Describe how lipids and proteins are broken down by extracellular and intracellular catabolism

Triglycerides are a form of long-term energy storage in animals. They are made of glycerol and three fatty acids. Phospholipids compose the cell and organelle membranes of all organisms except the archaea. Phospholipid structure is similar to triglycerides except that one of the fatty acids is replaced by a phosphorylated head group. Triglycerides and phospholipids are broken down first by releasing fatty acid chains (and/or the phosphorylated head group, in the case of phospholipids) from the three-carbon glycerol backbone. The reactions breaking down triglycerides are catalyzed by lipases and those involving phospholipids are catalyzed by phospholipases. Proteins are degraded through the concerted action of a variety of microbial protease enzymes. Extracellular proteases cut proteins internally at specific amino acid sequences, breaking them down into smaller peptides that can then be taken up by cells. Some clinically important pathogens can be identified by their ability to produce a specific type of extracellular protease.

Describe the binomial nomenclature system and the information it provides about an organism.

Two name system- Genus is the first name (Capitalized) Species is the second name (lowercase) Scientific names are italicized binomial nomenclature is essential to integrate the naming system across life sciences and therefore assign one particular unique name identifier for a particular species across different languages.

Describe type II hypersensitivities: cytotoxic and noncytotoxic

Type II hypersensitivities, also called cytotoxic hypersensitivities, are the result of antibody (IgG and IgM) interactions with body cells and tissues that lead to cell destruction. Once bound to a cell, the antibody initiates a cascade of events, known as complement, that causes inflammation and cell lysis. Two common type II hypersensitivities are hemolytic transfusion reactions and hemolytic disease of newborns. the third way for type II reactions to inflict damage occurs without causing cytolysis. Instead of lysing it causes the receptor to inactivate or an over-activation.

Describe why biochemical tests are useful

allow us to detect metabolic end products, intermediates, or particular enzymes are extremely useful in identifying microbes

Discuss the features of the genetic code and how these features benefit a cell

Universal- common to ALL life forms Triplet Code- 3 nucleotides in a sequence code for 1 amino acid, 3 nucleotides in a sequence are called a codon Non-Overlapping- means that the triplet code does NOT overlap such that nucleotides in a sequence can ONLY function to code for one specific amino acid Redundant- (degenerate) refers to the fact that most amino acids have more than one triplet code (codon). 64 codons vs. 20 amino acids.

Explain the significance of a virus' host range and tropism

Virus-receptor interactions play a key regulatory role in viral host range, tissue tropism, and viral pathogenesis. Viruses utilize elegant strategies to attach to one or multiple receptors, overcome the plasma membrane barrier, enter, and access the necessary host cell machinery.

Describe a host-microbe interaction that influenced human evolution.

When human populations adapt genetically to new environments, their microbiotas may also participate in the process. Microbes can evolve faster than their host, which allows them to respond quickly to environmental change. They also filter the host's environment, thereby altering selective pressures on the host.

Explain how the CRISPR-Cas9 protein system edits genetic material

allows researchers to perform gene surgery-CRISPR-Cas9 can locate a specific DNA sequence and cut it out with surgical precision so that new DNA can be plugged into the cut site.

State what tools or techniques, aside from biochemical tests, are useful for identifying a bacterial specimen

amino acid catabolism tests- reveal which amino acids a bacterium can break-down fermentation tests- biochemical test commonly used to identify an unknown specimen. oxidase and catalase tests- oxidase can be used to determine if a bacterium has cytochrome c oxidase in its respiratory chains. catalase is another commonly used test in introductory microbiology labs.

Give an example of a rapid analysis technique and how it works

a specialized test strips like the Analytical Profile System. the media are inoculated with a pure culture, and the entire strip is then incubated for 18-24 hours. An index number can then be generated using an automated reader or by manually observing and recording the test results.

Explain why cancer can be considered a failure of the immune system

any defect or deficiency in our immune system can lead to an increased cancer risk, but in particular, T cytotoxic cells are important for destroying cancer cells.

Explain how type IV sensitivities are mediated, how they progress, and why they are called delayed hypersensitivities

any immune response, whether it's mediated by antibodies (humoral response) or by T cells (cellular response), it is considered a hypersensitivity if it is directed at self-tissues or is aimed at an otherwise harmless substance. They manifest 12-72 hours after the stimulating antigen is encountered.

Describe at least three roles of public health

assessment, policy development, and assurance

Describe factors that contribute to the re-emergence of vaccine-preventable diseases

autism

Compare bacteriostatic to bactericidal drugs, discuss scenarios where each may be useful, and explain why these terms are less concrete in clinical scenarios

bacteriostatic prevents bacteria from growing bactericidal actively kills bacteria. bacteriostatic drugs, such as erythromycin, are typically effective for patients who have a healthy immune system that can destroy the bacteria during the drug course. Bactericidal drugs might seem more effective but a potential drawback of these drugs, especially if there spectrum is broad, is that while targeting the pathogen they also tend to kill off normal microbiota. they can also lead a spike in bacterial toxin release that can be deadly.

Explain why viruses are classified as nonliving microbes.

because they do not contain cells or exhibit metabolism

Define the terms broad spectrum and narrow spectrum as they relate to antimicrobials and state why an empiric therapy may be intentionally broad spectrum

broad spectrum drugs are effective against both graham negative and graham positive bacterial cells. narrow spectrum drugs target a limited range of bacteria. Because it takes several days to get a specific identifying causative agent, empiric theory is commonly started to protect the patient. broad spectrum is given until a definitive bacterial identification is made.

List the most common sources and classes of HAIs, and give examples of pathogens that cause them

clostridioides difficile, gastrointestinal infections; urinary tract infections associated catheterization of the urethra, surgical wound infections, methicillin-resistant staphylococcus aureus blood stream infections (MRSA bacteremia), intravascular device related bloodstream infections (usually associated with a central line/catheter in a vein), and ventilator associated events (respiratory infections such as pneumonia that can develop during mechanical ventilation). Bacteria are the most common cause of HAI's.

State how an emerging disease differs from a reemerging disease

emerging disease is identifying new agents as pathogens reemerging is an infectious agent that was under control before resurfacing.

Name the branches of adaptive immunity and compare adaptive to innate immunity

innate immunity and adaptive immunity Innate immunity is general and non-specific, it is also the first line of defense against pathogens. Short/ Immediate response. Low potency compared to adaptive immunity. Can be inherited. Cannot "remember" pathogens. Present at birth. Adaptive immunity- Also called acquired immunity, this type of immunity is built up as we are exposed to diseases or get vaccinated. Second line of defense. If pathogens pass through innate immunity, then adaptive immunity kicks in. Specific. Slower than innate. Highly effective against pathogens. Cannot be inherited. Adaptive immunity can "remember" past pathogens that has been encountered. Develops over the lifespan of the individual.

Explain why epidemiological measures are useful

is the study of the occurrence, determinants, and distribution of health and disease within healthcare setting facilities-includes any activities designed to study and improve patient care outcomes. infection control and the prevention of associated infections

Discuss the general approaches to diagnosing and managing autoimmune disorders

it can be challenging for clinicians to identify the autoimmune disorder causing the pt's condition because of the large number of options, variability of symptoms, and the fact that signs and symptoms can take a long time to fully develop and may change over time. Diagnosis often involves detecting self-reactive immune system cells and/or autoantibodies, which are antibodies that bind to self-tissues. Managing usually involves suppressing the immune response and reducing inflammation that damages tissues. Thus, treatments for autoimmunity usually lead to secondary immunodeficiency, including the host of complications just discussed. So far, there are no cures for autoimmune disorders, and no way to prevent them.

Explain why neurological disorders such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis are described as prion-like neurological disorders.

like prion-induced spongiform encephalopathies, a number of other neurodegenerative diseases have been associated with misfolded proteins in the brain.

Define the term pleomorphic and discuss how this property may impact an organism's ability to cause infection.

meaning it can take on different forms This enhances its survival, and appears to be important for transmission to a new human host. Makes it hard to do Biofilms.

Describe the considerations made in collecting clinical samples.

samples are collected aseptically to prevent contamination by wearing: gloves during sample collection. quickly seal samples in containers. samples collected on sterile materials. proper hand washing before and after specimen collection.

Define the following, and discuss how they relate to drug development: therapeutic index, selective toxicity, and drug half-life

selective toxicity- inhibits or kills the targeted microbe without damaging host cells. therapeutic index- the ratio of the maximum tolerated or safe dose to the minimum effective therapeutic dose. drug half-life: the time it takes for half of a dose to be eliminated or deactivated by the body-- often the kidneys or liver

Define self-tolerance and describe how and why the body screens immature T and B cells for this feature

self-tolerance immunological tolerance to the body's own ANTIGENS (self antigens), achieved by preventing the production of functional B-CELLS and T-CELLS reactive to such antigens

Define minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and discuss the various ways these measures may be determined

the lowest concentration of the antimicrobial drug that inhibits the microbes growth. the minimum concentration of the drug that kills at least 99.9% of the bacteria present.

Define cellular respiration

the metabolic process in living organisms by which oxygen is combined with carbon in a cell to form carbon dioxide and generate energy.

Explain what healthcare workers can do to manage outbreaks

they must have a firm grasp of standard and transmission precautions needed to limit their own risk and that of others in their care