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233 Cards in this Set
- Front
- Back
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What is a reducer?
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Fungi and other organisms who gain their biomass from oxidizing organic materials are called reducers and are NOT primary producers.
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What 3 important roles do microorganisms play in nature?
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Primary producer, decomposer, recycle vital elements
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What is a food chain?
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Food chains, also called, food networks and/or Social Networks, describe the eating relationships between species within an ecosystem or a particular living place.
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What is a photoautotroph?
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Microorganism which requires light energy and uses carbon dioxide as a carbon source. Plants and algae.
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What is a Chemoautotroph?
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Microorganism that uses carbon dioxide as a carbon source and catabolizes organic molecules for energy.
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What is a primary producer?
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Primary producers, commonly forming autotrophs, produce complex organic substances (essentially "food") from an energy source and materials. These organisms are typically photosynthetic plants, which use sunlight as their energy source. A few, such as those organisms forming the base of deep-sea vent food webs, are chemotrophic, using chemical energy instead.
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What kinds of organisms can serve as primary producers?
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Those organisms in an ecosystem that produce biomass from inorganic compounds (autotrophs). Photoautotroph’s (require light energy) and chemoautotroph’s (require chemical energy).
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What microorganisms are found in soil?
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Protozoa, algae, fungi, bacteria and Actinomycetes. Obligate Anaerobes such as Bacillus Anthracis (anthrax), Clotridium Tetani (Tetanus), Clostridium Botulinum (botulism) and Clostridium Perfrigens (Gas Gangrene)
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Which group of microorganisms is the most abundant?
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Bacteria
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What is the Carbon Cycle?
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The series of processes that converts CO2 to organic substances and back to CO2 in nature.
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What are the four steps in the carbon cycle?
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Photosynthesis, Chemoheterotrophs ingests photoautotrophs, Respiration and Microbial Decomposition.
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Which steps in the carbon cycle give rise to CO2?
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Respiration and Microbial Decomposition
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Describe Microbial Decomposition in the carbon cycle.
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Part of the carbon cycle when plants and animals die, these organic compounds are decomposed by bacteria and fungi. During decomposition, the organic compounds are oxidized, and CO2 is returned to the cycle.
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Describe photosynthesis in the carbon cycle.
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Part of the carbon cycle that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight.[1] Photosynthesis occurs in plants, algae, and many species of Bacteria, but not in Archaea. Photosynthetic organisms are called photoautotrophs, but not all organisms that use light as a source of energy carry out photosynthesis, since photoheterotrophs use organic compounds, rather than carbon dioxide, as a source of carbon.
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Describe Chemoheterotrophs ingests Photoautotrophs in the carbon cycle.
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Part of the carbon cycle where animals and protozoa eat photoautotrophs and may in turn be eaten by other animals.
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Describe respiration in the carbon cycle.
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Part of the carbon cycle where some of the organic molecules are used by chemoheterotrophs, including animals, to satisfy their energy requirements. When this energy is released through respiration, carbon dioxide immediately becomes available to start the cycle over again. Much of the carbon remains within the organisms until they excrete it as wastes or die.
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Microorganisms are involved in which steps of the carbon cycle?
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All (But Primarily Photosynthesis and Microbial Decomposition)
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Define Nitrogen Cycle
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Biogeochemical cycle involving ammonification, nitrification, denitrification and nitrogen fixation.
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Describe nitrogen fixation in the Nitrogen Cycle.
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Part of the nitrogen cycle where the conversion of atmospheric nitrogen to ammonia by bacteria such as cyanobacteria and Rhizobium in symbiosis with leguminous plants. No eukaryotes can use nitrogen gas.
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Describe ammonification in the Nitrogen Cycle..
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Part of the nitrogen cycle where microorganisms such as bacteria and fungi disassemble proteins in soil wastes into amino acids, which are then converted to ammonia.
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Describe nitrification in the Nitrogen Cycle..
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Part of the nitrogen cycle where chemoautotrophic bacteria such as nitrosomonas and nitrobacter convert reduced nitrogen compounds such as ammonia into nitrate, which is more available to plants.
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Describe Denitrification in the Nitrogen Cycle..
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Part of the nitrogen cycle where the conversion of nitrate into nitrogen gas by anaerobic respiration of denitrifying bacteria. Nitrates are lost from the soil.
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Why is nitrogen fixation so important?
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This is an essential process for life because fixed nitrogen is needed to make nucleotides which are needed to make DNA and also to make amino acids which in turn are needed to produce proteins.
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Microorganisms are involved in which steps of the Nitrogen Cycle?
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ALL
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What types of microorganisms are used in the Nitrogen Cycle?
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Free-living and symbiotic. Bacteria and Fungi
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Only what organisms carry out the process of nitrogen fixation?
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A few species of bacteria including cyanobacteria.
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Which organisms serve as primary producers (initiate the food chain) in fresh water?
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Photosynthetic algae is the primary producer in fresh water. Algae then cyanobacteria.
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Which organisms serve as primary producers (initiate the food chain) in seawater?
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Photosynthetic Bacteria and phytoplankton are the primary producers in seawater. Cyanobacteria then algae.
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What organisms can be found in saltwater upper levels?
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Aerobic photoautotrophs – algae and cyanobacteria.
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What organisms can be found in freshwaters upper levels?
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Aerobic photoautotrophs – algae and cyanobacteria.
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What organisms can be found in freshwater lower levels?
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Anaerobic photoautotrophs – purple and green sulfur bactreria.
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What organisms can be found in saltwater lower levels?
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chemoautotrophs
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In what 4 ways does normal microbiota benefit the body?
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Microbial Antagonism, Vitamin Synthesis, Normal Development of Defense Systems, and Normal Development of Intestinal Wall.
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What does pathogenic mean?
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A microorganism that has the ability to cause infection.
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What does infection mean?
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Successful invasion of the body by a pathogenic microorganism.
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What does infectious disease mean?
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An infectious disease is a clinically evident disease resulting from the presence of pathogenic microbial agents, including pathogenic viruses, pathogenic bacteria, fungi, protozoa, multicellular parasites, and aberrant proteins known as prions.
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What is the difference between infection & infectious disease?
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Infection is the invasion of the body, Infectious Disease refers to the infection results in ANY change from a state of health.
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What is normal microbiota?
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Microorganisms that colonize the surfaces of the human body without normally causing disease. They may be resident or transient.
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What different types of organisms normally inhabit the colon?
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Escherichia coli, Bacteroides, Fusobacterium, Lactobacillus, Enterococcus, Bifidobacterium, Enterobacter, Citrobacter, Proteus, Klebsiella, Candida (fungus)
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Define Microbial Antagonism?
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Also known as competitive exclusion, where normal microbiota can benefit the host by preventing the overgrowth of harmful microorganisms.
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What regions of the body normally have microorganisms?
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Skin, Eyes, Mouth, Upper Respiratory Tract, Colon, Lower Urinary System and Vagina.
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What regions of the body are normally free of microorganisms?
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Internal Organs, Blood and Lymphatic System, Lower Respiratory Tract, Central Nervous System and Upper Urinary System
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What type of organisms normally inhabits the skin?
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Propionibacterium, Staphylococcus, and Cornyebacterium
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Define Transmission when regarding disease:
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Passing of a disease from one to another; such as the common cold.
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Define carrier when regarding disease:
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Many people harbor pathogens and transmit them directly or indirectly to others. People with signs and symptoms of a disease may transmit the disease; in addition, some people can harbor pathogens and transmit them to others without exhibiting any signs of illness.
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Define reservoir of infection when regarding disease:
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Either a living organism or an inanimate object that provides a pathogen with adequate conditions for survival and multiplication and an opportunity for transmission.
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Spread of Infection is what, when regarding disease:
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the ability to perpetuate itself.
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Which TYPE of microorganism is the most common in the colon?
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Escherichia Coli, aka = E. Coli, OBLIGATE ANAEROBES
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Are the 2 organisms that are mainly responsible for nosocomial infections--Gram-positive or Gram-negative ?
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BOTH are Gram +
S. Aureus is Gram + Enterococcus is Gram + |
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Name the various ways pathogens are transmitted:
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Contact, Vehicle and Vectors. Such as Direct Contract (human to human, sex), Indirect Contact (Fomites – fork, towel, money), Droplet (Sneeze), Common Vehicle (food, water, blood, fecal-oral route), airborne (TB, pollen), Vector (Ticks, Mosquitoes, human/dog bite)
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Define Nosocomial Infections:
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An infection acquired in a health care facility.
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How common are Nosocomial infections in U.S. hospitals?
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According to the CDC, 5% to 15% of all admitted patients acquire a Nosocomial Infection. 2 Million cases a year, 20,000 die.
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What 2 organisms are most often the cause nosocomial infection?
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Staphylococcus Aureus and Enterococcus
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What is the most common kind of nosocomial infection?
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40% by Urinary Tract Infections (UTI) from Foley catheterization, then 20% by Surgical Site Infection.
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Define compromised host in regards to disease:
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One whose resistance to infection is impaired by disease, therapy, or burns.
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What factors contribute to a person being a compromised host by a pathogen (refer to defense integrity)?
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Broken Skin or mucus membranes, and a suppressed immune system.
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Define host:
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Organism in which another, usually parasitic, becomes resdient
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Define pathogenicity:
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A microorganism's ability to cause disease or the ability of an organism to cause disease by overcoming the defense of the host
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Define pathogen:
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A disease causing microorganism
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Define virulence:
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A measure/degree of pathogenicity or intensity/severity of organism to cause disease
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How do most pathogens enter the body?
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Most pathogens enter through the mucous membranes of the gastrointestinal and respiratory tracts. IE – inhaling or swallowing.
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What tissue lines the internal surfaces of the body?
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Mucus Membranes
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Is Skin an effective barrier?
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YES, unless compromised by cuts, abrasions or burns
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What tissue lines the exterior surfaces of the body?
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Skin
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How do many pathogens adhere to host tissues?
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By means of surface molecules on the pathogen called adhesins or ligands that bind specifically to complementary surface receptors on the cells of certain host tissues. Adhesins may be located on a microbial surface structures, such as pili, fimbriae, and flagella. Fimbriae is an attachment point of E. Coli.
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What is the parenteral route?
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Access to the body when they are deposited directly into the tissues beneath the skin or into mucous membranes when penetrated or injured. Punctures, injections, bites, cuts, wounds, surgery, and splitting due to swelling or drying can all establish parenteral routes. HIV, the hepatitis viruses, and bacteria that cause tetanus and gangrene can be transmitted parenterally.
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Define Adherence:
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Attaching themselves to host tissues at their portal of entry. The attachment of a pathogen to another cell’s membrane or surface through adhesins such as pili, fimbriae, and flagella.
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How will the Capsule, Cell wall & Fimbriae Components of a pathogen affect virulence?
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Increases the virulence of the microorganism. Virulence means the intensity of a microorganism to cause disease.
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How do Capsule, Cell wall & Fimbriae Components promote pathogenicity?
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The capsule resists the host’s defenses by impairing phagocytosis. The cell walls of certain bacteria contain chemical substances that contribute to virulence. The M protein of fimbriae mediates attachment of the bacterium to the host cells. The M protein thereby increases the virulence of the microorganism. Virulence means the intensity of a microorganism to cause disease.
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Define M Protein of the cell wall and fimbriae:
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A heat and acid resisitant protein of fimbriae which helps resist phagocytosis
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Define Mycolic Acid of the cell wall and fimbriae:
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Long chained fatty acid that helps resist phagocytosis
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What affect does production of Capsule, Cell wall & Fimbriae Components have?
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They increase Virulence which means the intensity of a microorganism to cause disease.
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What defense mechanism of the body is inhibited by the Capsule, Cell wall & Fimbriae Components of a pathogen?
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Phagocytosis, the white blood cell reaction to kill the pathogen.
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List eight bacterial enzymes that contributes to pathogenicity of a microorganism:
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Protease
Hyaluronidase Collagenase Leukocidin Hemolysin Coagulase Kinase (and Streptokinase) Lecithinase |
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Define Protease which contributes to pathogenicity of a microorganism:
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Enzyme that breaks down proteins
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Define Leukocidin which contributes to pathogenicity of a microorganism:
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Enzyme that can destroy Neutrophils
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Define Hemolysin which contributes to pathogenicity of a microorganism:
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Enzyme that lyses RBC’s
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Define Coagulase which contributes to pathogenicity of a microorganism:
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Bacterial enzyme that causes blood plasma to clot
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Define Kinase which contributes to pathogenicity of a microorganism:
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Bacterial enzyme that breaks down clots
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Define Streptokinase which contributes to pathogenicity of a microorganism:
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Blood clot dissolving enzyme
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Define Hyaluronidase which contributes to pathogenicity of a microorganism:
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Enzyme secreted by bacteria that helps spread the bacteria
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Define Collagenase which contributes to pathogenicity of a microorganism:
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Enzyme that hydrolyzes collagen
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Define Lecithinase which contributes to pathogenicity of a microorganism:
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Enzyme that breaks down lecithin, a component of the plasma membrane
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What is invasiveness?
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Invasiveness is the ability of a microorganism to establish residency in a host.
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Production of which enzymes contributes to invasiveness of a microorganism?
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MAINLY Hyaluronidase, Collagenase and Protease (but also Leukocidin, Lecithinase)
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Define Pyrogen:
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Chemical that triggers the hypothalamic "thermostat" to reset at a higher temperature, inducing fever.
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Define Toxin:
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Poisonous substances that are produced by a microorganism, 2 main types are Exotoxin and Endotoxin
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Define Exotoxin:
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Bacterial PROTEIN toxin released from living bacterial cells (Gram +)
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Define Toxoid:
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An inactivated Exotoxin (innoculator)
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Define Antitoxin:
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A specific antibody produced in response to a bacterial Exotoxin (Bacterial Protein) or Toxoid (inactivated bacterial protein)
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Define Enterotoxin:
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An Exotoxin (bacterial protein) that causes GI tract wall alteration
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Define Endotoxin:
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Only released when the bacterial cell dies or ptentially fatal toxin released from the cell wall of dead and dying Gram-negative bacteria. Usually causes fever, weakness, aches and sometimes shock
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What effects do all endotoxins cause?
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All Endotoxins cause fever, weakness, aches and sometimes shock
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What is the Exotoxin; Toxic Shock Syndrome?
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An Exotoxin that causes a potentially fatal syndrome characterized by fever, vomiting, red rash, low blood pressure, and loss of sheets of skin, usually caused by systemic infection with strains of Staphylococcus.
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What is the Exotoxin; Exfoliative Toxin?
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Exotoxins of certain strains of Staphylococcus aureus that break down desmosomes in the skin, causing the outer layers of skin to slough off.
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What is the Exotoxin; Diphtheria Toxin?
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An Exotoxin which inhibits protein synthesis causing mild to potentially fatal respiratory disease caused by diphtheria toxin following infection with Corynebacterium diphtheriae.
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What is the Exotoxin; Tetanus Toxin?
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An Exotoxin, (neurotoxin) which causes spastic paralysis (Lockjaw)
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What is the Exotoxin; Botulinum Toxin?
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A neurotoxin which causes flaccid paralysis (immobility)
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What effects do all Enterotoxins cause?
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All Enterotoxins alter permeability of intestinal wall. Enterotoxins such as Cholera toxin, Staphylococcal Enterotoxin and Clostridial Enterotoxin
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What is the chemical compositions of Exotoxins and Endotoxins?
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Exotoxins are protein/peptide and Endotoxins are lipid
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How are Exotoxins and Endotoxins related to the cell?
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Exotoxins are a metabolic product and Endotoxins are part of Lipopolysaccharide of outer membrane (A polysaccharide found in the external membrane of Gram-negative cell walls)
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What kinds of Exotoxins and Endotoxins bacteria make Gram + or Gram -?
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Exotoxins are mostly Gram - and Endotoxins are Gram -
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How do the effects that Exotoxins and Endotoxins cause differ?
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Exotoxins effects are specific and vary by Exotoxin and Endotoxins effects are general for all endotoxins
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What are the toxicity of Exotoxins and Endotoxins?
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Exotoxins are high in toxicity and Endotoxins are low in toxicity
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Can Exotoxins and Endotoxins be neutralized by an antitoxin?
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Exotoxins are neutralized by an antitoxin and Endotoxins are NOT easily neutralized by an antitoxin
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Define Period of Decline of infectious disease:
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Signs and symptoms subside; patient is vulnerable to secondary infections.
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What is the difference between the acute stage and the incubation period?
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Incubation period is the period of time the infection manifests leading to the acute stage to take hold showing signs and symptoms of the infection at its highest point of compromise.
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Define Period of Convalescence of infectious disease:
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Strength returns and the body returns to its prediseased state. Spread of the disease is still possible for some diseases such as typhoid fever and cholera, in which the convalescing person carries the pathogen for months or even years.
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Define Period of illness or Acute Stage of infectious disease:
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The disease is most severe with signs and symptoms of fever, chills, muscle pain, sensitivity to light, sore throat, lymph node enlargement, and gastrointestinal disturbances. White blood cells may increase or decrease, immune response and other defense mechanisms overcome the pathogen, and the period of illness ends or the patient dies during this period.
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Define Prodromal Period of infectious disease:
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Short period of early or mild symptoms such as aches and malaise
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Define Incubation Period of infectious disease:
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Period of time between initial infection and the first appearance of signs and symptoms
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Name the stages of an infectious disease:
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Incubation Period, Prodromal Period, Period of illness or Acute Stage, Period of Decline and Period of Convalescence
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Define nonspecific defense:
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Also known as Innate (Nonspecific) Immunity and is a type of defense that protects the body against a wide variety of pathogens and that operates in a generalized way independent of the nature of the intruder.
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Define Resistance (or immunity) :
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The ability to ward off disease caused by microbes or their products and to protect against environmental agents such as pollen, drugs, foods, chemicals and animal hair.
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Define susceptibility:
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Vulnerability or lack of immunity
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What is lysozyme?
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A lysozyme is an Antibacterial protein secreted in sweat, saliva, tears and nasal secretions
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What two types of tissues make up the first line of defense?
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Skin and Mucous Membranes
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How do pathogens most often enter the body?
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Most pathogens enter through the mucous membranes of the gastrointestinal and respiratory tracts. IE – inhaling or swallowing.
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What are the 4 parts to the 2nd line of defense?
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Phagocytosis, inflammation, fever and Antimicrobial Substances (other than antibodies)
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Which phagocyte is most abundant in the blood?
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Neutrophils
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What cells are phagocytes in the human body?
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White Blood Cells such as Neutrophils are the most important phagocytes. Also there are Basophils, Eosinophils, Lymphocytes (Natural killer cells, T and B cells), Dendric cells
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Define phagocytosis:
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Phagocytosis is the ingestion of microorganisms or particulate matter by a cell.
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What effect does opsonization have on phagocytosis?
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Enhances phagocytosis by using opsonin to coat the microorganism; enabling the phagocyte the ability to grab the microorganism to be engulfed and destroyed.
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Where are macrophages located?
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Fixed Macrophages (larger and stronger than Neutrophils) are located in selected tissues and organs of the body such as liver, spleen, lymph nodes, and bone marrow.
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Define opsonization:
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The coating of pathogens by proteins called opsonin, making them more vulnerable to phagocytes.
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Why is inflammation beneficial?
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It offers protection and a contained space for tissue repair or confinement of the injurious agent.
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Define inflammation:
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Inflammation is the host’s response to tissue damage with redness, pain, heat and swelling.
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What 2 processes cause inflammation?
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Vasodilatation (blood vessel dilation) and increased permeability of blood vessels.
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What is the purpose of inflammation?
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Destroy the injurious agent, confining or walling off the injurious agent and its by-products, to repair or replace tissue damaged by the injurious agent or its by-products.
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Why is a fever beneficial?
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Fever is considered a defense against disease. Inhibits growth of microorganisms due to raising the body’s thermostat, speeds up the body’s chemical reaction including the line of defense which is to make more immune system cells.
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Define fever:
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A fever is an abnormally high body temperature, above 37°C. The most frequent cause of fever is infection from bacteria (and their toxins) or viruses.
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What is the function of a Complement in regards to Antimicrobial Substances other than antibodies?
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Ultimately effect the destruction of microorganisms through phagocytosis and lysis of the foreign pathogen by enhancing the process.
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Define Complement in regards to Antimicrobial Substances other than antibodies:
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Set of blood plasma (Serum) proteins that act as chemotactic attractants, trigger inflammation and fever.
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Define antiviral protein:
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Proteins triggered by alpha and beta interferons that prevent viral replication.
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Define Interferon:
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Interferons (IFNs) are a class of similar antiviral proteins produced by certain animal cells, such as lymphocytes and macrophages, after viral stimulation. One of the principal functions of interferons is to interfere with viral multiplication.
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What are the effects of activating the complement system?
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Opsonization (Opsonin coating of the microorganism to be grabbed), inflammation (containment of the microorganism) and cytolysis (destruction of the microorganism)
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How can the compliment system be activated?
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Antigen-antibody complexes or through substances on microorganisms
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What effect does Interferon have on cells?
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Because viruses depend on their host cells to provide many functions of viral multiplication, it is difficult to inhibit viral multiplication without affecting the host cell itself. One way the infected host counters viral infections is with interferons.
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Define antiserum:
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A blood derived fluid that has antibodies
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Define adaptive immunity:
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Resistance against pathogens that acts more effectively upon subsequent infections with the same pathogen. Only works against specific organisms.
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Name the 4 types of immunity:
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Naturally Acquired Active Immunity, Naturally Acquired Passive Immunity, Artificially Acquired Active Immunity and Artificially Acquired Passive Immunity.
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Define immune serum globulin:
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When serum is separated by gel electrophoresis, antibodies are found in the gamma fraction of the serum and are termed immune serum globulin, or gamma globulin.
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Define Artificially Acquired Passive Immunity:
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Type of immunity that occurs when the body receives via injection preformed antibodies in antitoxins or antisera, which can destroy fast-acting and potentially fatal antigens such as rattlesnake venom.
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Define Artificially Acquired Active Immunity:
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Type of immunity which occurs when the body receives antigens by injection, as with vaccinations, and mounts a specific immune response.
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Define Naturally Acquired Passive Immunity:
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Type of immunity that occurs when a fetus, newborn, or child receives antibodies across the placenta or within breast milk.
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Define Naturally Acquired Active Immunity:
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Type of immunity that occurs when the body responds to exposure to antigens by mounting specific immune responses.
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What is the difference between active and passive immunity?
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Actively = when a person is exposed to microorganisms or foreign substances; Passively is when antibodies are transferred from one person to another.
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What is the difference between naturally acquired & artificially acquired immunity?
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Naturally Acquired is an immunity that is obtained through natural means such as born with, or given through the mothers immunity system, artificially acquired is through synthetic means such as inoculation, vaccination or antiserum.
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Define antigenic determinant:
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A specific region on the surface of an antigen against which antibodies are formed
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Define antigen:
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Molecule that triggers a specific immune response.
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Define Immunoglobulin:
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Any of five classes of structurally distinct antibodies produced by lymph tissue in response to an invasion of a foreign substance
Define antigen-antibody complex – The combination of an antigen with the antibody that is specific for it. |
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Define Antibody:
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Protein produced by lymph tissue in response to the presence of an antigen and capable of combining with that antigen
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Define Hapten:
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A substance of low molecular weight that does not cause the formation of antibodies alone, BUT WITH CARRIERS.
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What are the benefits of an activating complement?
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Opsonization (Opsonin coating of the microorganism to be grabbed), inflammation (containment of the microorganism) and cytolysis (destruction of the microorganism)
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Name the benefits of forming antigen-antibody complexes:
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Agglutination, opsonization, neutralization and activation of a compliment (compliment system)
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What effect does agglutination have on phagocytosis?
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Clumping together of antigen carrying calls which improves phagocytosis
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How does opsonization affect phagocytosis?
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Enhances phagocytosis by using opsonin to coat the microorganism; enabling the phagocyte the ability to grab the microorganism to be engulfed and destroyed.
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What is neutralization?
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An antigen-antibody reaction that inactivates and destroys or inhibits its infectivity or virulence (The disease invoking power of a pathogen)
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Name the 5 classes of immunoglobulins:
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IgA
IgE IgG IgD IgM |
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What is the function of the immunoglobulin IgM?
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Efficiently enhances phagocytosis against microorganisms.
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What is the function of the immunoglobulin IgA?
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Localizes protection on mucosal surfaces for initial infection.
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What is the function of the immunoglobulin IgE?
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Allergic Reactions
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What is the function of the immunoglobulin IgG?
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Enhance Phagocytosis, Neutralizes Exotoxin and viruses, protect fetus and newborn
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What is the function of the immunoglobulin IgD?
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Communication between cells of immune system
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Which of the immunoglobulin’s is involved in allergic reactions?
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IgE
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Which of the immunoglobulin’s crosses the placenta?
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IgG
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Which of the immunoglobulin’s is the first to appear during primary response?
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IgM
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Which of the immunoglobulin’s is most abundant in secretions?
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IgA
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Which of the immunoglobulin’s is most abundant in blood?
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IgG
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Define anti-human immune serum globulin (Anti-HISG):
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An antibody that reacts specifically with human antibodies.
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Define serology:
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The study of reactions between antibodies and antigens is called serology.
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Define serum:
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The liquid remaining after blood plasma has clotted, contains antibodies (immunoglobulin’s)
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Define serial dilution:
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The process of diluting a sample several times (ie – 1/2, 1/4, 1/8, 1/16, 1/32, 1/64)
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Define titer:
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This is the measure of titer, or concentration of serum antibody. Determined by serial dilution and expressed as the reciprocal of the dilution. (ie. Positive up to dilution 1/16, expressed as 16)
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Define seroconversion:
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It can be demonstrated that the person’s blood had no antibody titer before the illness but has a significant titer while the disease is progressing, this change, called seroconversion, is also diagnostic. This situation is frequently encountered with HIV infections
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What can serological tests detect?
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(antigen, antibody or both) Both
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What is the basis of all serological tests?
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Antigen-Antibody complexes
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What are serological tests used for?
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To diagnose disease when the pathogen is unknown, evaluating the level of antigen
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How is antibody titer measured?
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Diseases can be diagnosed by a rising titer or seroconversion (from no antibodies to the presence of antibodies). THE HIGHEST DILUTIONS POSITIVES RECIPRICOL. IE – POSIVITVE AT 1/32 SO TITER IS 32
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How is titer related to antibody concentration?
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The antibody level in the blood is a reflection of past exposure to an antigen or to something that the body does not recognize as belonging to itself. THE HIGHER THE CONCENTRATION THE HIGHER THE TITER.
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What happens to antibody titer during the acute stage of an infectious disease?
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The titer is higher later in the course of the disease than at its outset. RISES
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How is antibody titer affected by seroconversion?
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Diseases can be diagnosed by a rising titer or seroconversion (from no antibodies to the presence of antibodies).
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Give an example of fluorescent-antibody techniques:
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Direct – detect Antigen (identify an organism) or Indirect – detect Antibody
HIV, RABIES, SYPHILIS, Streptococcal Pharyngitis (Strep throat) |
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Give an example of agglutination tests:
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BLOOD TYPING
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Give an example of enzyme-linked immunosorbent assays (ELISA):
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Direct – detect Antigen or Indirect – detect Antibody
HIV, HOME PREGNANCY, DRUG TESTING |
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Give an example of complement fixation tests:
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Determine ANTIBODY TITER, SYPHILIS
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Give an example of radial immunodiffusion tests (RID):
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Determine ANTIGEN CONCENTRATION, PRECIPITIN RING TEST
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Define the vaccine DtaP:
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Diphtheria - Toxoid
Tetanus - Toxoid Pertussis - Acellular |
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Define the vaccine IPV:
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Poliomyelitis - Inactivated Virus
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Define the vaccine MMR:
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Measles - Attenuated Virus
Mumps - Attenuated Virus Rubella - Attenuated Virus |
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Define the vaccine HiB:
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Haemophilis - Polysaccharide
Meningitis - Conjugate |
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Define the vaccine VAR:
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Chickenpox - Attenuated Virus
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Define the vaccine Hep B:
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Hepatitis B - Subunit
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Define the vaccine Td:
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Tetanus - Toxoid
Diphtheria - Toxoid |
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Define the vaccine PPV:
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Pneumoccal - Polysaccharide
Pneumonia - Polysaccharide |
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Define the vaccine Hep A:
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Hepititus A - Inactivated Virus
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Define Cell-mediated immunity :
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An immune response that does not involve antibodies or complement but rather involves the activation of macrophages, natural killer cells (NK), antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen.
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Define B cell:
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Type of lymphocyte, proliferates (multiplies) into a large population, then differentiates into plasma and memory B cells
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Define T cell:
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A type of lymphocyte which develops from a stem cell processed in the thymus gland that is responsible for cell-mediated immunity
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Define helper T cell:
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A specialized T-cell that interacts with antigen, recognizes it then activates B cells
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Define CD8 T cell:
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A cytotoxic T cell which belongs to a sub-group of T lymphocytes (a type of white blood cell) that are capable of inducing the death of infected somatic or tumor cells; they kill cells that are infected with viruses (or other pathogens), or are otherwise damaged or dysfunctional.
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Define Cytokine:
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Proteins secreted by many types of cells that regulate adaptive immune responses.
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Define Interleukin:
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Immune system cytokines that signal among leukocytes.
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Define Apoptosis:
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Cell Suicide
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Define Antibody-mediated immunity:
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The aspect of immunity that is mediated by secreted antibodies (as opposed to cell-mediated immunity which involves T lymphocytes) produced in the cells of the B lymphocyte lineage (B cell). Secreted antibodies bind to antigens on the surfaces of invading microbes (such as viruses or bacteria), which flags them for destruction.[1] Humoral immunity is called as such, because it involves substances found in the humours, or body fluids.
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Describe the mechanism Antibody-mediated immunity:
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1. Activation of B cell
Antigen attaches to receptor on B cell Antigen is internalized and processed by B cell Antigen fragment is displayed on B cell surface Helper T cell recognizes antigen and activates B cell 2. B cell proliferates 3. B cell differentiates into plasma cell and memory B cells |
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List all the cells involved & explain their role in Antibody-mediated immunity:
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Helper T cell – interacts with antigen, recognizes it then activates B cells
B cell – proliferates (multiplies) into a large population, then differentiates into plasma and memory B cells Plasma Cells – Morphed from activated B cells, they produce specific antibodies Memory B Cells – A durable B cell responsible for memory response and a secondary response if an antigen repeats infection |
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What is the purpose of booster shots?
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Booster shots differentiate into plasma cells and immediately proliferate, producing large amounts of antibodies.
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What are the results of Antibody-mediated immunity?
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Antibodies, a primary response, creation of a memory response or secondary respsonse
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What cells are involved in primary response in Antibody-mediated immunity?
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B cells, Helper T cells, and Plasma Cells
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Define “Memory Response” in Antibody-mediated immunity:
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A rapid rise in antibody titer after exposure to an antigen. Poses response to another attack from like antigens and is also known as Secondary Response or Anamestic Response.
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Define “Primary Response” in Antibody-mediated immunity:
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Antibody production in response to the first contact with an antigen
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Describe the mechanism, Cell-mediated immunity:
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1. Activation of Helper T Cell (TH cell)
Antigen attaches to receptors of APC (antigen presenting cell) (APC Cell is either a Dendritic cell or Macrophage) APC Cell ingests and processes Antigen Antigen Fragment is displayed on surface of APC Cell TH cell recognizes antigen on surface of APC Cell TH cell is activated and secretes cytokines 2. TH Cell proliferates (multiplies in large numbers) 3. TH Cell differentiates (morphs) into TH1 cells and Memory TH1 cells 4. TH1 cells remain activating CD8 T Cells to become CTL Cells (Cytotoxic T Lymphocyte) CD8 T Cells defend against cancer and intracellular pathogens 5. TH1 Cells also activate Macrophages |
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List the cells involved & explain their role in Cell-mediated immunity:
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Helper T Cell – Activates cytokines, CD8 T cells, proliferates, morphs into TH1 cells
APC Cells – Ingests and processes antigen, activates TH cells Memory TH1 cells – Secondary response, activate CD8 T-cells and macrophages CD8 T Cells – differentiate into CTL cells (Cytotoxic T Lymphocyte), defend against cancer and intracellular pathogens CTL Cells (Cytotoxic T Lymphocyte) - capable of inducing the death of infected somatic or tumor cells; they kill cells that are infected with viruses (or other pathogens) |
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What are the results of Cell-mediated immunity?
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CTL Cells (Cytotoxic T Lymphocyte), apoptosis or cell suicide of target cell, activation of macrophage for clean-up.
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Antibody-mediated immune system combats what?
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Exotoxins
Extracellular Bacteria Extracellular Viruses |
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Name Antibody-mediated immune Components:
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B Cells
TH Cells Memory B Cells Plasma Cells Antibodies |
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Cell-mediated Immune system combats what?
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Cancer
Intracellular Bacteria Intracellular Viruses |
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Name Cell-mediated immune Components:
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Antigen Presenting Cells (APC Cells)
Helper T Cells (TH Cells) Memory TH1 Cells TH1 Cells CD8 T Cells CTL Cells (Cytotoxic T Lymphocyte) Activated Macrophages |
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Define Allergen:
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An Allergen is Antigens that invoke a hypersensitivity response, such as pollen
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Define Hypersensitivity:
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Hypersensitivity is an altered and enhanced immune system reaction occurring when a person who has been sensitized to an antigen is re-exposed. (Example – Hay fever)
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Distinguish between systemic and localized Type I (Anaphylaxis) Reactions:
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Systemic drops BP, vasodilatation, and shock. Treatment in 15 minutes or death, treated with epinephrine or adrenaline. Ingestion results in swelling, numbness, tingling, wheezing, inability to breathe. Injection results in system wide reaction. IE – insect/snake venom, drug allergies, severe food allergies
Localized is restricted to a limited area of skin or respiratory tract where symptoms include inflammation, redness, and heat. IE - asthma, hay fever, latex. |
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Define Type I (Anaphylaxis) Reactions:
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Type I Reactions are also known as Anaphylaxis. It is the most common of all allergic reactions.
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What components are involved in Type I (Anaphylaxis) Reactions?
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IgE immunoglobulin, Mast Cells (connective tissue cell that releases histamine), Basophils (Leukocyte – releases histamine and leukotriene), chemical mediators such as histamine (Vasodilator, neurotransmitter) and leukotriene (inflammatory response).
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List examples of Type I (Anaphylaxis) Reactions:
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Bee stings, peanut allergy, drug reactions, hay fever and asthma
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What components are involved in Type II Reaction or Cytotoxic Reaction?
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IgG or IgM Immunoglobulin, Antigen on cells (APC Cells), Compliment System Activates
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Define Type II Reactions or Cytotoxic Reaction:
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Generally involves the activation of a complement by the combination of IgG or IgM antibodies with an antigenic cell. This activation stimulates the complement to lyse the affected cell, which might be a foreign cell or a host cell that carries a foreign antigenic determinant (such as a drug) on its surface.
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List examples of Type II Reaction or Cytotoxic Reactions:
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a. Drug Induced Thrombocytopenic Purpura – if antigens attach to platelets, purple spots appear on the skin due to hemorrhages. This is when the immune system is attacking its own platelets.
b. Hemolytic Anemia – antigens attaches to red blood cells. c. Hemolytic Disease of Newborn – ABO and Rh incompatibility. |
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What components are involved in Type III (Immune Complex) Reactions?
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Antigen-Antibody Complexes
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Define Type III Reactions or Immune Complex Reaction:
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Occurs when antigen-antibody complexes get trapped in blood vessel walls. If the complement is activated and the antigen-antibody complexes are still trapped in the blood vessel walls, a harmful long-term inflammatory response is derived.
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List examples of Type III (Immune Complex) Reactions:
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a. Systemic Lupus Erythematosus – antigen-antibody complexes trapped in blood vessel walls.
b. Rhematoid Arthritis – antigen-antibody complexes trapped in joints. |
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Define Type IV Reaction or Cell-mediated Reactions and its components.
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Composed of T-cells and foreign antigens bound to tissues. There is a varying and lengthy delay in reaction due to T-cells having to migrate to the site of infection.
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List examples of Type IV (Cell-mediated) Reactions:
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a. Tuberculin Positive Skin Test
b. Allergic Contact Dermatitis due to poison ivy, cosmetics, nickel jewelry, and latex. c. Rejection of transplanted tissue d. Diabetes Type 1 wherein the person’s immune system is destroying its own Islets of Langerhan in the Pancreas. |
