Untitled Flashcards Set

• UNIT 1

  Chapter 1

  • Benefits from fermentation: 

    • Enhanced taste, extend shelf life (preservation), in some cases better nutrition (or safer)

    • S. cerevisiae makes bread rise

  • Hippocrates: father of wester medicine, believed that diseases had natural, not supernatural causes

  • Thucydides: Athenian plague survivors were immune to infection after

  • Varro: disease could be caused by creatures that cannot be seen by the eye

  • Leeuwenhoek: first to descibe observations of bacteria - “animalcules” or “wee little beasties”

  • Pasteur: Pasteurization and Germ Theory

  • Koch: first to tie a microbe to a specific disease, made “Koch’s postulates”

    • Anthrax, cholera, TB

  • Binomial nomenclature: Genus species

  • Taxonomy: scientific classification of living organisms, originally based on physical characteristics

    • Linnaeus: standard taxonomic classification system

      • Kingdom, class, order, family, genus, species

      • Binomial nomenclature

      • Not necessarily grouped by relatedness

  • Phylogeny: organization of taxa taking into the relatedness (evolutionary) into account

    • Can ignore physical characteristics with DNA and RNA sequencing

    • Phylogenetics is better understanding of relatedness

  • Problems with classification of microbes: 

    • Small, mostly transparent, have few readily observable features

    • Solutions: biochemical properties, staining and serology, and genetic seq. 

  • Groups of microorganisms:

    • Algae, archaea. Bacteria, fungi, helminths, protozoa, viruses

  • Bacteria vs. Archaea:

    • Both have no nucleus

    • Bacteria have peptidoglycan cell walls, archaea have pseudopeptidoglycan

    • Bacteria are described with cell morphology

    • Both are found everywhere (but Archaea really is)

    • Some bacteria and some archaea are photosynthetic

    • Most bacteria are harmless/helpful but some are pathogenic. Archaea not known to be pathogenic 

  • Cell morphology:

    • To know: coccus, bacillus, vibrio, coccobacillus, spirillum, spirochete

  • Protists: eukaryotes thar are not animals, plants or fungi

    • Algae: 

      • Photosynthetic

      • Uni or multicellular and plant-like (cellulose)

      • Useful to environment, food industry, and lab

    • Protozoa: 

      • Some are photosynthetic

      • Unicellular

      • Very diverse in movement: cilia, flagella, pseudopods

      • Can be free-living or parasitic, harmless or pathogens 

        • Plasmodium falciparum: malaria

        • Trypanosoma brucei: ASS

  • Apicomplexans: have apical polar ring structures used to invade host cells

  • Fungi: 

    • Closer to animals than plants

    • Chitin walls rather than cellulose

    • Non-photosynthetic

    • Unicellular: yeasts

      • Can be beneficial/non-harmful or cause disease (yeast infections)

      • Candida albicans

    • Multicellular: molds and mushrooms

      • Decomposers and can cause disease

      • Penicillin and cyclosporine

  • Helminths: 

    • Macroscopic as worms, eggs and larvae are microscopic

    • Fecal-oral

  • Acellular: viruses:

    • DNA or RNA encased in protein coat

    • Must be in host cell to replicate (co-opt host)

    • Can infect pro and euk cells

    • Many don’t cause disease

  Chapter 2

  • ROYGBIV: highest wavelength to lowest, lowest energy to highest

  • Longer wavelength is lower energy

  • Wavelength determines color, and amplitude determines intensity 

  • Amplitude = height of wave, frequencies = rates of vibration

  • Interactions of light: 

    • Reflection: light bounces off material

    • Refraction: light passes through one medium and changes the direction of the light ray (pole in the water)

  • Resolution can be increased by: 

    • Shorter wavelength, lenses with high numerical aperture, increased contrast, using phase interference

  • Microscope power can be described in terms of magnification and resolution

  • Fluorescence: electrons emit photons of lower energy 

  • Fluorescence microscopy: can stain specific structures by using antibodies conjugated to flourochrome 

  • Leeuwenhoek: first person to observe microbes “wee little beasties:

  • Hooke: used compound microscope to view cork cells 

  • Compound vs. simple microscopes??

  • Light microscopy: focus light on a specimen to produce an image

    • Brightfield, darkfield, phase-contrast, differential interference contrast, and fluorescence microscopy

    • Brightfield: dark image on light background

    • Dark field: light stop, sample appears on dark background, high contrast

    • Phase contrast/DIC: separate diffracted and un-diffracted light. In phase adds, out of phase subtracts

      • Increase contrast, can observe live/unstained samples

  • Electron microscopy: focus electrons on the specimen using magnets, increasing magnification (TEM and SEM)

    • Faster the electrons, the higher the magnification

    • TEM: electrons pass through to the detector. Well-defined internal structures of cells

    • SEM: electrons scatter off sample and bounce (3D). 3D images of the surface structure of cells 

  • Live samples are observed as a wet mount, where sample is suspended in liquid

  • Types of stains: 

    • Acidic: chromophore has - charge

    • Basic: chromophore has + charge

• Positive: cells are stained

• Negative: background is stained

• Simple: only one dye

• Differential: multiple dyes are used to differentiate organisms

  • Examples:

  • India ink can show capsules

  • Crystal violet/copper sulfate show capsules 

Chapter 3

• Fracastoro: early version of germ theory: seed-like spores can be transferred

• Hooke: cork cells observed under microscope

• Redi: maggot experiment

• Leeuwenhoek: single celled organisms observed

• Needham: boiled organic matter in open container generated life

• Spallanzani: Neeham wrong, boiled organic matter did not spontaneously generate life

• Semmelweis: hand washing reduces puerperal infections

• Snow: cholera transmitted in contaminated water, 1st epidemiological study

• Pasteur: disproves spontaneous generation with swan-neck flash experiment

• Pasteur: microbial fermentation

• Lister: carbolic acid as a disinfectant in surgery

• Koch: determine causative agents for many bacterial infections (germ theory solidified)

• Evidence for endosymbiotic theory??

• Prokaryotes:

  • Nucleoid (no nucleus)

  • Cell wall resistant to osmotic shock

  • Bacteria: ester linked phospholipid

  • Archaea: ether linked phospholipid

  • Ribosomes different from eukaryotic cells

    • 70s complete, with 30s and 50s subunits

• Gram positive bacteria: thick peptidoglycan layer

  • NAG, NAM, pentapeptide, and tetrapeptide

  • Teichoic acid in outer layer

    • Acid fast: mycolic acid

• Gram negative bacteria: thing peptidoglycan layer surrounded by an outer membrane

  • NAG, NAM with direct link 

    • Antibiotics target crosslinking of peptidoglycan (penicillin) 

  • O antigen, LPS, Lipid A in outer membrane. Below is the periplasmic space

    • Highly inflammatory, can cause endotoxic shock at high concentrations

  • Some prokaryotes can produce glycocalyx coatings (capsules/slime layers) that can aid in attachment to surfaces and/or evasion of immune system 

• Endospores: 

  • DNA replicates

  • Membranes form around DNA

  • Forespore forms additional membranes

  • Protein cortex forms around the spore

  • Protein coat forms around the cortex

  • Spore is released 

• Polysaccharide capsules: 

  • Prevent dehydration, aid in adherence and biofilm formation

  • Resist chemicals and avoid immune detection

• Prokaryotic appendages: 

  • Fimbriae and pili aid in attachment to cells

    • Pili used in transfer of genetic material between cells

  • Flagella can help move through water

    • Pertrichous bacteria: runs and tumbles in the direction of chemical attractant (chemotaxis)

      • Runs: counter clockwise motion of flagella makes it so the bacteria moves in a straight line

      • Tumbles: clockwise rotation, goes in a circle 

Chapter 4:

• Community: group of interacting populations of organisms

  • Cooperative interactions (beneficial) or competitive interactions

• Mutualism: both species benefit

• Amensalism: one is harmed, the other is unaffected

• Commensalism: one benefits, one is unaffected

• Neutralism: both are unharmed

• Parasitism: one benefits while the other is harmed

• Proteobacteria: Gram-negative bacteria

  • Alphaproteobacteria: oligotrophs (slow growing), obligate intracellular pathogens 

    • Some can convert atmospheric nitrogen to nitrites

  • Betaproteobacteria: eutrophs (need organic nutrients), difficult to culture (fastidious), Neisseria and Bordetella pertussis

  • Gammaproteobacteria: largest and most diverse, many are human pathogens that are aerobes and facultative aerobes

    • Coliform: ferment lactose completely and produce acid and gas

    • Non-coliform: ferment lactose incompletely, produce acid or gas

  • Deltaproteobacteria: reduce sulfate, some form myxospores (multicellular fruiting bodies)

  • Epsilonproteobacteria: smallest group, H. pylori

• Gram negative nonproteobacteria:

  • Many representatives of phototropic bacteria

  • Spirochetes: motile, spiral bacteria with long narrow body (syphillis and lyme disease)

  • Cyanobacteria: blue-green algae, thicker than normal layer of peptidoglycan

    • Produce oxygen, can produce neurotoxins harmful to aquatic species

• Gram positive bacteria

  • High GC

    • Actinobacteria: mycobacterium tuberculosis, M. leprae

  • Low GC

    • Bacilli: bacillus and staphylococcus - anthrax and S. aureus

    • Clostridia (tetnus and botulism)

    • Lactobacillales

• Archea:

  • Methane-producing archaea are called methanogens

UNIT 2

Chapter 5

• Fungal phyla are organized by reproductive mechanisms and structures 

  • Zygomycetes: haploid spores on short stalk called sporangium (zygospores)

  • Ascomycetes: haploid spores in sacs (asci) (ascospores)

  • Basidiomycetes: haploid spores in gills of basidia (basidiospores)

• Unique characteristics: cell wall is chitin, steol is ergosteol 

• Fungi grow as molds or yeasts

  • Molds: multicellular structure called hyphae

    • Septate: have cell walls and membranes between 

    • Mycelium: tangled network of hyphae

  • Yeasts: single cells which may aggregate as psuedohyphae

• Organisms!

  • Candida albicans: 

    • Yeast infections, normal flora in URT, GI, and vagina, invasive hyphae form in tissue

      • Immunocompromised and IV drug users at risk

  • Histoplasma capsulatum

    • Dimorphic resp. Pathogen: can switch between yeast and mold form in response to temperature

      • In the environment - mold form

      • Inhaled spores convert to yeast in the lungs

        • Immunocompromised = disseminated disease

  • Aspergillus

    • Bread mold

    • Can be opportunistic pathogens 

      • Some produce aflatoxin - most potent natural carcinogen

  • Saccharomyces cerevisiae

    • Unicellular, with haploid and diploid forms

    • Model organism: cell signaling, regulation of gene expression, cell division

    • Brewer’s and Baker’s  yeast 

  • Cryptococcus neoformans

    • Inhaling basidiospores can lead to respiratory disease or meningitis

    • Polysaccharide capsule helps evade killing 

    • Rarely causes disease in the healthy

• Dermatophytes: 

  • Multi-genus group of organisms able to infect skin

    • Ascomycota, ringworm, athlete’s foot, etc.  

• Amanita

  • Mushroom, oral consumption 

  • Toxins are heat stable 

    • Inhibit RNA polymerase

    • Phalloidin: toxin that binds to f-actin 

      • High resolution staining of the cytoskeleton 

    • A and B amanitin: inhibit RNA polymerase

      • Being tested for cancer theraputics 

• Algae

  • Produce a majority of dissolved oxygen in aquatic enviournments

  • Agar/Agarose used to solidify media or as a medium for electrophoresis

    • Food thickener 

  • Lichen: 

    • Combo of green algae OR cyanobacterium and fungus

    • Break down rocks to contribute to soil production

    • Fix nitrogen, and food sources

Chapter 6

• Dimitri Ivanosvski: unable to filter the causative agent of tobacco mosaic disease (TMD), suggesting that it was smaller than any known bactera

• Beijerinck: latin name for toxin = virus

• Stanley: particles made of nucleic acids and protein had the activity in tobacco mosaic virus. Produced electron microscope image of viruses

• Characteristics of viruses: 

  • Infectious, acellular pathogens 

  • Obligate intracellular parasites with host and cell-type specificity

  • DNA or RNA genome

  • Genome is surrounded by protein capsid and in some cases a phospholipid membrane 

  • Lack genes for many products that are needed for successful reproduction

    • Enveloped: have phospholipid membrane

• Not all viruses can infect all hosts (parvovirus)

• Some are specific for only bacteria (bacteriophage)

• Lytic cycle: 

  • The phage replicates and lyses the host cell. 

• Lysogenic cycle: 

  • Phage DNA is incorporated into the host genome, forming a prophage, which is passed on to generations of cells 

    • Stressors like starvation of exposure to toxic chemicals can cause the lytic cycle to happen 

• Specialized transduction: host DNA flanking the phage genome is also excised 

• Generalized: host is mistakenly packaged in the capsid ???

• Latent virus: dormant periods where they cannot be detected, and are not causing the disease. Can reactivate later due to stimuli like stress, light exposure, or immunocompromise (Herpes)

• RNA viruses

  • +ssRNA can be directly read by ribosomes

  • -ssRNA must use -ssRNA template for the synthesis of +ssRNA before viral proteins are synthesized (error-prone because of RdRP) 

• PrPC is converted in disease PrPsc when it encounters a variant form 

  • CJD 

Chapter 8

• Metabolism: sum of all chemical reactions in a biological system

• Includes catabolism and anabolism 

  • Anabolic: the growth or addition, catabolism: breakdown 

• Energy and carbon sources: 

  • Autotroph: self feeders that make their own organic molecules from inorganic carbon 

  • Heterotroph: other feeders that use organic molecules as a carbon source

  • Chemotroph: energy source comes from energy in chemical compounds

  • Phototrophs: energy harvested from photons of light 

• OIL RIG

  • Molecules that accept high energy electrons include 

    • NAD+ and FAD

    • Energy is converted into ATP

• Exergonic reactions: release energy, do not require enzymes, are catbolic

• Endergonic: require energy, build molecules and are anabolic 

• Enzymes 

  • Cofactors: inorganic ions that stabilize enzyme conformation and function 

  • Coenzymes: organic molecules that are required for proper enzyme function 

  • Apoenzyme: enzyme without a cofactor or coenzyme 

  • Holoenzyme: enzyme with bound cofactor or coenzyme 

  • Competetive inhibitor: bind to enzyme active site, preventing substrate binding 

  • Noncompetitive inhibitor: bind to allosteric site, change conformation of enzyme 

• Organic molecules energy

  • EMP/glycolysis: starts with glucose, ends with pyruvate

  • ED: converts glucose to ethanol, only one ATP

  • PPP: favored when the need for nucleic acids and amino acids is greater than ATP

• Fermentation is used to regenerate NAD+

  • Homolactic: only lactic acid

  • Heterolactic: mix acid

  • Alchohol fermentation 

Chapter 9

• Bacterial cell division 

  • Binary fission: microbe will replicate and form an exact copy of itself 

    • Cytokinesis: partitioning of DNA and cytoplasm during binary fission  

      • Z ring made of FtsZ proteins 

        • Z ring pinches membrane in two and stimulates remodeling of peptidoglycan 

      • Exponential growth

  • Lag phase: no increase in number of living bacterial cells 

  • Log phase: binary fission results in exponential growth, dependent on genetics and environmental conditions 

  • Stationary phase: available nutrients decline, waste accumulates. Cells dying are equal to cells fividing 

  • Death phase: nutrients depleted. Dying cells provide nutrients to persister cells and formation of endospores 

• Direct cell counts:

  • Serial dilution: pour plate and spread plate 

• Indirect cell counts: 

  • Turbidity: measure of cloudiness 

  • ATP testing 

• Quorum sensing: 

  • Activate pathways in density dependent manner 

  • Gram positive: short peptide 

  • Gram-negative: N-acetlated homoserine lactone (AHL)

• Types of growth media

  • Enriched: specific nutrients for fastidious organisms 

    • Neisseria need heme found in lysed blood 

  • Chemically defined: all components are known

  • Complex: chemical components are not all known

  • Differential: indicated phenotype by color change on media 

  • Selective: contains additives to inhibit growth of one group and select for another 

  • Enrichment: preferential growth of one species present in a mixture 

  • 
    

Chapter 13

• For use on fomites:

  • Disinfection: reduces the microbial load of an inanimate item through heat or chemicals

  • Sanitization: reduces microbial load to safe public health levels 

  • Sterilization: completely eliminates bad things 

• Living tissue:

  • Antispesis: reduces microbial load with chemicals, such as surgery 

  • Degerming: hand washing reduces microbial load on skin 

• Microbial death curves: D- value is 90% reduction in the microbe population 

• Pasteurization 

  • HTST: lower temp for more time, stored in fridge

  • UHT: high temp for less time, can be sealed without refrigeration

• Filtration: 

  • HEPA: removes microbes from air

  • Membrane filtration: removes microbes from liquid 

• Phenolics: disrupt membranes and precipitate proteins 

• Triclosan: bad for you, removed from hand soap 

• Havy metals: dentaure proteins 

• Halogens oxidize cellular components

• Sodium hypochlorite: bleach 

• Alcohols denature proteins and disrupt membranes: not effective against spores like C. Diff 

Chapter 14

• Antimicrobial drugs destroy structures and inhibit enzymes 

• Bacteriostatic is slowed growth, bactericidal is death 

  • Bacteriostatic: reversible, less toxic to patient 

  • Bactericidal: infections are life-threatening or immunocompromised patients 

• Paul Ehrlich: discovered arsinic containing coumpound 606, an antimicrobial treatment for syhpillis 

• Dogmagk: synthetic dye prontosil could kill streptococci. First synthetic antimicrobial 

• Fleming: found penicillin 

• Waksman: actinomycetes have antimicrobial production capabilities 

• Hodgkin: crystallographer, confirmed structure of penicillin. Allowed for development of semisynthetic anitmicrobial 

• Narrow spectrum vs. broad spectrum”

  • Narrow: target specific group of pathogens

  • Broad: used when pathogen is unknown, or narrow has failed 

    • Can kill normal flora, allow growth of resistant bacteria 

  • Drug resistance can be transferred horizontally

    • Conjugation: transfer of resistance gene through a sex pilus

    • Transduction

    • Transformation: uptake of naked DNA from dead cell 

• Penicillins

  • Beta-lactams: inhibit cross-linking or peptidoglycan enzymes, inhbit cell wall biosynthesis, bactericidal, have good selective toxicity 

• Tetracyclines

  • Inhibit 30S subunits of ribosomes, block tRNA, broad-spectrum, resistance can be from efflux pumps 

• Macrolides: 

  • Bacteriostatic, inhibits 50s subunits, prevents peptide chain elongation, broad-spectrum, resistance from efflux pumps 

• Polymyxin B

  • Detergent like, disrupt gram negative membranes, bacteriocidal, narrow spectrum, not selectively toxic

• Rifamycins

  • Inhibit RNA polymerase, bactericidal, selective toxicity, narrow spectrum against gram positives, TB treatment 

• Fluoroquinolones

  • Bactericidal drug that inhibits DNA gyrase, side effects, broad spectrum againt both G- and G+

• Sulfonamides: 

  • Oldest, prevents the synthesis of folic acid, broad-spectrum, bacteriostatic, allergy is common

UNIT 3

Chapter 15

• Infectious disease: colonization with microorganisms that damage structure or function of the body

• Signs: measurable, objective (vital signs and antibodies)

• Symptoms: subjective (nausea, pain)

• Classification of disease:

  • Infectious: caused by pathogen

  • Noninfectious: not caused by pathogen

  • Communicable: spread person to person

  • Noncommunicable: not spread person to person

  • Contagious: spread easily person to person (some more than others)

  • Nosocomial: hospital/healthcare-acquired (poor sanitation/sterilization and compromised population)

  • Iatrogenic: infection as a result of a procedure

  • Zoonotic: spread by animals 

    • Example: What terms could be applied to a bacterial infection that is acquired from surgery from instruments that were not sterilized properly?

      • Infectious, Iatrogenic, communicable, nosocomial

•  Periods of disease:

  • Incubation, prodromal, period of illness, period of decline, and period of convalescence 

• Koch’s postulates:

  • Causative agent must not be found in healthy animals 

  • Isolate causative agent and grow in pure culture

  • Cultured agent must cause the same disease after inoculating a healthy organism

  • Agent must be reisolated

    • Flaws: 

      • Not all organisms can be grown in a pure culture

      • Disease susceptibility/severity vary

      • Infection may be unethical

      • Some organisms that cause disease are commensal 

• Pathogenicity: the ability of an organism to cause disease

  • Virulence describes how pathogenic. Related to

    • Virulence factors

    • Dose (how many needed to cause disease (ID50)

    • Lethality (how many needed to cause death(LD50)

  • Primary pathogens can cause disease in a healthy host

  • Opportunistic pathogens can only cause disease with the host being compromised 

• Bacterial toxins:

  • Endotoxins: inflammatory lipids from gram-negative cells

  • Lipid

  • High heat stable, high LD50

    • LPS

    • Lipid A:

      • Highly conserved, sensed as foreign by the immune system, inflammation

      • Loos of blood pressure, organ failure, death

      • Always immunopathic 

  • Exotoxins: proteins that are secreted from Gram negative or Gram positive cells that have specific activities

  • Low LD50

  • Protein

    • AB toxins

      • Receptor specific: active (A) binding (B)

      • Clostridial toxins

        • Botulism: no acetylcholine

        • Tetanus: no GABA

    • Pore forming

      • C. diff

      • Monomers oligomerize in target membranes

      • Streptolysin O, cause osmotic lysis

    • Superantigens 

      • Activate immune cells in a nonspecific manner, leading to excessive proinflammatory cytokines

        • S. aureus - TSST 

• Antigens: specific structures that are recognized by B and T cells of the immune system

• Capsules are virulence factors

• Antigenic drift: happens through many infections over time 

• Antigenic shift: hemagglutin/neuraminidase mutation, quick shift

Chapter 16

• Contact transmission:

  • Direct: vertical or horizontal

  • Indirect: fomites, nosocomial

• Vehicle transmission: spread through food, water, air (greater than 1 meter)

• Vector transmission:

  • Mechanical: spread by an animal that does not itself become infected

  • Biological: usually arthropods, pathogen replicates in vector

• Prevalence: total cases

• Incidence: specified time period, proportion

• Morbidity: being in a state of illness

• Mortality: death

• Patterns of incidences:

  • Sporadic: rarely and without geographic focus

  • Endemic: constant and low level within a population

  • Epidemic/pandemic: outbreak occurs on a significantly larger level, either locally or globally

• Reservoirs:

  • Living:

    • Active: infected and can pass

    • Passive: not infected and pass to other individuals

  • Asymptomatic: infected but do not show symptoms

• Snow: father of epidemiology, mapping of cholera incident in contaminated water pump

• Florence Nightingale: fatalities of soldiers in the Crimean war

• Lister: carbolic acid (phenol) during surgeries

• Point source: short-duration

• Propagation: extended duration 

• Descriptive epidemiology relies on case analysis and patient histories

  • Retrospective: historical data to identify associations with the disease state of present cases 

  • Prospective: gather data and follow cases to find associations with future disease state

• Analytical: observational, compare groups for associations between environment/genetic factors and disease

• Experimental: causation, experiment

• Fomites: nonliving objects that facilitate the indirect transmission of pathogens

• Food is an important vehicle of transmission for pathogens 

• Diseases:

  • Y. pestis: plague, flea

  • R. prowaskiii: typhus, louse

  • P. falciparum: malara, mosquito

  • Borrelia: Lyme, tick 

  • Trypanosoma brucei: ASS, tsetse fly

Chapter 17

• Immunity: to be exempt from

• Adaptive: specific, has memory and gets better with subsequent exposure

• Innate:nonspecific, general mechanisms effective against many pathogens, each exposure to a pathogen is like the first, no memory, rapid response

• Innate immune defenses

  • Physical

    • Physical barriers, mechanical defenses, microbiome

      • Skin, mucous membranes, endothelial cells (barrier)

      • Shedding of skin cells, peristalsis, urine and tears (removal)

      • URT, GI, genitourinary (competetion)

  • Chemical

    • Chemicals/enzymes in body fluids, antimicrobial peptides, plasma protein mediators, cytokines, inflammatory mediators 

    • Complement activation: 

      • Inflammation, opsonization, MAC (cytolysis), chemotaxis

      • Soluble proteins in the blood that “complement” action of antibodies 

    • Chemokines/cytokines:

      • Autocrine: same cell secretes and receives cytokine signal

      • Paracrine: signal secreted to nearby cell

      • Endocrine: circulatory, can be dangerous 

  • Cellular:

    • Granulocytes and agranulocytes 

• Granulocytes

  • Mast cell

    • NOT FOUND IN CIRCULATION, mucosal barriers in tissues

    • When activated, releases histamine that dilates vessels 

      • Mediator of allergy 

  • Basophil

    • Activation = degranulation

    • Support inflammatory response because components are chemotactic and vasodilatory 

      • Bring serum components to inflamed tissue

  • Neutrophil

    • In blood, recruited with chemotaxis

    • 1st responder to bacterial pathogens, phagocytotic 

    • Release toxic molecules, can trap bacteria in DNA NETs

    • Produce pus

  • Eosinophil

    • Activation = degranulation into extracellular space

    • Specialized to defend against protozoa and helminths 

• Macrophages bridge adaptive and innate

  • Monocytes circulate for up to three days

  • Present antigen to the adaptive immune system

• How infection induces fever:

  • Exogenous pyrogens (LPS) signal leukocytes

  • Leukocytes signal endogenous pyrogens

  • Prostaglandin E2 stimulates hypothalamus

    • COX1 and COX2 regulate (inhibited by aspirin/ibuprofen)

• Timing:

  • Chemical/physical barriers- immediate

  • Mehcanical: induced, very fast

  • Cellular: minutes to hours

  • Adaptive: 5-10 days 

Chapter 18

• Adaptive immunity maintains memory - specificity and memory

• First exposure stimulates a primary response, subsequent exposures stimulate secondary response

• Antigens: immunogens, that activate adaptive immunity.

  • Single antigen possesses smaller epitopes, each capable of inducing a specific adaptive immune response 

• Humoral: antibodies produced by B cells

• Cellular: T cells that target intracellular pathogens 

• Humoral

  • Antibodies: B cell receptors, aka immunoglobulins

  • When naive B cells are activated by their antigen, they secrete antibody, can take 5-10 days

  • Activation of B cell requires helper T cells

  • Some B cells well become memory B cells 

  • Two regions:

    • Fc region: activate complement, binds to phagocytotic cells

    • Fab: binds to antigens 

  • Functions:

    • Neutralization: binding of specific antibodies to antigens, preventing them from attaching to target cells 

    • Agglutination: bind to two or more epitopes simultaneously 

    • Opsonization: tagged for destruction by macrophages, dendritic cells, and neutrophils

      • Use Fc receptors 

• Cellular: T cells

  • CD4 T cells: helper T cells

    • Activate macrophages to phagocytose more efficiently, activate B cells to make antibody, activate CD8, and become memory 

  • CD8 T cells: cytotoxic T cells

    • Circulate through the body, killing mediated by perfornin and granzymes that induce apoptosis

  • T cell receptors are always bound to the cell surface

  • Have variable regions to recognize unique antigens presented by other cells 

• Dendritic cells: secrete cytokines when activated by pathogens. 

  • Required for activation of naive CD4 and CD8 T clls 

  • Collect antigens and present them to B and T lymphocytes

  • Bridge innate and adaptive

• Vaccine: intentional exposure to immunogen that does not cause disease

• Types of immunization

  • Active: transfer of antigen. CREATES MEMORY 

  • Passive: transfer of protective antibodies

  • Natural: immunity acquired naturally

    • Passive: placenta/breast milk

    • Active: illness and recovery

  • Artificial: not natural 

    • Antibodies from another person (passive)

    • Vaccine (active)

• Herd immunity: enough individuals are immune to prevent the spread throughout the community 

  • R0 above 1: disease will spread in the community

  • R0 below 1: the disease will burn out 

Chapter 19

• Hypersensitivities: immune responses that produce pathologies

  • Mediated by adaptive immune response

• Type 1: IgE and Mast cells (allergy)

  • Individuals prone to allergy = atopic

  • IgE circulates in blood stream and binds to mast cells

  • When re-exposed,  binds to IgE on mast cells, causing degranulation 

    • Inflammation can be localized or systemic 

• Type 2: IgG and IgM usually involve complement

  • Directed against cell surface molecules 

  • Complement activation causes inflammation and tissue damage

  • Hemolytic transfusion reaction - ABO blood groups 

  • Hemolytic disease of the newborn - Rh factor 

• Type 3: IgG and IgM forming immune complexes

  • Directed against soluble antigens

  • Immune complexes deposit in tissues and joints, activating complement

  • Too large to be phagocytized, release enzyme to degrade the complex

    • Blood clots form as coagulation pathways are activate

    • Serum sickness

    • RA, SLE

• Tyoe 4: T cell mediated

  • NOT MEDIATED BY IMMUNOGLOBULIN

  • T cell-mediated, also known as delayed sensitivities 

  • Dermatitis and delayed transplant rejection 

  • Inflammation happens on the second exposure when memory cells are activated 

  • Each exposure can be worse 

    • Haptens and poison ivy 

    • Multiple sclerosis and diabetes 

• Autoimmunity:

  • Self antigens that are not normally exposed can be released when tissue is damaged

• Hygiene hypothesis

• Antigen vs. antibody

  • Antigen: structures that are recognized by the adaptive immune system (provoke response)

  • Antibody: soluble B cell receptors that contribute to immunity 

• Direct ELISA: measures the amount of antigen

  • Can tell you if you have an active infection 

• Indirect ELISA: antigen-specific antibodies 

  • Would tell you if you’ve ever been infected with something 

UNIT 4

Part 1

SKIN INFECTIONS

• Follicultis 

  • Head and neck: P acnes

• Bacterial

  • Staphylococcus aureus

    • Pyoderma

    • Pus

    • Impetigo

      • Rheumatic fever

      • Glomerulonephritis 

    • SSSS

      • Peeling

  • Streptococcus pyogenes

    • Cellulitis

      • Warm and painful rash

    • Erythema nodosum

      • Red lumps/nodules

    • Erysipelas

      • Raised rash CB

    • Impetigo

    • Necrotizing fasciitis 

  • Pseudomonas aeruginosa

    • Otitis externa

    • Hot tub folliculitis

    • Wound infection (burns)

• Fungal

  • Tinaes

    • Capitas= scalp

    • Corporis= body

    • cruris= groin

• Viral

  • HSV-1

  • Papillomavirus

EYE INFECTIONS

• Keratitis

  • Cornea

• Conjunctivitis

  • Bacterial 

  • Viral

• Blepharitis

  • Eye lid

• Endophthalmitis

  • Interior/retina

• Gonococooal ophthalmia neonatorum

• Chlamydia trachomatous

  • Trichiasis

• Protozoa

  • Loa loa

  • Acanthamoeba 

RESPIRATORY INFECTIONS

• URT

  • Bacterial

    • Diptheria

      • C. diphtheriae

    • Acute otitis media

      • Otitis media with effusion

      • S. pneumonaie H. influenzae

• LRT

  • Bacterial

    • Pneumonia

      • S. Pneumoniae, H influenzae

      • Mycoplasma pneumonia 

        • Walking pneuomonia 

      • Pseudomonas

        • P. aeruginosa

        • Cystic fibrosis

      • Tuberculosis

        • Tuburcles and Ghon complex

        • Mycobacetium tuberculosis

      • Pertussis

        • Whooping cough

        • Bordetella pertussis 

• Lancefield 

  • Group A: streptococcus pyogenes

    • Scarlet fever

    • Rheumatic fever

    • Glomulonephritis 

• Respiratory droplets

  • Measles 

  • Coccidioidomycosis

  • VZV (chicken pox)

    • HSV-3

UROGENITAL INFECTIONS

• Bacterial

  • Urinary

    • Gonorrhea

      • N. gonorrhea

    • Bacterial vaginosis

      • G. vaginalis

    • Cystitis

      • E. coli

    • Polynephritis

    • NGU

      • C. trachomatis M. genitalium

  • Reproductive

    • Chlamydia

      • C trachomatis

    • Syphilis

      • T. pallidum

• Viral (repro)

  • Genital herpes

  • HSV-2

• Fungal

  • Candida

    • Candida spp. 

• Protozoa

  • Trichomoniasis

    • T. vaginalis

Part 2

DIGESTIVE

Bacteria

• S. aureus

  • Staph food poisoning

    • Intoxication, enterotoxins, acid and heat stable, self-limiting

    • Superantigens = cause non-specific activation of T cells, increasing cytokine production and inflammation

• V. cholera

  • Cholera, increases Cl- ions in lumen, ORS treatment, poor sanitation

    • Motile cells can swim through mucous to attatch to epithelial cells and secrete toxin

• H. pylori

  • Peptic ulcers, mucus production decreased, increased risk of gastric cancer

• S. enterica

  • Typhoid fever, salmonellosis, TIII injection into cytosol, fecal-oral

• C. difficile

  • C. diff, disrupts normal microbiota, psuedomembrane formed

• E. coli

  • ETEC: enterotoxin (similar to cholera)

    • Mild

  • EIEC: invasive

    • Maybe dysentery/colitis

  • EPEC: pathogenic

    • Vomiting, could be fatal

  • EHEC: hemorrhagic 

    • Antibiotics are never first line, can develop HUS

    • Bloody diarrhea

Viral/Unicellular

• Hepatitis 

  • Hep B and C associated with increased risk of cirrhosis and liver cancer

    • Hep A: contaminated food, water, is mild

    • Hep B: body fluid contact

    • Hep C: body fluid contact, asymptomatic mostly

Protozoan

• Cryptosporidium

  • Municipal bodies of water (pools)

• Pinworm

  • Fecal-oral, itching/insomnia 

CIRCULATORY/LYMPHATIC

Bacteria

• S. aureus

  • Osteomyelitis (bone inflammation)

  • Toxic shock

• C. perfinges

  • Gas gangrene

    • Untreated = 100% fatal, anaerobic bacteria in wounds that have lost blood supply 

• B. henslae

  • Cat scratch 

    • Pus at site, swollen draining lymph node

• Bacterial endocarditis: inflammation/infection of the heart

Vector-borne Bacteria

• Y. pestis

  • Plague, flea

    • Bubonic, pneumonia (contagious), septicemic (ischemia and necrosis)

• R. prowazekii

  • Endemic typhus, lice

    • Rash on trunk that spreads to extremities, doxycycline

• R. rickettsia

  • RMSF, tick 

    • Rash at extremities spreads to trunk, doxycycline, long term causes bad things

• B. burgdorferi

  • Lyme disease, tick 

    • Bulls-eye rash, chronic inflammation, doxycycline

Viral/Unicellular

• HIV

  • Flu like, CD4 cells lost, leading to immune system weakened

• Yellow fever

  • Mosquito, flavivirus

    • Africa, Central and South America, bilirubin in blood 

• Mononucleosis

  • EBV, HSV4, Burkitt lymphoma 

Protozoan

• Malaria

  • Plasmodium, mosquito 

    • Blood and liver stages

NERVOUS SYSTEM

Bacteria

• Listeria monocytogenes

  • Foodborne

    • 20% spread to meningitis, spont. Abortion in pregnant women

• N. menengitids

  • Meningitis, gram - diplococci, LOS, pili, IgA

    • Vaccine

• H influenza

  • Meningitis, gram - coccobacillus, Hap and Hgp

    • Hib: vaccine for children 

• S. pneumonia

  • Meningitis, gram + diplococci, capsule, pili, pneumolysin 

    • Pneumococcal vaccine

• S. agalactiae

  • Neonatal meningitis, mother-child, capsule + CAMP factor

    • IV antibiotics during labor is prevention

• C. tetani

  • Tetanus, inhibits GABA release, rigid paralysis

    • Can be localized or generalized

• C. botulism

  • Botulism, inhibits Acetylcholine release, flaccid paralysis

    • Wound infection, adult intestinal intoxication 

Viral/Unicellular

• Zika

  • Mosquitos and sex transmitted can lead to fetal microcephaly 

    • Arboviral, no vaccine or drugs

• Rabies

  • Infected mammals

    • Slow progression to CNS, furious or paralytic, PEP is suspected (vaccination and anti-rabies IgG)

• Polio

  • Fecal-oral and droplet transmission

    • Replication in motor neurons or motor cortex causes death of neurons and flaccid paralysis

      • Salk (IPV): first vaccine

      • Sabin (OPV)L live virus, not for immunocomprimised patients

• Prion disease

  • Misfolded protein aggregates, kill neurons (CJD and Kuru)

    • No cure

Eukaryotic

• Naegleria fowleri

  • Olfactory nerve, non-hemotgenous, PAM, warm water up nose 

GENRAL INFO

Digestive

• Infection: must be a living microorganism

• Intoxication: pathology caused by microbial toxins and would cause pathology even without living organisms

• Gastitis: inflammation of the stomach lining

• Enteritis: inflammation of the intestinal mucosa

• Gastroenteritis: combo 

• Hepatitis: inflammation of liver

• Colitis: inflammation of colon

• Dysentery: intestinal damage resulting in bloodand mucous in stool

• Ulcer: open sore

• Goblet cells: produce mucus to prevent pathogens from getting a foothold

• Peyer’s patches: specialized lymphatic tissue for surveillance of the gut microbiota

• Pathogens are kept low by:

  • Normal flora through competetive exclusion and bacteriocins

  • Movement of materials

  • IgA: antibody secreted in lumen by B cells

Circulatory/Lymphatic

• Bacterial pathogens require a breach to colonize circulatory system (arthropod vector)

• Normal flora not a thing bc of the strong immune presence

• Baceteremia: bacteria in blood

• Septicemia: growth of bacteria in the blood

• Lymphangitis: inflammation of lymph vesciles

• Bubo: swollen lymph nodes

• Spleen and lymph nodes are obstacles to infection

• Shock

  • IL-1 and TNF-alpha coordinate immune response, causes vasodialtaion (tight junctions become leaky)

  • Septic shock: bacterial growth causes high cytokines, leading to loss of blood volume and pressure

  • Toxic shock: endo or exo toxins (S. aureus)

    • TSST

Nervous System

• CSF is sterile bc of meninges and BBB

• Breach of BBB

  • Intercellular: virulence factors, like toxins or inflammation pass between cells

  • Transcellular: virulence factors adhere, pass through cells

  • Leukocyte facilitated: trojan horse

  • Non-hematogenous: olfactory or trigeminal nerve

• Encephalitis: inflammation of brain

• Meningitis: inflammation of meninges

• Increased WBC, glucose, or protein indicates infection

• GuillIian Barre

  • Autoimmune: anitbodies directed against myelinated cells (oligodendrocytes)

    • Myelin sheath is lost, resulting in paralysis, self-limiting

• Meningitis:

  • Normal flora, easily spread in immunocomprimised patients

  • 15%-70% fatality rates