final review

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final review
2010-05-25 03:25:47
final review

last chapters
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  1. The stages of disease
    Incubation- infection is present, no signs and symptoms, organism is replicating, body is not producing a response, most likely to get transmitted becasue since there are no signs and symptoms, people act normally

    Prodromal- increase in pathogen numbers, starting to have vague signs and symptoms like aches and tiredness

    Acute- highest amount of microbes, easisest to be transmitted because there are the most pathogens most severe signs and symptoms, when diagnosis happens

    Decline- treatment or natural health of hte immune system, decline in signs and symptoms and in the amount of pathogens

    Convalescence- may still be populated but no signs and symptoms
  2. Types of contagious diseases
    • Endemic- disease that is always present at about the same level within a given population
    • Epidemic- unusual increase in prevalence (number of cases) in a given population
    • Pandemic- epidemic diseases that are seen worldwide ex- HIV, SARS
    • Sporadic- shows up here and there without satisfying any of the other requirements, usually recurring and small
  3. The ways diseases can be transmitted
    • Animals (vector)- Zoonoses- Schistosoma, tapeworms, rabies, comes from animals
    • Humans (direct)- looks at sources within humans, 2 types: Active and Asymptomatic
    • Active- known people that have the disease
    • Asymptomatic- some members of the population that do not show typical signs and symptoms of the disease
    • Environmental (vehicle)- Soil, Water, Food
  4. Incidence vs. Prevalence
    • Incidence- epidemiology statistics- number of new cases (new infected individuals withing the population, always a lower number than prevalence
    • Prevalence- number of cases withing a population, usually given as a #/100,000 population, sometiems as percentages
  5. Ways to stop transmission
    • Reduction of source- environmental isolate it and deal with it, after
    • Isolation- people to people- isolation of the infected individuals, after
    • Quarantine- used to be applied to populations, couldn’t leave their houses, after
    • Destruction- destruction of source, related to reduction, not the people, but the animals, after
    • Treatment- drugs, reduce propagation of disease, happens after exposure
    • Immunization- preventative, most efficient
    • Sterilization : Destruction of all microbes and viruses (removes ALL life)
  6. Different mehods to reduce microbial populations
    • Sanitation-
    • Chlorination- water borne diseases
    • Pasteurization- food, milk
    • Sewage treatment- fecal oral transition
    • Monitoring food handling
    • Destruction of vectors- West Nile Virus, Malaria
    • Reducing susceptibility- general health
  7. Physical means to reduce microbial populations
    Heat, Cold, Desiccation, Radiation, Filtration, Osmotic pressure
  8. Heat
    denatures enzymes (ex- dry heat (incineration) wet heat/ steam (autoclave), pasteurization)
  9. Cold
    slows rate of microbial growth (retards growth), has to be bellow 7 degrees
  10. Desiccation
    Bringing things out, Removal of water slows growth because microbes need water to grow.
  11. 2 types of Radiation
    • Ionizing- forms ions on a variety of cellular chemicals, destroying genetic material in enzymes. Stronger than non ionizing. Ex- X- Ray, Gamma rays, Irradiated food
    • Non ionizing- ex- UV ray light- damages DNA. Light cannot pass through physical barriers (ex- lid on petri dish)
  12. Filtration
    • Small holes that will let only the liquid go though and not the microbes.
    • 2 types: Exclusion filtration, HEPA
    • Exclusion filtration- purposely trying to remove something from a liquid, ex- membrane filters- can be used to sterilize drugs, liquids must be dilute or the liquid will not pass through
    • HEPA: High Efficiency Particulate Air- filters air. Air flow must be laminar (not have turbulence) for it to be effective
  13. Osmotic Pressure
    Increasing osmotic pressure of environment. Ex- salt, sugar
  14. Parameters of Sterilization
    • Nature of material- what are we trying to do, incinerate, can it withstand autoclave, dry heat
    • Degree of susceptibility - do we want to get rid of all of the organisms or target organisms
    • Environmental conditions
    • Temperature- higher = more effective
    • pH- halogen are usually effective at low pHs, heavy metals
    • Organic material- Cl- attaches to any organic material (blood, urine, food)
    • Time- less concentration- the more time you need to apply it
    • Concentration- higher concentration- the less time you need to apply it
    • Examples- Autoclaves- Temperature, pressure (15 psi / 121 degrees Celsius (15 minutes), Bleach 6%- leave for 5- 10 minutes
  15. Antisepsis
    Antisepsis: Reduction of pathogens on living tissue (contrast of disinfection)
  16. Aseptic
    Aseptic: Free of pathogenic organisms (kills microbes)
  17. Disinfection
    Disinfection: Destruction of most microbes on non-living surfaces (opposite of antisepsis)
  18. Pasteurization
    Pasteurization : Heating foods to reduce pathogens and spoilage organisms. Gets rid of organisms
  19. Sanitization
    Sanitization : Removal of total microbes to “safe” levels
  20. Sterilization
    Sterilization : Destruction of all microbes and viruses (removes ALL life)
  21. Chemical agents
    Phenols, Alcohols, Halogens, Peroxides, Heavy metals, Aldehydes, Detergents, Gases
  22. Phenols
    • denatures proteins, disrupts membranes of cells
    • ex- carbolic acid (antiseptic), Triclosan (antibacterial soaps)
  23. Alcohols
    • denatures proteins (gram positive)
    • disrupts cell membranes(gram negative)
    • ex- ethyl alcohol, isopropyl alcohol
  24. Halogens
    • Oxidize enzymes- get inside the cell
    • Ex- Iodine: iodophors: iodine-containing organics, benidine solution
    • Ex- Chlorine : hypochlorite (bleach)
  25. Peroxides
    • doesn’t destroy living tissues, but gets rid of the microbes inside the tissues.
    • Ex- hydrogen peroxide
  26. Heavy metals
    • Interfere with protein function
    • inserts itself in membrane and changes shape of active site
    • ex-Hg, Ag, Cu, Ar
  27. Aldehydes
    • Effective at low concentrations but can only be used as disinfectants
    • good antimicrobial agents but can be damaging to host
    • denatures proteins
    • ex- formaldehyde and glutaraldehyde
  28. Detergents
    • Reduce surface tension of water, dissolves lipids
    • ex- Zephrin
  29. Gases
    • Denatures proteins and DNA
    • highly toxic, flammable
    • Cant be used as antiseptics
    • ex- Ethylene oxide, propylene oxide
  30. Ways antimicrobial agents target cells
    (cell membrane, cell wall, Protein synthesis, DNA replication, Metabolic disruption)
    • Cell membrane- disrupt cell membrane function ex- polymyxin, nystatin
    • Cell wall- inhibits cell wall synthesis ex- Penicillin, Cephalosporin (they interfere with cross links of peptidoglycan layer)
    • Protein synthesis- a lot of targets in its process, affects ribosome function, ex-tetracycline, streptomycin, erythromycin
    • DNA replication- how DNA is replicated, rifamycin (transcription), nalidixic acid (quinolome- effects DNA replication- gyrase- supercoling in transcription and replication)
    • Metabolic disruption- interrupt normal metabolic processes, sulfanilamide- sulfa drugs (competitive inhibition of PABA which is used to produce folic acid), thrimethoprim (if you have resistance to sulfa drugs, you need to add trimethoprim)
  31. Specific actions of Beta Lactams
    • 2 families: penicillin’s and cephalosporin’s
    • They wok the same but don’t function the same
    • Have been altered to change the composition to make them more effective or make them more broad on the spectrum
    • Ex- penicillin G, Penicillin V- Penicillin G- original, not resistant to stomach acid so has to be injected into patient Penicillin V- acid resistant, can be taken orally
    • They interfere (disrupts) with the peptidoglycan cross links
    • EXAMPLE- Penicillin, Cephalosporins (both kill bacteria)
  32. Specific actions of Quinolones
    • interfere with DNA, they are DNA gryase inhibitors
    • DNA gyrase- does the super coiling of DNA, effects DNA replication or transcription so cell division cannot occur
    • EXAMPLE- Ciprofloxacin, Nalidixic acid
  33. Specific actions of Sulfa Drugs
    • interferes with folic acid production
    • competitive inhibitor of PABA
    • EXAMPLE- Sulfanilamide
  34. Specific action of Tetracylcines
    Broad spectrum drugs that interfere with ribosome function by sitting in the ribosome during translation
  35. The ways that drug reistance is acquired and spread
    • Acquired:
    • Acquisition of R (resistance) plasmid- done by conjugation, transformation and transduction
    • Ex- penicillin resistance from Beta- lactometers
    • Mutation of drug target site- ribosome changes, RNA polymerase changes
    • Multi drug pumps (pumps drug our as fast as it gets in)
    • Spread by:
    • Improper use of antibicrobials- using antibiotics when you shouldn’t Overuse of antimicroials
  36. Examples of emerging diseases
    West Nile Virus, SARS, HIV, Ebola, Nipha virus, Hantavirus
  37. Reasons of emerging diseases
    Microbial adaptation and change, Human susceptibility to infection, Changes in climate and weather, Human demographics and behavior, Economic development an land use, International travel and commerce, Technology and industry, Changes social behavior, Breakdown of public health measures, Poverty and social inequality, War and famine, Bioterrorism
  38. Tools of biotechnologists
    • Enzymes that interact with DNA and RNA
    • Plasmid DNA- may be responsible for drug resistance, toxin production (Need to have: origin of replication, promoter (host cell), marker (antibiotic resistance)
    • Host organisms- plasmids must work in the host organism
    • Electrophoresis- enzymes that can cut DNA in the middle of the strand leaves ragged ends that could be specifically bound to other pieces of DNA, allows ability to cut and paste different pieces of DNA together, this is how insulin and penicillin and many antibiotics are produced
  39. Results of Genetic Manupulaion
    • Forensics- fingerprinting
    • Drug production- general way, all therapeutic drugs ex- insulin production in E. coli, antibiotics like penicillin production
    • GMO- genetically modified organisms
    • GMF- genetically modified food
  40. The ethical difficulties of the used of gene therapy
    • Supremacist view – humans are of greater value than animals
    • Long-term effects of transgenic manipulations are unknown
    • Unforeseen problems arise from every new technology and procedure
    • Natural genetic transfer could deliver genes from transgenic plants and animals into other organisms
    • Transgenic organisms could trigger allergies or cause harmless organisms to become pathogenic
    • Standards imposed on labs involved in recombinant DNA technology
    • Can create biological weapons using same technology
  41. Examples of Biofilms
    • Dental plaque
    • Prosthetics
    • Resident foreign materials: pacemakers, catheters
    • Wounds
    • Primary environmental surfaces: Rocks, ship hulls, submarine equipment
  42. Biofilms
    • Genetically diverse collections of different microbial species growing on
    • solid surface held together by an extra cellular matrix
    • Glycocaylyx- Extra cellular matrix hetero polysaccharides (made of different types of sugars)
  43. Steps in the formation of a biofilm
    • 1. Attachment of bacteria- A few species attach- do not produce a gylcocaylyx, Colonizing organisms stick to a solid surface (wet surface)
    • 2. Initial colonization- Form a gylcocaylyx, Formation happens within hours- ex- teeth cleaning- within hours it starts colonizing again
    • 3. Secondary colonization- Recruitment occurs, traps floating organisms, Increasing in matrix, gets bigger,
    • 4. Mature Biofilms- Very complex architecture, aerobic organisms on top, anaerobic in the middle, Circulation of liquid all around the biofilm, difficult to get drugs in there because they must attack the cells themsleves
  44. The results of the formation of Biofilms
    • Doesn't happen unless there is a certain cell density
    • Substrate destruction
    • Metabolic shifts- quorum sensing- how metabolic shifts happen
    • Toxin production
    • Drug resistance
    • Pigment production