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2015-09-14 00:55:12
section 1: -lay foundation -lessons from history -health system organization -biosecurity -pathogenic -microbes -disease
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  1. Pathogen
    "is a biological agent that can/may cause disease/illness to its host"

    -Any microorganism whose survival is dependent upon its capacity to replicate and persist on / within another species by actively breaching / destroying host barrier that ordinarily restricts / inhibits another microorganism.
  2. Factors that can/may cause disease
    • -young/old
    • -sexually active
    • -state of health
    • -immuno-compromised
  3. Virulence Factors
    • toolbox of proteins 
    • adhesions 
    • toxins 
  4. Pathogens do not want to kill host...
    • -source of nutrients, stable, save environment
    • -disease accidental?
    •        -Bubonic Plague
    •        -Lyme Disease
  5. Multiplicity of Infection
    aka MOI

    - # of organisms required to cause disease 

    • EX : Samonella: 10 million
    • E. coli 0157: >10
  6. Development of Disease depends on complex interactions:
    • 1.Host's susceptibility to infections 
    • 2.Organism's virulence potential
    • 3.Opportunity for interaction btwn host-organism
    • 4.Opportunity/circumstances that allows transmission of the organism w/in a population
  7. Bacteria have evolved....

    -any organism that lives within the body/cells of another organism
  8. Plasticity of endosymbiont's genome...
    • -gene arrangement 
    • -mutations 
    • -acquisition of new DNA - allows expression of new proteins 
    •         -virulence factors/ability to evade host defenses 
  9. Medical Advances
    • -Antibiotics/Drugs 
    • -Vaccines
    • -Surgeries/transplants/prosthetic devices etc.
    • -Gene & nerve therapy 
  10. 7 basic questions
  11. one of the basic "think like a scientist" question...
    Who is at risk from the disease?
    • young/elderly 
    • sexually active 
    • immuno-compromised 
  12. one of the basic "think like a scientist" question...
    "Where does the organization cause infections (body & geographical area)?"
    • skin/urogenital tract, respiratory tract, GI tract 
    • Europe, USA, Africa, etc
  13. one of the basic "think like a scientist" question...
    "When is the isolation of this organism important?"
    • Host: time limit with physical symptoms 
    • Bacteria: life cycles, vectors, seasonal, intracellular 
  14. one of the basic "think like a scientist" question...
    "Why is the organism able to cause disease?"
    -breach of skin and other body defenses, non-specific & specific immune systems, immuno-compromised
  15. one of the basic "think like a scientist" question...
    "Which genera and species are medically important?"
    • Clostridium difficile (+ve) rod 
    • C. botulinum (+ve) rod-shaped
    • Staphylococcus (MRSA) (+ve)

  16. one of the basic "think like a scientist" question...
    "What diagnostic test should be performed?"
    -Gram stain, culture(?), Serology(specific antibodies)

    -Increasing use of molecular-based methods 
  17. one of the basic "think like a scientist" question...
    "How is the infections managed?"
    -Antibiotics, surgery, blood transfusion, 

    -Organ transplant, chemtherapy, quarantine

    -Gene therapy, prosthetic devices 
  18. Mortality
    incidence of deaths (# of deaths in a population)
  19. Morbidity
    refers to incidence of ill health in population (# of people INFECTED)
  20. Based on similarities in ___________, living organisms are categorized into 3 domains; bacteria, archaea, and eukarya
  21. Milestones in Microbiology:
    Discovery of Bacteria (1684)
    Antoni van Leeuwenhoek
  22. Milestones in Microbiology 
    Binomial naming system (1735)
    Carolus Linnaeus Binomial naming system
  23. Milestones in Microbiology:
    First vaccination (Smallpox) 1798
    Edward Jenner
  24. Milestones in Microbiology:
    Germ Theory (1840)
    Friedrich Henle
  25. Milestones of Microbiology:
    Bacterial/yeast characterization (lactic
    acid fermentation)/vaccines (1857)
    Louis Pasteur
  26. Milestones in Microbiology:
    Antiseptic principles in surgery (1867)
    Robert Lister
  27. Milestones in Microbiology:
    Methods for study of bacteria in pure culture (1881)
    Robert Koch
  28. Milestones in Microbiology:
    Gram staining method (1884)
    Christian Gram
  29. Milestones of Microbiology: 
    Discovery of Penicillin (1929)
    Sir Alexander Fleming 
  30. Milestones of Microbiology:
    Structure of DNA (1953)
    Crick and Watson
  31. Milestones of Microbiology: 
    DNA sequencing (1977)
    Fred Sanger
  32. Milestones of Microbiology:
    16S rRNA cataloguing/sequencing 1960s & 70s
    Carl Woese/George Fox
  33. Milestones of Microbiology: 
    Discovery of Archaea (1977)
  34. Milestones of Microbiology:
    Bacterial Genome Sequenced
    1997 –E. coli, H. pylori, Borrelia burgdorferi
  35. Milestones of Microbiology:
    Next Generation DNA Sequencing
  36. Emerging and remerging diseases:
    New-new Disease
    caused by newly discovered organism (bacterial species)
  37. Emerging and remerging diseases:
    New-old Disease
    caused by newly discovered pathogens but organism itself has been known for a long time 
  38. Emerging and remerging diseases: 
    Old-new Diseases
    old diseases with known causes, which were thought to have been eliminated but have reappeared 
  39. Emerging and remerging diseases: 
    Old-old diseases
    old diseases with known causes that are now being recognized by the public and media.
  40. Epidemic
    occurs when new cases of a certain disease in a given human population and during a given period, substantially exceed what is "expected," based on recent experience, 
  41. Pandemic
    an epidemic of infectious diseases that's spread thru human populations across, a large region; for instance a continent/worldwide.
  42. Current issues in Pathogenic Microbiology: Infectious Diseases
    • water/food - bourne 
    •  hospital acquired infections 
    •  antibiotic resistance 
    •  microbiota shift diseases 
    •  (bioterrorism)
  43. Factors contributing to infectious disease events...
    • ease in travel
    •  population increase
    •  population displacement
    •  agricultural activity
    •  changing socio-economic structures 
    •  international conflicts 
    •  pollution; global warming
  44. "Actions or lack-of consequences"
    3 categories:A,B, and C.

    • A: most dangerous and useful to to bioterrorists, AKA "high priority agents."
    • B: less dangerous and useful
    • C: potentially dangerous and useful
  45. Top 4 Bioterrorist Agents:
    Bacillus anthracis 

    Smallpox virus 

    Yersinia pestis (plague)

    Clostridium botullinum toxin (botulism)
  46. B. anthracis (anthrax)
    produces spores that can be "weaponized" 

    2001: US mail attacks, 11 cutaneous infections, 11 inhalation of which 5 were fatal.
  47. Small pox virus
    US and Russia and other states have stockpiles of vaccines for 100% coverage of population.

    -small pox = harder to obtain, it was at one time only known to exist in 2 labs in the world.

    Natural case of human smallpox has not occured since 1977(Somalia)
  48. Post-eradication
    Last cases of smallpox in the world occured in outbreak of 2 cases (one was fatal) in Birmingham, England in 1978, medical photographer, died after scientist responsible for unit, Prof. Henry Bedson committed suicide.

    Stocks of smallpox were destroyed or transferred to CDC(Centers for Disease Control and Prevention) in US and State Research of Viology and Biotechnology in Koltsovo, Russia.

    WHO recommended destruction of virus, then policy changed to be against final destruction for ongoing research for new vaccines, antiviral drugs, diagnostic tests.
  49. Yersinia pestis: Bubonic / Black plague
    High-density, fatal septicemia 

    high fever, painful bubo (inflammation of lymph nodes) in neck and grion

    100% mortality if not treated (now easily treated with antibiotics)
  50. Clostridium botulinum toxin (botulism)
    -protein from a bacterium that can cause paralysis of the muscles, this toxin prevents muscles from contracting leaving a person limp. 

    no DNA/RNA for PCR detection

    nerves not killed and can regenerate if person is kept on respirator 

    --# of respirators available, most hospitals are at 95% capacity so large numbers would be impossible to treat.

    --time 4-6 months required.
  51. Future problems/most vulnerable targets...
    Food(central processing plants) and water sources 

    CDC/USDA monitoring/ reporting programs 

    global warming, less water available
  52. Combating bioterrorism
    1. Understand transmission of agents 

    • 2. Management of resources 
    •  -prevention
    •  -treatment/containment (enforced?-unpopular with public)
    •  -predictive models

    3. Eduction and preparedness 

  53. Microbiota shift diseases
    fall outside normal classifcation schemes 

    -they're not caused by a single organism; normally commensal organisms are generally protective in nature but imbalances can occur.
  54. Commensal Organisms
    -living in a relationship in which one organism dervied food or other benefits from another organism without necessary hurting or helping it. 

    -commensal bacteria=part of normal flora in mouth, GI tract, vagina and on skin.

    mainly viewed as benficial but under particular circumstances some species can become pathogenic. 
  55. GI tract Microbiota shift Diseases
    • -involve shift from Gram +ve organisms such as Lactobacillus and Bifidobacterium a mix of G -ve/+ve anaerobes- 

    • Clostridium (+ve)
    • Fusobacterium (-ve)
    • Bacteroides (-ve)
  56. Development of Gut Flora
    • Birth: initial colonisers
    • First Week: conditions favourable for growth 
    • Breast fed: bifidobacteria predominate
    • Formula fed: similar profile to days 4-7
    • Probiotics: 'bacteriotherapy' for promoting healthy gut microflora
  57. Pathological Gut Disorder
    • Acute inflammation
    • Pseudomembranous colitis 
    • Inflammatory bowel disease
    • Bowel cancer
    • Irritable Bowel Syn. 
  58. Bacteria are everywhere
    Vast majority of bacteria are harmless or beneficial but those few that are pathogens have an enormous impact on human life. 

    -our skin and esp. the GI tract carry a heavy bacterial load.

    blood and tissue -- normally sterile
  59. Colonization
    bacteria occupy and multiply in a particular area of the human body
  60. Infection
    Colonization of the body by an organism capable of causing disease 
  61. Disease
    An infection that produces symptoms
  62. Carrier
    Sub-clinically infected individual who may spread a disease 

    -Asymptomatic states-- no observable symptoms 

    -May be individuals in incubation period 

    • may have recovered from disease but still harbor the pathogen
    •    may even have been so mild that no/few symptoms may have been observed 

  63. Case Study: Oregon Salad Bars
    1984 large outbreak (740) of Salmonellosis, Wesco county, Oregon.

    Salad-bar of 10 restaurants infected by S. enteric serovar typhimurium

    • unusual, because the normal source = meat,milk or eggs.
    • FBI investigation

    Attempt by locals to close a Religious commune.
  64. West Nile Virus Facts
    2nd person died in OK from that virus, in Stephens County.

    21 cases of West Nile Virus in US so far.

    Symptoms: fatigue, figure, headache, body aches, rash, and swollen lymph nodes.

    1st case reported in Uganda in 1937. 

    common in Africa, Central Asia, and Middle East 

    1999-First case of West Nile in NYC.
  65. Pollution...
    can change fish gender