Micro 3

  1. Pathogen
    • any disease causing microorganism
    • 2 types: true/primary & opportunistic
    • by nature are parasites
  2. true/primary pathogen
    • can cause infection and disease in healthy people
    • aka frank pathogen
  3. opportunistic pathogen
    can infect host only when immune defense is weakened
  4. parasite
    • any organism that lives on or in another organism and is either metabolically dependent upon that organisms or derives nutrients from that organism
    • have complex microbial interaction where one organism benefits from the assoiciation and the other organism is usuaully harmed or killed
  5. host
    a larger organism that supports the survival and growth of a smaller organism
  6. parasitism
    • requires an extended relationship or coexistence between parasite and host
    • is an example of symbios (living together of organism)
  7. Parasitic infections usually involve several hosts
    • definitive host
    • intermediate host
  8. definitive host
    • maintains the mature form of the parasite
    • maintains the sexually reproductive form of the parasite
  9. intermediate host
    • maintains the immature parasites
    • immature parasite usually undergoes various stages of maturation before being transferred to the definitive host
  10. pathogenicity
    • ability of microbes to cause disease
    • the capacity of a pathogen to invade and harm a host
  11. Pathogenesis
    the steps involved in disease progression within the host
  12. virulence
    • degree or intensity of pathogenicity
    • important indicator of disease progression after infection by a pathogen
    • is determined by factors associated with the pathogen
  13. virulence factors
    • product of microbes that increases the invasiveness or pathogenicity of the organism
    • contribute to tissue damage
    • can be integral microbial cell components or secreted products
    • can be secreted products
    • can be genetic
  14. pathogenicity islands
    • large segments of DNA that code for virulence factors
    • often acquired during horizonatal transfer
  15. infectivity
    the ability of microorganisms to establish an infection
  16. infectious dose (ID50)
    number of pathogens that infect 50% of hosts within a specified period of time
  17. invasiveness
    ability of microorganisms to spread to adjacent tissues or other anatomical areas
  18. lethal dose
    • number of pathogens that kill 50% of the hosts within a specified period of time
    • associated with toxin production
  19. disease
    • deviation of the host from a healthy state to an unhealthy state
    • abnormal state where part or all of the host is unable to perform the normal functions of the body
    • termed a morbid state
    • change is manifested by signs and symptoms
  20. morbidity
    diseased state or condition
  21. signs
    • objective evidence of disease
    • characteristics of a disease that can be observed by someone else in addition to the patient
  22. symptoms
    • subjective evidence of disease
    • characteristics of disease that can only be determined by the patient
  23. inflammation
    nonspecific defense mechanism by the body in response to infection, injury, or chemical irritation
  24. rubor
    • redness
    • from blood accumulation
  25. calor
    • heat
    • warmth generated from the blood dur to vascoconstriction
  26. tumor
    • swelling (edema)
    • from the accumulation of fluid in surrounding tissue
  27. dolor
    • pain
    • soreness or tenderness from injury to local nerves
  28. proctitis
    inflammation of the colon
  29. meningitis
    inflammation of the meninges
  30. nephritis
    inflammation of the kidney
  31. lyphadenitis
    swollen lymph nodes
  32. inflamed
    organ or tissue undergoing inflammation
  33. granuloma
    • small mass or nodule of inflamed tissue
    • due to action of phagocytes and the subsequent accumulation of pus
  34. abscess
    collection of pus in a tissue, cavity or confined area surrounded by inflamed tissue
  35. bacteremia
    bacteria present in the blood but not multiplying
  36. fungemia
    fungi present in the blood but multiplying
  37. virema
    viruses present in the blood, but not necessarily multiplying
  38. septicemia
    • multiplying microbes in the blood
    • presence of toxins
  39. syndrome
    • Combination of signs and symptoms that occur together and are indicative of a diseased or abnormal condition
    • A complex of symptoms indicative of a morbid state
  40. sequela
    • Permanent damage to tissues as a result of infection and disease
    • Plural:sequelae
  41. pathology
    • The study of diseased states
    • The study of the structural and functional manifestations of disease
    • A branch of medicine that examines the nature of disease, how the disease is manifested, and changes to the body that occur as a result of disease
  42. immunopathology
    • hypersensitivity reaction
    • Associated with a second exposure or the chronic exposure to a pathogen
    • Signs and symptoms are not associated with the direct action of the pathogen
    • Instead, host has an exaggerated immune response to the presence of pathogen
  43. diagnosis
    • The process of determining the cause of the disease
    • Commonly involves the use of chemical or immunological tests
  44. prognosis
    • The projected outcome of a disease
    • The prospect of recovery from a disease
    • The recovery success (or a lack thereof) is based on the nature (pathology) of the disease
  45. prophylaxis
    • Simply, prevention
    • Measures used to prevent the spread and development of disease
    • Is based on understanding the etiology and mode of transmission
    • Includes vaccination, improving hygiene and sanitation, standards of living, education, etc.
  46. palliative care
    • Relieving or soothing the symptoms of a disease or disorder without effecting a cure
    • Providing relief from pain and other distressing symptoms
  47. epidemiology
    The study of the frequency and distribution (spread) of disease and other health-related problems within human populations
  48. etiology
    • The study of how diseases are causedFactors that cause disease include:Pathogens (infection) Genetics (genetic disorders)Immune dysfunction Biochemical/physiological deficiencies or changes, Psychological dysfunction
    • Sometimes the etiology, pathology and prognosis is unknown (idiopathic disease)
  49. idiopathic disease
    ethiology, pathology, and prognosis is unknown
  50. infectious disease
    • disease caused by the presence and action of microorganisms
    • deviation from a healthy state that is caused and maintained by microorganisms
  51. 2 categories based on pathogenesis
    • infection
    • toxinosis (intoxication)
  52. infection
    signs and symptoms result from the growth of microbes and their invasion into tissue.
  53. toxinosis (intoxication)
    signs and symptoms are the result of the action of toxins
  54. 2 categories based on the transmissibility of the microbe between humans
    • communicable
    • noncommunicable
  55. communicable
    • Disease that is spread from one person to another
    • Usually applies to human infections
    • Associate the term “catch” with this form.
  56. noncommunicable
    • disease that is not spread directly from one person to another
    • Disease may be caused by the movement of normal flora, ingestion of pre-formed toxins, or exposure to microbes in the environment.
  57. categories based on transmission of the microbe from the environment
    • zoonotic
    • phytogenic
  58. zoonotic
    • disease that is spread from animals to humans
    • disease cause by animal pathogens
  59. phytogenic
    • disease that is spread from plants to humans
    • disease caused by plant pathogens
  60. categories based on the expression and duration of an infectious disease
    • overt
    • subclinical
    • latent
  61. overt
    • signs and symptoms are clearly evident
    • symptomatic
    • Acute: Expression of disease is severe and short
    • Fulminating: microbe is multiplying at a high level or with great intensity
    • Chronic: Disease is persistent and lasts over long periods
  62. acute
    expression of disease is severe and short
  63. fulminating
    microbe is multiplying at a high level or with great intensity
  64. chronic
    disease is persistent and lasts over long periods
  65. subclinical
    • The patient lacks symptoms
    • not detected by clinical examination or laboratory tests
    • Also called asymptomatic, inapparent, or covert
  66. latent
    • The microbe persists in host tissues for long periods of time
    • the disease alternates between an acute and a subclinical state.
  67. categories based on location
    • local
    • focal
    • systemic
  68. local
    Microbes restricted to a limited region or anatomical area
  69. focal
    spread from one localized area to other localized areas
  70. systemic
    microorganism circulates throughout the body and infects many different tissues
  71. categories based on sequence of infection
    • primary
    • secondary
  72. primary
    • host is colonized by a single pathogen type
    • Initial infection often results in decreased immune surveillance and response; leaves patient immunocompromised
  73. secondary
    once host is infected, other pathogens will colonize the host
  74. influenza infection
    caused by the influenza virus, an orthomyxovirus
  75. strep throat
    inflammation of the pharynx caused by Streptococcus pyogenes
  76. categories based on the types or species of organisms
    • polymicrobial
    • cross-infection
  77. polymicrobial
    • the simultaneous establishment of infection by several different microbes
    • Also referred to as a mixed infection
    • Can include different taxonomic groups; e.g. bacteria and fungal spores in a puncture wound
    • Can include the same taxonomic groups but different species
  78. cross infection
    co-infection of a host where pathogens were transmitted between hosts infected with different organisms
  79. nosocomial infection
    • Infectious diseases that are acquired and/or develop in hospitals
    • Usually refers to infections acquired by patients during hospitalization but can also be applied to infections acquired by medical personnel
  80. opportunistic infection
    Infection resulting from endogenous microbiota when the host immune’s system is compromised or if the microbe moves from its normal location to a new location in the body
  81. pyogenic
    Infection resulting in pus formation
  82. pyrogenic
    • Infection resulting in fever; fever-inducing
    • Pyrogen: microbe that induces fever
  83. incubation
    • Time from the first exposure to the pathogen to the time symptoms become apparent
    • Length of incubation period varies considerably for some microorganisms
    • Depends on the health of the host, the virulence of the microbe, the generation time of the pathogen, time for organism to migrate from point of entry to site of infection
  84. prodromal
    • A short period before specific symptoms set in where the patient experiences malaise
    • Malaise= a general feeling of discomfort
  85. invasion
    • Pathogen multiplying, producing toxins, etc.
    • Signs and symptoms can include cough, rash, diarrhea, etc.
    • Immune system is responding to pathogen
    • Corresponds to symptoms seen during an acute or chronic infection
  86. decline
    • The patient’s condition worsens
    • The patient’s immune system is working to contain and eliminate the microbe but has thus far been unsuccessful
    • There are high levels of immunological molecules, e.g. antibodies Elevated white blood cell count
    • The patient either recovers or the disease is fatal
    • Not evident in all infections
  87. convalescence
    • Patient survives the infection
    • Microbes and/or toxins are eliminated from the body
    • Signs and symptoms abate and patient starts to feel better
    • Affected tissues and systems are repaired
  88. non infectious disease
    inherited, congenital, degenerative, nutritional, endocrine, mental, immunological, neoplastic, iatrogenic, idiopathic
  89. idiopathic
    cause of disease is unknown
  90. iatrogenic
    caused by medical procedures or treatments, surgical errors, and or drug interactions
  91. neoplastic
    abnormal cell growth that leads to formation of tumors
  92. immunological
    disease of the immune system: allergies, autoimmune, aids
  93. mental
    • can result from infection
    • mostly due to emotional, psychological factors
    • biochemical imbalance
  94. endocrine
    due to excesses or deficiency in hormones
  95. nutritional
    disease from lack of specific nutrient
  96. degenerative
    disorders affecting one of more body systems that develop as patient ages
  97. congenital
    structural and functional defects present at birth
  98. inherited
    genetic disorders passed from parent to child
  99. successful pathogen
    maintains a reservoir, leaves the reservoir and transported to the host, enters the host, establishes a site of reproduction and growth, evade the host defenses, multiply within the host, damage the host, leave the host and return to the reservoir or find a new host
  100. maintain a reservoir
    • a place to live before and after infecting a host
    • 3 types: animal, human, environmental
  101. animal reservoir
    • wild and domestic
    • zoonosis
  102. zoonosis
    • disease spread from animals to humans
    • SARS:corona virus in bats and pigs
    • avian flu:H5N3 influenza in wild and domestic birds
    • plague:yersinia pestis in rats
    • cutaneous anthrax: Bacillus anthracis in cattle
  103. human reservoirs
    • symptomatic carriers
    • asympotomatic carriers
  104. symptomatic carriers
    those who are sick
  105. asymptomatic carriers
    • incubatory carriers: people who are infected with a pathogen but appear healthy; will get sick soon
    • chronic carriers: people who are infected with a pathogen but do not become sick for months or years
    • Latent/Dormant carriers: people who are infected with a pathogen that undergoes latency
  106. environmental reservoirs
    • soil, water, food, air, insects, animals, house dust, fomites
    • fomite: inanimate object that is used to spread diseases (door knob, toilet, tissue)
  107. encounter with a pathogen
    • exogenous
    • endogenous
  108. exogenous
    Exogenously acquired disease results from encounters with pathogens in the environment
  109. endogenous
    Endogenously acquired disease are caused by agents in or on the body.
  110. transmission
    • The spread of a pathogen from one organism to another
    • The transfer of disease from one organism to another
    • Vertical: mother to child
    • Lateral: person to person, environment to person, etc.
    • If a disease is transmissible (capable of being spread from one organism to another) then the disease can be termed
    • Infectious, contagious or communicable (are used interchangeably)
  111. parenteral transmission
    • the pathogen is deposited directly into the blood stream, into tissue below the skin or into mucous membranes
    • needle injection, deep wounds, insect bites
  112. portals of entry
    • mucous surface (eye)
    • skin-pathogen enters through break in skin
    • ex. Clostidium tetani and tetanus. Herpes
    • alimentary and respiratory tract
    • genitourinary tract
    • birth canal
  113. alimentary tract
    • Mouth: enter via ingestion of contaminated food, drink, etc.
    • Ingested pathogens can survive stomach pH and enzyme activity
    • e.g., Salmonella, poliovirus, hepatitis A virus
  114. respiratory tract
    • Nose: pathogen enters the body through inhaled droplets or aerosols
    • inhaled particles can be deeply inhaledbacteria: sore throat (streptococci), meningitis, diphtheria, pneumonia
    • viruses: measles, mumps, chickenpox, cold
  115. colonization
    • The establishment of a site of microbial reproduction on or within a host
    • The presence of micoorganisms in a site of the body that may lead to tissue damage and signs of disease
    • Structures involved in colonization are considered virulence factors
    • requires attachment to surfaces on or in the host
    • many pathogens penetrate the host's mucous membranes and epithelial surfaces
Card Set
Micro 3