Basic Principles of Cellular and Organ Pathology Infection

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General Pathology

• Basic Principles of Cellular and Organ Pathology
• Infection - I

http//www1.lf1.cuni.cz/jdusk/
Jaroslava Dušková Inst. Pathol. ,1st Med.
Faculty, Charles Univ. Prague
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Inflammation - causes

• nonliving
• physical
• chemical

• living
• prions (?)
• viral
• bacterial
• mycotic
• parasitic
• AUTOIMMUNE

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Interaction of Organism and Microorganism Terms

• Bacteriemia (transient)
• Sepsis/ Septicemia
• Pyemia
• Toxemia
• Viremia

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Bacteriemia

• transient presence of microbes in the
  bloodstream

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Sepsis / Septicemia (Severe Bacteremia)

• increasing numbers of microbes ( their
  toxins) in the bloodstream

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Sepsis/Septicemia

• Def.
• systemic response to infection manifestating as
• tachypnoe gt 20/min.
• tachycardia gt 90/min.
• temperature gt 39 st. C. (ev. lt 36st.C)
• leucocytosis gt 15 000/1?l (ev. lt 4000/1?l)

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Sepsis Pathogenetic Factors

• Endotoxin, toxins G
• Macrophages
• Cytokins
• NO
• PAF (Platelets
• Activating Factor)

• TNF, IL1
• TNF, IL1, IL6
• NO synthesis
• vasodilation
• coagulation

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Syndrome of Systemic Inflammatory Response

• Def.
• systemic response to an AGENT
  manifestating as
• tachypnoe gt 20/min.
• tachycardia gt 90/min.
• temperature gt 39 st. C. (ev. lt 36st.C)
• leucocytosis gt 15 000/1?l (ev. lt 4000/1?l)
• AGENT pancreatitis, injury, burns..

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Pyemia

• presence of infected thrombemboli bearing
  virulent microbes in the bloodstream

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Toxemia

• presence of microbial toxin (s) without the
  microbes themselves in the bloodstream

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Endotoxin

• lipopolysaccharide component of G- bacteria
  outer wall
• effects fever, shock, DIC, RDS
• effects mediated by IL-1, TNF

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Exotoxins -1

• often enzymes (leukocidins, hemolysins,
  hyaluronidases, coagulases, fibrinolysins)
• others.

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Exotoxins -2

• diphteria toxin inhibition of cellular
  proteosynthesis
• botulotoxin block of the cholinergic
  transmission
• choleratoxin increase in cAMP, losses of
  isoosmotic fluid via enterocytes

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Host Microorganism Encounter

• General
• Natural defenses
• Inflammation
• Immune status

• Successful transmission
• Site of attack
• Number of microorg.
• Pathogenicity

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Host

• Inflammation
• leucocytes
• macrophages -phagocytosis
• Immune status
• immunity (or lack of it)
• active, passive immunisation, contact
• lymphocytes
• immunoglobulins
• complement

• General
• age, race, nutrition, other diseases (diabetes)
• Natural defenses
• skin, mucose integrity
• mucus, cilliary action, unobstructed flow
• protective secretion (lysosym in tears, gastric
  acid, IgA

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Microorganism

• Successful transmission
• Site of attack
• Number of microorg.
• Pathogenicity invasiveness
• toxin production
• multiplication
• resistence to host
  defence mechanisms
• ability to cause necrosis
• enzyme release

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INFECTION versus DISEASE

• Pathogenicity (virulence)
• Incubation Period
• Carrier State

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Agent Host Interaction

• cytocidal
• stabilised (steady state)
• transformation ONCOGENS

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Virus Host Cell Interaction

• cytocidal
• stabilised (steady state)
• transformation ONCOGENS

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Inflammation - causes

• non infectious
• physical
• chemical

• infectious
• prions
• viral
• bacterial
• mycotic
• parasitic
• AUTOIMMUNE

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Infectious Agents of Humans

• prions
• viruses (DNA, RNA)
• bacteria (incl. chlamydia, mycoplasma,
  rickettsia obligatory intracellular parasites)
• fungi (yeasts, molds)
• parasites (protozoa, helmints, ectoparasites-
  insects lice, mites, ticks spiders)

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Infectious Agents of Humans
Bacteria

• simple cells prokaryotes
• both DNA and RNA
• cocci, bacilli (AFB!), spirochetes.
• Gram positive /negative
• extra- and/or intracellular
• aerobic/ anaerobic

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Infectious Agents of Humans Fungi

• complex cells eukaryotes
• both DNA and RNA
• yeasts, molds (hyphae, pseudohyphae)
• PAS, impregnation
• extra- or intracellular
• mostly opportune pathogens

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Infectious Agents of Humans
Parasites -1

• Protozoa
• complex cells eukaryotes
• both DNA and RNA
• extra- or intracellular
• (Amebas, Trichomonas,Trypanosoma, Toxoplasma,
  Plasmodium, Pneumocystis)

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Infectious Agents of Humans
Parasites -2

• Metazoa (helmints and flukes)
• multicellular
• both DNA and RNA
• flat and round worms
• extracellular
• (Taenia, Ascaris, Enterobius, Trichuris
  Echinococcus, Clonorchis, Schistosoma,
  Wuchereria)

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Infectious Agents of Humans
Parasites -3

• Insecta, Arachnida
• multicellular
• both DNA and RNA
• extracellular
• (Sarcoptes scabiei, fleas, ticks, lice)