general pathology basic principles of cellular and organ pathology infection - i jaroslava dušková...
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General Pathology Basic Principles
of Cellular and Organ Pathology
Infection - I
Jaroslava Dušková
Inst. Pathol. ,1st Med. Faculty, Charles Univ. Prague
Infection–I – table of contents Defenses against infection Interaction of organism and microorganism
Bacteriemia (transient) Sepsis/ Septicemia Pyemia Toxemia Viremia
Bacterial toxins & their action Host & microorganism encounter Infection versus disease Infectious agents of humans – part one
bacteria fungi parasites worms insects
Inflammation - causes
nonlivingphysical
chemical
livingprions
viral
bacterial
mycotic
parasitic
AUTOIMMUNE
Defenses Against Infection – 1.
Surface
– barriers: skin, conjunctiva, mucous membranes
– mechanical removal: shedding, tears, mucus,
ciliary action, coughing, salivation, swallowing,
urination, defecation
– normal bacterial flora
– chemical inhibitors: gastric acid, lactic acid, fatty
acids,bile salts..
– antimicrobial substances: lysozym, secretory IgA
Defenses Against Infection – 2.
Nonspecific resistance factors– fever, interferon, complement, lysozyme, C-reactive
protein, lactoferrin, α1- antitrypsin Inflammation- soluble factors
– clotting system –Hageman fc. (XII)
– complement system: chemotactic fc, anaphylatoxins
– kinin system: bradykinin
Inflammation- phagocytes– circulating: neutrophils, eosinophils, monocytes, macrophages
– fixed: alveoli, spleen, liver, bone marow, brain
Defenses Against Infection – 3.
Immune response– humoral: B-cells, plasma cells, immunoglobulins
– cell-mediated: T-cells, lymphokins
Interaction of Organism and Microorganism – Terms
Bacteriemia (transient) Sepsis/ Septicemia Pyemia Toxemia Viremia
Bacteriemia transient presence of
microbes in the bloodstream
Sepsis / Septicemia (Severe Bacteremia)
increasing numbers of microbes (& their toxins) in the bloodstream
Sepsis/SepticemiaDef.
systemic response to infection presenting as
tachypnoe > 20/min. tachycardia > 90/min. temperature > 39 st. C. (ev. < 36st.C) leucocytosis > 15 000/1l (ev. < 4000/1l)
Sepsis – Pathogenetic Factors
Endotoxin, toxins G+ Macrophages Cytokins
NO PAF (Platelets Activating Factor)
TNF, IL–1
TNF, IL–1, IL–6
NO synthesis
vasodilation coagulation
Syndrome of Systemic Inflammatory ResponseDef.
systemic response to an AGENT manifestating as
tachypnoe > 20/min. tachycardia > 90/min. temperature > 39 st. C. (ev. < 36st.C) leucocytosis > 15 000/1l (ev. < 4000/1l)
AGENT : pancreatitis, injury, burns…..
Pyemia presence of infected thrombemboli bearing virulent microbes in the bloodstream
Endocarditis bacterialis acuta
Toxemia presence of microbial toxin (s) without the microbes themselves in the bloodstream
Endotoxin
lipopolysaccharide component
of G- bacteria outer wall
effects: fever, shock, DIC, RDS
effects mediated by IL-1, TNF
Exotoxins -1
often enzymes (leukocidins,
hemolysins, hyaluronidases,
coagulases, fibrinolysins)
others………….
Exotoxins -2
diphteria toxin – inhibition of cellular
proteosynthesis
botulotoxin – block of the cholinergic
transmission
choleratoxin – increase in cAMP, losses of
isoosmotic fluid via enterocytes
Host & Microorganism Encounter
General Natural
defenses Inflammation Immune status
Successful transmission
Site of attack Number of microorg. Pathogenicity
Host 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
Inflammation– leucocytes– macrophages -
phagocytosis
Immune status– immunity (or lack of
it)active, passive
immunisation, contact
– lymphocytes– immunoglobulins– complement
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
INFECTION versus DISEASE
Pathogenicity (virulence) Incubation Period Carrier State
Agent – Host Interaction
cytocidal stabilised (steady– state) transformation –
ONCOGENS
Inflammation - causes
non infectious
physical
chemical
infectiousprions
viral
bacterial
mycotic
parasitic
AUTOIMMUNE
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)
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
G+ cocci Staphylococcus aureus Staphylococcus epidermidis Staphylococcus
saprophyticus
Streptococcus α-hemolyticus Streptococcus β-hemolyticus
Skin: impetigo, furunculus, carbunculus, panaritium,
hidradenitis mastitis osteomyelitis pharyngitis enterotoxicosis
impetigo tonsilitis, angina scarlet fever erysipelas (St. Anthony´fire)
complications: rheumatic fever, glomerulonephritis
G+ rods non-spore forming aerobes
– Corynebacterium diphteriae– Listeria monocytogenes – Erysipelothrix rhusiopathiae
spore forming aerobes– Bacillus anthracis
Diphteria Listeriosis Erysipeloid
Anthrax
G- rods Bordetella pertusis Pseudomonas aeruginosa Legionella pneumophilla Brucella abortus, Francisella
tularemiae, Campylobacter Helicobacter pylori Escherichia coli Klebsiella pneumoniae Salmonella typhi Shigella dysenteriae Vibrio cholerae Haemophillus influenzae,
Ducreyi
Pertussis respir and urinary inf. pneumonia granulomatous, typhoid,
pneumonia gastritis, ulcers, tumours urinary inf. pneumonia typhoid fever dysenteria cholera pneumonia, ulcus molle
G- Cocci
Neisseria gonorrhoeae Neisseria meningitidis
Gonorrhoea Meningitis
Anaerobic bacteria
non-spore forming anaerobs– Actinomyces israeli G+– Fusobacterium G-
spore forming anaerobs– Clostridium tetani– Clostridium botulinum– Clostridium perfringens,
septicum, histolyticum– Clostridium difficile
Actinomycosis cellulitis
Tetanus Botulismus Gangrene pseudomembranous
colitis
Infectious Agents of Humans Fungi complex cells – eukaryotes both DNA and RNA yeasts, molds (hyphae, pseudohyphae…)
PAS, impregnation extra- or intracellular mostly opportune pathogens
Infectious Agents of Humans Parasites -1Protozoa complex cells – eukaryotes both DNA and RNA extra- or intracellular
(Amebas, Trichomonas,Trypanosoma, Toxoplasma, Plasmodium, Pneumocystis…)
Infectious Agents of Humans Parasites -2Metazoa (helmints and flukes) multicellular both DNA and RNA flat and round worms extracellular
(Taenia, Ascaris, Enterobius, Trichuris Echinococcus, Clonorchis, Schistosoma, Wuchereria…)
Infectious Agents of Humans Parasites -3Insecta, Arachnida multicellular both DNA and RNA extracellular
(Sarcoptes scabiei, fleas, ticks, lice……)
The tick-borne diseases
Babesiosis (a malaria-like infection Babesia microti) Ehrlichiosis (rickettsia Ehrlichia canis) Lyme disease (Borelia Burgdorferi) Rocky Mountain spotted fever (Rickettsia rickettsi)
Tularemia (rabbit fever Francisella tularensis ) Tick paralysis (virus a member of the family Flaviviridae)