5 Intro Flashcards
Examples of Pathogens
Extracellular (3)
Intracellular (5)
Toxins (3)
Pathogenicity factors (4+examples)
Extracellular
Streptococci, Pseudomonas, Yersinia, Giardia, Aspergillus, Borrelia
Intracellular
Mycobacterium, Salmonella, Clamydia, Rickettsia, Coxiella, Listeria, Legionella Trichinella
Toxins
Botulism (clostridium), Aflatoxin (Aspergillus), Pfisteria (Algae)
Pathogenicity factors
Exotoxins: Tetanus, Cholera, Shigella, Helicobacter, Diphteria
often with A+B part
Endotoxins: LPS
PAMPs: dsRNA, cell wall, LPS, DNA,Flaggelin. glycan
Superantigen: Streptococci
Virulence factors example
enter host (3)
avoid pathogenisis (5)
enter host cell (3)
promote intracellular growth (2)
enter host
adhesion
invasion
establishment of infection
niche
avoid pathogenisis
capsules (Pneumococci, Haemophilus, Crytococcus)
Protein A (Streptococci) to bind FC part of antibodies
Biofilm (Streptococci, Pseudomonas)
pilus (Streptococcus)
Bact products like Leukocidin that lyse phagocytes (Streptococcus)
enter host cell
receptors, adhesins, invasins
promote intracellular growth
Viral relication machinery, Host cell reprogramming (Trichinella)
Virulence factors causing disease for transmission
examples and mechanism (7)
Host cell death releasing pathogens
Rabies induces aggression for bite
Cholera/Shigatoxin causes diarrhea
Influenza, Pneimococci, Bordatella induces coughing
Ascaris stage 3 larvae induce coughing
Myc tub. caseous granuloma to release bacteria into brochia -> coughing
Shistosoma eggs rupture bladder/colon to be released
How can listeria survive in the water?
It can infect amoebae, therefore stay in the enviroment/water as an intracellular bacterium
Why do pathogens use intracellular niche?
Why do intracellular pathogens use distinct niches?
example of niches and which bacteria uses them?
Why do pathogens use intracellular niche?
Protection gainst humoral immune response
Abuse uptake by phagocytosis to enter macrophages
Access to specific nurtrients
Silent entry into macrophages after delaying cell death of granulocytes
Why do intracellular pathogens use distinct niches?
Avoid degradative pathway (lysosome, cytoplasma)
Transfer to next cell (cytoplasm, actin tails)
Need for nutrients, auxotrophy, energy
example of niches and which bacteria uses them?
Early endosome - Myc tub. for iron
Autophagosomes - Leishmania for purin and carbon source
Golgi versicles - Chlamydia, Legionella for host cell lipids, iron
Cytoplasma - Listeria for hexose phosphate, lipoic acid, iron, Rickettsia for ATP
Host cell types and pathogenic life style
Invasion of non-phagocytic cell (4)
Invasion of phagocytic and non-phagocytic cells (5)
Invasion of phagocytic cells (4)
Invasion of erythrocytes (1)
and obligate or facultative ?
Invasion of non-phagocytic cell
obligate: Rickettsia, Chlamydia, Coxiella
facultative: Plasmodium
Invasion of phagocytic and non-phagocytic cells
obligate: Viruses, Myc. leprae
facultative: Salmonella, Listeria
Invasion of phagocytic cells
obligate: Ehrlichia
facultative: Mycobacteria, Legionella Leishmania
Invasion of erythrocytes
facultative: Plasmodium
Where do MHC class 1 and 2 molecules (from pathogen) come from ?
Where to pathogen evade from this or inhibit maturation?
MHC2
Phagosome, Endsome and Autophagosome will merge to from Autophagolysosome where MHC 2 molecules can be loaded
e.g. Mycobacteria in early endosome
leishamnia Phagolysosome
MHC1
happens in ER from molceules from the cytosplams that have been degradated in proteasome
e.g. Listeria
7 steps to control infection
Barrier
Recognition through Antibody/PRR
Innate immunity
Aquired immunity
Isolation / Elimination (T killer cell, macrophages)
Regulation (Treg, limit immunopathology)
Remember (memory t and B cells, vaccination)
Polymorphnuclar neutrophils
function
function
phagocytosis, NET formation, granula for defensins , lysozyme and also ROS production
well controlled because half life is very short
History
scientists and their achievement
18th century
Jenner: pox vaccination
19th century
Lister: antiseptic surgery
Semmelweis: hygiene for birth
Pasteur: Germ theory, vaccinnes using attenuated pathogens
Koch: Postulates, staining, solid media, sanitation( cholera in Hamburg)
Metchnikoff: Phagocytosis, Probiotics
19-20th century
Behring, Shibasaburo: Immunology, Diptheria, Tetanus Vaccine
Ehrlich: Immunology, memory, staining
Flemming: Penicilin
Waksman: Streptomycin
Griffith, Avery: DNA as carrier
Löffler, Frosch: Virus infections
Calmette, Guerin: BCG vaccine against tuberculosis
Salk, Sabin: Polio vaccines
Examples of different pathogens
Prions (3)
Bacteria (4)
Protozoal (4)
Fungi (2)
Helminths (3)
Insects (2)
Prions
Scrapie
CJD
Kuru
Bacteria (4)
gram+ spore forming Colstridium, Bacillus
gram+ non spore forming: Listeria, Streptococcus, Staphylococcus, Enterococcus, Corynebacteria
gram-: Pseudomonas, Legionella, EHEC
acid-fast: Mycobacteria
no cell wall: Mycoplasma
Protozoal (4)
Apicomplexa: Plasmodium, Toxoplasma
Flagellates: Leishmania, Trypanosoma
Amoebae: Entamoeba
Microsporidia
Fungi (2)
Yeast: Candida, Crytococcus, Histoplasma
Filamentous fungi: Aspergillus, Trichopyton
Helminths (3)
Trematodes (Shistosoma)
Cestodes (Echinococcus, Taenia)
Nematodes (Ascaris, Hookworkm, Trichinella)
Insects (2)
Vectors: tick, bug, mosquito
Ecto/Endoparasites: Ticks, Scabies mite, lice
Transmission via
human to human vertical
Rubella, HBV, Toxoplasma, HIV, Leukemia Virus
human to human fecal-oral contaminated food / water
Salmonella, Norovirus, Rotavirus, EHEC, Shigella, Crytococcus, Entamoeba, Enterobius
human to human contact
sexually, blood transfusion: HBV, HCV, HIV, Trichomonas
aerosols/direct contact: tuberculosis, neisseria, Influenza, Bordatella pertussis
Zoonosis
Rabies, EHEC, SARS, many parasites
Enviromental
Legionella, Shistosoma, Crytococcus
Vectors human to human
Rickettsia, Dengue, Malaria
Vectors zoonosis
FSME, Yersinia pestis
Epideminology
Endemic
region with certain conditions like tick
Neisseria meningitidis: Meningitis belt in Africa, mostly Dec-June
Lyme disease: tick species
Burkholderia pseudomallei (Meliodosis)
Pneumonia infections in southeast asia mostly
Epidemic
HIV, Ebola
EHEC outbreak 2011
Pandemic
epidemic with at least 2 continents
Influenza outbreaks often, H5N1, SARS-CoV-2
Different ways to cross blood brain barrier
Trancytosis
common
Paracellular
Trypanosoma
Infection
Rickettsia, Bacteria, HIV
Receptor Hijacking
Neisseria
Trojan horse (macrophages)
Viruses, Toxoplasma
Receptor aquisition
HIV
Cross epithelial barrier
3 ways and example
Intracellular like Myc. tuberculosis
colonize epithelial barrier like pseudomoas aeruginosa and streptococcus pneumoniae
