Microbiology TEST 2

Lectures 5 - 7

Lectures 5 - 7


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Cartes-fiches 343
Langue English
Catégorie Biologie
Niveau Université
Crée / Actualisé 28.11.2016 / 06.02.2020
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Leptospira has 2 species name them:

Leptospira interrogans - pathogenic species 

Leptospira biflexa - saprophytes

Name non-flexible spiral bacteria 

  • helicobacter 
  • campylobacter 
  • vibrio 

Name flexible spiral bacteria 

  • Treponema 
  • Borrelia 
  • Leptospira 

Where is endoflagella ?

  • characteristic ONLY in spirochetes 
  • under the phospholipid-rich outer membrane - protects from immune recognition 
  • in periplasm

Endoflagella also known as ?

axial filament

Function of axial filament 

  • rotation of flagella spins the spirochete around 
  • generates corkscrew type movement 

Composition of flexible spiral bacteria from inner sheath to outer

  • innermost portion: cytoplasmic membrane 
  • 2nd layer: Cell Wall or periplasmic layer 
  • 3rd  : periplasmic space with endoflagella 
  • 4th: outer membrane - surrounding endoflagellla and protects from immune recognition

Virulence factors of flexible spiral bacteria

  • Motility - active penetration into tissue 
  • low immunity - protect from immune recognition 
  • OMP - adhesion 
  • fibronectin-binding - anti-phagocytic 
  • hyaluronidase 
  • endothelial cells damage - inflammation 

 

 flexible spiral bacteria - spirochete - bacteria with endoflagella/axial filament 

Leptospira reservoir 

Leptospira transmission 

Leptospira penetrate human through

  • intact mucous membrane 
  • or scretched skin (abresions - schürfwunde)
  • or conjunctiva 

Leptospirosis can be 

Leptospira interrogans causes a more severe illness of leptospir-osis

Most important species of Mycoplasma

Mycoplasma pneumonia - Eaton agent

Mycoplasma pneumoniae also named 

Eaton agent

Other species of mycoplasma

  • mycoplasma genitalium 
  • mycoplasma hominis 
  • ureaplasma urealyticum 

Mycoplasma are unique why ? 

  • have NO CELL WALL - no peptidoglycan layer 
  • HAVE a CELL MEMBRANE conatining STEROLS 
  • sterols - responsible for resistance against antibiotics (penicillin)

Mycoplasma pneumoniae virulence factors: 

  • Protein P1/ adhesin P1 - adhesion to epithelial cells of respiratory tract 
  • H2O2 production
  • Functions of SUPERANTIGENS - stimulating inflammatory cells to migrate at site of infection and to release cytokines (TNF-alpha and IL-1 & IL-6) 

Mycoplasma and Ureaplasma produce toxin true or false? 

Mycoplasma are 

Mycoplasma and ureaplasma morphology? 

Mycoplasma are able to pass pore filters why ? 

  • they are the smallest free-living bacteria 

Mycoplasma Pneumoniae has function as superantigens explain why ?

  • stimulates inflammatory cells to migrate site of infection and to release cytokines (tumor necrotizing factor- alpha and interleukins IL-1 & IL-6)

Mycoplasma Pneumoniae resevoir 

  • Asymptomatic/infected humans (nose, throat, trachea and lower airways) 
  • is therefore a strict pathogen (also M.genitalium) 

 strict pathogen - bacteria must cause disease in order to be transmitted from one host to another 

Mycoplasma Pneumoniae transmission: 

  • inhalation - respiratory droplets 
  • close contact
  • risk group: children (60%)

Mycoplasma pneumoniae is extracellular or intracellular pathogen? 

  • extracellular pathogen - can not survive inside phagocyte 

Mycoplasmas cell membrane containing STEROLS protect them from what

Mycoplasma pneumoniae results in what sort of carriage

Mycoplasma pneumoniae most common clinical presentation is ? 

Mycoplasma pneumoniae clinical presentation after a 2-3 week incubation period ? 

Mycoplasma Pneumonia can cause secondary complications name them: 

Mycoplasma Hominis clinical presentation 

Mycoplasma genitalium clinical presentation 

Ureaplasma Urealyticum virulence factors: 

 

  • urease - break down urea 
  • cell membrane with sterols 

Ureaplasma urealyticum clinical presentation 

Mycoplasma species and Ureaplasma urealyticum reservoir

  • NAtural Flora 
  • M. hominis and Ureaplasma urealyticum - in genitourinary tract and respiratory tract 
  • M. genitalium only in genitourinary tract 

Ureaplasma urealyticum transmission: 

  • sexual intercourse 
  • in utero or during birth (mother-to-child) 

 

 

Chlamydia and Chlamydophila are obligate intracellular parasites explain:

  • only survive inside host cell 
  • ENERGY PARASITES - need their host's ATP
  • unable to synthesize ATP

Chlamydias characteristic feature is ? 

developmental cycle (chlamydia life cycle)

Chlamydias Developmental Cycle is complex explain: 

  • bacteria exists in 2 forms EB & RB
  • EB = elementery bodies
  • RB = reticulate (initial) bodies