Microbiology TEST 2
Lectures 5 - 7
Lectures 5 - 7
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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
