Chlamydia + Mycoplasma Flashcards
Describe the morphological and gram staining characteristics of Chlamydia
Chlamydia is an obligate intracellular (remember the ship on the island in the sketchy video) gram negative bug
Chlamydia takes on 2 forms in its life cycle, namely the ___ which is the infectious form that enters the host cell via endocytosis, and the ___ form that is metabolically active and replicates inside the host cell
Chlamydia takes on 2 forms in its life cycle, namely the elementary body (EB) which is the infectious form that enters the host cell via endocytosis, and the reticulate body (RB)/form that is metabolically active and replicates inside the host cell
Describe the stages below in Chlamydia’s life cycle
A few hours post contact, the Elementary body gets internalized in a tight vacuole (or I guess the elementary body is the bug now in a vacuole in the host cell).
The dark center is the nucleoid with the bug’s dna.
The EB form is the form that’s specialized for infection. Note that since the dna is compacted and the cell not being metabolically active, this EB form does NOT replicate
The metabolically active form are the RBs (reticulate bodies) that have inclusion (the reticulate body has now multiplied but the daughter cells are still in a membrane bound vacuole)
At 20 hours post infection, the RBs have replicated more and occupy more space in the infected cell. Note that they’re still in a vacuole
Describe the stages below in Chlamydia’s life cycle
At 23 hpi, there are differentiating forms (so some RBs are differentiating back into the EB form). At 48 hpi, there are more Ebs differentiating into RBs. The point: the bug goes back and forth between the EB and RB forms at different times
After the bug has replicated enough, some of the EBs are extruded out or the host cell lyses and all the forms are released
The most important factor in Chlamydia growth inside the host cell is the ___
Another way Chlamydia transports virulence proteins into the host cell is by ___
The most important factor in Chlamydia growth inside the host cell is the Type III Secretion system
Another way Chlamydia transports virulence proteins into the host cell is by outer membrane blebbing (the Chlam forms blebs that contain virulence factors which fuse with the host cell membrane and the factors are released into the host cell)
**Finally there are also cytotoxins that are related to clostridial cytotoxins but no one knows what they do so there’s that. Note also that Chlamydia has to co-opt nutrients from the host, so there are transport proteins that serve to grab metabolites and such from the host to promote Chlam’s growth (autottransport)**
Using the image below, describe the Chlamydal life cycle
Basically, the EB enters the host cell and undergoes early differentiation into the RB form (at which point all of the preloaded T3S effectors that were ass’d with the EB form are released into the host cell)
The RB form replicates in the vacuole and continues to do so until some of the forms are stuck to the periphery of the inclusion membrane and there isn’t any more room for more RB forms to grow (the T3S effectors ass’d with RB replication and inclusion expansion are released while the RBs are replicating)
The T3S effectors ass’d with EB differentiation (and RB detachment from the inclusion membrane) are loaded on to the RBs that are stuck to the periphery of the inclusion membrane. Those RBs are then prompted to fall off the membrane and differentiate into EB forms again
**The RBs are also squeezed off of the inclusion membrane periphery and into the center**
Some common themes in Chlamydial infections include that infections are ___ in the abscence of treatment, repeated following natural clearance/antibiotic treatment, and ___(symptomatic/asymptomatic)
Some common themes in Chlamydial infections include that infections are long lasting in the abscence of treatment, repeated following natural clearance/antibiotic treatment, and asymptomatic
C trachomatis causes infection mainly in the ___ and ___
C. trachomatis causes infection primarily in the human urogenital tract and conjunctiva
Inclusion conjunctivitis is caused by Chlamydial infection of the eye, specifically by types ___
The chronic version of this is called ___ and is the leading cause of preventable blindness worldwide
Inclusion conjunctivitis is caused by Chlamydial infection of the eye, specifically by types A-C
The chronic version of this is called trachoma and is the leading cause of preventable blindness worldwide
Trachoma can be transmitted by direct __ to __ contact
Repeated exposure leads to corneal inflammation, resulting in in scar tissue in the cornea and neovascularization aka ___
Scarring results in contraction of the conjunctiva – eyelashes turn inward and abrade the cornea further aka ___
hand to eye contact
pannus
trichiasis
C trachomatis infection can also lead to ___ syndrome of the newborn and ___ (hint: its an eye disorder)
How would you treat these disorder? (name two types of drugs)
Pneumonia syndrome of the new born (remember the baby being held by the mermaid with clam shells on baby’s chest)
Ophthalmia neonatorum (aka neonatal conjuctivitis) (remember the mermaid mom covering baby’s eyes)
Treatment: erthromycin + macrolides
T/F: Genital C trachomatis is usually asymptomatic and can lead to PID, ectopic pregnancy and infertility in women
T/F: Genital C trachomatis involves both antibody and cell mediated immunity (which is short lived) and ain’t no vaccine for it
Truth
Also true
____ is another bug that can cause atypical pneumonia and in case of chronic infection, can lead to chronic bronchitis, asthma and excerbation of COPD
Chlamydia pneumoniae
Disseminated chronic C pneumoniae infection can be ass’d with reactive arthritis, ___, stroke, ___, Alzheimer’s disease and has the strongest association with ___
Reactive arthritis
Abdominal aortic aneurysm
Stroke
MS, Alzheimer disease
Strongest association with atherosclerosis**
How would you Dx C pneumoniae?
Name 3 drugs you could give to treat C pneumoniae
Dx: CF assay using genus specific Ag
Treatment: Doxycycline (the boat’s steering wheel in the sketchy video)
Quinolones
Macrolides
Ceftriaxone
How does Mycoplasma grow/divide?
How do you identify Mycoplasma morphologically?
Either binary fission or cell elongation
Fried egg colony morphology (see below)
