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Chlamydia & Mycoplasma (Hull)

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Both mycoplasma and chlamydia grow (well/difficult) in the laboratory...
difficult, can also make assumption that these organisms are going to require CLOSE person-person contact in order to cause disease (because if they require such strict and fastidious growth requirements in the lab will likely be that way in real life transmission)
Organisms that require CLOSE person to person contact are likely going to cause ______ infections and ________ infections.
respiratory tract, and sexually transmitted
The most common reportable STD in the US, and the #1 cause of infertility in the US.
Chlamydia
FACT: Chlamydia has the minimum structure of LOS in addition to having NO peptidoglycan
FACT: Chlamydia cannot grow on their own. Their genome size is 1/4 the size of E. Coli's, therefore they don't have enough genes to grow on their own
Chlamydia are ________ _______ parasites
obligate intracellular
Chlamydia are known as the energy parasites. Why?
Because they DON'T generate their own ATP, steal it from the eukaryotic cell they are invading. Lack enzymes/genes to make their own ATP.
What components of LPS do Chlamydia have?
Just the Lipid A and KDO sugar (KDO is the bridge between core oligosaccharide and Lipid A)
Chlamydia makes contact with what types of cells (does it prefer)?
It has a predelection for columnar epithelial cells such as the ones in the conjunctiva, respiratory, and urogenital tracts
Which one is the infectious type and which one is the replicative type between the reticulate and elementary bodies?
Reticulate - replicative
elementary - infectious
On colonization/phagocytosis which form of chlamydia is taken up by the cell?
The infectious form (elementary body)
The elementary bodies evade killing by....
preventing lysosomal/phagosomal fusion
FACT: as elementary bodies are differentiating into reticulate bodies in the phagosome, its getting bigger and bigger, and almost takes up the entire cytoplasm of the eukaryotic cell, then they differentiate back into elementary bodies, the phagosome mem
FACT: The cell is not very effective anymore, and in order for it to get better, these damaged cells have to turnover. In order for disease to resolve completely, the damaged cells have to turnover. So, people may have these infections for quite a while.
Does the chlamydia directly kill cells?
NO, it will only scar the cell because the phagosome's membrane fuses into the cytoplasmic membrane upon release, thus only scarring.
Most common cause of urethritis is...
chlamydia!
The most common reportable infectious disease in the US is...
NGU (non-gonoccocal urethritis)
FACT: not as much inflammation, not as strong, so puss is a little bit thinner, little bit clearer for chlamydia urethritis than gonococcal urethritis
FACT: MEN are more likely to notice this (and gon) than women, because they notice the exudate coming out of them and get worried. Not the case for women
What is a woman with pelvic inflammatory disease likely to present with?
abdominal pain!
The inflammatory responses to chlamydia are NOT AS A STRONG/AS STRONG AS/STRONGER THAN gonorrhoeae.
NOT AS STRONG AS, therefore they don't look as bad!
Transmission by flies and not having access to clean water are common causes of _________
trachoma (remember the leading cause of blindness in the world!) more a third world country problem. Cornea opacifies as the inflammatory response continues due to hypervascularization around the area
FACT: Infections following chlamydia are WORSE following reinfection.
FACT: You can get pneumonia from an infected bird (with C. psittaci)
Does a vaccine work against Chlamydia trachomatis?
NO, because their symptoms were worse because a stronger inflammatory response is induce.
Birds imported into the US are quarantined and treated with tetracycline. Why?
To kill the Chlamydia psittaci
True/False: Chlamydia pneumoniae has been implicated in atherosclerosis?
TRUE (similar basis to rheumatic fever with Group A Strep)
What is the only way to culture chlamydia?
With McCoy Cells (HAS TO BE IN TISSUE CULTURE, will NOT grow on culture media)
What organism sticks projections through the vacuolar membrane allowing the organism to get nutrients from the host and to send regulatory signals to the host, perhaps to prevent cell death and permit the organism to grow?
CHLAMYDIA
How do you prevent chlamydia?
Wear condums, clean water (trachoma), quarantine of psittacine birds
What are the SMALLEST cellular organisms?
Myocplasma!
Unlike ________, _______ ARE capable of growth on artificial media BUT this media MUST be enriched with ________
chlamydia, mycoplasma, cholesterol
FACT: Mycoplasma can't make their own cholesterol and sterols so they must get this from their environment (reason you supplement their media with this)
FACT: Mycoplasma don't invade cells, they may, but not a regular process for them
What organism makes fried egg colonies on the culture plate?
Myocplasma!
What are the two means of transmission of mycoplasma?
Transmission is either via inhalation or sexual contact
FACT: Mycoplasma know which end is which, they have pointed tips which fuse to end of the host cell, used to steal nutrients from the host
FACT: epithelial cell is induced to sort of wrap itself around the pointed tip of the mycoplasma (via inducing cytoskeletal rearrangements)
What kind of pneumonia do you get from Myocplasma?
Walking pneumonia, called walking because these people don't appear to be as sick as pneumonia from other pathogens (painful cough, may hold their chest, get a headache when they cough)
FACT: family sizes greater than 4 persons are a risk factor for mycoplasma pnuemoniae infection, because likely have school children in the family (the population that gets this the most).
FACT: Incidence of ALL pneumonias follows a U curve (age is X bar). Seen a lot in childhood, early years, and adulthood (in middle years incidence is lower). THIS is in direct contrast to a chart of ONLY mycoplasma pneumonias (don't see it in infants or older people because they aren't mounting a strong response to it)
FACT: Just like with chlamydia, patients with mycoplasma have WORSE symptoms if they mount a stronger immune response. So, the two spikes we see on this chart are for 5-15 years (school age) and then they bring it home to the 25-40 year old blip (in pare
FACT: mycoplasma pneumoniae is not a real thick pneumonia, (NOT a lobar, segmental pneumonia), see a patchy pnuemonia (atypical)
Why does it take a long time to completely recover from Mycoplasma pneumoniae? (ie 40 days)
Because have to shed ALL affected cells off. All the damaged cells have to be totally replaced before the people are totally recovered.
Why do you put the serum of a person you suspect with mycoplasma pneumonia into a cold bucket?
Because of the cold agglutinins, if blood agglutinates then you know its Mycoplasma pneumoniae
Distinguish epidemiologically between all pneumonias and mycoplasma pneumonia?
Most cases of pneumonia are seen in the very young and very old; however, for M. pneumoniae, peak incidence is seen in school aged children and as a result their teachers and parents (double hump, not a U shape)
FACT: There is evidence of mycoplasma also causing genital infections as well
FACT: STDs rarely occur by themselves
The more sexual partners a woman has in her lifetime, the more likely she is to be infected by Mycoplasma __________ or Ureaplasma _________
hominis, urealyticum (know that incidence rises with increasing # of partners)
Why can't we say for sure that these organisms (mycoplamas) are the cause of genitals disease?
Because we CAN'T use Koch's postulates on them. We have no animal model for them! Can just make associations. Also, rarely are able to isolate this by itself in a STI, usually they occur together (more than one type present, ie the whole Chinese buffet thing)
3 big causes of nongonorrhoeael urethritis are ....
chlamydia trachomatis, ureaplasma urealyticum, niserria gonorroheae
Elementary Body
NO binary fission
NO metabolically active
DNA is tightly coiled
YES induce phagocytosis
YES infective
YES capsule
YES rigid cell wall
Reticular Body
Dispersed DNA
YES binary fission
YES metabolically active
NO rigid cell wall
NO extracellular stability
NO infective
NO induces phagocytosis

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