Woychik - Mycoplasma, Spirochetes, Chlamydia, Lyme, Ricketssia, And Others Flashcards
Why are mycoplasma difficult/impossible to gram stain?
They do not have a cell wall. Rather, they have a 3 layered cell membrane.
- therefore they are resistant to penicillin.
Mycoplasmas morphology
Have unusual colonies on agar plates.
- M. Pnemonia - has mulberry shaped colonies but can also be spherical
- the other three types of mycoplasmas generally have a fried egg appearance.
Nutritional requirements for growth of mycoplasmas
They require cholesterol or a cholesterol source because they need it for their cell membranes. So, this is added to their medium.
- very slow growing bacteria.
How is mycoplasma pneumonia transmitted?
It is transmitted from person to person through respiratory secretions.
What populations are more likely to get pneumonia??
Populations in closed quarters such as military or college
How does Mycoplasma pneumonia cause respiratory pathogenicity?
It has a high affinity for respiratory epithelial cells. It attaches at the base of the cilia, which causes loss of ciliary action, followed by loss of cilia, then sloughing of the cell into the lumen, which produces the cough.
How long is the incubation period of mycoplasma pneumonia?
2-3 weeks
Typical symptoms of mycoplasma pneumonia
Gradual onset of fever, malaise, headache, and cough.
How does the age of the patient affect what kind of symptoms they present with?
3 or less - upper respiratory
5-20 - bronchitis and pneumonia
Older - pneumonia
Laboratory diagnosis for mycoplasma pneumonia
Cold agglutination - obsolete
PCR - most specific and rapid
- usually just go undiagnosed so they treat with standard drugs for community acquired pneumonia, which won’t work because they are usually beta-lactams
What does mycoplasma pneumonia cause?
Walking (atypical) pneumonia
What are the spirochetes?
BLT
- borrelia Burgdorferi and borrelia recurrentis
- leptospira Interrogans
- treponema Pallidum
What is the name of the tick that caries Lyme disease???
Ixodes
What animals are reservoir for Lyme disease?
White footed mouse and deer
Why are confections common with Lyme disease?
Ixodes tic is a vector for other pathogens as well.
For how many hours does the tic need to be attached to get Lyme disease?
24 hours
What is the prophylactic treatment for Lyme disease?
Doxycycline
What did the Lyme disease vaccine target?
The surface lipoproteins, OspA-F, which are the virulence factors.
OspA-F
Virulence factors for Lyme disease that cause attachment to mammalian cells.
Stage 1 Of Lyme Disease
- Erythema migrans
- feverish symptoms
Stage 2 of Lyme Disease
Days to weeks after tick bite - flue like symptoms
Weeks to months after tick bite - musculoskeletal pain in joints and bones, cardiac disease, and Bell’s palsy.
Stage 3 of Lyme Disease
Months to years after tick bite - chronic nervous system and joint involvement. Causes Lyme arthritis in large joints such as the knee.
Laboratory diagnosis of Lyme Disease
Usually you just treat if you see the erythema migrans. If it isn’t there, you do a two tiered approach of ELISA and then Westerb Blot.
When doing a Wester Blot, how many lanes have to be positive to make a diagnosis of Lyme Disease?
IgG - 5 out of 10
IgM - 2 out of 3
What is the name of the disease caused by borrelia recurrentis?
Relapsing fever
How does one get endemic relapsing fever?
Tick bite - but not same tick as Lyme disease.
- reservoir is small animals and rodents