Week 5 - Intracellular Bacteria & Other Medically Important Bacteria Flashcards
What gram-variable bacteria causes bacterial vaginosis and how is this diagnosed?
Gardnerella vaginalis -
DX: clue cells - epithelial cells covered in bacteria
What is it about the cell wall of Tuberculosis spp that make this infection difficult to treat?
It contains mycolic acid in the cell wall - a lipid - so it is difficult for ABs to kill.
How is tuberculosis diagnosed?
- Mantoux test - Tuberculin skin test
- observation of acid-fast bacteria in sputum, blood or bone marrow by Kinyoun/Ziehl Neelson Stains
- Chest X-ray
- DNA sequencing
Can you describe a big problem faced by HIV patients that also have tuberculosis?
Often the TB is antibiotic resistant.
What is Hansen’s Disease and what bacteria is it caused by?
Leprosy - caused by Mycobacterium leprae
What is walking pneumonia usually caused by?
Infection with Mycoplasma pneumoniae !
What can you state about the cell wall of the bacteria that causes walking pneumonia?
Mycoplasma pneumoniae - has NO CELL WALL!
How can you diagnose Mycoplasma pneumoniae if you can’t culture it?
PCR or serological testing.
Which serotype of Chlamydia is responsible for cystitis, reproductive tract abnormalities and eye infections in koalas?
Chlamydia pecorum
Which serotype of Chlamydia is sexually transmitted in humans?
Chlamydia trachomatis
What two forms does Chlamydia exist in? What type of bacteria does this make it?
- Reticulate body - larger
- Elementary body - smaller “seed”
It is an intracellular bacteria - needs to live and reproduce inside host cell.
What are some symptoms and complications of Chlamydia trachomatis infections in humans?
Men - acute urethritis Women - can be asymptomatic - PID - damage cilia in Fallopian tube -tubal infertility -risk of ectopic pregnancy -chronic pelvic pain
What is trachoma? How is it transmitted? What are some complications?
Caused by Chlamydia trachomatis serotypes A-C
- chronic inflammation of cornea and conjunctiva (karatoconjunctivitis)
- Transmitted through direct contact or towels, clothes, flies
- Can lead to scarring and blindness
Can you culture Chlamydia for a diagnosis?
No - it’s intracellular.
Therefore direct fluorescent antibodies or PCR
How is Typhus contracted in humans?
Tick/louse bite and faeces rubbed into bite wound. The faeces contain causative bacteria:
Epidemic typhus: Rickettsia prowazekii
Rocky Mountain Spotted Fever: Rickettsia rickettsii
What organism causes Q Fever?
Coxiella burnetii
What is the implication with the Q Fever vaccination?
If you are serologically positive for past or present infection, you may develop anaphylaxis upon administration of the vaccine. Therefore you must be NEGATIVE before vaccine can be given.
What is the causative microorganism for the Syphilis?
Treponema pallidum
What is the primary stage of syphilis?
Chancres at the site of infection.
Eg penis, vagina, lips
What is the secondary stage of syphilis?
Rash
What is the tertiary stage of syphilis?
Gummas on many organs
How is syphilis diagnosed?
Since Treponema pallidum can not be grown on plates, diagnosis is made from indirect method: fluorescent-labelled monoclonal antibodies.
What animals does Treponema pallidum infect?
Only known to infect humans
What are some considerations when a pregnant mother has been diagnosed with syphilis?
-High risk of stillbirth, premature delivery, neonatal death or congenital syphilis.
-CONGENITAL SYPHILIS: rhinitis, skin and mucosal lesions, hepatosplenomegaly, lymphadenopathy, abnormalities of bones, teeth and cartilage.
Treatment: antibiotic treatment.
