Exam 2 Quiz Questions Flashcards
A human does not become infected with Borrelia from the tick until about 24-48 hours into the bloodmeal. Why?
Borrelia expresses OspA in the tick midgut and it has to switch expression to OspC to migrate to the tick’s salivary glands and transfer to the human.
A person has a painless ulcer on his penis that doesn’t seem to be healing very well. What is the most likely cause of the ulcer?
Treponema pallidum (syphilis)
All of the spirochete can cause similar disease symptoms in a multiphasic presentation. What is the most obvious symptom in leptospirosis that is not typically present in syphilis or Lyme disease?
jaundice
- Lepto is more likely to cause significant liver damage than either Treponema or Borrelia
Chlamydia goes through a unique life cycle. Which form is infectious?
the elementary bodies
Syphilis rates decreased dramatically in the late 1940s because of the introduction of _______ but rates began increasing again, mainly in men who have sex with men, associated with _______.
penicillin
HIV
Hutchinson’s Triad, associated with congenital syphilis, consists of which 3 characteristics?
Teeth malformations, keratitis, and deafness.
If infected by both N. gonorrhoeae and C. trachomatis during a sexual encounter, you are more likely to develop symptoms from which infection?
N. gonorrhoeae if you’re a guy but with girls it’s about the same.
if it burns when you pee, you have:
either gonorrhea, chlamydia, or both
The most typical presentation of gonorrhea or chlamydia in women is:
asymptomatic
The primary reason that effective vaccines have not been generated against N. gonorrhoeae is because:
N. gonorrhoeae is highly variable antigenically making it a poor vaccine candidate.
There are striking similarities in the late-stage disease symptoms of leprosy and syphilis. Why do you think that is?
Both diseases are characterized by chronic inflammation and destruction of cutaneous, cartilaginous, and bone tissue by the immune system, leading to similar physical characteristics, although the mechanisms differ.
There were several problems with the Lyme vaccine on the market from 1998-2002. What were the problems?
- The vaccine was recombinant OspA, which is only expressed in the tic, not the human.
- OspA antibodies have been detected in Stage III arthritis, so the vaccine could be responsible for development of autoimmune-mediated arthritis
- Public opinion of vaccines in general at that time severely, influenced sales of the vaccine, making it unmarketable.
What is the mechanism of Borrelia motility?
Periplasmic flagella attached at both ends extend the length of the spirochete, wrapping around the body of the spirochete inside the outer membrane. Torsion of these flagella cause a corkscrew-like action.
Why do syphilis and Lyme diseases have multiple phases?
Spirochetes are localized in the skin at the site of infection during the first phase and disseminate hematogenously for the second phase, leading to systemic disease.
Two major bacterial factors that contribute to infection with Neisseria gonorrhoeae or Chlamydia trachomatis are:
antigenic variation of outer membrane proteins and intracellular survival
If a person has a rash on the palms of his hands and soles of his feet, he may have:
secondary syphilis
Why are most infections with Neisseria gonorrhoeae or Chlamydia trachomatis unrecognized or undiagnosed in women? (2)
- most are asymptomatic
- The primary site of infection is the cervix and minor discharge may not be noticed.
most likely Org. for :
- college students who have not been vaccinated, living in dorms
Neisseria meningiditis
most likely Org. for :
- men who have sex with men
Treponema pallidum (syphilis)
most likely Org. for :
- young sexually active teens and young adults
Neisseria gonorrhoeae
most likely Org. for :
- Hikers, campers, and hunters in the northeast states (CT, DE, ME, MA, VT), Minnesota, and Wisconsin or southwest Virginia.
Borrelia borgdorferi
most likely Org. for :
- elderly female non-smokers who suppress their coughs
Mycobacterium avium
most likely Org. for :
- People living in poor areas of Brazil, Madagascar, Mozambique, Tanzania, and Nepal, and people who play with armadillos
Mycobacterium leprae
most likely Org. for :
- Young sexually active teenagers, and children in developing countries.
Chlamydia trachomatis
most likely Org. for :
- tourists swimming in inland lakes in Hawaii
Leptospira
Bacillus anthracis edema factor and lethal factor are incapable of causing disease symptoms without:
protective antigen
botulinum toxins function by ____ at the ____ to prevent release of _____, resulting in _____
- cleaving SNARE proteins
- neuromuscular junction
- excitatory neurotransmitter
- flaccid paralysis
Tetanus toxin functions by ______ at the _____ to prevent release of _____, resulting in spastic paralysis
- cleaving synaptobrevin
- interneuron-motor neuron junction
- inhibitory neurotransmitter
- spastic paralysis
most likely org. to cause dz post-exposure:
- Hikers in northern NC in July
Rickettsia rickettsii
most likely org. to cause dz post-exposure:
- people playing with flying squirrels with fleas in rural eastern states
Rickettsia prowazekii
most likely org. to cause dz post-exposure:
- Farmers delivering newborn sheep or their children drinking unpasteurized goat milk
Coxiella Burnettii
most likely org. to cause dz post-exposure:
- people with immune suppression who have cats
Bartonella hensellae
most likely org. to cause dz post-exposure:
- Travellers to S. America who eat soft cheeses made from raw milk or veterinarians delivering calves
Brucella abortus
most likely org. to cause dz post-exposure:
- people eating meat on a buffet (particularly pork and sweet potatoes)
Clostridium perfringens
most likely org. to cause dz post-exposure:
- Deer hunters in the mid-Atlantic states bitten by ticks
Ehrlichia Chaffeensis
