SPIROCHETES!!! MICROM 442 Deck 14

Question 1

B.hermsii disease=

Answer 1

relapsing fever

Question 2

B. burgdoferi disease =

Answer 2

Lyme disease

Question 3

T. pallidum disease =

Answer 3

syphilis

Question 4

L. interrogans disease =

Answer 4

leptospirosis

Question 5

structure is distinctively

Answer 5

corkscrew shaped with Lipid-rich outer membrane covering periplasmic
flagella; thin peptidoglycan layer covering
cytoplasmic membrane

Question 6

what is special about the leptospira shape?

Answer 6

has hooked ends

Question 7

B. hermsii + B. burgdorferi have what type of chromosome structure

Answer 7

linear

Question 8

all expect one has high genetic variability?

Answer 8

T. pallidum/syphillis

Question 9

which two do not have confirmed plasmids (the other 2 have both circular and linear)?

Answer 9

syphillis and leptospirosis

Question 10

all have a small genome size except?

Answer 10

L. interrogans which makes sense because she is able to infect people although we are accidental hosts

Question 11

One circular chromosome in

Answer 11

T. pallidum

Question 12

Two circular chromosomes in

Answer 12

Leptospira

Question 13

Syphilis manifestations

Answer 13

• Chronic bacterial infection, sexually transmitted
• Early manifestations involve primarily skin
• Late manifestations involve virtually all organs
  and tissue sites, including the central nervous
  system

Question 14

Syphilis habitat

Answer 14

Human only

Question 15

Syphilis: Transmission

Answer 15

• Direct, usually sexual, contact with infectious
  person (1⁰ or 2⁰ stage)
• Organism is highly invasive; gains access to blood
  stream and disseminates throughout body,
  including central nervous system
• May also cross placenta to cause congenital
  syphilis

Question 16

Congenital Syphilis

Answer 16

• Infection of fetus during
  pregnancy
• Results in prematurity,
  spontaneous abortion,
  stillbirth, neonatal illness
  or death, latent infection

Question 17

Syphilis: Pathogenesis

Answer 17

• Immune response ultimately clears primary
  and secondary lesions, but infection is not
  eradicated systemically
• Causes lifelong persistent, chronic infection
  in untreated persons
• Antigenic variation if pivotal to persistence

Question 18

Antigenic Variation of TprK

Answer 18

• Surface-exposed protein
• Has 7 variable regions
• Antigenic variation by
  segmental gene conversion
  o One expression site
  o 53 variable region donor
  sites
  Accounts for development of SECONDARY stage,
  lifetime persistence

Question 19

Syphilis: Treatment

Answer 19

• Penicillin –first line
• Alternatives: doxycycline, tetracycline, amoxicillin
• Macrolides – high rates of resistance in circulating strains – no
  longer recommended

Question 20

Syphilis: Lab Diagnosis

Answer 20

– PCR, RT-PCR not commercially available
– Darkfield microscopy
– No culture technique available (in vitro
cultivation system is not yet adapted)

Question 21

relapsing fever passed on by two arthopods which are?

Answer 21

louse-bourne and tick-borne

Question 22

Tick borne (B. hermsii) relapsing fever

Answer 22

Humans infected via tick saliva (or feces) during tick bite—
only short feeding is required for transmission

Question 23

Louse borne (B. recurrentis) relapsing fever

Answer 23

‒ No invasion of louse tissue (stay in the hemolymph). No
transovarial transmission
‒ Humans are infected by hemolymph/feces when parasite is
crushed (mechanical transmission only)

Question 24

ultimately relapsing fever has a decreasing burden but reinfections because of the

Answer 24

different serotypes and the the antibodies having to compensate

Question 25

Relapsing Fever has which genes for antigenic variation?

Answer 25

vlp and vsp

Question 26

Lyme Disease surface proteins

Answer 26

OspA, OspB, OspC

Question 27

lyme disease major resevoir=

Answer 27

small rodents mostly but also birds and deer and TRANSMITTED via TICK bite

Question 28

Lyme Disease: Pathogenesis

Answer 28

* Organism is very invasive, reaches blood stream and disseminates to many organs, including central nervous system * Persistent, chronic infection (due to antigenic variation of surface antigens?)

Question 29

Lyme Disease: Clinical Course

Answer 29

1: Erythema chronicum migrans (ECM) and secondary lesions 2: Neurologic and cardiac abnormalities: headache, stiff neck, conjunctivitis, muscle pain, (weeks to months after ECM) 3: Arthritis (weeks to years after ECM) - intermittent or chronic

Question 30

Lyme Disease: Treatment

Answer 30

Penicillin, ceftriaxone, tetracyclines * Later treatment may not be successful: chronic inflammation in absence of bacteria (Autoimmunity, chronic inflammation due to PG fragments?)

Question 31

Leptospirosis: Habitat

Answer 31

* Most widespread zoonosis in the world * Free-living in water * Animal reservoir--domestic and wild animals

Question 32

Leptospirosis: Transmission

Answer 32

* Source of infection is water contaminated with the infected urine of “carrier” animals * Portal of entry is skin, mucous membranes * Carrier state persists for months to years

Question 33

Leptospirosis: Pathogenesis

Answer 33

* Invasive * Disseminates to infect multiple organs, including central nervous system

Question 34

Clinical Outcomes of Leptospiral Infection

Answer 34

inapparent infx -> undifferentiated fever -> Complex, multi-system disease (Aseptic meningitis Renal failure Jaundice Myocarditis Pulmonary hemorrhage Refractory shock)

Question 35

Leptospirosis: Clinical Course

Answer 35

* Sudden onset of fever (spiking), severe myalgia, headache * Bacteria present in blood, CSF, urine * Usually self-limited, but can be protracted and severe