Unculturable Bacteria: Spirochetes, Rickettsia, Borrelia, Ehrlichia

Question 1

class of organisms that have been kept alive in conditions with reduced oxygen, but are genomically aerobic

Answer 1

treponemes

Question 2

mechanism of pathogenecity of this class of organisms includes programmed antigen variation

Answer 2

Borrelia

Question 3

clinical presentation of this illness may happen 5-10 days after a tick bite, with high fever, chills, headache, myalgias, and a rash migrating from hands and feet to the trunk

Answer 3

Rocky Mountain Spotted fever

Question 4

Similar to Shigella and Listeria, this class of organisms targets endothelial cells and uses actin polymerization to propel from cell to cell

Answer 4

Rickettsia

Question 5

causes relapsing fever and Lyme disease

Answer 5

Borrelia

Question 6

Rocky Mountain Spotted Fever is found mainly in what US regions?

Answer 6

The Ozarks and Appalachians

Question 7

Which of the following statements regarding tertiary syphilis is true?

A. most people who have untreated secondary syphilis will develop tertiary syphilis

B. immunity is dependent on the activation of cytotoxic CD8 T cells

C. patients may present with “Hutchinson” teeth or “Sabre” shins

D. approximately half of all these patients will develop either symptoms of neurosyphilis (paralytic dementia, seizures, meningitis) or aneurysms

E. patients commonly present with evidence of a delayed type hypersensitivity reaction affecting dermal elements and support structures

Answer 7

E. Approximately 20% of patients with tertiary syphilis will present with a delayed type hypersensitivity reaction that affects dermal and support structures of the skin. The reaction is marked by nonprogressive granulomatous lesions called gummas.

A is incorrect - only 40% with secondary will develop tertiary syphilis. B is incorrect - immunity is dependent on Th1 activation of macrophages. C. is incorrect - Hutchinson teeth and Sabre shins are symptoms of congenital syphilis. D is incorrect - only about 7% and 10% of patients, respectively, develop these symptoms.

Question 8

disease by this organism occurs primarily in the southeastern and south central regions of the US

Answer 8

E. chaffeensis (HME)

Question 9

a sensitive but not specific screening test for this class of organisms includes the presence of serum antibodies that will agglutinate beef cardiolipin

Answer 9

treponemes

*the test is not confirmatory. need to run PCR to confirm.

Question 10

two major vectors of this spotted fever group organism in the US are the American dog tick and the Rocky Mountain wood tick

Answer 10

R. rickettssii

Question 11

small gram negative cocci that infect leukocytes

Answer 11

ehrlichia

Question 12

three important components of the clinical presentation of rocky mountain spotted fever

Answer 12

fever, rash, previous tick bite

Question 13

class of small gram negative obligate intracellular bacteria that grow in endothelial cells

Answer 13

Rickettsia group

Question 14

class of organisms characterized by long slender rods that are related to gram negatives and have endoflagella under a sheath

Answer 14

spirochetes

Question 15

strain of organism that resembles Rocky mountain spotted fever without the rash, and is transmitted by dog and lone star ticks

Answer 15

E. chaffeensis

Question 16

strain of organism that is transmitted by ixodes deer ticks, causing migrating eyrthematous rash which then develops into arthritis, myocarditis and dementia-like neurological disease

Answer 16

Borrelia burgdorferi

Question 17

causes milder chickenpox like illness and is spread via mites of infected house mice

Answer 17

R. akari

Question 18

virulence of this class depends on suriving in the host following a break in the skin or mucous membrane

Answer 18

treponemes

*they readily attach to endothelial cells and pass thorugh blood vessel walls, which facilitates their dissemination

Question 19

condition acquired in childbirth that is often fatal, and leads to tooth and bone abnormalities as well as mental retardation in surviving children

Answer 19

congenital syphilis

Question 20

Which of the following statements about Rickettsia are true?

A. immunity is dependent on CD8 memory T cells

B. diagnosis can only be made with fluorescent antibody tests

C. infection with R. rickettsia does not appear to play a role in immunity against reinfection

D. immunity is dependent on Abs when the organism is extracellular

E. these organisms are able to live inside PMNs and macrophages

Answer 20

D.

Question 21

this organism causes syphilis and is indistinguishable from non-pathogenic strains of the same class

Answer 21

treponema pallidum

Question 22

simple and low cost treatment of choice for primary and secondary syphilis

Answer 22

IM shot of penicillin G

Question 23

class of organisms that causes endothelial damage leading to increased vascular permeability, hypovolemia, edema, ischemia and organ failure

Answer 23

Rickettsia

Question 24

also called human granulocytic ehrlichiosis (anaplasma), transmitted by deer and dog ticks

Answer 24

E. equi

*again, similar to RMSF but no rash

Question 25

A fluorescent antibody test for T. pallidum may give a false positive if the patient has what condition?

Answer 25

rheumatoid arthritis

Question 26

Which of the following is not a characteristic of primary syphilis?

A. lesions generally resolve within 6 months

B. patient typically presents with general lymphadenopathy and a rash on the palms and soles of feet

C. formation of a hard, non-tender chancre around the site of infection

D. the primary lesion is often missed in women vaginally

E. it is a disease of blood vessels and the perivascular area

Answer 26

B.

Lymphadenopathy and rash are symptoms associated with secondary sphilis, which occurs in 25% of patients 2-10 weeks after untreated primary syphilis. Other symptoms of secondary syphilis include: fever, sore throat, multiple secondary lesions filled with spirochetes, condylomata lata, and possibly nephrotic syndrome/immune complex disease.

Question 27

endotoxin shock like reaction that may occur following treatment of Syphilis or Lyme disease

Answer 27

Jarisch-Herxheimer reaction

*this is due to the release of LPS from the organism once it is lysed

Question 28

only member of this family of ticks are naturally infected with Rickettsia rickettsii

Answer 28

Ixodes deer ticks

Question 29

causes endemic tick borne illness in 50% of people bitten

Answer 29

Borrelia hermsii

Question 30

causes louse borne epidemic illness in 4-10 day periods of high fever and hypotension

Answer 30

borrelia recurrentis

Question 31

divide to form vacuole-bound colonies known as morulae

Answer 31

ehrlichia