Spirochetes

Question 1

• helical-shaped, motile, unicellular
• Treponema
• Borrelia
• Leptospira

Answer 1

Spirochetes

Question 2

• obligate aerobic helical rods
• tightly coiled, thin, flexible
• 20 serovars
• reduced phagocytosis, hemolysis and endotoxins

Answer 2

Leptospires

Question 3

Leptospires (diseases)

Answer 3

• associated with mud or water
• breaks in skin or mucosa
• contact with INFECTED URINE
• leptospirosis (Swineherd’s disease)
• Weil’s disease (severe systemic disease)
• zoonotic disease

Question 4

Zoonotic disease (leptospires)

Answer 4

• animal workers
• rat-infested surroundings
• excreted in urine
• freshwater recreational exposure
• water contaminated by urine
• can survive for months in water

Question 5

Leptospires (culture)

Answer 5

• Fletcher’s media
• Stuart’s media
• mostly identified by serology

Question 6

Leptospira susceptibility

Answer 6

susceptible to tetracycline and doxycycline

Question 7

• loosely coiled
• arthropod borne
• stain easily, can use light microscopy
• microaerophilic
• long-chain fatty acids

Answer 7

Borrelia

Question 8

Borrelia (culturing)

Answer 8

some have been cultered in vitro on Kelly medium

Question 9

Borrelia recurrentis (infection)

Answer 9

• transmitted via tick
• widespread disease through E. and W. hemispheres
• RELAPSING FEVER
• antigenic variation (avoid immune response)

Question 10

Relapsing fever

Answer 10

• incubation 2-15 days
• high fever, delirium
• severe muscle aches, bones and joint pain, hepatosplenomegaly, jaundice
• remission and relapse of symptoms
• neurologic symptoms (meningitis)
• rarely fatal

Question 11

B. recurrentis (culturing/detection)

Answer 11

• direct exam of spirochetes in peripheral blood
• Kelly medium
• serologic testing is difficult and not practical

Question 12

B. recurrentis (treatment)

Answer 12

• TETRACYCLINES

- Jarisch-Herxheimer reaction (death of spirochetes can cause sudden endotoxin release)

Question 13

• Lyme disease
• transmitted via tick bite (Ixodes)
• complement evasion (binds factor H)

Answer 13

B. burgdorferi

Question 14

Lyme Disease

Answer 14

• Stage 1: ECM LESIONS
• Stage 2: acute (disseminated infection)
• Stage 3: chronic (chronic arthritis, skin lesions, neurologic symptoms)

Question 15

B. burgdorferi (treatment/detection)

Answer 15

• antibiotics in early stages
• serology tests
• only screen those with symptoms and high risk factors

Question 16

Treponema (virulence)

Answer 16

• penetrate intact mucous membranes
• crosses placenta
• dissemination
• antigenic variation

Question 17

Syphilis infection

Answer 17

• caused by sexual contact

- dissemination in 10-90 days

Question 18

Primary syphilis

Answer 18

• chancre at infection site (penis or vagina/cervix)
• painless, tender
• heals in 3-6 weeks, infectious
• spirochetes may be identifiable with darkfield microscopy

Question 19

Secondary syphilis

Answer 19

• 2-12 weeks after chancres
• widespread macular rash (palms and soles of feet)
• secondary lesions (Condylomata lata)
• systemic symptoms, infectious

Question 20

Latent syphilis

Answer 20

• patient is not infectious, relapses occur (early latent)
• indefinite duration, sometimes no complications (late latent)
• detected through serology

Question 21

Late syphilis (tertiary)

Answer 21

• complications involving many organs
• CNS disease, cardiovascular, aortitis and valve insufficiency, granulomatous lesions
• asymptomatic CNS disease
• congenital syphilis

Question 22

Congential syphilis

Answer 22

• non-immune hydrops (placental disease causing fetal death)
• bone lesions, hepatosplenomegaly
• visible deformities (tibias, Hutchinson’s teeth)

Question 23

Syphilis (transmission/detection)

Answer 23

• sexual contact, direct contact with lesions, transplacental transmission, autoinoculation, congenital
• serum on slide with saline, use darkfield microscopy
• serology or direct exam
• don’t use oral lesions (flora)

Question 24

Syphilis treatment

Answer 24

• Penicillin, tetracycline, doxycyline

- can develop Jarisch-Herxheimer reactions

Question 25

Treponema pertenue (disease)

Answer 25

Yaws

Question 26

Treponema endemicum (disease)

Answer 26

Endemic syphilis (bejel)

Question 27

Treponema carateum (disease)

Answer 27

Pinta

Question 28

Syphilis serology tests

Answer 28

- nontreponemal tests (VDRL, RPR) | - treponemal tests (FTA-ABS, agglutination test, EIA)