Spirochetes Flashcards Preview

Microbiology > Spirochetes > Flashcards

Flashcards in Spirochetes Deck (28):
1

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

Spirochetes

2

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

Leptospires

3

Leptospires (diseases)

- 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

4

Zoonotic disease (leptospires)

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

5

Leptospires (culture)

- Fletcher's media
- Stuart's media
- mostly identified by serology

6

Leptospira susceptibility

susceptible to tetracycline and doxycycline

7

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

Borrelia

8

Borrelia (culturing)

some have been cultered in vitro on Kelly medium

9

Borrelia recurrentis (infection)

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

10

Relapsing fever

- 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

11

B. recurrentis (culturing/detection)

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

12

B. recurrentis (treatment)

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

13

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

B. burgdorferi

14

Lyme Disease

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

15

B. burgdorferi (treatment/detection)

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

16

Treponema (virulence)

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

17

Syphilis infection

- caused by sexual contact
- dissemination in 10-90 days

18

Primary syphilis

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

19

Secondary syphilis

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

20

Latent syphilis

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

21

Late syphilis (tertiary)

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

22

Congential syphilis

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

23

Syphilis (transmission/detection)

- 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)

24

Syphilis treatment

- Penicillin, tetracycline, doxycyline
- can develop Jarisch-Herxheimer reactions

25

Treponema pertenue (disease)

Yaws

26

Treponema endemicum (disease)

Endemic syphilis (bejel)

27

Treponema carateum (disease)

Pinta

28

Syphilis serology tests

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