Spirochetes Flashcards
- helical-shaped, motile, unicellular
- Treponema
- Borrelia
- Leptospira
Spirochetes
- obligate aerobic helical rods
- tightly coiled, thin, flexible
- 20 serovars
- reduced phagocytosis, hemolysis and endotoxins
Leptospires
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
Zoonotic disease (leptospires)
- animal workers
- rat-infested surroundings
- excreted in urine
- freshwater recreational exposure
- water contaminated by urine
- can survive for months in water
Leptospires (culture)
- Fletcher’s media
- Stuart’s media
- mostly identified by serology
Leptospira susceptibility
susceptible to tetracycline and doxycycline
- loosely coiled
- arthropod borne
- stain easily, can use light microscopy
- microaerophilic
- long-chain fatty acids
Borrelia
Borrelia (culturing)
some have been cultered in vitro on Kelly medium
Borrelia recurrentis (infection)
- transmitted via tick
- widespread disease through E. and W. hemispheres
- RELAPSING FEVER
- antigenic variation (avoid immune response)
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
B. recurrentis (culturing/detection)
- direct exam of spirochetes in peripheral blood
- Kelly medium
- serologic testing is difficult and not practical
B. recurrentis (treatment)
- TETRACYCLINES
- Jarisch-Herxheimer reaction (death of spirochetes can cause sudden endotoxin release)
- Lyme disease
- transmitted via tick bite (Ixodes)
- complement evasion (binds factor H)
B. burgdorferi
Lyme Disease
- Stage 1: ECM LESIONS
- Stage 2: acute (disseminated infection)
- Stage 3: chronic (chronic arthritis, skin lesions, neurologic symptoms)
B. burgdorferi (treatment/detection)
- antibiotics in early stages
- serology tests
- only screen those with symptoms and high risk factors
Treponema (virulence)
- penetrate intact mucous membranes
- crosses placenta
- dissemination
- antigenic variation
Syphilis infection
- caused by sexual contact
- dissemination in 10-90 days
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
Secondary syphilis
- 2-12 weeks after chancres
- widespread macular rash (palms and soles of feet)
- secondary lesions (Condylomata lata)
- systemic symptoms, infectious
Latent syphilis
- patient is not infectious, relapses occur (early latent)
- indefinite duration, sometimes no complications (late latent)
- detected through serology
Late syphilis (tertiary)
- complications involving many organs
- CNS disease, cardiovascular, aortitis and valve insufficiency, granulomatous lesions
- asymptomatic CNS disease
- congenital syphilis
Congential syphilis
- non-immune hydrops (placental disease causing fetal death)
- bone lesions, hepatosplenomegaly
- visible deformities (tibias, Hutchinson’s teeth)
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)
Syphilis treatment
- Penicillin, tetracycline, doxycyline
- can develop Jarisch-Herxheimer reactions
Treponema pertenue (disease)
Yaws
Treponema endemicum (disease)
Endemic syphilis (bejel)
Treponema carateum (disease)
Pinta
Syphilis serology tests
- nontreponemal tests (VDRL, RPR)
- treponemal tests (FTA-ABS, agglutination test, EIA)
