Section 4: Spirochetes Flashcards
What are Spirochetes
They are thin, helical, Gram negative bacteria
What are the 3 genera of spirochetes responsible for human disease
Treponema, Borrelia, and Leptospira
What is the more common name for Treponema pallidum
Syphilis
What is the epidemiology for Treponema pallidum
- Transmission is by contact with mucous membranes. Sexually transmitted.
- Microbe can also be transmitted in blood
- A reportable condition
What is the pathology of Treponema pallidum
- Treponema pallidum enters the body by penetrating mucous membranes
- Immediately begin moving through body via blood and lymph vessels
- Incubation period= 2-3 weeks
What is the characteristic of Primary syphilis
lesion is a chancre
What is a chancre
- Hard, painless
- Mostly found on genitals, I 0% not
- Highly infectious, filled with T. pallidum
What is Secondary Syphilis
- Between 6 weeks to 5 years later the bacteria multiply and spread throughout the body
- Secondary is systemic; widespread rash, swollen lymph nodes and flu-like symptoms= “great imitator”
- Most infectious stage, “kissing disease”
- Skin rash
- Condylomata lata
What is tertiary syphilis
Develops 5-40 years following initial infection in 1/3 oflatent cases
- Typical presentation= gummas, destructive lesions= necrosis of tissue
- Painless on skin, painful in organs and bone
What is cardiovascular syphilis (tertiary)
Occurs in 10% of patients
• Involves destruction of heart and blood vessels, aneurysms
• Typically inflammation of aorta, valve involvement
What is neurosyphilis
Occurs in 8% of patients
• Syphilitic meningitis
• Organisms attack blood vessels in brain and meninges resulting in cerebrovascular occlusions and death of nerve tissue in the brain
• Tabes dorsalis
• General paresis (of the insane)= paralytic dementia
What is Tabes Dorsalis
- Degeneration of the posterior columns of spinal cord and dorsal roots
- Incoordination (ataxia), sensory difficulty
- Charcot’s joint-destructive joint disease caused by diminished proprioceptive sensation, with gradual destruction of the joint by repeated subliminal injury
What are other pathologies of Syphilis
- Bone infection
- Periostitis-inflammation of the periosteum
- Saber shin = periosteal inflammation of tibia leading to bowing
- Infection of skin, eyes
What is congenital syphilis
- Infection of the fetus via placenta
- T pallidum rapidly disseminates throughout fetus
- T pa/lidum does not cross and damage fetus until the fourth month of gestation, if treated prior, child born free of syphilis
What are possible outcomes of congenital syphilis
- High mortality rate (stillbirth, spontaneous abortion)
- Infant has secondary syphilis
- Infant is healthy, develops disease years later
What are symptoms of early congenital syphilis
- Occurs within 2 years of birth
- Runny nose, “snuffles”
- “Blueberry muffin” rash= raised vesicles (different then Jim’s muffin top)
What are the symptoms of late congenital syphilis
- Similar to adult tertiary syphilis (rarely cardiovascular)
- Neurosyphilis results in impaired hearing and sight
- Bone and teeth destroyed-Hutchinson’s teeth
- Saber shin
- Saddle nose -no bridge in nose
How is syphilis T. Palladium diagnosed
Dark-field microscopy
Fluorescent antibody microscopy
Serological Tests for Syphilis (STS
What is the Jarisch Herxheimer reaction
- Acute worsening of symptoms after beginning antibiotics
- Symptoms = fever, chills, headache, malaise
- Due to the release of endotoxin from killed T. pallidum
- Self-limiting in 12-24 hours
What is Treponema pertenue
- Causative agent ofYaws
- Restricted to the tropics
- Transmission occurs through nonsexual human-to-human contact
What is the pathology of Treponema pertenue
- Primary lesion, or mother yaw, develops within 2 to 4 weeks at the site of skin entry as a painless erythematous papule or group of papules
- Treponemes disseminate in 1 to 12 months, secondary lesions appear, similar to the mother yaw
- Secondary lesions develop initially on the face and moist areas of the body and then spread to the trunk and arms
- infection of the soles and palms is characteristic
- Late destructive stage involves treponema! infection of the bones and periosteum, especially the long bones of legs and forearms, and the bones of the feet and hands
What is Treponema carateum
- Causative agent of Pinta
- Purely a skin disease
- Transmission occurs through human-to-human nonsexual contact
- Limited to South America
- Infection is by direct contact, red lesions that tum blue in the sun
- Lesions then become depigmented, turning white
What is Treponema vincentii
- One of the causative agents of Vincent’s angina (aka Trench mouth)
- Lesions of gingiva (gums)
What is another name for Borrelia
Relapsing fever
How is relapsing fever spread
lice and ticks
What is the pathology of borrelia
Lesions on internal organs (liver, spleen)
-High fever 4-5 days
-Fever disappears, returns 7-10 days later
• Tick borne = relapses average = 3
• Louse borne= more than 10
-Find spirochetes in blood (spirochetemia)
What is Borrelia burgdorferi
First recognized in 1975 in Lyme, CT
• Borrelia burgdorferi recognized as cause of Lyme disease in 1982
What is the epidemiology of Borrelia burgdorferi
transnsmitted primarily by the deer tick (Ixodes) in the nymph stage oflife cycle-(black legged hard ticks)
-B. burgdorferi is iJ1jected by the tick in saliva or by regurgitation of tick’s midgut contents .
What is the primary stage of Borrelia burgdorferi
skin lesion “bulls eye” or target shaped 3 days to 4 weeks following tick bite
What is the secondary stage of Borrelia burgdorferi
erythema chronicum migrans (ECM)-often appears at the site of the infecting tick bite. It is a red, enlarging rash, flat or slightly raised, and may reach from 4 to 20 inches across
What is the tertiary stage of Borrelia burgdorferi
- Meningoencephalitis
- Myocarditis
- Musculoskeletal pain
- Chronic arthritis
What is leptospira
- Fine, coiled spirochete
- Hooked on each end
- Highly motile
- Cultured in lab
What is the epidemiology of leptospira
-Worldwide distribution
-Fewer than 100 cases/year in U.S.
-Reservoirs of infection
• Dogs, rodents, domestic/wild animals
• Bacteria persist in the kidneys of animals, found in urine
• Contaminate soil and water
What is the pathology of leptospira
-Bacteria penetrate mucous membranes and invade blood and eventually vanous organs
-Experience chills, fever, headache, muscle pain
-Some strains cause Wei!’ s disease or infectious jaundice
• Renal failure, hepatitis with jaundice, mental status change and hemorrhage in various organs.
• Up to 25% mortality
