MMI 301: Lecture 23: Borrelia and Treponema

• Gram -    -Stain poorly
•    -Use Giemsa or Wright
• Visible under bright-field

Motile, endoflagellar structure in periplasm.

• recurrentis: blood
• burgdoferi: rarely visualized in clinical specimens.

• -Grow Slowly
• -Require complex media
• -Microaerophilic conditions
• -Optimal growth at 30 degrees

Periplasmic endoflagella move in helical waves

• Caused by Borrelia
• Arthropod vector required
•      -recurrentis carried by louse, epidemic (more dangerous, humans only reservoir)
•      -hermsii carried by tick, endemic (less severe, animal reservoirs)
• -Results in bacteremia, one week after bite, fever, headaches, last 3-7 days
• -Can have several relapses
•      -VMP (variable major protein) undergoes anti-genic change, body must make new antigens, causing bouts of the disease

Borrelia burgdorferi

• burgdorferi
• Identified in 1981
• Endemic to many parts of Wisconsin
• One of most common arthropod diseases

• Transmitted to human by tick bite
•      -Ixodes scapularis most common in wisco
• Nymph and young responsible for most disease
• Natural reservoirs: white-tail, field mouse, other mammals

• Born in summer to larvae
• Dormant nymph through fall-spring
• Become adults over summer, lay eggs in fall which become larvae next summer
• -See most disease from them in spring/early summer

• Spirochete
•     -Can be seen under bright-field, with Giesma/Wright
•      -burgdoferi rarely seen in clinical specimens

• Linear chromosomes and plasmids
• Major outer membrane proteins (Osp's) encoded by unusual linear plasmids
• High rate of recombination leading to antigenic variation
• No relapse- Osp variation has no effect on pathogenesis

• Similar to other Gram -, but:
• -No LPS in outer membrane
• -Produce large # lipoproteins, many in OM-Osps (outer surface proteins)
• -Have endo-periplasmic flagella (EF)

• Linear plasmid encodes variable lipoprotein VlsE
• Plasmid contains one full vlsE gene and 16 partial copies
• Partial copys can be put into full gene with recombinants
• 16 flavors of LP allow avoidance of immune system

• Stage 1: Erythema migrans (bulls eye rash) 3-30 days after infec, fever, headache, malaise, chills, muscle pain, stuff neck
• Stage 2: Occurs in only 10-20%, secondary lesions, arthritis, Bell's palsy, neurological and cardiac symptoms.
• Stage 3: Neuro/Cardio symp, arthritis resolves, 10% sever destructive arthritis, immune over-response the cause at this point.

• Easily diagnosed, bull's eye rash/bite
• Not seen in blood/tissues
• Can use symptoms, history or serology in advanced cases
•      -Anti-IgG borrelia antibodies more reliable than anti-IgM

• Developed 1998
• Contained OspA (outer surface lipoprotein, immunodominant)
• OspA only found in Borrelia infected ticks, prevented infection (blood goes into tick when they eat, fight bacteria)
• Vaccine caused arthritis, no good

Iron, Manganese instead (fact-check)

Treponema pallidum

• Order
• Includes T. pallidum, B. burgdorferi, L. interrogans
• Placed based on helical cell shape

• Thin, relatively long helical structure
• Cannot be seen on bright-field microscopy
• Posses periplasmic flagellar structure used for motility
• Technically gram -

Majorly unknown, cannot be grown on media, cannot be tested in animals, hard to research

• Stage 1: Lesion at site of infection
•    -Painless, site of neutrophil/macrophage infiltration
•    -Other aspects of disease from immune response
• Stage 2: 2-12 weeks later, Organism spreads through body, general rash, lesions at local replication sites
• Stage 3: Can occur years later, chronic inflammatory disease (granulomatous lesions in bone, brain, heart, skin), Neurosyphilis (chronic inflammation of CNS-->Paralysis, dementia, sensory loss)

• Transplacental transmission from mother-->fetus
• Can result in deformation/stillborn
• Child may be born into rapid secondary syphilis

• Sexual Transmission
• Contact with primary/secondary lesions can cause infection
• Rarely transferred via infusion
• Humans are reservoir
• Bacteria sensitive to low temp/drying
• Third most common STD

• Clinical presentation/dark-field microscopy on material from the lesions
•      -helical organisms spotted      /Immunofluorescence with anti-treponemal antibodies also used 
• Cannot be cultured in lab
•      -No useful assays, can be killed with penicillin

• Non-treponemal:
•    -Test for antibodies to cardiolipin
•         -Antibodies produced in response to infection can aggregate cardiolipin
•     -VDRL (Venereal Disease Research Laboratory)
•           -Use patient sera to cause cardiolipin to flocculate
•            -Very false positive

• -Fluorescent Treponemal antibody absorbtion (FAT-ABS)
•       -Measure presence of specific anti-Treponema pallidum antibodies in the serum
• -Immunoblotting
•         -T. pallidum antigens separated by electrophoresis
•         -Use patient serum and measure reactivity of the patients antibodies to the antigens.

Researchers observed african-american that were infected with syphilis over 40 years, never treated them. Resulted in passage of laws for informed consent.