T23 Spirochetes

spirochetes - common characteristics

• endoflagella

• mucoid layer

spirochetes - disease stages

1. primary lesion at site

2. signs and symptoms

3. disease

fill in the blank: 1-3

Treponema, Treponema pallidum subspecies pallidum, Treponema pallidum subspecies pertenue

fill in the blank: 4-5

Leptospira, Leptospira interrogans

fill in the blank: 6-7

Borrelia, Borrelia burgdorferi

Treponema pallidum subspecies pallidum - characteristics & morphology

• poor stain → dark-field

• microaerophilic/anaerobic

• no LPS

Treponema pallidum subspecies pallidum - virulence factors

• outer membrane protein

• hyaluronidase

• fibronectin coating (stealth)

fibronectin coating 

hide from immune

Treponema pallidum subspecies pallidum - disease

syphilis

syphilis

• great imitator 

• acquired: direct sexual contact, needle, transfusion

• congenital: transplacental

congenital syphilis - symptoms

hutchinson’s teeth (barrel)

primary syphilis

chancres: painless ulcer with raised border

secondary syphilis

spirochetemia: reach blood → mucocutaneous rash (palm, sole, oral, body), condylomata lata

latent syphilis

no symptoms but serology +
- infectious if less than 1 year

tertiary syphilis

gummas: destructive lesion, CVS involvement (aortic aneurysm), CNS neurosyphilis (at any stage)

Treponema pallidum subspecies pallidum - diagnosis

• giemsa stain

• silver impregnation → black

• dark-field microscopy

• fluorescence microscopy

• nontreponemal: VDRL, RPR

• treponemal: FTA-Abs, MHA-Tp

nontreponemal tests

• VDRL: CSF, neurosyphilis

• screen antibody against cardiolipid

• false + in pregnant

• used in follow-up because levels can drop

treponemal tests

• FTA-Abs (indirect)

• confirmation

• positive for life

• use IgM to diagnose congenital

syphilis - treatment

penicillin will lead to Jarisch-Herxheimer reaction

Treponema pallidum subspecies pertenue - disease

yaws

Treponema pallidum subspecies pertenue - diagnosis

• dark-field microscopy

• immunohistochemistry: present in spinous layer

Treponema pallidum subspecies pertenue - treatment

azithromycin, penicillin

other Treponemal species - flora

oral flora seen in direct exam despite not being causative

other Treponemal species - disease

periodontal disease

Leptospira interrogans - characteristics and morphology

• smallest spirochete

• hooked on 1/both ends

• obligate aerobe

Leptospira interrogans - reservoir

urine/feces → soil and water → ingest/contact with wound

Leptospira interrogans - disease

leptospirosis

leptospirosis

• mouse pee zoonosis

• spread to bloodstream → found in CSF

• aseptic meningitis (can’t culture but muscle aches)

anicteric leptospirosis

mild, self-limited

icteric leptospirosis (weil disease)

triad:

• icterus (jaundice)

• hemorrhage

• renal impairment

Leptospira interrogans - diagnosis

• microscopic agglutination test (MAT) with live antigen

• macroscopic slide agglutination test with killed antigen

Leptospira interrogans - drugs

• treat: penicillin, erythromycin

• prevent: doxycycline

Borrelia - common characteristics

• large with multiple endoflagella

• vector-borne

Borrelia - disease

lyme disease
relapsing fever

lyme disease - vector

tick-borne rodent/deer

lyme disease - symptoms

erythema migrans (target)

Borrelia - treatment

• amoxicillin, tetracycline, cefuroxime: early

• ceftriaxone: severe

Borrelia - diagnosis

• ELISA, serology

• western blot