Spirochetes & Treponema palladium

Spirochetes

A microscopic bacterial organism in the spirohaetaceae family spirochetes, have  a worm –like spiral-shaped form and wiggle vigorously when viewed under a microscope treponema palladium, the cause of syphilis ,is a particularly well known member of spirochete,

Classification of Spirochetes :

1. Pathogenic for humans : Three genera.

1. Treponema-causes syphilis, bejel , yaw and  painta,
2. Borrelia –causes relapsing fever and lyme disease.
3. Leptospira-causes leptospirosis (wails disease)

2. Communal and saprophytes: communal of the mouth and genital tract.

Treponema palladium:

Disease: syphilis-the great pox:

Morphology:

1. T. palladium is about 5-15 ×0.2 µm
2. It is a flexuous helix having evenly distributed 6-12 coils.
3. It is actively motile-rotating and slow bending motility often forming a complete circle.

Staining : staining by silver impregnation causes thickening of the organism and can be seen by dark field microscope. It can not be stained by gram method.

Treponema: three species are of medical importance-

1. Teponema palladium-causes syphilis and bejel.
2. Treponema preemie- causes yaws.
3. Treponema carteum –causes pinta.

Pathogen city: T.pallidum causes

1. Syphilis: Syphilis is a sexually transmitted disease(STD)

Syphilis are two types:

a.       Sexually acquired (venereal )syphilis.

b.      Congenital syphilis.

2. Bejel : bejel group of diseases, or endemic syphilis or non –venereal syphilis .

Transmission of syphilis :

1. Sexual contact with an infected person.
2. Transplacental transmission from infected mother to newborn.
3. From transfusion of infected blood
4. Intravenous drug abusers who share a common needle.
5. Accidental transmission in laboratory workers.

Stages of acquired syphilis:

1. Primary syphilis
2. Secondary syphilis.
3. Latent syphilis.
4. Tertiary syphilis.

Laboratory diagnosis of syphilis:

Principle: Laboratory diagnosis of syphilis consists of direct demonstration of treponemas by microscopic examination and serological test,

Steps:

-          From lesion fo primary syphilis(hared chancre) and secondary syphilis (condylomata lata).

-          Serum .

-          CSF.

Macroscopic  examination:

1.Dark ground illumination (DGI)

Findings: Cork screw movement of T.pallidum.

2.Direct florescent antibody (DFA)test.

Findings : Typical fluorescent stained spirochetes.

Serological tests:

1. Non –treponemal regain tests.

-          VDRL.

2. Treponemal detection

-          TPHA

-          FTA-ABS

-          ELISA.