1. 4.3 Spirochaetes

2. Background.. Gram negative Motile organism
Tightly coiled bacteria typically slender and flexouas shape.
The cell made up of protoplasmic cylinder located in periplasm of cell, endoflagella and outer sheath.
Move by bending and rotating body according to the viscosity of the medium

3. Motility of spirochetes
Unusual mode of motility
Endoflagellum located at one end and extends about two-third of the cell. Its rotate.
Protoplasmic cylinder is rigid, whereas the outer sheath is flexible, therefore when both endoflagella rotates in the same direction while protoplasmic cylinder in opposite direction causing torsion of cell.

5. Medical important
3 genera:
Treponema
Leptospira
Borrelia

6. Treponema Treponema pallidum pallidum, which causes syphilis
T. pallidum endemicum, which causes bejel or endemic syphilis
T. pallidum carateum, which causes pinta
T. pallidum pertenue, which causes yaws

7. YAWS
PINTA
SYPHILIS

8. Normal habitat
Host associated spirochetes are parasites of humans or animals.
Found in lesion of treponematoses
Can also found in mucous membranes in the mouth and genital tract, also in skin ulcers

9. Pathogenicity (T.pallidum)
Acquired syphilis transmitted congenitally or sexual intercourse - Known as sexually acquired syphilis and congenitally acquired syphilis
Non-venereal syphilis – endemic syphilis, bejel, njovera, siti and dichuchwa

10. Microscopy Small 6-15µm size, 0.2µm diameter. Motile spirochaetes.
Use metallic silver techniques or known as impregnation techniques. Metallic silver precipitates on the wall of the spirochete, enlarging its outline and making it opaque, features that make it visible in tissue sections.
Best seen by dark-field illumination or phase contrast

11. Culture Microaerophilic Hardly to grow in routine culture
Able to survive in some fluid including citrated whole blood
Maintained by intratesticular inoculation in rabbit.

12. Serology tests Cardiolipin antigens test
VDRL test – Venereal Diseases Reference Laboratory
RPR test – Rapid Plasma Reagin
Treponemal antigen test
TPHA test (Treponema pallidum haemagglutination test)

13. Leptospira interrogans
Scanning electron micrograph of a number of Leptospira sp. bacteria atop a 0.1 µm polycarbonate filter
Leptospira interrogans

14. Normal Habitat Gram negative, obligate aerobe spirochete.
Variety in domestic and wild animals such as rats, rodents, cattle, pigs and dogs. Humans are accidental host.
Largely secreted in urine
Survive many weeks in soil and water, in alkaline and 28 – 32oC

15. Transmission Direct or indirect contact with urine of infected animal
Enter damaged skin which has immersed for a long time in water or mud contaminated with infected urine
m/o penetrate the lining of the mouth, nose and eyes
Person to person transmission rarely occurs

17. Risk factors
Person most at risk of infection include workers in rice fields and sugar-cane fields, livestock farmers, irrigation canal workers, meat and animal handlers, fresh water fish pond workers, veterinarians, pest control officers, forest workers and those involved in road building
High cases in rainy seasons and times of flooding

18. Pathogenicity
Mild form usually misdiagnosed as viral illness and influenza
More serious infection causing a high continuous fever, severe headaches and body pain especially in the muscles of legs, redness of the eye and weakness.
Can also causing jaundice and renal failure

19. Microscopy Small 6-20µm in size 0.1 µm diameter
Actively motile spirochetes
Screw-tight coils and hooked ends
Easily stain only by impregnation techniques
Best seen by dark-field illumination or phase contrast

20. Culture Leptospires are strictly aerobes
Can be cultured in a serum or albumin-Tween medium
Late grow so resulting less efficient diagnostic
Preferable serology test to identify several serogroups

21. Other tests Haematological and biochemical tests in leptospirosis
Antimicrobial sensitivity – high doses of penicilin will be effective against L. interrogans
ELISA test, Polymerase Chain Reaction (PCR)

22. Borrelia
Borrelia burgdoferi
Borrelia recurrentis
Borrelia duttoni

23. Normal habitat B.burgdorferi – deer tick,Ixodes scapularis.
B.recurrentis – parasite of Pediculus lice
B.duttoni – parasite of Ornithodorus soft ticks

24. Pathogenicity B.burgdorferi– causing Lyme Disease.
B.recurrentis – louse-bourne relapsing fever in poverty, overcrowding, and during time of drought and famine.
B.duttoni – tick-bourne relapsing fever infecting CSF causing lyphocytic meningitis

25. Microscopy Large 10-20µm in size,0.5µm diameter
Actively motile spirochaetes wt coils of varying size
Agglutinate together
Easily stain in Giemsa, Field’s or other Romanowsky stain; prolonged Gram staining (Gram negative)
Well seen by dark-field illumination

26. Culture
Borreliae are aerobes
Can be cultured in Kelly’s medium

27. Serology test
Used to diagnose relapsing fever, usually cross reaction with Treponema
Antimicrobial sensitivity
Sensitive to penicillin and tetracycline

28. THE END