Spirochetes and Neisseria (Gram negative) Lecture 44

1. SpirochetesandNeisseria(Gram negative)Lecture 44 Faculty: Dr. Alvin Fox

2. Spirochete Axial filament Treponema pallidum Syphilis Chancre Primary lesion Darkfield microscopy Secondary Lesion Tertiary Lesion Anti-cardiolipin antibodies Anti-treponemal antibodies Borrelia burgdorferi Lyme disease Relapsing fever (other borrelia) Leptospira (leptospirosis) Neisseria Thayer Martin agar Oxidase test N. gonorrhoeae Gonorrhea N. meningitidis Meningitis Key Words

3. SPIROCHETES Treponema, Borrelia and Leptospira

4. Spirochetes • Gram negative • long, thin, helical, motile • axial filaments • locomotion • between peptidoglycan layer/outer membrane • runs parallel

5. www.orl.cz/choroby/ustni/jazyk/zanet/1 Histology: Treponema pallidum - testis infected rabbit

6. Treponema pallidum • transmission • genital/genital • in utero or during birth

7. Syphilis • chronic • slowly progressive

8. primary lesion - chancre • 10 to 60 days • area of ulceration/inflammation • many organisms

9. Secondary (2-10 weeks later) • - systemic spread • - flu-like symptoms • - skin, particularly • - many organisms • - Highly infectious Patients right thigh www.lib.uiowa.edu/hardin/MD/cdc/syphilis33.html mouth muosa

10. Tertiary • several years later • rare • skin • central nervous system • delayed hypersensitivity • few organisms • control by immune response

11. Microbiological diagnosis • not culturable • dark field microscopy • actively motile organisms • brightly lit against dark backdrop • light shines at an angle • reflected from thin organisms • enters objective • conventional light microsrcopy • light shines through • NOT visualized

12. fluorescence microscopy • antibody staining

13. Secondary and Tertiary Syphilis- serology • screening method • antibodies to cardiolipin • specific diagnosis • antibodies to treponemal antigen

14. Autoimminty • cardiolipin • self antigen

15. no vaccine • antibiotics (e.g. penicillin) • effective

16. Other treponemal diseases • bejel, yaws and pinta • extremely rare in US

17. Borrelia burgdorferi and Lyme disease

18. Ixodes scapularis, tick vector for Lyme disease. Also known as Ixodes dammini. CDC

19. Lyme Disease erythematous rash

20. A tick bite leads to transmission of B. burgdorferi

21. Lyme disease - symptoms • bacteremia • acute • arthritis • cardiac • neurologic • chronic • weeks, months later

22. Therapy • early antibiotic therapy • curable • penicillin • tetracycline • late antibiotic administration • ineffective

23. Diagnosis • serum antibodies to B. burgdorferi. • laboratory strains • grow extremely slowly • tissue culture media • not bacteriological media • patient body fluids/tissue sample • almost never growth

24. A physicians dilemma • acute • responds to antibiotic • antibodies not detectable • late diagnosis • not curable • antibodies detectable

25. Lyme Disease -etiology • reactive arthritis similar to • Reiter's syndrome • rheumatic fever • resembles rheumatoid arthritis

26. Relapsing fever • <100/ per year in US • transmission • tick-B. hermsii • rodent, primary host • lice-B. recurrentis • human, primary host

27. “Relapsing” fever • immune response develops • disease relapses • new antigens expressed • no immunity • disease reappears

28. Diagnosis • no culture • no serological test • detected - blood smear

29. Leptospirosis

30. Leptospirosis • <100 cases per year in US • symptoms • flu-like • severe systemic disease • kidney • brain • eye

31. Transmission • infected urine • rodents • farm animals • water • through broken skin.

32. Laboratory Diagnosis • serology • most readily culturable of spirochetes • culture still extremely difficult

33. NEISSERIA Neisseria gonorrhoeae

35. Neisseria • Gram negative • diplococci (pairs of cocci) • oxidase positive • culture • Thayer Martin. • selective • chocolate agar • heated blood (brown)

36. N. gonorrhoeae the “Gonococcus" • found only in man • gonorrhea • second most common venereal disease

38. Smear • polymorphonuclear cell • Gram negative cocci • many in cells

39. Dissemination -gonococci • gonoccocal arthritis • “septic” arthritis • dermatitis

40. Antibiotic therapy • βlactamase-resistant cephalosporin • e.g. ceftriaxone • resistant strains • common • produceβ lactamases • destroy penicillin

41. Pathogensis • adhesion to genital epithelium • outer membrane • pili • Antigenicity • highly variable among strains • no vaccine • IgA protease • also N. meningitidis

42. N. gonorrhoeae • Tissue injury • lipopolysaccharide • peptidoglycan

43. N. meningitidis(the “Meningococcus")

44. N. meningitidis • resides in man only • usually sporadic cases • mostly young children • outbreaks • adults • crowded conditions • e.g. army barracks, dorms

45. Neisseriameningitidis • upper respiratory tractinfection • adhesion pili • bloodstream brain

46. Meningococcal meninigitis • second most common meningitis • pneumococcus, most common • fatal if untreated • responds well to antibiotic therapy • penicillin

47. Laboratory Diagnosis • spinal fluid • Gram negative diplococci • within polymorphonuclear cells • meningococcal antigens • Culture • Thayer Martin agar

48. Capsule • capsule • inhibit phagocytosis • anti-capsular antibodies • stop infection • antigenic variation • sero-groups • vaccine • multiple sero-groups