1. Chlamydia, Rickettsia, and Mycoplasma Infections kkelly@mednet.ucla.edu 206-5562

2. Chlamydia, Rickettsia, and Mycoplasma  Microbiology  Infectious disease presentations  Treatment

4. Chlamydiacea  Three organisms cause human disease –Chlamydia trachomatis (genus = Chlamydia) –Chlamydia pneumoniae (genus = Chlamydophila) –Chlamydia psittaci (genus = Chlamydophila)  Recent taxonomy changed based on the 16S rRNA sequence

5. Chlamydial Biology  Prokaryotes  Gram negative with LPS  Lack peptidoglycans?  Obligate intracellular life cycle

6. Chlamydia Developmental Cycle  Elementary body; –Infectious form, metabolically inert –Extracellular spore-like state  Reticulate body; –Non-infectious form, metabolically active –obligate intracellular form in eukaryotic cells  48-72 hour cycle

7. Chlamydia Developmental Cycle 1-6 hrs 12-16 hrs 24-72 hrs

8. Attachment & Internalization to Epithelial Cells

9. Chlamydial Inclusion

10. Type III Secretion System - Contact with Host Cell ?

11. Chlamydial Genome  1.043 million base pairs  Contains genes for LPS, glycolysis, fatty acid and phospholipid synthesis and, peptidoglycan synthesis  Missing genes for amino acid and purine- pyrimidine biosynthesis, anaerobic fermentation, and transformation competence proteins

12. Chlamydia trachomatis: Disease Presentations  Genitourinary tract infections  Perinatal infections  Trachoma

13. Chlamydia trachomatis & Sexually Transmitted Infections  Urogenital infections: cervicitis, urethritis, PID, epididymitis/prostatitis  4-6 million cases/year, U.S.  Prevalence highest in young women, 3-11% (age 15-24)  Lymphogranuloma venereum (LGV)

14. Urethritis Non purulent discharge

15. Cervicitis

16. Serious Consequences of C. trachomatis STI's  Tubal infertility  Pelvic inflammatory disease  Ectopic pregnancy  Reactive arthritis (Reiter's syndrome)

17. * Recent studies showed that 50% of infections occurred in 15-19 year old individuals.

18. Acute Inflammation in the Cervix

19. Chronic Inflammation in the Cervix

20. Fallopian Tube Pathology Normal Cross-section Tubal dilation and epithelial cell destruction

22. C. trachomatis Perinatal Infections  Neonatal inclusion conjunctivitis (20-45% of infants from infected mothers)  Infant pneumonia (10-20% of infants from infected mothers)

23. C. trachomatis and Trachoma  Blinding conjunctival infection  600 million cases worldwide  Develops over years, chronic inflammation  Endemic in Middle East, Asia & Africa

25. Trachomatis Inflammation Thickening on the tarsal conjunctiva appears red, rough and thickened. Usually associate with numerous follicles (aggregates of immune cells).

26. Cornea Scarring & Trichiasis Scars (white streaks) visible on cornea. Trichiasis = Eyelashes rub the eyeball

27. Tryptophan Starvation by Indoleamine 2,3 dioxygenase J. Biol. Chem., Vol. 277, 26893-26903, 2002 Molecular Basis Defining Human Chlamydia trachomatis Tissue Tropism POSSIBLE ROLE FOR TRYPTOPHAN SYNTHASE** Christine Fehlner-Gardiner, et al Genital isolates (D-K) Use trp B gene to form tryptophan from indole Ocular isolates (A-C) Can NOT metabolize indole

28. C. trachomatis: Diagnosis  Serology (MIF=microimmunofluorescence)  Culture  EIAs/DFA (direct fluorescent antibody)  Direct hybridization  Nucleic acid amplification (PCR, LCR, others)

29. Fluorescent inclusion (green) inside cell (red)

30. Stary sky appearance of green fluorescent chlamydiae detected by DFA in smear

31. NAATS; Nucleic Acid Amplification Tests  Routine clinical use 1990s  Major impact of epidemiology of Chlamydia infections

32. C. trachomatis: NA Amplification  Improved Sensitivity, 90%+, specificity >99% – Use of novel specimens: urine, vaginal swabs, patient collect tampons and cervical/urethral specimens  Access difficult patient populations: male cases  Performed in diverse clinical settings

33. C. trachomatis: Treatment  Azithromycin, (single 1000 mg dose acceptable) (single 1000 mg dose acceptable)  Tetracyclines (Doxycycline) –(erythromycin for pregnant women and neonates/children)

34. Chlamydia pneumoniae  1983, described as a distinct chlamydial pathogen  Approximately 50% of US population is seropositive  Less than 10% DNA homology with C. trachomatis  Similar life cycle but different cell wall construction

35. C. pneumoniae: Disease Presentations  Pharyngitis, bronchitis  Pneumonia (7-10% of cases)  Other syndromes (otitis media, endocarditis)

36. C. pneumoniae and Chronic Diseases  Atherosclerosis (seroepidemiologic studies, experimental disease)  Asthma  Neurological disease? (MS, Alzheimer’s)

37. C. pneumoniae: Diagnosis  Serology (MIF = microimmunofluorescence)  Culture  PCR

38. C. pneumoniae: Treatment  Azithromycin/clarithromycin (macrolides)  Erythromycin  Tetracycline (Doxycycline)

39. Chlamydophila psittaci  Recently distinguished as a separate genus using sequence phylogeny  Zoonosis, typically from pet birds, occupational exposure  80 cases/year in the U.S

40. Chlamydophila psittaci: Clinical Disease/Dx/Tx  Severe pneumonia  Endocarditis, other systemic presentations  Diagnosis by serology, culture  Prolonged therapy with tetracycline

41. Rickettsia Family  Includes the genera:  Rickettsia, Orientia, Coxiella, Ehrlichia, Bartonella  Intracellular Gram negative bacteria

44. Diseases Caused by Rickettsiae Family  Spotted fever group (R. rickettsii)  Typhus group (R. prowazekii, R. typhi)  Scrub typhus group (Orientia tsutsugamushi)  Q fever group (C. burnetti)

45. Rocky Mountain Spotted Fever  More common in midwest, south central states  Ixodid tick transmission  Infects vascular endothelial cells

47. Rocky Mountain Spotted Fever: Clinical Presentation  Skin rash, extremities  Fever  High mortality if untreated

48. Rocky Mountain Spotted Fever: Dx/Tx  Culture (blood or biopsy should be frozen, -70 degrees C.)  Direct immunofluorescence  Serology  PCR  Doxycycline/Chloramphenicol Ciprofloxacin –within 5 days of onset

49. Epidemic Typhus  Unsanitary conditions  Spread by the human louse  Also infects endothelial cells

50. Epidemic Typhus: Clinical Presentation  Intense fever, headache  Rash, axillary folds, trunk  Mortality as high as 40% due to clinical complications

51. Epidemic Typhus: Dx/Tx  Serology (no longer use Weil-Felix)  Culture  PCR  Tx: Doxycycline/Chloramphenicol

52. Q Fever  Tick (animals), aerosols, infected milk  Animal exposure (skins, dust, excreta, POC –poc = products of conception, ie placenta)

53. Q Fever: Clinical Presentation  Highly contagious  Febrile illness, rash is rare  Primarily pneumonia  Granulomatous hepatitis, bacterial endocarditis

54. Q Fever: Dx/Tx  Culture  Serology (Antigenic variation)  PCR

55. Ehrlichiosis  Emerging infectious disease –monocytic –granulocytic  Similar to Rocky Mountain Spotted Fever - but no rash  Dx: Serology  Tx: Doxycycline/Chloramphenicol

56.  Three human pathogens –Mycoplasma pneumoniae –M. hominis –Ureaplasma urealyticum Mycoplasma and Ureaplasma

57. Mycoplasma & Ureaplasma Biology  Lack a rigid cell wall  Very small genome, limited metabolic capabilities  Requires sterol for growth  Most closely related to lactobacilli

58. Morphology “Fried egg”

60. Mycoplasma pneumoniae: Clinical Disease  Atypical pneumonia (2 million cases/yr)  Bronchitis  Older children, young adults  Insidious onset

61. PathogenicityPathogenicity  Attachment via P1  Host receptors –Sialoglycoproteins –Sialoglycolipids H 2 0 2 & O 2- produced as a metabolic by product from Mycoplasma can damage host cells.

62. Mycoplasma hominis and Ureaplasma urealyticum  Isolated from genital tracts of both men and women  Uncertain associations with urethritis, amniotic infections, abortion

63. Mycoplasma: Dx/Tx  Culture (identification based on use of glucose, arginine, urea)  Typical "fried egg" colonies  Nucleic acid based tests (hybridization, PCR)  Tx with doxycycline/tetracycline