1 / 36

Chlamydia trachomatis

Chlamydia trachomatis. The Biology of a Sexually Transmitted Bacterium. Chlamydial Life Cycle. Reticulate body, obligately intracellular in eukaryotic cells Elementary body, metabolically inert, an extracellular spore-like state 48-72 hour cycle. Chlamydial Biology. Prokaryotes

shoushan-mccoy
Télécharger la présentation

Chlamydia trachomatis

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chlamydia trachomatis The Biology of a Sexually Transmitted Bacterium

  2. Chlamydial Life Cycle • Reticulate body, obligately intracellular in eukaryotic cells • Elementary body, metabolically inert, an extracellular spore-like state • 48-72 hour cycle

  3. Chlamydial Biology • Prokaryotes • Gram negative with LPS • Lack peptidoglycans? • Obligate intracellular life cycle

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

  5. Chlamydia trachomatis: Disease Presentations • Perinatal infections • Genitourinary tract infections • Trachoma

  6. Chlamydia trachomatis and 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

  7. Serious Consequences of C. trachomatis STI's • Tubal infertility • Ectopic pregnancy • Reactive arthritis (Reiter's syndrome)

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

  9. C. trachomatis and Trachoma • Blinding conjunctival infection • 600 million cases worldwide • Develops over years, chronic inflammation • Endemic in Middle East, Asia

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

  11. C. trachomatis: NA Amplification • Nucleic acid amplification can be used on urine, cervical/urethral specimens • Vaginal specimens also have been used • Sensitivity, 90%+, specificity >99% • Identifying more male cases, providing easier specimen collections

  12. C. trachomatis: Treatment • Azithromycin, (single 1000 mg dose acceptable) • Tetracyclines (erythromycin in children)

  13. Chlamydia pneumoniae • 1983, described as a distinct chlamydial pathogen • Less than 10% DNA homology with C. trachomatis • Similar life cycle but different cell wall construction

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

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

  16. C. pneumoniae: Diagnosis • Serology (MIF = microimmunofluorescence) • Culture • PCR

  17. C. pneumoniae: Treatment • Azithromycin/clarithromycin (macrolides) • Erythromycin • Tetracycline/doxycycline

  18. 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

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

More Related