CHLAMYDIA by Dr munir HMC PICO.slideshare

Chlamydia

1. CHLAMYDIA

2. General features: Chlamydiae are obligate intracellular organisms Depend on the host cell for energy (ATP). Therefore can grow only inside host cells. Chlamydiae are small, round-to-ovoid organisms that vary in size during different stages of their life cycle

3. There are three important human pathogens: Chlamydia trachomatis Chlamydophila psittaci Chlamydophila pneumoniae . C. pneumoniae and C. psittaci are different molecularly from C. trachomatis .

4. Therefore have been placed into a new genus called Chlamydophila . Thus Chlamydophila pneumoniae and Chlamydophila psittaci . But still known as Chlamydia pneumoniae and Chlamydia psittaci

5. Structure: They have a rigid cell wall but do not have a typical peptidoglycan layer. C. trachomatis is the most common cause of STDs. Chlamydia pneumoniae causes atypical pneumonia. C. psittaci causes psittacosis ( mainly disease of birds)

6. Pathogenesis: Chlamydiae have a unique life cycle, with distinct infectious and reproductive forms. The infectious form is called elementary body. It is a tiny, condensed structure that is extracellular and initiates an infection. The elementary body enters by phagocytosis into susceptible host cells.

7. The elementary body is present in phagosome inside the host cell. Inside the cell, the elementary body prevents fusion of the phagosome and lysosome . The particle reorganizes over the next 8 hours into a larger, noninfectious reticulate body. The phagosome now becomes a larger structure.

8. This vacoule /larger phagosome is called inclusion body. Reticulate body divides repeatedly by binary fission. After 48 hours, multiplication ceases, and reticulate bodies condense to become new infectious elementary bodies. This whole process causes host cell death and release of elementary bodies.

9. C. psittaci and C. pneumoniae each have 1 immunotype , whereas C. trachomatis has at least 15. Laboratory identification Chlamydiae are not seen by Gram stain Can be visualized under light microscope by Giemsa stain. Direct immunofluorescence is also a common and useful procedure

10. Chlamydia trachomatis Inclusion Nucleus of cell

11. CHLAMYDIA TRACHOMATIS C. trachomatis has 15 serotypes, which are related to different diseases. C. trachomatis infects only humans. Mainly causes NGU (Non Gonococcal Urethritis ) and Trachoma. Usually transmitted by close personal contact.

12. Pathogenesis & Clinical Findings: C. trachomatis exists in more than 15 immunotypes (A–L). Trachoma: Types A, B, and C cause trachoma, a chronic keratoconjunctivitis . Endemic in Africa and Asia.

13. Previously known as Egyptian ophthalmia . Primarily affects the superficial epithelium of conjunctiva and cornea simultaneously. The word 'trachoma' ('rough' )comes from the Greek word because surface appearance of the conjunctiva in chronic trachoma is rough or granular.

14. It is still one of the leading causes of preventable blindness in the world. Because of persistent /repeated infection over several years leads to scarring causing permanent opacities of the cornea and distortion of eyelids.

15. Trachoma can be further divided into Blinding trachoma Non blinding trachoma Paratrachoma 1. Blinding trachoma . It is caused by serotypes A, B, Ba and C of Chlamydia trachomatis .

16. It is associated with secondary bacterial infection. It is transmitted from eye to eye by transfer of ocular discharge. There is mucopurulent conjunctivtis 2. Non-blinding trachoma . It is also caused by serotypes A, B, Ba , and C; but is not associated with secondary bacterial infections.

17. It is a mild form of disease with limited transmission due to improved hygiene. Symptoms are minimal and include mild foreign body sensation in the eyes. 3. Paratrachoma . It is caused by serotypes D to K and L1,L2 and L3 as well. It spreads from genitals to eye.

18. It manifests as either Adult inclusion conjunctivitis or Chlamydial ophthalmia neonatorum . Trachoma is a chronic infection.

19. Follicular conujnctivitis Intense follicular inflammation

20. Tarsal conjunctival scarring Blinding trachoma with entropion and trichiasis

21. Genital infections: Types D–K cause genital tract infections. In men, it causes NGU, which may progress to epididymitis or prostatitis . In women it causes cervicitis which may progress to salpingitis and pelvic inflammatory disease (PID). Repeated episodes of salpingitis or PID can result in infertility or ectopic pregnancy.

22. Neonatal conjunctivitis ( chlamydial ophthalmia neonatorum ) : In infants born to genitally infected women. Inclusion conjunctivitis: Conjunctivitis also occurs in adults due to transfer of organisms from the genitals to the eye. Patients with genital infections have a high chance

23. of developing Reiter's syndrome ( urethritis , arthritis and uveitis ) C. trachomatis directed antibodies cross react. Lymphogranuloma venereum : C. trachomatis serotypes L1, L2, and L3 cause LGV More invasive STD. It is uncommon in the United States but endemic in Asia, Africa, and South America.

24. Formation of transient papules on genitalia, followed in 1 to 2 months by painful swelling of inguinal and perirectal lymph nodes. The affected lymph nodes suppurate and then chronic inflammation and fibrosis leads to blockage of regional lymphatic drainage.

25. Lab diagnosis: Infections can be diagnosed by demonstrating typical intracytoplasmic inclusion bodies. For detection of inclusion bodies, fluorescent antibody, iodine staining and Giemsa staining techniques are used.

26. Inclusion body

27. Chlamydial antigens can also be detected in exudates or urine by ELISA. PCR based test using the patient's urine can also be used to diagnose chlamydial STD. Cell culture: In this case suspected specimen is added to special cells, which are then cultured in laboratory.

28. The infected cells are stained with iodine to detect the glycogen-positive inclusions. The presence of chlamydial inclusions can be demonstrated after 2 to 7 days of incubation.

29. Chlamydia trachomatis on cell culture Inclusion Nucleus of cell

30. Treatment: All chlamydiae are susceptible to tetracyclines , ( doxycyline ), and macrolides (erythromycin and azithromycin ). The drug of choice for STDs is azithromycin . The drug of choice for chlamydial ophthalmia neonatorum is erythromycin.

31. Because of co-infection with gonococci, any patient with a diagnosis of genital infections should also be treated for Gonorrhoea and vice versa. Prevention: There is no vaccine against any chlamydial disease. So other preventive measures should be used.