CHLAMYDIA by Dr munir HMC PICO.slideshare
- 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: 1. Chlamydia trachomatis 2. Chlamydophila psittaci 3. 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.
- 9. • 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.
- 12. • C. psittaci and C. pneumoniae each have 1 immunotype, whereas C. trachomatis has at least 15. • Laboratory identification 1. Chlamydiae are not seen by Gram stain • Can be visualized under light microscope by Giemsa stain. 2. Direct immunofluorescence is also a common and useful procedure
- 14. 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.
- 15. • Pathogenesis & Clinical Findings: • C. trachomatis exists in more than 15 immunotypes (A–L). A. Trachoma: • Types A, B, and C cause trachoma, a chronic keratoconjunctivitis. • Endemic in Africa and Asia.
- 16. • 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.
- 17. • 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.
- 18. • Trachoma can be further divided into 1. Blinding trachoma 2. Non blinding trachoma 3. Paratrachoma 1. Blinding trachoma. • It is caused by serotypes A, B, Ba and C of Chlamydia trachomatis.
- 19. • 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.
- 20. • 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.
- 21. • It manifests as either a. Adult inclusion conjunctivitis or b. Chlamydial ophthalmia neonatorum. • Trachoma is a chronic infection.
- 23. Tarsal conjunctival scarring Blinding trachoma with entropion and trichiasis
- 24. B. 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.
- 25. a. Neonatal conjunctivitis (chlamydial ophthalmia neonatorum) : • In infants born to genitally infected women. b. 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
- 26. of developing Reiter's syndrome (urethritis, arthritis and uveitis) • C. trachomatis directed antibodies cross react. c. 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.
- 27. • 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.
- 28. • Lab diagnosis: 1. 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.
- 29. Inclusion body
- 30. 2. 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. 3. Cell culture: • In this case suspected specimen is added to special cells, which are then cultured in laboratory.
- 31. • 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.
- 32. Chlamydia trachomatis on cell culture Inclusion Nucleus of cell
- 34. • 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.
- 35. • 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.