➢General characteristics of Chlamydia
● Chlamydia is an energy parasite
● Chlamydia is obligate intracellular.
★Chlamydia is an organism not classified as a bacterium nor as a virus. Why?
Chlamydia is not a virus: Has both DNA and RNA.
Chlamydia is not a bacterium: Has no peptidoglycan in its cell wall.
This means that the cell wall inhibitors don’t work on it (like mycoplasma).
Chlamydia
➢Biotypes:
● Chlamydia trachomatis: infection resembles Neisseria Gonorrhoea.
● Chlamydophila: Chlamydophila Psittaci and Chlamydophila Pneumoniae (both of them cause atypical pneumonia).
Structural forms of Chlamydia
- Elementary body (EB):
● Extracellular.
● Spore-like(very resistant to harsh conditions).
● The infectious form.
● Non-replicating and non metabolically active.
- Reticulate body (RB):
● Intracellular.
● Fragile.
● Non-infectious form.
● Replicating and metabolically active.
Development cycle of Chlamydia
● EB enters the body and binds then gets inside: epithelial cells (by endocytosis) and macrophages (by phagocytosis)
● EB then enters the cell and becomes RB which is multiplied by binary fission to form daughter RB.
● Daughter RB then developed into EB.
● EB forms an inclusion body inside the phagosome
● Release of EB from the cell.
Mechanism of release of Chlamydia
- Release of EB in C.Trachomatis and C. Pneumoniae is by:
Extrusion.
- Release of EB in C.Psittaci is by: Lysis
➢Diseases caused ,Biovar ,Serovar of Chlamydia
- Ocular infections: Mainly Trachoma Biovar: Trachoma biovar. Serovar: A,B,C. Or D-K
- Urogenital tract disease: Biovar: Trachoma biovar or LGV biovar. Serovar : D-K.
- Lymphogranuloma venereum (LGV): Biovar: LGV biovar Serovar: L1,L2,L3,L24,L26.
developmental cycle we said that the EB binds two cells
● Epithelial cell: In Trachoma and UGT diseases.
● Macrophages: In LGV.
What are Ocular infections of chlamydia
A. Trachoma (conjunctivitis and keratitis).
B. Adult inclusion conjunctivitis .
C.Ophthalmia neonatorum
Ophthalmia neonatorum serovar
D-K serovar
How to differentiate between neisseria and chlamydia in Ophthalmia neonatorum
- Incubation period:
First week (2-3 days): Neisseria gonorrhoeae Second week (5-14 days): Chlamydia Trachomatis
- Upper respiratory infection symptoms: Chlamydia Trachomatis.كيييييف 🫴
Adult inclusion conjunctivitis sevouar
D-K serovar
Trachoma Serovar
Serovar : A,B,C.
Case presentation of trachoma
sandy sensation in the eye .
Phases of trachoma
- Follicular trachoma
- Inflammatory trachoma
- Scarring (By entropion= distortion of the eyelid).
- Trichiasis (=inversion of the eye lashes)
- Corneal opacity (can lead to blindness).
Complications of trachoma
● Trichiasis
● Entropion
● Blindness caused by scarring and trichiasis.اهم
● Chronic or repeated infections.
➢Transmission of ocular infections
➢Prevention of trachoma
● Hand to eye (Auto-inoculation)
● Sharing personal belongings
● Delivery through the birth canal
Prevention :
Personal Hygiene.
.Presentation of STI in men in chlamydia
.How to differentiate it from Gonococcal Urethritis
. Complicationsشبه مكررة 👍
Urethritis (Dysuria, urgency , frequency, urethral discharge)
Differentiation
- Make culture:
● If it grows: Neisseria Gonorrhoea.
● If does not grow: Chlamydia Trachomatis (it’s an obligate intracellular organism).
- Look at the discharge:
● If it’s clear: Chlamydia Trachomatis
● If it contains pus: Neisseria Gonorrhoea
Complications
● Epididymitis
● Prostatitis
● Proctitis
● Reiter’s syndrome
● Infertility.
● Orchitis.
.Presentation of STI in women in chlamydia
.How to differentiate it from Gonococcal Urethritis
. Complicationsشبه مكررة 👍
Cervicitis (dysuria, urgency, freqeuncy and cervical discharge).
زي الmen
➢Complications:
● Pelvic inflammatory disease(PID): (Salpingitis + Endometritis + Peritonitis).
● Perihepatitis.
● Reiter’s syndrome.
● Ectopic pregnancy.
● Infertility.
Clinical manifestations of PID
● Lower back pain, lower abdominal pain or suprapubic pain .
● Discharge.
Most common cause of Reiter’s syndrome generally
Chlamydia Trachomatis (60-80% of Riter Syndrome cases).
➢Clinical presentation of LGV and where this infection occurs
● Infection occurs in the macrophages.
● First stage: Painless vesicular lesions in the genitalia.
● Second stage : Enlargement of the lymph nodes (buboes) + proctitis+ elephantiasis in the scrotum + orchitis.
● Third stage : Fibrosis of the draining lymph nodes.
➢Transmission of LGV
LGV is sexually transmitted.
➢Diagnosis of chlamydia
- Specimen collection:
According to the site of the infection:
● STI: Urethral or cervical swab.
● Eye infection: Eye Swab.
- Cytology:
● Stain by Iodine or Geisma stain to detect the inclusion bodies
● It’s not specific.
- Culture:
Cell culture (McCoy cell line) because it’s on obligate intracellular organism
- Antigen detection (ELISA).
- Serology.
- PCR.
