Chlamydia trachomatis

 

Elementary bodies are the extracellular, infective form of chlamydia. Once taken up by receptor-mediated endocytosis, EBs reside in a protected vesicle called an inclusion body and form reticulate bodies that multiply by binary fission.

RBs rearrange and condense into EBs, which are released

 

They are composed of outer membrane proteins, no replication

reticulate bodies reproduce by binary fission. They need host cells for metabolism.

Upon cell rupture

 

Epidemiology

C trachomatis is thought to be the most common bacterial STI in the US.

 

Classification and Characteristics

Virulence Factors

 

 

Transmission and Infection

Usually gains access through minute lesions or lacerations, with granuloma formation characteristic.

C. trachomatis is an obligate intracellular parasite that enters cells via receptor-mediated endocytosis

Receptors for EBs are restricted to nonciliated columnar, cuboidal, or transitional epithelium.

Trachoma is transmitted by eye-to-eye by droplet, hands, clothing, and flies. it may also be transmitted by respiratory droplet or fecal-oral route.

C trachomatis is thought to be the most common bacterial STI in the US

 

 

 

Clinical Manifesations

Perhaps 40-60% of people infected with chalymdia are asymptomatic.

Infection does not cause long-lasting immunity; instead, re-infection results in acute inflammation and tissue damage. Vision loss and sterility can result.

Trachoma is endemic in the Middle East, North Africa, and India. It causes follicular conjunctivitis, with inward-turning eyelids and corneal ulceration and scarring.

Adults and infants may also develop conjunctivitis from C trachomatis strains associated with STIs

LGV (lymphogranuloma venereum) begins with a small, painless lesion and is marked by serious inflammation and lymph node swelling

 

 

Diagnosis

Culture is 70-80% senstive - not great.

Antigen detection works

PCR

Blood tests of limited value because titres persist for a long time.

 

Treatment