Case 1

Chlamydia trachomaris

Urethritis

Urethritis, or inflammation of the urethra, is caused by an infection characterized by the discharge of mucoid or purulent material and by burning during urination.
However, asymptomatic infections are common.

Common agents causing urethritis

The two bacterial agents primarily responsible for urethritis among men are

less common

Nongonococcal urethritis.

Nongonococcal urethritis, or inflammation of the urethra not caused by gonococcal infection, is characterized by a mucoid or purulent urethral discharge.
In the presence or absence of a discharge, NGU may be diagnosed by > 5 PMN per oil immersion field in a smear of an intraurethral swab specimen.
C. trachomatis is the most frequent cause of NGU (23-55% of cases); however, prevalence varies among age groups, with lower prevalence found among older men.
U. urealyticum causes 20-40 % of cases, and Trichomonas vaginalis 2-5% herpes simplex virus is occasionally responsible for cases of NGU.

Postgonoccccal urethritis.

Postgonococcal urethritis refers to the clinical syndrome in which symptoms recur after treatment for gonorrhea.
It is a manifestation of dual urethral infection.
Chlamydia trachomatis has been recovered from 11-50% of men with gonorrhea. Occasionally, dual infection with ureaplasma may occur.

General charecteristics of Chlamydia

Chlamydia are small, rounded organisms that show morphologic variation during their replicative cycle.
The cell envelope is similar to Gram-negative bacterial types but the outer membrane lacks peptidoglycan.
They are obligate intracellular bacteria that fail to grow outside in artificial media.
They are metabolically deficient compared with free-living bacteria, because they require the host-derived ATP for survival.

Chlamydia species

The three species are

Reproduction cycle of Chlamydia.

It has two forms of the organism, an elementary body and a larger intracellular replicative reticulate body.
The elementary body infects cells by its attachment to the plasma membrane.
Host cell metabolism is used during the entry.
The elementary body transforms to a reticulate body by protein modification.
Reticulate bodies then divide by binary fission within the endocytic vacuole.
The newly formed organisms condense to yield multiple elementary bodies with the capacity to infect other host cells when it ruptures.

Other serovarieties of C. trachomatis can cause infection -

Species	Subtype	Diseases
C. trachomatis	A,B,C	Trachoma (chronic conjuncitivitis)
	D,E,F,H,I,J,K	Nongonococcal urethritis, cervicitis, endometritis, salpingitis, proctitis, epididymitis, inclusion conjunctivitis in newborns, infant pneumonia syndrome.
	L1, L2, L3	Lymphogranuloma venereum

Other sites can be involved with sexually transmitted Chlamydia trachomatis

Other sites include

Serovarieties, the diseases they cause, and how each is transmitted.

Serovarieties A, B, Ba and C cause trachoma, a chronic conjunctivitis that often leads to blindness.
- Spread is via hand to eye contact with infected secretions.
Serovarieties D-K cause inclusion conjunctivitis and infant pneumonia, which is acquired during passage through an infected birth canal.
Serovarieties L₁, L₂ and L₃ cause lymphogranuloma venereum, a sexually transmitted disease.

Treatment

Tetracycline (especially doxcycline) and erythromycin are commonly used.
Azithromycin is effective given as a single dose, but is expensive.
Ciprofloxacin may be used in adults.
In pregnant women and infants, erythromycin is used because of tooth staining of the fetus or infant with tetracycline.