Cell wall-less organisms

Chlamydiaceae general characteristics

obligate intracellular parasite (can’t replicate unless in host cell), very tiny Gram - cells, resevoir is human body, most severe in infants/children

Chlamydiaceae virulence

intracellular replication (gain access through mucus membranes), prevention fusion of phagosome w/ cellular lysosome, pathologic effects from body’s reaction

Chlamydiaceae life cycle

elementary body (small, metabolically inactive, infectious form, shielded by impervious envelope, allows survival outside of host cell)

reticulate body (larger, actively dividing, noninfectious, cell wall allows to divide, can’t make energy on own, are energy parasites

Chlamydiaceae clinical disease (most by C. trachomatis)

ocular trachoma (infection of eye, major cause of blindness, pebbled appearance of eyelid), inclusion trachoma (acquired from asymptomatic mother, infantile conjuctivitis, will heal spontaneously but still treat, why all newborns are treated w/ eye drops), STI (one of top 5 STI, high amount asymptomatic, resembles gonorrhea, cervicitis in females, nonidentification can cause long term damage), lymphogranuloma vererum (very virulent strain STI, not common in US, usually painless lesion then buboes form, backs up lymphatic fluid, chronic/deforming edema of genetalia), pneumonia (C. pneumoniae, strict human pathogen, not closely related to other Chlamydias, normally mild in adults/severe is asthmatic patients), ornithosis (C. psittaci, pneumonia like illness from birds, untreated can become systemic)

Chlamydiaceae lab identification

direct assay w/ immunofluorescence, nuclei acid probe (inexpensive, rapid but insensitive), NAAT (more sensitive, rapid, test of choice)

Chlamydiaceae treatment & prevention

drugs that act intracellularly LGV=tetracyclines, ocular/genital infections= azuthromycin/doxycycline, newborn conjunctivitis/pneumonia=erythromycin

prevention-high carrier rate & diff in detection make this public health problem, drug therapy for partners of infected/promote condom use