Chlamydial Infections Flashcards
Chlamydiae
Obligate intracellular parasites
cannot generate ATP
2 distinct morphologic forms in life cycle:
Chlamydiae Elementary body
smaller metabolically inactive form, survives extracellularly
Attaches to appropriate host cell & induces endocytosis, forming a vacuole.
Transforms into the larger metabolically active form
Chlamydiae Reticulate Body
Lager metabolically active form
Commandeers the host cell metabolism to fuel chlamydial replication
C. trachomatis
causes genital & neonatal disease, lympogranuloma venereum, trachoma
Perinatal transmission causes neonatal conjunctivitis and pneumonia.
Organisms spreads in genital secretions, Infection is chronic and is often asymptomatic.
Elicits an infiltrate of neutrophils and lymphocytes,
Lymphogranuloma Venereum
Necrotizing lymphadenitis- C. trachomatis
Begins as a genital ulcer, spreads to lymph nodes where abscesses develop & extend to adjacent lymph nodes & may cause scarring.
necrotizing process produces enlarged & matted lymph nodes
Endemic to tropics and subtropics-homosexual men
Trachoma
bacterial infection of the eye- C. trachomatis
Chronic infection that causes progressive scars of the conjunctiva and cornea
Reproduces in the conjunctival epithelium
Characterized by abrupt onset of palpebral and conjunctival inflammation.
C. psittaci
Psittacosis (ornithosis)- self limited pneumonia transmitted to humans via birds.
1st infects pulmonary macrophages,which carry organism to phagocytes of liver and spleen, reproduces.
Dissemination is characterized by foci of necrosis in the liver and spleen & diffuse mononuclear cell infiltrates in the heart, kidneys and brain.
persistant dry cough, pneumonia is interstitial w/ lymphocytotic inflammatory infiltrate
C. pneumoneiae
Acute self-limiting mild respiratory tract infections,including pneumonia.
Transmitted person to person
Severe pneumonia occurs only if there is an underlying pulmonary condition.
