Chlamydia!!! MICROM 442 Deck 13 Flashcards
(30 cards)
Elementary body (EB)
-infectious
-EXC spore-like form
-Metabolically inert, non-replicating
Reticulate body (RB)
-Non-infectious
-Intracellular replicating form
-Divide within membrane-bound inclusion
-Osmotically unstable, can’t survive extracellularly
Genome for family chlamydiaceae
Small chromosome
what type of organism is chlyamdia??
obligate & intracellular
what does it secrete?
type III secreted effectors, which both EBs and RBs express
EBs induce epithelial cell internalization
¤ Pre-formed effector protein, Tarp, secreted into target cell
¤ Tarp induces actin polymerization, phagocytosis of EB
RBs secrete Inc proteins: modify the inclusion membrane
Prevent lysosome fusion by blocking SNARE-mediated interactions
C. trachomatis infects mucosal epithelial cells
¤ Secretory antibodies are produced but are not associated with
disease resolution
¤ Infection controlled by T H 1 (interferon-g-associated) immune response
¤ Provokes a low level chronic inflammatory response
¤ Necrosis, epithelial cell proliferation, and scar tissue formation
¤ Scarring responsible for most disease-associated complications
C. trachomatis servoars A-C =
trachoma
C. trachomatis servoars D-K =
¤ Urethritis/Cervicitis
¤ Perinatal infections
¤ Inclusion conjunctivitis
C. trachomatic L1, L2, L3=
Lymphogranuloma venereum (LGV)
LGV serovars specically invade the
lymph nodes where they survive/replicate in phagocytes
A-K serovars are taken up and killed by
phagocytes & invade immune cells
CT infx in men -> urethritis
Dysuria with some urethral discharge
¤ Commonly less purulent (pus-inducing) than
gonorrhea
¤ More likely to be asymptomatic than gonorrhea
¤ Epididymitis is common complication
¤ Frequently unilateral, not associated with infertility
CT infx in women
¤ Dysuria, frequency
¤ Absence of WBC in the urine (in contrast to E. coli UTI)
e.coli vs CT UTI
no WBCs in urine when CT
CT cervicitis
¤ Most infected women are asymptomatic
¤ Mucopurulent cervical discharge
¤ Friability (easily induced bleeding)
¤ Untreated infections persist for months
Chlamydia trachomatis:
Urogenital infections
¤ Pelvic inflammatory disease (PID)
¤ Endometritis (uterine lining)
¤ Salpingitis (fallopian tubes)
¤ Peritonitis (peritoneal cavity)
¤ Symptoms range from none to acute and severe
¤ Discharge, bleeding, fever, abdominal tenderness and pain
¤ Symptomatic PID occurs in ~10-15% of women with endocervical C.
trachomatis infections
CT neonatal infx
inclusion conjunctivitis & pneumonia
CT Dx
-NAAT
-screening
CT stages
1° -> Small ulcer on genital mucosa or
adjacent skin & Few or no symptoms, rapidly heals
2° -> Inguinal lymphadenopathy, fever,
headache, muscle pain
3° -> Chronic procto-colitis mimics inflammatory
bowel diseases
CT A-C pathogenesis
Chronic follicular conjunctivitis -> Ulceration and scarring of cornea, loss of vision
trachoma is most active in
infected children who are a resevoir -> transmission from nasopharyngeal secretions via hands/flies/objects
chlamydia pneumoniae
C. pneumoniae infects and multiplies within a wide range of cell types,
including monocytes/macrophages
