Chlamydiaceae Flashcards
What are Chlamydiaceae?
Small gram negative obligate intracellular parasites
What are Chlamydiaceae referred to as?
○ “Energy Parasites”
○ Since they can’t make ATP or survive outside an animal host cell
What is so unique about Chlamydiaceae’s life cycle?
○ they exist as elementary bodies (EB) outside a host
○ Inside the host they form larger reticulate bodies (RB) that replicate
○ Once replicated they reorganize back into EB
○ After which they are released when the cell is lysed
Elementary bodies
○ Chlamydiaceae with a rigid cell wall
○ capable of adhering to host cells and being phagocytized
○ small and round and is infectious
For the sake of this test, what speices of Chlamydiaceae are of focus?
○ Chlamydia trachomatis
○ Chlamydophila psittaci
○ Chlamydophila pneumoniae
What is the main concern of Chlamydia Trachomatis?
It can be asymptomatic in the body but will eventually present itself in 3 ways
What are the 3 ways Chlamydia Trachomatis can present itself?
○ Genitourinary
○ Pulmonary
○ Ocular
Can C. trachomatis infect everything?
○ No it can only infect 3 things:
○ Nonciliated columnar
○ Cuboidal
○ Transitional epithelial cells
Trachoma
○ a disease of the eyes that causes the inflammation of eyes (Kerato-conjunctivitis)
○ Leading cause of preventable blindness in the world
What group is trachoma common in? how does it spread?
Common among small children and spread through:
○ direct contact of eye secretions
○ contaminated unwashed hand
○ indirectly through personal items such as clothing
○ Biting flies
○ Respiratory secretions
○ vaginal delivery- towards newborns from mothers
What is the most common STD in the US
○ Chlamydia
○ most common cause of nongonococcal urethritis in the US (meaning not gonorrhea)
Chlamydial infections in females can cause…
○ PID - Pelvic inflammatory disease (damaged fallopian tubes)
○ Infertility
○ Ectopic pregnancies
Lymphogranuloma venereum (LGV) can be caused by what?
3 unique strains of Chlamydia trachomatis
Describe LGV
○ small, often asymptomatic skin lesion, followed by regional lymphadenopathy in the groin or pelvis.
○ secondary stage: lymph nodes enlarge and become inflamed and buboes develop
What are the 3 strains of C. trachomatis that cause LGV?
serotypes L1, L2, L3
How do you collect C. trachomatis?
○ Scrapings or tissues
○ Swabs too but not with cotton, Dacron
○ Transported with media containing sucrose, phosphate buffer and antibiotics to inhibit other organisms
Cytological tests
used to examine for presence / absence of Chlamydia Trachomatis
How do cytological tests work?
○ Patient’s epithelial cells scraped from infected areas
○ stained (iodine or Giemsa)
○ examined for cytoplasmic inclusions
Cell cultures are used for what?
○ to grow Chlamydia Trachomatis
○ Monolayer of cells inoculated with patient sample, cover slipped and incubated
○ Slides of these are stained and examined after 48-72 hours
What are other detection methods of C. trachomatis?
○ Nucleic acid probes
○ NAAT - Nucleic acid amplification tests
○ PCR - Polymerase Chain Reaction
○ Antigen Detection Methods
Of the detection methods for C. trachomatis which one is considered the best?
○ NAAT - Nucleic acid amplification tests and PCR - Polymerase Chain Reaction
○ Considered the Gold standard
What is the benefit of antigen detection methods?
It is inexpensive and can be used on large number of specimens
How do you treat Chlamydia?
○ tetracyclines
○ Erythromycin or fluoroquinolones
Psittacosis and ornithosis is caused by what?
Chlamydophila psittaci
