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
Who are the carriers of psittacosis?
psittacine birds like parrots, parakeets or cockatoos
Who is the carrier of ornithosis?
non-parrot birds such as chickens, turkeys and pigeons
How can Chlamydophila psittaci be transmitted?
inhalation of contaminated aerosols or through infected excrements
hat does C. psittaci cause?
○ severe or fatal pneumonia
○ can disseminate to liver or spleen
How is C. psittaci treated?
macrolides (erythromycin) and tetracyclines
What species of chlamydiaceae is rormerly known as TWAR?
Chlamydophila pneumoniae
What is C. pneumoniae associated with?
○ Mild respiratory tract infections
○ Sinus infections
○ Pharyngitis
Describe C. pneumoniae
pear shaped with a large periplasmic space and round elementary bodies
Treatment for C. pneumoniae
macrolides, tetracyclines, or fluoroquinolones
