Chlamydiaceae

Question 1

What are Chlamydiaceae?

Answer 1

Small gram negative obligate intracellular parasites

Question 2

What are Chlamydiaceae referred to as?

Answer 2

○ “Energy Parasites”
○ Since they can’t make ATP or survive outside an animal host cell

Question 3

What is so unique about Chlamydiaceae’s life cycle?

Answer 3

○ 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

Question 4

Elementary bodies

Answer 4

○ Chlamydiaceae with a rigid cell wall
○ capable of adhering to host cells and being phagocytized
○ small and round and is infectious

Question 5

For the sake of this test, what speices of Chlamydiaceae are of focus?

Answer 5

○ Chlamydia trachomatis
○ Chlamydophila psittaci
○ Chlamydophila pneumoniae

Question 6

What is the main concern of Chlamydia Trachomatis?

Answer 6

It can be asymptomatic in the body but will eventually present itself in 3 ways

Question 7

What are the 3 ways Chlamydia Trachomatis can present itself?

Answer 7

○ Genitourinary
○ Pulmonary
○ Ocular

Question 8

Can C. trachomatis infect everything?

Answer 8

○ No it can only infect 3 things:
○ Nonciliated columnar
○ Cuboidal
○ Transitional epithelial cells

Question 9

Trachoma

Answer 9

○ a disease of the eyes that causes the inflammation of eyes (Kerato-conjunctivitis)
○ Leading cause of preventable blindness in the world

Question 10

What group is trachoma common in? how does it spread?

Answer 10

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

Question 11

What is the most common STD in the US

Answer 11

○ Chlamydia
○ most common cause of nongonococcal urethritis in the US (meaning not gonorrhea)

Question 12

Chlamydial infections in females can cause…

Answer 12

○ PID - Pelvic inflammatory disease (damaged fallopian tubes)
○ Infertility
○ Ectopic pregnancies

Question 13

Lymphogranuloma venereum (LGV) can be caused by what?

Answer 13

3 unique strains of Chlamydia trachomatis

Question 14

Describe LGV

Answer 14

○ 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

Question 15

What are the 3 strains of C. trachomatis that cause LGV?

Answer 15

serotypes L1, L2, L3

Question 16

How do you collect C. trachomatis?

Answer 16

○ Scrapings or tissues
○ Swabs too but not with cotton, Dacron
○ Transported with media containing sucrose, phosphate buffer and antibiotics to inhibit other organisms

Question 17

Cytological tests

Answer 17

used to examine for presence / absence of Chlamydia Trachomatis

Question 18

How do cytological tests work?

Answer 18

○ Patient’s epithelial cells scraped from infected areas
○ stained (iodine or Giemsa)
○ examined for cytoplasmic inclusions

Question 19

Cell cultures are used for what?

Answer 19

○ 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

Question 20

What are other detection methods of C. trachomatis?

Answer 20

○ Nucleic acid probes
○ NAAT - Nucleic acid amplification tests
○ PCR - Polymerase Chain Reaction
○ Antigen Detection Methods

Question 21

Of the detection methods for C. trachomatis which one is considered the best?

Answer 21

○ NAAT - Nucleic acid amplification tests and PCR - Polymerase Chain Reaction
○ Considered the Gold standard

Question 22

What is the benefit of antigen detection methods?

Answer 22

It is inexpensive and can be used on large number of specimens

Question 23

How do you treat Chlamydia?

Answer 23

○ tetracyclines
○ Erythromycin or fluoroquinolones

Question 24

Psittacosis and ornithosis is caused by what?

Answer 24

Chlamydophila psittaci

Question 25

Who are the carriers of psittacosis?

Answer 25

psittacine birds like parrots, parakeets or cockatoos

Question 26

Who is the carrier of ornithosis?

Answer 26

non-parrot birds such as chickens, turkeys and pigeons

Question 27

How can Chlamydophila psittaci be transmitted?

Answer 27

inhalation of contaminated aerosols or through infected excrements

Question 28

hat does C. psittaci cause?

Answer 28

○ severe or fatal pneumonia
○ can disseminate to liver or spleen

Question 29

How is C. psittaci treated?

Answer 29

macrolides (erythromycin) and tetracyclines

Question 30

What species of chlamydiaceae is rormerly known as TWAR?

Answer 30

Chlamydophila pneumoniae

Question 31

What is C. pneumoniae associated with?

Answer 31

○ Mild respiratory tract infections
○ Sinus infections
○ Pharyngitis

Question 32

Describe C. pneumoniae

Answer 32

pear shaped with a large periplasmic space and round elementary bodies

Question 33

Treatment for C. pneumoniae

Answer 33

macrolides, tetracyclines, or fluoroquinolones