1. Chlamydiaceae

2. Chlamydia Chlamydophila 2 genera Chlamydia trachomatis
Chlamydophila psittaci
Chlamydophila pneumoniae

3. Chlamydiaceae Small enough to pass through 0.45 mm filters
Obligate intacellular parasites
Are they viruses?

4. They are bacteria.... : Possess inner and outer membranes
(as Gram- negative bacteria) Cell wall +
DNA & RNA
Prokaryotic ribosomes
Synthesize their own proteins, nucleic acids, lipids
Susceptible to numerous antibacterial antibiotics
Cell wall but no peptidoglycan!!

5. Chlamydiaceae/ Physiology & structure
Exist in morphologically distinct forms
Elementary body
infectious
Resistant to harsh environmental conditions
No replication in this form
Reticulate body
Noninfectious
Metabolically active
fragile

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7. Cell wall The major outer membrane protein (MOMP)
Different for each species.
Variable regions in the gene encoding this protein are found in C. trachomatis and are responsible for serologic variants (called serovars-serotypes).

8. Chlamydia trachomatis
biovars exist
Trachoma
LGV (lymphogranuloma venereum)
These have been further divided into 19 serotypes
Trachoma: A, B, Ba, C, D, Da, E, F, G, Ga, H, I, Ia, J, K
LGV: L1, L2, L2a, an L3

9. Chlamydia trachomatis/ Diseases
Adult inclusion conjunctivitis
Neonatal conjunctivitis
Infant pneumonia
Ocular lymphogranuloma venereum
Urogenital infections
Urethritis, cervicitis, endometritis, salpingitis,....
Lymphogranuloma venereum

10. Epidemiology
Most common sexually transmitted bacteria in United States
Ocular trachoma primarily in North and sub-Sahara Africa, the Middle East, southern Asia, South America
LGV highly prevalent in Africa, Asia, and South America

11. Chlamydia trachomatis/pathogenesis & immunity
Infects nonciliated, cuboidal or transitional epithelial cells in
Mucous membranes of the urethra, endocervix, endometrium, fallopian tubes, anorectum, respiratory tract, conjunctivae

12. Chlamydia trachomatis/epidemiology
Pulmonary infection
in newborns
a diffuse interstitial pneumonia in %

13. Chlamydia trachomatis/epidemiology
“C. trachomatis is thought to be the most common sexually transmitted disease in US”
4 million new cases /year,
50 million new cases/year, worldwide
most with serotypes D-K
with N. gonorrhoeae, most common cause of epididymitis in sex. act. men
15% of the cases of proctitis in ½ men

14. Chlamydia trachomatis/epidemiology
LGV
is a chronic STD
C. trachomatis serotypes L1, L2, L2a, L3
sporadic in N. America, Australia, Europe
highly prevalent in Africa, Asia, S. America
in US, male homos. being the major reservoir

15. Chlamydia trachomatis/Clinical Diseases
serovars A, B, Ba, C
follicular conjunctivitis scarred conjunctiva eyelids turn inward in-turned eyelashes abrade cornea corneal ulceration, scarring, pannus formation LOSS OF VISION

16. Chlamydia trachomatis/Clinical Diseases
Urogenital infections I
most GTI in women are asymptomatic 80 %
may become symptomatic
clinical manifestations:
cervicitis, endometritis, urethritis, salpingitis, bartholinitis, perihepatitis
A mucopurulant discharge and hypertrophic ectopy are seen in symptomatic patients

17. Chlamydia trachomatis/Clinical Diseases
Urogenital infections II
most genital infections in men are symptomatic ( 75%)
35-50 % NGU are caused by Ct
dual infections with N. gonorrhoeae not uncommon

18. Chlamydia trachomatis/Clinical Diseases
Urogenital infections III
Reiter’s syndrome
urethritis, conjunctivitis, polyarthritis, and mucocutaneous lesions
caused by Chlamydia trachomatis !! ??

19. Chlamydia trachomatis/Clinical Diseases
Lymphogranuloma venereum
1-4 weeks of incubation
primary lesion
penis, urethra, glans, scrotum, vaginal wall, cervix, vulva
often overlooked: small, “painless”, heals rapidly
secondary stage
inflammation and swelling of the lymph nodes
inguinal nodes, most commonly involved
buboes

20. Chlamydia trachomatis/Laboratory diagnosis
symptomatic infections are easier to diagnose than asymp.infc.
the quality of the specimen is important intracellular bacteria
a specimen of pus or urethral exudate is inadequate
( 30 % of specimens submitted for study in patients with suspected Chlamydia infection are inappropriate)

21. Diagnosis
Molecular amplification tests are the most sensitive and specific tests currently available

22. Chlamydia trachomatis/Laboratory diagnosis
Serology
detection of specific IgM antibodies in infants with chlamydial pneumonitis

23. Chlamydia trachomatis/Laboratory diagnosis
Serology
can be helpful in the diagnosis of LGV

24. Chlamydia trachomatis/Prevention & Control
Prevention difficult population with endemic disease (limited access to medical care)
Chlamydia conjunctivitis and genital infections safe sexual practices

25. Chlamydophila pneumoniae
First isolation from the conjunctiva of a child in Taiwan TW-183 (related to AR-39) TWAR Chlamydia pneumoniae Chlamydophila

26. Chlamydophila pneumoniae/Epidemiology
It’s a human pathogen
important cause of bronchitis, pneumonia, and sinusitis
transmission: person-to-person by respiratory secretions
common: cases annually
>50 % of people have serologic evidence of past infections

27. Chlamydophila pneumoniae/Clinical Diseases
most infections are asymptomatic or mild
persistent cough and malaise
cannot be differentiated from other atypical pneumonias
Is there a role of C. pneumoniae in the pathogenesis of atherosclerosis ?

28. Chlamydophila pneumoniae/Laboratory diagnosis
NA techniques
serology!!

29. Chlamydophila psittaci
The cause of psittacosis
“parrot fever” (psittakos is “parrot” in Greek)
The natural reservoir is any species of bird
Ornithosis, ornithos= bird

30. Chlamydophila psittaci/epidemiology
Infection in:
Humans, sheep, cows, goats
In: blood, tissues, feces and feathers of infected birds
Infection occurs by means of the respiratory tract (RES of the liver & spleen blood)

31. Chlamydophila psittaci/epidemiology
Transmission:
Inhalation of dried bird excrement, urine or respiratory secretions
“Most infections result from exposure to psittacine birds” (parrots (a tropical bird with a curved beak, which is often kept as a pet and can be trained to copy the human voice), parakeetsa small parrot with a long tail, macaws(a brightly coloured bird of the parrot family found in Central and South America), cockatiels)

32. Chlamydophila psittaci/epidemiology
Person-to-person transmission is rare
Veterinarians,
Zookeepers
Pet shop workers
Employee of poultry-processing plants
increased risk”

33. Chlamydophila psittaci/clinical disease
Incubation: days
Pulmonary signs
CNS involvement is common (death may occur)
GIT symptoms
...

34. Chlamydophila psittaci/Laboratory diagnosis
Based on serologic findings: antibody detection
Species specific MIF test

35. Chlamydophila psittaci/Prevention and control
Psittacosis can only be prevented through the control of infections in domestic and imported pet birds
No vaccine!