1. GENUS: CHLAMYDIA Prof. Khalifa SifawGhenghesh
بسم الله الرحمن الرحيم
GENUS: CHLAMYDIA
Prof. Khalifa SifawGhenghesh

2. Small Gram-negative bacteria (Stain poorly with Gram’s stain)
Like Bacteria
Have both DNA and RNA, Ribosomes, a Cell wall, and Divide by Binary fission
Like Viruses
Obligate intracellular parasites
Differ from Bacteria
Have no peptidoglycan in their cell wall
Can not produce their own ATP
Require to use host ATP (Energy parasite)

3. Chlamydia species C. trachomatis 3 biovars
Those causing trachoma and inclusion conjunctivitis (TRIC)
Those causing lymphogranuloma venereum (LGV)
The one causing mouse pneumonitis (MoPn)
C. psittaci > Infect both mammals and birds
C. pneumoniae > both humans and animals
C. pecorum > Some infect mammals

4. Trachoma biovars LGV biovars 14 Serovars: A-K 3 Serovars: L1, L2, L3
Serovars A, Ba, B, C
Classic trachoma
Serovars D-K
Inclusion conjunctivitis and Genital infections
LGV biovars
3 Serovars: L1, L2, L3

5. Can be stained with Giemsa stain Elementary body (EB)
Extracellular, infectious metabolically inert form of chlamydiae
Reticulate body (RB)
Intracellular, non-infectious, metabolically active particle

7. Infection to Humans Ocular infection
Trachoma > in countries where sanitation and hygiene standards are poor
Spread by eye seeking flies, or fingers, from one patient to another
Blindness
“Trachoma belt” > North Africa to South-East Asia
Adult inclusion conjunctivitis (paratrachoma)
Acute stage >> follicular conjunctivitis
Self-limited

8. Chlamydial ophthalmia neonatrum (inclusion blennorrhoea)
5-21 days after birth
If not treated > after 1 year > secondary bacterial infection > ocular damage and even blindness
Source:
infected genital tract of the mother

9. Genital infection
C. trachomatis is the Commonest cause of non-gonococcal urethritis in males (30%)
LGV
In both males and females in tropics and subtropics

10. In females Mucopurulent cervicitis and urethritis
Vaginitis and vaginal discharge
Asymptomatic females if not treated
Ascending infection >> Pelvic inflammatory disease (endometritis or salpingitis or both)
Tubal damage >> ectopic pregnancy and infertility

11. Infection in pregnancy
C. psittaci
Miscarriage or intra-uterine death
Patients had contact with sheep
C. trachomatis
Isolated from abortion products

12. Respiratory infection
C. pneumoniae
3rd or 4th cause of pneumonia
Pharyngitis, bronchitis, otitis and sinusitis
C. psittaci
Psittacosis in humans from avian strains
Disease ranges from an influenza-like illness, to severe illness with typhoidal state ad pneumonia.

13. C. trachomatis
Pneumonitis in neonates (infection acquired from the mother)

14. Laboratory Diagnosis Cultivation Antigen detection
MacCoy cells treated with cycloheximide
Organism detected by staining for inclusions or EBs
Detects only living cells
Antigen detection
Using probes for DNA or mRNA that identify the infected cells
PCR
Amplification of parts of the genome

15. Chlamydia trachomatis from a urethral scrape

16. Serology Micro-immunofluorescence test Complement fixation test
Using Ags from all chlamydial strains to detect species-specific and serovar-specific Ab
Complement fixation test
Detecting Ab in serum directed against group Ag

17. Chlamydia psittaci Direct FA stained mouse brain impression smear

18. Treatment and Control Chemotherapy Contact tracing
Tetracycline in adults and Erythromycin in babies
For 3 weeks
Azithromycin
Single dose
Contact tracing
Partners of index cases (even if clinically normal)
Neonatal infection
Both parents should be treated

19. Animal contact Hygiene
Avoidance of contact with sources of infection (specially pregnant women)
Sheep, milking and shearing
Control of importation of psittacine birds
Hygiene