بسم الله الرحمن الرحيم

1. 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 • 14 Serovars: A-K • 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 • 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 • 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 psittaciDirect FA stained mouse brain impression smear

18. Treatment and Control • Chemotherapy • 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 • Avoidance of contact with sources of infection (specially pregnant women) • Sheep, milking and shearing • Control of importation of psittacine birds • Hygiene