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

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)

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

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

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

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

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

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

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

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

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.

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

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

Chlamydia trachomatis from a urethral scrape

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

Chlamydia psittaci Direct FA stained mouse brain impression smear

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

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