1. Diagnostic microbiology lecture: 17 CHLAMYDIA Abed ElKader Elottol MSc. Microbiology 2010 1Abed ElKader ElOttol

2. General Characteristics Obligate intracellular bacteria. Have ribosomes like bacteria. Are metabolically deficient. Morphology Small rounded organism. Multiply by binary fission. Cell wall consists of inner & outer membranes but differ from that of Gram negative bacteria by absence of peptidoglycan. 2Abed ElKader ElOttol

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4. Important Species C. psittaci C. pneumoniae C. trachomatis Cultural Characters Grow in: Yolk sac of chicken embryo Tissue culture (McCoy cells) PATHOGENESIS Infect epithelial cells of mucous membranes & lungs Virulence is due to: Resistance to phagocytic killing by lysosomal enzymes Heat-labile toxin Competition with host cell for nutrients Host’s immune response may account for inflammation & tissue destruction. 4Abed ElKader ElOttol

5. C. trachomatis inclusion bodies (brown) in a McCoy cell culture.

6. CHLAMYDIA PSITTACI A zoonotic respiratory disease. Natural habitat : birds Transmitted through inhalation of : Respiratory secretions & dust from faeces of infected birds Common in poultry workers Disease : Pneumonia (Psittacosis) Diagnosis Isolation of organism from sputum by tissue culture Complement fixation test to detect specific Abs Treatment Tetracycline in adults Erythromycin in babies 6Abed ElKader ElOttol

7. CHLAMYDIA PNEUMONIAE Also known as TWAR (TW – Taiwan & AR – acute respiratory) Cause atypical pneumonia like Mycoplasma pneumoniae Treatment Tetracycline in adults Erythromycin in babies 7Abed ElKader ElOttol

8. CHLAMYDIA TRACHOAMATIS 15 serotypes (A-L) C. trachomatis includes three human biovars: trachoma (serovars A, B, Ba or C), urethritis (serovars D-K), and lymphogranuloma venereum (LGV, serovars L1, 2 and 3). Transmission: Through close personal contact like: Sexual Passage through birth canal Finger to eye or fomite to eye (Trachoma) DISEASES 1. Trachoma Caused by serotypes A, B, Ba & C One of the leading causes of blindness in developing countries with dry & hot weather Chronic conjunctivitis : leads to scarring of eye lids and cornea 8Abed ElKader ElOttol

9. spread by direct contact with eye, nose, and throat secretions from affected individuals, or contact with fomites

10. 2. Genital Tract Infections (Serotypes D-K) Non-gonococcal urethritis in men A common cause of non-gonococcal urethritis Mucopurrulent urethral discharge May progress to epidydmitis & orchitis (testes inflamation) Cervicitis & Vaginitis Mucopurrulent vaginal discharge Pelvic Inflammatory Disease (PID) May lead to secondary infertility 10Abed ElKader ElOttol

11. 3. Neonatal Infections (Caused by serotypes D-K) Acquired from mother’s birth canal Inclusion Conjunctivitis Profuse mucopurrulent discharge 7-12 days after birth Pneumonia. 4. Lymphogranuloma Venereum (LGV) Caused by serotypes L1, L2 & L3 A STD with lesions on genitalia & LNs (buboes) 5. Reiter’s Disease An autoimmune disease caused by Abs formed against C. trachomatis which cross react with antigens on cells of urethra & joints(arthritis, redness of the eyes, and urinary tract signs). 11Abed ElKader ElOttol

12. LAB DIAGNOSIS Specimens from urethra, conjunctiva, sputum & cervix. Microscopy. Chlamydial “cytoplasmic inclusions” are detected by: Giemsa staining Fluorescent Ab staining PCR Cell Culture Sero-diagnosis TREATMENT Tetracycline in adults Erythromycin or Azithromycin in babies 12Abed ElKader ElOttol

13. Calymmatobacterium granulomatous Klebsiella granulomatis GRANULOMA INGUINALE 13Abed ElKader ElOttol

14. General characteristics Capsulated short Gram-negative rod A STD with higher incidence in homosexuals Clinical Features Initially papules appear on external genitalia which ulcerate and extend widely – ulcer formation Base of ulcer is “BEEFY”; spreads by contact so is known as “KISSING ulcers” Lymph Nodes may enlarge Treatment : Tetracycline 14Abed ElKader ElOttol The disease is commonly known as donovanosis Small, painless nodules appear after about 10–40 days of the contact with the bacteria. Later the nodules burst, creating open, fleshy سميك, oozing رشح lesions.

15. MYCOPLASMA An older name was Pleuropneumonia-Like Organisms PPLO 15Abed ElKader ElOttol

16. GENERAL CHARACTERISTICS The smallest free-living organism (0.3 μ diameter). Have no cell wall. Insensitive to penicillins & cephalosporins. Poorly stained by Gram-staining. Cytoplasmic membrane contains cholesterol. Slow growth on specialized artificial culture media (a week). Typical “fried-egg” appearance of colonies by a plate microscope 16Abed ElKader ElOttol

17. 17 Formulae Difco™ PPLO Agar Approximate Formula* Per Liter Beef Heart, Infusion from 50 g................................... 6.0 g Peptone................................................................... 10.0 g Sodium Chloride........................................................ 5.0 g Agar......................................................................... 14.0 g

18. MYCOPLASMA PNEUMONIAE MAIN DISEASE Primary atypical pneumonia Common in late summer and early autumn PATHOGENESIS & EPIDEMIOLOGY Droplet infection. Organism adhere to respiratory epithelium. Inhibit ciliary motion. Damage epithelium. Common in chidren & young adults Increased incidence in winter 18Abed ElKader ElOttol

19. CLINICAL FEATURES Sore throat, fever & headache. Cough with small amount of whitish non-purulent sputum. Some extrapulmonary symptoms. Opacities on chest X-Rays. IMMUNITY Incomplete: second episode can occur. 19Abed ElKader ElOttol

20. UREAPLASMA URELYTICUM 20Abed ElKader ElOttol

21. Differentiated from mycoplasma due to urease enzyme production Like mycoplasma produce “fried egg” colonies on specialized medium. Diseases Non-gonococcal, non-chlamydial urethritis in men. Post-partum fever in women. Transmitted by sexual contact. MYCOPLASMA & UREPLASMA LAB DIAGNOSIS Culture : “Fried egg” colonies on specialized medium Cold Agglutinin detection A titer of 1:128 or higher – indicates recent infection TREATMENT Tetracycline OR Spectinomycin 21Abed ElKader ElOttol

22. RICKETTSIA & COXIELLA 22Abed ElKader ElOttol

23. Rickettsiae – A genus of small, rod-shaped, round to pleomorphic microorganisms. – gram-negative – cultivable only in living tissues. – Transmitted by lice قمل and ticks قراد, they cause disease in humans and domestic animals but are also found in the cytoplasm of tissue cells of lice, fleas, ticks and mites سوس, which may act as reservoirs and vectors

25. Pathogenesis 1.Insect vectors for human transmission: arthropods such as fleas, ticks, mites عث, or lice 2.Rodents, humans, or arthropods: all can serve as reservoirs 3.Multiply in salivary glands of ticks & gut of lice/fleas 4.Site of Bite = Eschar (encrusted متقشر ulcer) → necrotic tissue:

26. Site of bite = point at which Rickettsia enters the body becomes blackened 1.Following bite, organisms taken into body by “phagocytosis process 2.Organisms multiply in both nucleus & cytoplasm of host cell.

27. Typhus Group Louse borne (epidemic) Typhus. –Etiological agent = Rickettsia prowazekii –Transmission: person-to-person by infected human body louse that excretes organisms in feces Introduction of pathogen form lice facilitated by scratching the louse bites –high fever, chills, rash possible –Duration of Disease: ~2 weeks; more severe in ederly –Complications: CNS dysfunction and myocarditis

29. Rock Mountain Spotted Fever Etiological agent = Rickettsia ricketsii Reservoir = rodents (mice, rats) Vector = Tick Bite Rickettsia in saliva of tick, transfer to humans after bite Human infection High fever & malaise, then rash – initially, but becomes petechial or hemorrhagic Rash starts on extremities, then rapid spread to entire body. Untreated cases – vascular disturbances with myocardial or renal failure possible

31. Coxiella Etiological agent = Coxiella burnetti Q fever Reservoir = cattle, sheep, rodents, ticks Vector = contaminated aerosol C. burnetti enters the body via mucous membranes, abrasions & GIT via consumption of milk for infected animals – Zoonosis becouse animal direclty transmits the organism to humans – high fever, cough, pneumonia, hepatitis – all self- limiting usually; rarely – endocarditis (scarring of hrt. valves) and scarring of liver – complicated by hepatitis, myocarditis, or encephalitis

33. Growth characteristics Grow only in eukaryotic cell like Tissue cultures OR embryonated eggs 33Abed ElKader ElOttol

34. RICKETTSIA & COXIELLA : LAB DIAGNOSIS Serology PCR Tissue culture Weil-Felix Reaction Antigens of several species of Rickettsiae cross-react with cell wall O antigen of Proteus OX-2, OX-19, OX-K. These Proteus antigens can be used in lab to detect presence of specific antibodies against certain Rickettsia in patients serum. Reaction negative in Q fever TREATMENT Tetracycline Chloramphenicol 34Abed ElKader ElOttol

35. End of Lecture 35Abed ElKader ElOttol