Chapter 21. Actinomycetes

Transcription

1 Chapter 21 Actinomycetes

2 Brief Introduction 1. filamentous prokaryotic microbes, form filament 2. structure and components similar to bacteria 3. sensitive to antibiotics 4. actinomyces colonies -- sulphur granule

3 Actinomyces Nocardia G+, non-acid fast G+, weak acid fast anaerobe aerobe normal flora in the soil endogenous infection exogenous infection chronic pyogenic inflammation pyogenic infection pelvic actinomycosis abdominal actinomycosis thoracic actinomycosis dental caries and peridentitis pneumonia mycetoma

4 Pathogenicity 1. Actinomyces -- A. israelii pelvic actinomycosis abdomen actinomycosis thoracic actinomycosis 2. Nocardia -- N. asteroides pneumonia

5 Microbiologic Examination Specimen (pus, tissues) sulfur granule

6 Prevention & Treatment penicillin sulfadiazine surgical excision

7 Chapter 22 Spirochete

8 Brief Introduction 1. prokaryotic microbe 2. long, thin, flexible, spiral rod, active motile through the contraction of axial filaments 3. situs is between bacterium and protozoa 4. general structure envelope/outer sheath, endoflagellum (axial filament), protoplast 5. sensitive to antibiotics (penicillin etc.)

9 Brief Introduction 6. classification: pathogenic organism Leptospira -- L.interrogans -- Leptospirosis Treponema -- T. pallidium -- Syphilis Borrelia -- B.burgdorferi -- Lyme Disease B.recurrentis -- Relapsing Fever

10 Leptospira

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12 Treponema pallidium

13 Borrelia burgdorferi

14 Borrelia recurrentis

15 Section 1. Leptospira I Biological Properties 1. Morphology 1) a tightly coiled spiral, long (6~12 µm) 2) hooked in one or both ends 3) active motility -- rhythmic contraction of axial filaments 4) silver-stain

16 I Biological Properties 2. culture 1) grow in artificial medium 2) aerobic growth 3) optimum temperature 28~30 4) slow growth

17 II Transmission & Epidemiology Leptospirosis -- classical zoonose Human infection results usually from ingestion of water and food contaminated with leptospirae.

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19 III Pathogenicity & Immunity 1. pathogenic substance 1) invasiveness 2) endotoxin-like substance (ELS) -- cause fever, inflammation, necrosis 3) hemolysin -- lysis RBC 4) cytotoxicity factor

20 III Pathogenicity & Immunity 2. disease infected animal discharge urine water/soil pass through human skin or mucous membrane circulate in blood stream and multiply in various organs leptospirosis (zoonose)

21 III Pathogenicity & Immunity first fever, hypodynamia, headache, muscular pain

22 III Pathogenicity & Immunity second liver damage -- jaundice impaired kidney function -- uremia dysfunction of pulmonary-- hemorrhage

23 III Pathogenicity & Immunity clinical type pulmonary -- hemorrhage type influenza -- typhoid type jaundice -- hemorrhage type renal -- failure type

24 III Pathogenicity & Immunity 3. Immunity humoral immunity, specific Ab can be examined after two weeks

25 IV Prevention & Treatment 1. rodent control 2. vaccine 3. penicillin (in large enough doses early in the infection)

26 Section 2. Treponema pallidium T. pallidum is the causative agent of human syphilis, a common sexually transmitted disease found world-wide.

27 I Biological Properties 1. fine, long, tightly coiled organism 2. silver-stain: brown 3. difficult to culture 4. sensitive to temperature (50 5min); dry (1~2hr); penicillin, tetracycline

28 II Pathogenicity & Immunity 1. pathogenic substance strong invasiveness, no endotoxin & no exotoxin

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30 II Pathogenicity & Immunity 2. disease Natural infection with T. pallidum is limited to the human host.

31 II Pathogenicity & Immunity (1) sexual syphilis -- It is generally transmitted by genital/genital contact. (2) congenital syphilis -- pregnant syphilitic women transmit organism to fetus through the placenta

32 acquired syphilis -- sexual contact *primary syphilis (10-60 days)--spirochetes multiply at the site of inoculation, nontender ulcer/chancre, heals spontaneously but spirochetes spread widely in tissues *secondary syphilis (2-10 weeks later) maculopapular rash on palm and sole, these lesion are highly infectious, heal spontaneously *tertiary syphilis (several years later)--central nervous system, cardiovascular lesion, bone lesion

33 secondary syphilis

34 secondary syphilis

35 secondary syphilis

36 secondary syphilis

37 tertiary syphilis

38 tertiary syphilis

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41 III Prevention & Treatment No vaccine exist, antibiotic therapy (usually penicillin G) is usually highly effective.

42 Chapter 23 Mycoplasma

43 Brief Introduction 1. the smallest free-living prokaryotic organism that can grow in artificial media 2. non-cell wall, pleomorphism 3. distributed extensively -- human, animals, plants, insects and sewage

44 I Biological Properties 1. size: 0.2~0.3um, pass through 0.45 filters. 2. polymorphic: coccoid, coccobacillary, ring, dumb-bell forms, short and long, branching non-cell wall (the essential differences between mycoplasma and L-type bacterium) 3. Giemsa stain: purple

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46 I Biological Properties 4. structure three layer of membrane: two protein membrane, one lipid membrane terminal structure: some mycoplasma have specialized structures at one or both ends by which they adhere to respiratory or genital tract mucous surfaces 5. propagation pattern: binary fission 6. both DNA and RNA

47 I Biological Properties 7. culture (1) facultative anaerobic (2) high nutrient: serum, yolk, cholesterol (3) slowly growth: 1~3 weeks, fried-egg colony mycoplasma--600 um ureaplasma--10~30 um

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49 I Biological Properties 8. classification Mycoplasmataceae mycoplasma ureaplasma

50 I Biological Properties 9. resistant (1) weak (2) resistant to penicillin, cephalosporin (3) sensitive to streptomycin, erythromycin, tetracycline

51 I Biological Properties 10. difference between mycoplasma and bacterial L-form

52 Mycoplasma and L-Form Bacteria MYCOPLASMA L-FORM BACTERIA genetic phenotypic variation, sometimes can revert cholesterol for their cell membrane stable in ordinary medium grow slowly, colony small (diameter mm) no cholesterol for their cell membrane need hyperosmotic solution colony larger (diameter mm)

53 II Pathogenicity 1.Mycoplasma pneumoniae [MP] 2.Ureaplasma urealyticum [UU]

54 1. Mycoplasma pneumoniae [MP] (1) terminal structure adherence epithelial cell, RBC damage cell membrane release products (H 2 O 2, toxic enzyme) injure cell (RBC, tracheal epithelial cell)

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56 (2) primary atypical pneumonia [PAP] (a) PAP often in children and adolescent (b) spread by respiratory, incubation 2~3 weeks; interstitial pneumonia (c) headache, cough, fever, malaise; (d) tetracycline -- adolescent, erythromycin -- children, pregnant women

57 Antibody titers in different age groups. Anti-MP Abs indicate pneumonia caused by this organism is highest in the 5-15 year age group

58 2. Ureaplasma urealyticum [UU] (1) genitourinary tract infection--std (2) nongonococcal urethritis (NGU) (3) vaginitis, cervicitis premature birth, abortion, sterility (4) erythromycin, tetracycline, doxycycline

59 Microorganisms causing Urethritis 20% 5% 5% 30% 40% Neisseria gonorrhoear Chlamydia trachomatis Ureaplasma urealyticum Unknown

60 Chapter 24 Rickettsia

61 Howard Taylor Ricketts (1871~1910)

62 I Biological Properties 1. small G - bacilli, cell wall 2. obligate intracellular parasites 3. binary fission 4. have both DNA and RNA 5. Culture: susceptible animal (guinea pig) yolk sac of chick embryo cell culture

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64 I Biological Properties 6. Rickettsiae normally enter the body (mammalian reservoir) through the bite or feces of an infected arthropod vector -- zoonotic organism Arthropod vector : louse, flea, tick, mite 7. resistance: weak, sensitive to antibiotic

65 I Biological Properties 8. Weil-Felix Reaction detect anti-rickettsial antibodies in a patients serum by non-specifically agglutination of the proteus organisms. (Rickettsia possess Ag that cross-react with O Ag of the X strains of proteus)

66 I Biological Properties 9. classification typhus group (R. prowazekii)-- epidemic typhus (R. typhi or R. mooseri)-- endemic typhus

67 II Pathogenicity Rickettsiae diseases are transmitted from animal to animal by the bite of arthropod vectors.

68 Epidemic typhus (R.prowazekii) (1) louse ; substandard living condition, poor sanitation; overwhelming bacterimia (2) transmitted way: from person to person by the human louse (3) fever (temperature rises to 40 ); (4) treatment: sanitation, eradication of human lice; tetracycline

69 Epidemic typhus (R.prowazekii) Rickettsiae arthropod vector, bite human skin,wound multiply in epithelial cells of small blood vessule damaged cells rickettsemia many organs disease Symptom: prolonged high fever, headache, maculopapular rash

70 Epidemic typhus (R.prowazekii) transmitted way human louse human human human louse

71 Endemic typhus (R. mooseri) transmitted way rat human louse rat flea rat louse rat flea Human human rat human louse fever, headache, maculopapular rash

72 Chapter 25 Chlamydiae

73 I Biological Properties 1. prokaryotic microbes, smaller than common bacteria, 2. G -, the cell wall similar to G -, 3. contain DNA and RNA, 4. obligate intracellular parasite, 5. unique life-cycle, binary fission

74 I Biological Properties elementary body (EB) -- very little (0.3μm in diameter), dense, extracellular, infectious form initial body / reticulate body (RB) -- larger (1μm in diameter), less dense, intracellular, non-infectious, replication form

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77 Elementary body phagocytic engulfment replication form initial body inclusion body lots of elementary body release from cell,infect another cell, 40hrs inclusion body -- consisted of replicating initial body and descendant elementary body in the infected cell

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80 6. classification 1.Chlamydia trachomatis (1) biovar trachoma (2) biovar lymphogranuloma Venereun (LGV) (3) biovar mouse 2. Chlamydia pneumoniae 3. Chlamydia psittaci

81 II Pathogenicity 1.pathogenic factor (1) endotoxin-like substance (2) main outer membrane protein (MOMP) prevent the fusion of phagosome and lysosome

82 2. Disease (1) biovar trachoma 1 trachoma 2 inclusion conjunctivitis 3 genitourinary tract infection -- STD nongonococcal urethritis (NGU) (2) biovar lymphogranuloma Venereun-- Lymphogranuloma Venereun (LGV)

83 Tang Fei Fan,1955

84 III Prevention & Treatment

85 C. pneumonia person-to-person spread by inhalation of infectious aerosols, no animal reservoir; atypical pneumonia