Veterinary Microbiology ( ) Systemic mycoses 1 Dimorphic fungi รศ.สพ.ญ.อรวรรณ นว ภาพ ภาคว ชาจ ลช วว ทยา คณะส ตวแพทยศาสตร จ ฬาลงกรณ มหาว ทยาล ย

Transcription

1 Veterinary Microbiology ( ) Systemic mycoses 1 Dimorphic fungi รศ.สพ.ญ.อรวรรณ นว ภาพ ภาคว ชาจ ลช วว ทยา คณะส ตวแพทยศาสตร จ ฬาลงกรณ มหาว ทยาล ย 2547

2 Systemic mycoses แบ งเป น 3 group 1. เก ดจาก true pathogenic fungi ซ งส วนใหญ จะเป น Dimorphic fungi ได แก Bastomyces, Coccidioides, Paracoccidioides, Histoplasma etc. 2. เก ดจาก Yeast-like fungi ได แก Candida, Cryptococcus, Malassezia, Trichosporon, Geotrichum. 3. เก ดจาก Opportunistic pathogenic fungi ได แก Aspergillus, Mucor, Rhizopus, Penicillium etc.

3 Systemic mycoses caused by Dimorphic fungi

4

5 Yeast and yeast like fungi

6 (Dimorphic fungi) (Yeast and yeast like fungi)

7

8 Dimorphic fungi Blastomycosis (North American Blastomycosis) Agent : Blastomyces dermatitidis (perfect stage as Ajellomyces dermatitidis) Clinical characteristic : mild respiratory infections - ---> Bronchopnemonia or lobar pneumonia ---> chronic or disseminate ---> skin lesion, other organs (percutaneous infection is rare) Geography : Central America, Central eastern sea coast state, Africa Therapy : Amphotericin B, Hydroxystilbamidine

9 Blastomycosis

10 37 o c : thick walled yeast cells (8-10 mm in diameter) daughter cells bud on a broad base

11 Blastomyces dermatitidis (Yeast phase)

12

13

14 25 o c : oval or pear shaped conidia (2-10 mm in diameter) ore born either on conidiophore or directly on the septate hyphae

15 Blastomyces dermatitidis (Mycelial phase)

16

17 Mycelial phase Yeast phase

18 Fig.1 The mould and yeast forms of Blastomyces dermatitidis.

19 Blastomyces dermatitidis Usual habitat : acid soil rich in organic matter Clinical infection : dog and human, other species (cat uncommon) Geography : North America, Africa, Middle east, India

20 Canine Blastomycosis Infection by inhalation Pulmonary Blastomycosis Symptom : chronic debilitating condition, coughing, exercise intolerance, dyspnoea, lymph node enlargement Dissemination to skin, eye, bone, central nervous system, urogenital tract in male dog (primary cutaneous Blastomycosis is uncommon)

21 Severe lesion : granulomatous or pyogranulomatous (yeast cells are numerous in this lesion) Treatment : Amphotericin B + Ketoconazole Hydroxystilbamidine

22

23 Paracoccidioidomycosis (South American Blastomycosis) Agent : Paracoccidioides brasiliensis Clinical characteristic : Pulmonary infection (lung involvement) ---> hematogenous and lymphatic route ---> mucous membrane and mucocutaneous junction ---> papules develop into vessels ---> ulcer, granulomatous ---> draining sinus ---> lymphatic system ---> spleen, intestine etc. (percutaneous is rare)

24 Geography : South America, Brazil Predisposing factors : malnutrition, exposure to soil or plant Therapy : Self limiting, Amphoteracin B

25 (intercalary) Single or multiple budding cell

26 Paracoccidioides brasiliensis Mycelial phase Yeast phase

27 Paracoccidioides brasiliensis Mycelial phase

28 Paracoccidioides brasiliensis Yeast phase

29

30 Coccidioidomycosis Agent : Coccidioides immitis Clinical characteristic : respiratory infection ---> inhalation of arthroconidia (from mold form of fungus in soil) ---> pulmonary lesion (tuberculosis like lesion), acute pneumonia (skin reaction may occur) Usual habitat : soil of arid or semiarid, dust (heavily contaminated with arthroconidia)

31 Geography : South Western America, Mexico, Central and South America (human, dog, horse) Predisposing factors : malnutrition, expose to soil (dust) or plant (contaminated arthroconidia), inhalation of mass of spores

32

33

34 Colony : 25 o -30 o c (mycelial form), colony are shiny, moist and grey becoming white and cottony Microscopic : thick walled, barrel shaped arthroconidia (fragmentation)

35 Canine Coccidioidomycosis Dog with mild pulmonary coccidioidomycosis, cough, fever, anorexia, may recover spontaneously Disseminated form pulmonary lesion ---> immunosuppression ---> osteomyelitis, lameness, bone destruction Treatment : Ketoconazole therapy for at least 6 months

36 Equine Coccidioidomycosis Non specific, intermittent fever, abdominal pain, loss of weigh, musculoskeletal involvement, musculoskeletal pain, osteomyelitis

37 Coccidioides immitis

38 Coccidioides immitis Spherule with endospores in lung tissue

39 Coccidioides immitis Spherule with endospores in lung tissue

40 Fig.3 The mould form and spherule of Coccidioides immitis.

41

42 Histoplasmosis, Darling s disease, Reticuloendotheliosis Agent : Histoplasma capsulatum (found in soil, bird or bat feces) Histoplasma farciminosum (soil saprophyte) Clinical characteristic : mild respiratory infection ---> lung (calcification lesion in lung) ---> lymph node enlargement ---> reticuloendothelial cell (leukemia, lymphoma) ---> many organs and tissues (percutaneous is rare)

43 Geography : North America, Central America, Africa Predisposing factors : inhalation of mass of spores (infected bat caves, chicken crop, staring nest)

44

45

46

47

48

49

50

51

52

53

54 Histoplasma capsulatum Mycelial phase

55 Histoplasma capsulatum Yeast phase

56 Histoplasma capsulatum Mycelial phase Yeast phase

57 Histoplasma capsulatum

58 Histoplasma capsulatum

59 Histoplasma capsulatum

60 Fig.2 The mould and yeast forms of Histoplasma capsulatum.

61 Canine and Feline Histoplasmosis Agent : Histoplasma capsulatum Clinical characteristic : asymptom at first ---> inhalation---> pulmonary alveolar macrophage (microconidia, yeast form), pulmonary lesion, dyspnoea depression, fever, loss of weigh ---> granulomatous lesion in lung of dog and cat (in dog may occur intestinal lesion but not in cat) ---> chronic cough, diarrhea, emalciation, skin ulcerative, skin nodule, lymphadenitis, eye lesion, lameness and neurological dysfunction Treatment : Amphoteracin B, ketoconazole

62

63 Epizootic lymphangitis Agent : Histoplasma farciminosum (contagious disease of equine) Clinical characteristic : skin abrasion on the limbs, ocular and pulmonary involvement, lymphocutaneous lesion (lympoidinopathy in any organs, occur yeast cell of Histoplasma farciminosum in macrophage) Treatment : excision of skin, sodium iodide therapy

64 Sporotrichosis Agent : Sporothrix (Sporotrichum) schenckii Clinical characteristic : chronic cutaneous or lymphocutaneous lesion (generalized are rare) Sporadic cases in horse, cat, dog, cattle, goat, pig, human

65 Sporothrix (Sporotrichum) schenckii Mycelial phase

66 Sporothrix (Sporotrichum) schenckii Yeast phase

67 Fig.4 The mould and yeast forms of Sporothrix schenckii.

68

69 Equine Sporotrichosis Agent : Sporotrix schenkii Clinical characteristic : lymphocutaneous in horse skin abrasion on the lower limb superficial lymnphatic vessel of nodule ulceration discharge (yellow exudate) subcutaneous edema cause by lymphatic obstruction Treatment : - inorganic iodide - excision of skin lesion

70 Feline Sporotrichosis Agent : Sporotrix schenkii Clinical characteristic : nodular skin lesion on limbs extremities, head, tail lymphadenitis nodule ulcerate and disease seropurulent exudate ulceration of muscle, bone to another animals by grooming to human by handle infected animals Treatment : - sodium iodide mix in feed, continue 30 days after recover - ketoconazole + sodium iodide

71 Canine Sporotrichosis Agent : Sporotrix schenkii Clinical characteristic : ulceration and crusted, alopecia, cutaneous lesion at head, trunk of dog lymphocutaneous infection (disseminated form is rare) Treatment : - sodium iodide mix in feed, continue 30 days after recover - ketoconazole + sodium iodide

72 Dimorphic fungi and disease production

73 Table 1 Dimorphic fungi which are associated with disease in animals and humans.

74