ACTINOMYCOSIS & Subcutaneous Mycoses Flashcards
A group of filamentous branching gram-positive organisms ?
Actinomycetes
Nocardia Streptomyces
Actinomadura?
Aerobic actinomycetes:
Actinomyces ?
Anaerobic actinomycetes:
It is a chronic suppurative abscess leading to scarring & disfigurement
?
Actinomycosis
Actinomyces israelii (anaerobic actinomycetes) Normal flora of the mouth, GIT & vagina
Causative organism of?
Actinomycosis
Pathogenesis of infection:
endogenous
-initiated by local trauma →
introduction of the organisms into the underlying tissues
“anaerobic conditions”→ the organism invades the tissues
→ grow in microcolonies
The lesion begins as a hard red non-tender swelling that
develops slowly & becomes filled with pus, and ruptures to
the surface discharging pus (inflammatory sinuses) Spreads laterally draining pus through sinuses. The pus contains small firm yellow granules (sulphur granules)
?
Actinomycosis
sulphur granules ? typical diagnostic sign”
Of?
Actinomycosis
Actinomycosis
Clinical forms: ? And they affect ? Associated with?
- Cervicofacial infection “lumpy jaw” 50%
•Affects face, neck & mandible
•Usually associated with tooth extraction/ bad oral hygeine
/trauma to the mouth or jaw. 2- Abdominal:
• Affects caecum, appendix
• Associated with trauma/ surgery 3- Pelvic: usually associated with intrauterine devices “IUD”.
Microscopic examination:
Filamentous branching Gram-positive bacilli
?
Actinomycosis
Actinomycosis
Laboratory diagnosis: ?
The “ sulphur granules are crushed and subjected to:
1. Microscopic examination:
Filamentous branching Gram-positive bacilli
2. Culture
“molar tooth” • Anaerobic conditions appearance on agar.
• at least 2 weeks.
Treatment of Actinomycosis
Surgical drainage of pus + Antibiotics (4-6 weeks)
Fungal infections of the dermis, subcutaneous tissue, and
bone?
Subcutaneous Mycoses
Subcutaneous Mycoses
Causative organisms
reside in the soil OR
decaying and living vegetation
Subcutaneous Mycoses
Almost always acquired through
acquired through traumatic lacerations of
the skin / puncture wounds
→ introduction of the organism into the tissues
Occupational hazard in farmers, gardeners, mine workers
?
Subcutaneous Mycoses
Confined to tropical & subtropical regions Difficult to treat & surgical intervention is frequently
employed.
>?
Subcutaneous Mycoses
Examples of Subcutaneous Mycoses
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Sporotrichosis
2. Mycetoma “ Madura Foot”
Causative organism:
“Sporothrix schenckii” ?
Sporotrichosis
dimorphic fungus
Farmers, gardeners, florists, miners
(Has a yeast form
“cigar shaped yeast” in infected tissue and a filamentous form in the environment/ lab culture media incubated at 30⁰C
Broad geographical distribution
?
Subcutaneous Mycoses 1. Sporotrichosis
Found in soil, on vegetation ; rose. ?
Sporotrichosis
occupational disease of
Farmers, gardeners, florists, miners
Sporotrichosis
Pathogenesis s:
Acquired through trauma (e.g., a thorn)
Characterized by a slowly developing small painless
nodule at the puncture site (develop 1-12 weeks after
the trauma)→ progress to a granulomatous ulcer
(local multiplication of the organism producing both pyogenic & granulomatous inflammation)
Mostly self-limited, but may persist in a chronic
form
May disseminate to distant sites in AIDS patients
Sporotrichosis
May produce secondary lesions along the draining
lymphatics
?
Sporotrichosis
Diagnosis of Sporotrichosis?
Specimen: Pus & tissue biopsy Microscopic examination: usually negative Culture
Treatment of Sporotrichosis?
Antifungal
neglected tropical disease
Mycetoma “ Madura foot”
It is an infection associated with trauma usually to the foot
causing inoculation of causative soil micro-organisms
typically in “barefooted” individuals
Mycetoma “ Madura foot”
Mycetoma “ Madura foot”
Distributed worldwide but are “endemic” in tropical and subtropical areas in the ?
Mycetoma belt
Pathogenesis:
Typically associated with “ trauma” that inoculate the
causative organism which are found in soil /on vegetation, usually on thorns/wood splinters → localized destructive subcutaneous chronic granulomatous disease of skin, subcutaneous
tissue, fascia and bones → massive deformity & disability.
Can be fatal
(2ry bacterial infection & septicemia)
Mycetoma
- Mycetoma
Clinical presentation:
?
t usually affects the foot & rarely the hands & buttocks A triad of
Painless subcutaneous mass
Multiple draining sinuses
Discharge containing
“ grains”.
(compacted microcolonies of the organism)
The color of the grains depends on the causative
organism
Many patients present late with advanced infection
where amputation may be the only available
treatment.
Causative organism: “Soil organisms” 1. Actimycetes (Actimycotic mycetoma) 60% 2. True Fungi (Eumycotic mycetoma?
Mycetoma
Actimycetes ?
Actimycotic mycetoma
- True Fungi?
Eumycotic mycetoma
Actinomycotic mycetoma usually respond to ?
antibiotics
fungal mycetoma needs ?
surgical treatment up to amputation
Fungal:
e.g. Madurella mycetomatis Madurella grisea Allescheria boydii
Eumycotic Mycetoma
Mainly black & white
Color of grains
Eumycotic Mycetoma
Bacterial: e.g. Actinomadura madurae Nocardia brasiliensis Streptomyces
somaliensis
Actinomycotic Mycetoma
May be pink / red /white culprit of grains
Actinomycotic Mycetoma
Mycetoma
Diagnosis:
?
- Specimen:
Surgical tissue biopsy & Sinuses discharge. - Microscopic examination 3. Culture
-Thick fungal hyphae spores?
-Thin fragmented filaments of actinomycetes?
Microscopic Examination
- Eumycotic Mycetoma
- Actinomycotic mycetoma
Culture
On SDA? blood agar,
aerobic & anaerobic
Eumycotic /Actinomycotic
Mycetoma
Chemotherapy
No / poor response
Needs surgical treatment & may be amputation.
Effective
Eumycotic /Actinomycotic
Mycetoma
