Dr. Nancy Cornish Director of Microbiology Methodist and Children’s Hospitals CUTANEOUS INFECTIONS

S. schenckii

LAB DX: Ulcers TISSUE IS BEST Ulcers –Poor correlation between organisms isolated from superficial ulcer swabs and those isolated from deep wound tissue –BEST specimens are obtained by tissue curettage of base of ulcer after removal of overlaying debris or direct surgical biopsy of deep tissue

LAB Diagnosis: Nodules TISSUE IS BEST Biopsy of subcutaneous nodular tissue after decontamination of skin surface –portion for culture –portion for Histology

Sinus Tracts A communication between an infected deep tissue or abscess, through subcutaneous tissue to open onto the skin surface.

Sinus Tracts CAUSES: –Osteomyelitis –Pyomyositis –Lymphadenitis –Intra-abdominal abscess

Sinus Tracts EXAMPLES: –Staph aureus - deep abscess, carbuncles –Mycobacterium tuberculosis - cervical lymphadenitis (scrofula) –Actinomyces israelii - Actinomycosis “lumpy jaw” –Nocardia spp. - mycetoma (madura foot)

Actinomycetes sp. gram positive rods