The application of laser microdissection in molecular detection and identification of aspergillus fumigatus from murine model of acute invasive pulmonary aspergillosis

Disseminated Cryptococcosis Presenting as Cellulitis Diagnosed by Laser Capture Microdissection: A Case Report and Literature Review

Disseminated cryptococcosis primarily affects immunosuppressed patients and has a poor outcome if diagnosis and treatment are delayed. Skin lesions are rarely manifest causing misdiagnosis. We present a case of cryptococcal cellulitis with severe pain in a kidney transplant recipient on long-term immunosuppressive therapy. Multiple organs were involved, and there was cutaneous dissemination of the lesions. Histopathology revealed abundant yeast-like cells with wide capsular halos in subcutaneous tissue, suggesting Cryptococcus spp. infection. Laser capture microdissection (LCM)-PCR on skin biopsies confirmed Cryptococcus neoformans var. grubii. A literature review of 17 cases of disseminated cryptococcosis with cutaneous cellulitis or panniculitis in HIV-negative individuals found that over half the patients (52.9%, 9/17) had a history of glucocorticoid therapy, and that the most common site was the legs (76.5%, 13/17). C. neoformans was the main pathogenic species, accounting for 88.2% (15/17) of cases. Fungal cellulitis should be included in the differential diagnosis of cellulitis that fails to respond to antimicrobial therapy in HIV-negative immunosuppressed individuals. Non-culture-based molecular techniques aid in rapid pathogen identification in histologically positive, unculturable specimens.

Application of laser capture microdissection and polymerase chain reaction in the diagnosis of Trichoderma longibrachiatum infection: a promising diagnostic tool for 'fungal contaminants' infection

Although Trichoderma species are usually considered to be culture contaminants, an increasing number of case reports have demonstrated their pathogenicity. Current diagnostic tools, including fungal culture, radiology, histopathology, and direct microscopy examination, are often unable to differentiate the pathogenicity of 'fungal contaminants' such as Trichoderma species in patients. Accurate diagnostic tools for 'fungal contaminants' infection have become the urgent needs. To that end, we applicated laser capture microdissection (LCM) and polymerase chain reaction (PCR) to confirm T. longibrachiatum infection for the first time. A 57-year-old man presented with a cough and hemoptysis lasting for more than 40 days. Computed tomography scan revealed a mass at the left hilum. In addition to pulmonary spindle cell carcinoma, fungal hyphae were also detected in histopathological examination. The cultured fungus was identified as T. longibrachiatum using molecular procedures. The results from DNA sequencing of DNA obtained by LCM revealed the identical result. Antifungal susceptibility testing revealed resistance to itraconazole, fluconazole and flucytosine. The patient was managed with oral voriconazole for 4 months. No relapse of Trichoderma infection was observed at a year follow-up visit. Although there are potential disadvantages, LCM-based molecular biology technology is a promising diagnostic tool for 'fungal contaminants' infection.