Using a Madurella mycetomatis-specific PCR on grains obtained via non-invasive fine-needle aspirated material is more accurate than cytology.

BACKGROUND: Eumycetoma is a chronic subcutaneous inflammatory fungal infection most often caused by the fungus Madurella mycetomatis. Using a species-specific PCR on DNA directly isolated from grains is currently the most reliable method for species identification. However, so far, PCR has been performed on grains obtained through deep-seated surgical biopsies, which are invasive procedures. Grains can also be obtained via ultrasound-guided fine-needle aspiration (US-FNA). Here we determined the diagnostic performance of species-specific PCRs performed on samples obtained through US-FNA. METHODS: From 63 patients, US-FNA was performed to obtain eumycetoma grains; 34 patients also underwent a deep-seated biopsy. From the grains, DNA was isolated, and one pan-fungal and two M. mycetomatis-specific PCRs were performed. The sensitivity and specificity were determined. RESULTS: Of the 63 patients who underwent US-FNA, 78% (49/63) had evidence of eumycetoma based on cytology and 93.7% (59/63) based on species-specific PCRs. In the 34 patients for whom surgical biopsies were performed as well, 31 patients had a positive PCR for M. mycetomatis when DNA was isolated from the deep-seated biopsy, and 30 had a positive PCR when DNA was obtained from the US-FNA material. This resulted in a 96.8% sensitivity, and 100% specificity with 97.1% diagnostic accuracy for PCR performed on US-FNA. CONCLUSION: PCR performed on the US-FNA material has a similar sensitivity and specificity as PCR performed on deep-seated biopsies. Therefore, when using PCR, a deep-seated biopsy may not be necessary to obtain grains.

Staphylococcus aureus causing primary foot botryomycosis mimicking actinomycetoma: a case report from Sudan.

OBJECTIVES: Botryomycosis is a rare chronic granulomatous inflammatory disease of bacterial origin. Two forms of the disease exist; the cutaneous and the visceral form. The subcutaneous form mimics actinomycetoma clinically and histologically; however, the treatment is different. In this communication, we report on a Sudanese male patient who presented with foot botryomycosis. DESIGN: Case report. RESULTS: The patient was initially diagnosed with actinomycetoma by the presence of Streptomyces somaliensis like-grains in the histological slides. The patient was treated with a combination of co-trimoxazole and amikacin sulfate and shifted after 1 year to co-trimoxazole, amoxicillin, and clavulanic acid. Despite treatment, the infection progressed, and the bone was invaded. The infected limb was amputated. The histopathological report of the surgical biopsy showed gram-positive cocci inside the grain. The 16S sequence identified these cocci as Staphylococcus aureus. CONCLUSION: This is the first reported botryomycosis case from Sudan, and it highlights why molecular identification is vital in diagnosis.