Detected in Malignant Melanoma, a Preliminary Study.

, , and are bacteria known to cause verruga peruana or bacillary angiomatosis, vascular endothelial growth factor (VEGF)-dependent cutaneous lesions in humans. Given the bacteria's association with the dermal niche and clinical suspicion of occult infection by a dermatologist, we determined if patients with melanoma had evidence of spp. infection. Within a one-month period, eight patients previously diagnosed with melanoma volunteered to be tested for evidence of spp. exposure/infection. Subsequently, confocal immunohistochemistry and PCR for spp. were used to study melanoma tissues from two patients. Blood from seven of the eight patients was either seroreactive, PCR positive, or positive by both modalities for spp. exposure. Subsequently, organisms that co-localized with VEGFC immunoreactivity were visualized using multi-immunostaining confocal microscopy of thick skin sections from two patients. Using a co-culture model, was observed to enter melanoma cell cytoplasm and resulted in increased vascular endothelial growth factor C (VEGFC) and interleukin 8 (IL-8) production. Findings from this small number of patients support the need for future investigations to determine the extent to which spp. are a component of the melanoma pathobiome.