A 50 year old man presents to the clinic with multiple abcesses and discharging sinus present on his left foot. X-ray of the foot shows destructive changes in the underlying bone. Which of the following is the most likely causative organism?

Patient in this question is most likely suffering from Actinomycotic mycetoma caused by Nocardia and Actinomadura species. Disease begins as a papule or a nodule and slowly progress into multiple abcesses and sinus tracts ramifying deep into the tissue. Trimethoprim sulfamethoxazole or dapsone are effective in the treatment.