Mycobacterium fortuitum infection in a renal transplant recipient

There are only a few reports of cutaneous infection due to atypical mycobacteria in renal transplant recipients [1–4] . Only one of these reported infection due to Mycobacterium fortuitum [1] . We present a renal transplant recipient who developed suture site infection with M. fortuitum. A 21-year old man underwent pre-emptive renal transplantation 13 months ago. His mother was the donor. He received I.V. methylprednisolone 15 mg/ kg/day for 3 days followed by prednisolone 20 mg/ day, tacrolimus 0.12 mg/kg/day, and mycophenolate mofetil 1.0 g/bid. On day 13 after transplantation, the sutures were removed. Two weeks later the patient developed an abscess of 1 9 1 cm on the suture site. There was no fever. The abscess was drained and the pus was sent to culture. The culture was sterile. Amoxicillin–clavulanate 1,000 mg bid was given for one week. After 2 weeks, another abscess appeared at an adjacent site (Fig. 1). Ultrasonography revealed subcutaneous collection suggestive of pus (Fig. 2) from the upper to the lower end of the suture site. The pus from the abscess and from the subcutaneous zone revealed acid-fast bacilli on Ziehl–Nieelsen staining. On Lowenstein–Jensen culture medium bacteria grew within 3 days and were identified as M. fortuitum. Patient was started on clarithromycin 500 mg bid, ciprofloxacin 500 mg bid, and trimethoprim 20 mg/ kg-sulphamethoxazole 100 mg/kg tid. Within a week of treatment, serum creatinine increased from 0.9 mg/ dL to 1.4 mg/dL. The patient also developed newonset diabetes after transplantation. Serum tacrolimus level was found to be 20.2 ng/mL, so the dose of tacrolimus was adjusted to bring its level to 5.4 ng/ mL. Tacrolimus was later replaced by everolimus, after 3 months from the renal transplantation. The treatment for M. fortuitum was given for 6 months. After 13 months of follow-up, the lesions subsided with a scar, blood glucose was in the normal range (without insulin therapy), and serum creatinine was 1.0 mg/dL. In a previously reported patient [1], two months after renal transplantation there was pain and swelling over the surgical wound. The CT scan showed small hyperdensities in the abdominal wall over the graft site, with no perigraft collection or hydronephrosis. The pus smear from the site showed acid-fast bacilli identified as M. fortuitum. The patient was treated with clarithromycin, ofloxacin, and amikacin. Amikacin was stopped after 2 weeks, due to nephrotoxicity, and the remaining two drugs were continued for 9 months. M. fortuitum is a rapid grower (group IV of Runyon’s classification of atypical mycobacteria) because of its ability to grow on a standard agar used for mycobacteria culture within a week. Nodular ulcers and abscesses induced by M. fortuitum may develop within a month after skin trauma, such as R. Ram (&) G. Swarnalatha G. D. Naidu B. H. S. Pai K. V. Dakshinamurty Nizam’s Institute of Medical Sciences, Punjagutta, Hyderabad, India e-mail: ram_5_1999@yahoo.com