A 46-year-old nondiabetic woman from a middle-class family, presented with discharging sinuses over the lower anterior abdominal wall for the past 2 years. There was no rise of temperature or weight loss. Her incision wound from laparoscopic appendectomy in 1998 did not heal properly and the surgical site was reopened after 1 month. There was no healing of the incision wound after reexcision. After that the whole area started to become erythematous and indurated and later on a keloid started developing over the scar. A large sinus developed over the operation scar and the other stitch sites also developed into sinuses discharging pus. However, there was no history of cough, haemoptysis, breathlessness, and anorexia. There was no history of intake of any immunosuppressive drugs/corticosteroids, any local trauma/injury, or tuberculosis. She had been treated off and on without having any definitive microbiological diagnosis with multiple injectable and oral antibiotics before consultation at this hospital. She did not have any contact with tuberculosis patients.
On examination, a previous-surgical scar was present over which a large keloid had formed, on the lower anterior abdominal wall in the midline (although a little more towards the right). There was no apparent mass over the abdomen, but 6 sinus openings were noted over the lower anterior abdominal wall (Figure 1). At the time of presentation a single sinus was discharging pus. On palpation, tenderness was noted over and around the sinuses. The sinus opening was bluish, wide, and undermined and it was discharging a serosanguinous exudate admixed with pus. Complete haemogram and clinical chemistry were within normal limits including blood sugar. HIV ELISA negative by two kits, C-reactive protein normal and the ESR, was peaked at 22 mm. Pus from the discharging sinus was collected and processed using standard procedures. Gram stained smear showed plenty of pus cells with Gram variable bacilli (many of which were Gram positive) and on Ziehl-Neelsen staining numerous acid fast bacilli could be observed. The discharge was cultured on blood agar, MacConkey medium, and Lowenstein-Jensen medium and inoculated into a BacT/ALERT MP bottle, which was incubated in the BacT/ALERT 3D system (bioMerieux, USA). The blood agar and MacConkey medium were incubated under aerobic conditions at 37 C. The blood agar plate showed numerous dry, small nonhemolytic colonies after 72 hours but there was no growth on the MacConkey medium. The BacT/ALERT MP showed positive growth in 5 days for acid fast bacilli, which on further subculture onto L-J medium gave dry, rough, pigmented, and yellow to orange colonies after one-week period (Figure 2). They were found to be scotochromogenic at 37 C. Speciation for the isolate was confirmed by the GenoType Mycobacterium CM/AS assay based on Mycobacterium DNA strip technology (Hain Lifescience, Nehren, Germany), following manufacturer's instructions. It showed a mixed infection caused by two NTM species, that is, Mycobacterium szulgai and M. intermedium. To confirm microbiological result, culture from repeat sample after one week showed the same dual infection caused by Mycobacterium szulgai and M. intermedium by the GenoType Mycobacterium CM/AS assay. Drug susceptibility testing (DST) was performed by standard disk diffusion method over Middlebrook 7H10 agar supplemented with OADC (oleic acid, dextrose, and citrate) and the following results were obtained: sensitive to linezolid, levofloxacin, clarithromycin, amikacin, and ciprofloxacin and found to be resistant to cotrimoxazole. DST for 1st and 2nd line antitubercular drugs were done by the GenoType MTBDRplus and MTBDRsl assay (Hain Lifescience, Nehren, Germany) which showed resistance to isoniazid and sensitive to rifampicin, fluoroquinolones, aminoglycosides/cyclic peptides, and ethambutol.
The patient was advised a combination of rifampicin 600 mg once daily, ethambutol 600 mg once daily, and clarithromycin 500 mg twice daily to be taken along with periodic follow-up based upon clinical response as well as microbiological response.
She was advised to continue the therapy and when she presented to the hospital after one month, there was no pus discharge from the sinus. She was advised to continue the therapy and report to hospital after another month. Again after one month of therapy, there was no discharge present and the sinus was almost completely healed. Thereafter, she was advised to continue the same therapy for another two months. Thereafter, patient was completely all right with no such discharge after completion of two-month antibiotic therapy.