The present case report is about a 31-year old male patient who presented to our medical center with a productive cough, hemoptysis and chest pain for a month. He had a history of pulmonary tuberculosis (TB) twice over the last 10 years. In the first episode, he was treated with the World Health Organization category (CAT) I standard regimen including: Isoniazid (H), Rifampin (R), Pyrazinamide (Z) and Ethambutol (E) for 6 months (2HRZE/4HR). In the second episode, a CAT II regimen including streptomycin in the 1st 2 months (2HRZES/1HREZ/5HRE) was prescribed for 8 months. His treatment was successful, however one year after completion of the second therapy, he presented with respiratory symptoms to our hospital. His vital signs were within the normal limits. On physical examination, he was pale and afebrile with generalized wheezing and bilateral bronchial rhonchi. Laboratory studies revealed the following values: Total white blood cell (WBC) count: 103,600 cells/ul with 5% neutrophils, 14% mature monocytes, 11% lymphocyte and more than 20% immature nucleated cells of myeloid lineage some with monocytoid morphology; hemoglobin 5.8 g/dl; platelets 233,000 cells/ul and erythrocyte sedimentation rate 125 mm/h. All other biochemical tests were unremarkable. Chest X-ray and spiral computed tomography scan of the thorax showed a cavitary lesion in the right upper lobe surrounding diffuse infiltrates with pleural thickening. There were also some areas of nodular infiltrate demonstrating a " tree-in-bud" appearance in left lung [Figure 1].
A sputum smear was positive for acid-fast bacilli, so anti-TB regimen (CAT I) was initiated, culture and drug susceptibility testing were initiated. In addition, bone marrow biopsy was performed and AML - M4 was diagnosed by histopathological examination, based on published criteria. Chemotherapy agents consisting Danurubicin 70 mg/q12h plus Cytarabine 1600 mg/q12h were started. The patient was transferred to the intensive care unit due to fever and severe neutropenia (WBC 880 cells/ul) on the 6th day of chemotherapy and Meropenem 1 g/q8 h, Vancomycin 1 g/q12h and Itraconazole 100 mg/daily were initiated.
The polymerase chain reaction (PCR) of deoxyribonucleic acid collected from sputum sample of patient (based on IS6110 primer) was negative for Mycobacterium tuberculosis complex. The Mycobacterium identification was performed by PCR-restriction fragment length polymorphism (RFLP) polymorphism analysis and subsequently M. branderi was isolated from the sputum of the patient. A 440 bp fragment of hsp65 gene was first amplified (based on TB11, TB12 primer) and then the PCR product digested using BstEII and HaeIII restriction endonucleases. The obtained digested pattern (BstEII; 235,211 bp: HaeIII; 130,106,80,41,37 bp) was compared with the standard strains published on database [Figure 2]. To further confirm the identification of M. branderi pure colonies were isolated at 25 C and 45 C within 3 weeks of incubation. Differentiation of M. branderi from Mycobacterium celatum was done based on phenotypic characteristic of colonies and pigment production. The colonies of M. branderi had not produced pigment.
The susceptibility testing observed for the clinical isolate included resistance to Isoniazid and Rifampin.
The anti-TB drugs were stopped and treatment was modified to Clarithromycin 500 mg/q12 h, Ciprofloxacin 500 mg/q12h and Doxycycline 100 mg/q12 h. This combination regimen was well tolerated and the patient's symptoms resolved. After 1 month of treatment, sputum smear and culture conversion was reported.
Following discharge from hospital, mycobacterial treatment was continued for 12 months and our patient remained smear negative and free of pulmonary symptoms in follow-up appointments.