Rifampicin-resistant Mycobacterium leprae in an elderly leprosy patient in the people’s Republic of China
A 66-year-old male Chinese leprosy patient was referred to the authors’ hospital for investigation as a suspected case of drug-resistant M. leprae caused by inadequate treatment, poor compliance, and clinical relapse. The patient was diagnosed with lepromatous leprosy at the age of 46 years and treated with DDS 50 mg/day. He stopped taking pills half a year later when the skin lesions had cleared. However, the patient continued experiencing progressive and worsening numbness of the limbs for the next 18 years, during which he was out of medical record and took alternative medicine instead. In April 2009, the patient sought medical help from a private practitioner for itchy rashes on his abdomen, buttocks, and groin. He was prescribed isoniazid, RFP, and DDS, but the patient only took RFP irregularly. An initial response to treatment was observed, but new nodules and ulcers soon developed all over the patient’s body. On July 4, 2011, the patient was finally admitted and smears showing a bacillary index of 5.0 were taken. He was diagnosed with relapsed lepromatous leprosy with possible RFP resistance.\nAcid-fast bacilli were isolated from a skin biopsy specimen (). Identification of the isolate by polymerase chain reaction and gene sequencing of M. leprae-specific repetitive element and 16S rDNA genes was carried out., The sequence analysis of M. leprae-specific repetitive element and 16S rDNA genes showed 100% similarity with M. leprae. Amplification and DNA sequencing of folP1, rpoB, and gyrA genes – involved in resistance to DDS, RFP, and quinolones, respectively – were also performed (). Sequence analysis of these genes revealed a mutation within codon 441 of the rpoB gene (GAT→AAC), which indicates that it is the third reported strain harboring this mutation but a new two-base substitution (). No mutation of folP1 or gyrA gene was found in this strain. The sequences were analyzed with the BLAST® version 2.0 software (National Library of Medicine, Bethesda, MD, USA), available at .\nA regimen including 500 mg clarithromycin twice daily, 400 mg moxifloxacin once daily, 100 mg DDS once daily, and 50 mg clofazimine once daily was prescribed. The patient attended regularly for 3 months and then was lost. On his last visit, observations showed that the skin lesions of the patient had gradually subsided and that his bacillary index had dropped to 3.2.