Singh Satyendra Kumar, Kumar Ajit, Nath Gopal, Singh Tej Bali, Mishra Mukti Nath
Department of Dermatology and Venereology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
Indian J Dermatol Venereol Leprol. 2018 May-Jun;84(3):275-279. doi: 10.4103/ijdvl.IJDVL_34_16.
: WHO MDT is the main drug regimen for treating leprosy and has been used for more than three decades. Many cases of relapse of leprosy have been reported, which points towards the emergence of drug resistance with the antileprotic drugs.
: To find the resistance with the antileprotic drugs by detecting the mutations in drug resistance determining region of the rpoB, folP1 and gyrA genes of Mycobacterium leprae.
Leprosy patients with bacterial index ≥2 were included in the study. The slides were further processed to extract genomic DNA, and polymerase chain reactions were performed to amplify the drug resistance determining region (DRDR) of rpoB, folP1 and gyrA genes. The samples in which genes could be amplified were subjected to DNA sequencing to detect mutations.
Out of 78 samples rpoB gene was amplified in 39 (50%), folP1 in 32 (41%) and gyrA in 45 (57.7%). In 20 (25.6%) samples no gene was amplified. Only 32 samples of rpoB, 25 samples of folP1 and 38 samples of gyrA gene were included in the study, rest were excluded due to sequencing error. No mutation was seen in rpoB gene and in folP1 gene. In gyrA gene samples mutations were seen in 8 (21%) samples, and were present at codon 91 GCA → GTA (Alanine → Valine).
: Small sample size and less efficient method to detect resistance.
Resistance is not a problem with conventional drugs in MDT. It is more common with quinolones.
世界卫生组织的多药联合化疗（MDT）是治疗麻风病的主要药物方案，已使用超过三十年。已有许多麻风病复发病例的报道，这表明抗麻风病药物出现了耐药性。
通过检测麻风分枝杆菌rpoB、folP1和gyrA基因耐药决定区的突变来发现抗麻风病药物的耐药性。
细菌指数≥2的麻风病患者纳入研究。玻片进一步处理以提取基因组DNA，并进行聚合酶链反应以扩增rpoB、folP1和gyrA基因的耐药决定区（DRDR）。能够扩增基因的样本进行DNA测序以检测突变。
78个样本中，rpoB基因扩增出39个（50%），folP1基因扩增出32个（41%），gyrA基因扩增出45个（57.7%）。20个（25.6%）样本未扩增出基因。本研究仅纳入了32个rpoB基因样本、25个folP1基因样本和38个gyrA基因样本，其余因测序错误被排除。rpoB基因和folP1基因未发现突变。gyrA基因样本中8个（21%）样本出现突变，位于密码子91处，GCA → GTA（丙氨酸 → 缬氨酸）。
样本量小且检测耐药性的方法效率较低。
MDT中的传统药物不存在耐药性问题。喹诺酮类药物的耐药性更常见。
