Ahmad Suhail, Mokaddas Eiman
Department of Microbiology, Faculty of Medicine, Kuwait University, P.O. Box 24923, Safat 13110, Kuwait.
Int J Antimicrob Agents. 2005 Sep;26(3):205-12. doi: 10.1016/j.ijantimicag.2005.06.009.
Mutations associated with rifampicin (RIF) resistance in two regions of the rpoB gene were studied by line probe (INNO-LiPA Rif. TB) assay (LiPA) and/or DNA sequencing in 32 RIF-resistant and 21 RIF-susceptible Mycobacterium tuberculosis strains isolated from 53 tuberculosis patients in Kuwait. The LiPA identified all susceptible strains as RIF sensitive, and the DNA sequences of the 81bp rifampicin resistance-determining region (RRDR) and the N-terminal region of the rpoB gene from five isolates were identical to the wild-type sequences from M. tuberculosis H(37)Rv. The LiPA identified 24 of 32 (75%) phenotypically documented RIF-resistant M. tuberculosis isolates as RIF resistant, with specific detection of mutation in 19 isolates, whilst 8 strains were identified as RIF susceptible. DNA sequencing of the RRDR confirmed the results for the 19 RIF-resistant isolates and identified precise mutations in five isolates for which specific base changes could not be determined by LiPA, as well as identifying a mutation (insertion 514TTC) in three isolates and no mutation in five of the eight isolates that were detected as RIF susceptible by LiPA. Two of the latter five isolates contained a V146F mutation in the N-terminal region of the rpoB gene and were recovered from patients of Middle Eastern origin. These analyses identified 11 different mutations in two regions of the rpoB gene. The majority of the isolates carrying identical or no mutations in the rpoB gene exhibited unique DNA banding patterns in fingerprinting studies. The occurrence of rare mutations in the rpoB gene, namely insertion 514TTC in 3 (9%) and V146F in 2 (6%) of 32 RIF-resistant M. tuberculosis isolates from Kuwait, is the highest reported so far.
通过线性探针（INNO-LiPA Rif.TB）检测法（LiPA）和/或DNA测序，研究了从科威特53例结核病患者中分离出的32株利福平（RIF）耐药和21株RIF敏感结核分枝杆菌菌株rpoB基因两个区域中与RIF耐药相关的突变。LiPA将所有敏感菌株鉴定为对RIF敏感，5株分离株的81bp利福平耐药决定区（RRDR）和rpoB基因N端区域的DNA序列与结核分枝杆菌H(37)Rv的野生型序列相同。LiPA将32株表型证实为RIF耐药的结核分枝杆菌分离株中的24株（75%）鉴定为RIF耐药，19株分离株检测到特异性突变，8株被鉴定为对RIF敏感。RRDR的DNA测序证实了19株RIF耐药分离株的结果，并确定了5株LiPA无法确定特定碱基变化的分离株中的精确突变，同时在3株分离株中鉴定出一个突变（插入514TTC），LiPA检测为RIF敏感的8株分离株中有5株未检测到突变。后5株分离株中有2株在rpoB基因N端区域含有V146F突变，且从中东血统患者中分离得到。这些分析在rpoB基因的两个区域鉴定出11种不同的突变。在指纹图谱研究中，大多数rpoB基因携带相同或无突变的分离株表现出独特的DNA条带模式。在来自科威特的32株RIF耐药结核分枝杆菌分离株中，rpoB基因中罕见突变的发生率，即3株（9%）出现插入514TTC和2株（6%）出现V146F，是迄今为止报道的最高发生率。
