Mutations conferring aminoglycoside and spectinomycin resistance in Borrelia burgdorferi
Mutations conferring aminoglycoside and spectinomycin resistance in Borrelia burgdorferi
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DOI：
10.1128/aac.50.2.445-452.2006
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发表时间：
2006-02-01
影响因子：
4.9
通讯作者：
Samuels, DS
中科院分区：
文献类型：
--
作者：
Criswell, D;Tobiason, VL;Samuels, DS
我们已经分离并鉴定了莱姆病病原体伯氏疏螺旋体的体外突变株，这些突变株对针对核糖体小亚单位的抗生素壮观霉素、卡那霉素、庆大霉素或链霉素具有抗药性。16S rRNA突变A1185G和C1186U与大肠杆菌核苷酸A1191和C1192同源，分别使其对壮观霉素产生2200倍和1300倍的抗性。16S rRNA A1402G突变，与大肠杆菌A1408同源，使>；对卡那霉素耐药90倍，对庆大霉素耐药240倍。在链霉素中选择的突变体中，在核糖体蛋白S12基因中发现了两个突变，位于与大肠杆菌残基Lys-87同源的位置。密码子88、K88R和K88E的替换分别使伯氏假单胞菌对链霉素产生7倍和10倍抗性。16S rRNA A1185G和C1186U突变与壮观霉素抗性相关，在伯氏杆菌亲本菌株B31中出现频率为6×10(-6)的突变。这些壮观霉素抗性突变体在体外共培养100代后，成功地与野生型菌株竞争。氨基糖苷抗性突变体在群体中出现的频率为3×10(-9)~1×10(-7)，100代后不能与野生型菌株B31竞争。这是首次描述伯氏杆菌核糖体突变，使其对抗生素产生耐药性。这些结果对抗生素耐药性的进化具有重要意义，因为导致壮观霉素耐药性的16S rRNA突变在体外没有显著的适应成本，也不适用于新的可选择标记的开发。
We have isolated and characterized in vitro mutants of the Lyme disease agent Borrelia burgdorferi that are resistant to spectinomycin, kanamycin, gentamicin, or streptomycin, antibiotics that target the small subunit of the ribosome. 16S rRNA mutations A1185G and C1186U, homologous to Escherichia coli nucleotides A1191 and C1192, conferred > 2,200-fold and 1,300-fold resistance to spectinomycin, respectively. A 16S rRNA A1402G mutation, homologous to E. coli A1408, conferred > 90-fold resistance to kanamycin and > 240-fold resistance to gentamicin. Two mutations were identified in the gene for ribosomal protein S12, at a site homologous to E. coli residue Lys-87, in mutants selected in streptomycin. Substitutions at codon 88, K88R and K88E, conferred 7-fold resistance and 10-fold resistance, respectively, to streptomycin on B. burgdorferi. The 16S rRNA A1185G and C1186U mutations, associated with spectinomycin resistance, appeared in a population of B. burgdorferi parental strain B31 at a high frequency of 6 X 10(-6). These spectinomycin-resistant mutants successfully competed with the wild-type strain during 100 generations of coculture in vitro. The aminoglycoside-resistant mutants appeared at a frequency of 3 X 10(-9) to 1 X 10(-7) in a population and were unable to compete with wild-type strain B31 after 100 generations. This is the first description of mutations in the B. burgdorferi ribosome that confer resistance to antibiotics. These results have implications for the evolution of antibiotic resistance, because the 16S rRNA mutations conferring spectinomycin resistance have no significant fitness cost in vitro, and for the development of new selectable markers.