Solcà N M, Bernasconi M V, Piffaretti J C
Istituto Cantonale Batteriosierologico, 6904 Lugano, Switzerland.
Antimicrob Agents Chemother. 2000 Aug;44(8):2207-10. doi: 10.1128/AAC.44.8.2207-2210.2000.
The rdxA gene of 30 independently isolated Helicobacter pylori strains was sequenced. A comparison of the rdxA sequences revealed a higher percentage of amino acid substitutions in the corresponding protein than in other housekeeping genes. Out of 122 point mutations, 41 were missense and 4 were nonsense. A resistant strain with a nucleotide insertion in the rdxA sequence was also found. With the exception of the point mutations and the insertion generating a stop signal, no particular nucleotide mutation or amino acid substitution could be associated to metronidazole resistance. Moreover, phylogenetic analysis of the 30 nucleotide sequences did not demonstrate specific clusters associated with the resistance phenotype.
对30株独立分离的幽门螺杆菌菌株的rdxA基因进行了测序。rdxA序列的比较显示，相应蛋白质中的氨基酸取代百分比高于其他管家基因。在122个点突变中，41个为错义突变，4个为无义突变。还发现了一株在rdxA序列中有核苷酸插入的耐药菌株。除了产生终止信号的点突变和插入外，没有特定的核苷酸突变或氨基酸取代与甲硝唑耐药性相关。此外，对30个核苷酸序列的系统发育分析未显示与耐药表型相关的特定聚类。
