Primary levofloxacin resistance and gyrA/B mutations among Helicobacter pylori in Japan
Primary levofloxacin resistance and gyrA/B mutations among Helicobacter pylori in Japan
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DOI：
10.1111/j.1523-5378.2006.00415.x
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发表时间：
2006-08-01
期刊：
影响因子：
4.4
通讯作者：
Kasuga, Masato
中科院分区：
文献类型：
--
作者：
Miyachi, Hideyuki;Miki, Ikuya;Kasuga, Masato
背景资料：近年来，由于幽门螺杆菌耐药性，特别是克拉霉素或甲硝唑耐药性，幽门螺杆菌根除率下降。作为标准治疗方案的替代方案之一，含左氧氟沙星的治疗被认为是一种有前途的治疗方案。材料与方法：采用E-test法对507例H. 2001年至2004年日本临床分离的幽门螺杆菌菌株。对68株左氧氟沙星耐药菌株和50株敏感菌株的gyrA和gyrB基因的喹诺酮类耐药决定区进行直接测序，分析其突变模式。68株左氧氟沙星耐药菌株中有57株（83.8%）存在gyrA的Asn-87或Asp-91点突变，而50株敏感菌株中有7株（14.0%）存在gyrA突变。左氧氟沙星耐药株和敏感株之间gyrA突变的发生率存在显著差异（p <0.001）。在左氧氟沙星耐药菌株中，无论最小抑菌浓度水平如何，Asn-87处的gyrA突变最常见，Asp-91处的gyrA突变往往与低水平耐药相关。Asn-87和Asp-91的双gyrA突变可能会产生额外的影响。至于gyrB，三个（4.4%）的68个左氧氟沙星耐药菌株，没有敏感菌株有mutation.Conclusions：主要左氧氟沙星耐药是常见的，在日本，主要与gyrA突变在Asn-87和Asp-91。
Background: Recent years have witnessed a decrease in the rate of Helicobacter pylori eradication due to antimicrobial resistance, clarithromycin or metronidazole resistance in particular. As one of the alternatives to the standard regimens, levofloxacin-containing therapy has been considered a promising regimen. Nevertheless, there is a little information concerning the prevalence of levofloxacin resistance and this resistance mechanism.Materials and Methods: Levofloxacin susceptibility was examined using E-test in 507 H. pylori strains clinically isolated in Japan from 2001 to 2004. Mutation patterns in the quinolone resistance-determining regions of the gyrA and gyrB genes were evaluated, performing direct sequencing of 68 levofloxacin-resistant and 50 susceptible strains.Results: Primary levofloxacin resistance was found in 76 (15.0%) strains. Fifty-seven (83.8%) of 68 levofloxacin-resistant strains analyzed had point mutations in gyrA at Asn-87 or Asp-91, while seven (14.0%) of 50 susceptible strains had gyrA mutations. There was a significant difference in the occurrence of gyrA mutations between levofloxacin-resistant and -susceptible strains (p < .001). In levofloxacin-resistant strains, the occurrence of gyrA mutations at Asn-87 was most common regardless of minimal inhibitory concentration levels, and that of gyrA mutations at Asp-91 tended to be associated with low-level resistance. A double gyrA mutation at Asn-87 and Asp-91 might have an additional impact. As for gyrB, three (4.4%) of 68 levofloxacin-resistant strains with no susceptible strains had mutations.Conclusions: Primary levofloxacin resistance was common in Japan and primarily related to gyrA mutations at Asn-87 and Asp-91.