Rimbara Emiko, Noguchi Norihisa, Kawai Takashi, Sasatsu Masanori
Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Science, Hachioji-shi, Tokyo 192-0392, Japan..
Microbiol Immunol. 2007;51(10):939-44. doi: 10.1111/j.1348-0421.2007.tb03990.x.
The correlation between the substitutions of penicillin-binding protein 1 (PBP1) and amoxicillin resistance was studied for the determination of the substitutions in PBP1 which confer amoxicillin resistance in Helicobacter pylori. By the comparison of the amino acid sequences of PBP1 in the amoxicillinresistant (n=3), low-susceptible (n=3), and susceptible (n=13) H. pylori isolates, the substitution Asn562-->Tyr, which is adjacent to KTG motif (555-557), was common and specific to amoxicillin-resistant H. pylori. Additionally, all amoxicillin-resistant isolates had multiple substitutions such as Ser414-->Arg in the transpeptidase region of PBP1 of H. pylori. Furthermore all transformants obtained by the natural transformation using the pbp1 genes of amoxicillin-resistant H. pylori isolates had multiple substitutions including Asn562-->Tyr. These results suggest that multiple amino acid substitutions in the transpeptidase region of PBP1 are closely related to amoxicillin resistance in H. pylori.
为了确定幽门螺杆菌中赋予阿莫西林抗性的青霉素结合蛋白1（PBP1）的替代位点，研究了PBP1替代与阿莫西林抗性之间的相关性。通过比较阿莫西林抗性（n = 3）、低敏感性（n = 3）和敏感性（n = 13）幽门螺杆菌分离株中PBP1的氨基酸序列，发现与KTG基序（555 - 557）相邻的Asn562→Tyr替代在阿莫西林抗性幽门螺杆菌中常见且具有特异性。此外，所有阿莫西林抗性分离株在幽门螺杆菌PBP1的转肽酶区域都有多个替代，如Ser414→Arg。此外，使用阿莫西林抗性幽门螺杆菌分离株的pbp1基因通过自然转化获得的所有转化体都有包括Asn562→Tyr在内的多个替代。这些结果表明，PBP1转肽酶区域的多个氨基酸替代与幽门螺杆菌对阿莫西林的抗性密切相关。
