Center for Proteomics, State Key Laboratory of Bio-Control, MOE Key Lab Aquat Food Safety, School of Life Sciences, Sun Yat-sen University, University City, Guangzhou 510006, People's Republic of China.
J Proteomics. 2013 Jul 11;87:78-88. doi: 10.1016/j.jprot.2013.05.019. Epub 2013 May 24.
In the present study, we have characterized low abundance of NarG and NarH, two components of respiratory nitrate reductase (Nar), in streptomycin (SM)-, gentamicine (GEN)-, ceftazidime (CAZ)-, tetracycline (TET)- and nalidixic acid (NA)-resistant Escherichia coli strains using native/SDS-PAGE based proteomics. We validate the finding using Western blotting and native/SDS-PAGE upon narG and narH deletion mutants. However, further functional evidence indicates that loss of narG and narH results in two types of growth behaviors, higher and lower than control, in these antibiotic-resistant E. coli strains. Specifically, SM-, GEN- and CAZ-resistant bacteria grow faster, whereas NA- and TET-resistant E. coli strains grow slower. Our data indicate that low abundance of respiratory Nar is essential for E. coli in resistance to aminoglycoside and cephalosporin antibiotics. Meanwhile, the results show that differential mechanisms exist in different antibiotic-resistant bacteria. The reason why the reversal growths are detected in NA- and TET-resistant E. coli strains waits investigation. Our findings serve to propose novel strategies for controlling of aminoglycoside- and cephalosporin-resistant E. coli strains through elevation of respiratory Nar activity.
Our data indicate that low abundance of respiratory Nar is essential for E. coli in resistance to aminoglycoside and cephalosporin antibiotics. Meanwhile, the results show that differential mechanisms exist in different antibiotic-resistant bacteria. Our findings serve to propose novel strategies for controlling of aminoglycoside- and cephalosporin-resistant E. coli strains through elevation of respiratory Nar activity.
在本研究中，我们使用基于 native/SDS-PAGE 的蛋白质组学技术对链霉素（SM）、庆大霉素（GEN）、头孢他啶（CAZ）、四环素（TET）和萘啶酸（NA）耐药大肠杆菌菌株中呼吸硝酸盐还原酶（Nar）的两个组成部分 NarG 和 NarH 的低丰度进行了表征。我们使用 Western blot 和 narG 和 narH 缺失突变体进行了验证。然而，进一步的功能证据表明，narG 和 narH 的缺失导致这些抗生素耐药大肠杆菌菌株的两种生长行为，高于和低于对照。具体来说，SM、GEN 和 CAZ 耐药菌生长更快，而 NA 和 TET 耐药大肠杆菌生长更慢。我们的数据表明，呼吸 Nar 的低丰度对于大肠杆菌对抗氨基糖苷类和头孢菌素类抗生素是必不可少的。同时，结果表明，不同的抗生素耐药细菌存在不同的机制。在 NA 和 TET 耐药大肠杆菌菌株中检测到逆转生长的原因有待进一步研究。我们的发现为通过提高呼吸 Nar 活性来控制氨基糖苷类和头孢菌素类耐药大肠杆菌菌株提供了新的策略。
我们的数据表明，呼吸 Nar 的低丰度对于大肠杆菌对抗氨基糖苷类和头孢菌素类抗生素是必不可少的。同时，结果表明，不同的抗生素耐药细菌存在不同的机制。我们的发现为通过提高呼吸 Nar 活性来控制氨基糖苷类和头孢菌素类耐药大肠杆菌菌株提供了新的策略。
