13种抗生素对产AmpC酶或同时产ESBLs细菌的体外抗菌活性

In vitro antibacterial activity of 13 antibiotics against bacteria producing AmpC β-lactamases or AmpC β-lactamases plus ESBLs

目的 了解临床下呼吸道感染常见革兰氏阴性杆菌产 Amp C酶或同时产超广谱β-内酰胺酶(ESBL s)的情况 ,检测常用 13种抗生素对这些菌株的体外抗菌活性 ,以指导临床合理选择抗生素。方法 采用酶提取物三维试验确证产 Amp C酶或同时产 ESBL s菌株 ,应用琼脂二倍稀释法测定抗生素对这些菌株的最低抑菌浓度 (MICs)。结果 从临床痰标本分离对第一、二代及一种以上第三代头孢菌素耐药的 2 2 6株常见革兰氏阴性杆菌 ,包括阴沟肠杆菌、弗氏柠檬酸杆菌、肺炎克雷伯氏菌、大肠埃希氏菌、鲍氏不动杆菌和铜绿假单胞菌 ,其中单产 Amp C酶 34株 ,同时产 Amp C酶和 ESBL s15株 ,总检出率分别为 15 .0 % (34/ 2 2 6 )、6 .6 %(15 / 2 2 6 )。无论单产 Amp C酶还是同时产 Amp C酶和 ESBL s的细菌对第三代头孢菌素、氨曲南及头孢美唑高度耐药 ,敏感率从 0～ 14 .7% ;对含 β-内酰胺酶抑制剂的复合制剂哌拉西林 /三唑巴坦、阿莫西林 /克拉维酸、头孢哌酮 /舒巴坦耐药情况亦严重 ,敏感率从 0～ 2 9.4 % ;对环丙沙星、左氧氟沙星除大肠埃希氏菌外有较高的敏感性 ,总敏感率均为 71.4 % ;而对亚胺培南高度敏感 ,仅有 1株铜绿假单胞菌耐药。单产 Amp C酶细菌对头孢吡肟、阿米卡星敏感率分别为 97.1%、6 4 .7% ,同时产 Amp C酶?

Objective To investigate the condition of common Gram-negative bacilli producing AmpC β-lactamases or AmpC β-lactamases plus extended-spectrum β-lactamases (ESBLs) in the lower respiratory tract infection, and to detect the antibacterial activity in vitro of 13 antibiotics against them, for guiding the rational use of antibiotics.Methods AmpC β-lactamases and were detected by three-dimensional extraction test, and the minimal inhibitory concentrations (MICs) were determined by standard agar dilution method. Results Among 266 isolates resistant to the first, second and at least one third-generation cephalosporins from clinical sputum samples, including E.cloacae, C.freundii, K.penumoniae, E.coli, A.baumannii and P.aeruginosa, producing AmpC β-lactamases and AmpC β-lactamases plus ESBLs were 34 strains (15.0%) and 15 strains (6.6%) respectively. The susceptible rate of producing either AmpC β-lactamases or AmpC β-lactamases plus ESBLs strains to the third-generation cephalosporins, aztreonam and cefmetazole were 0～14.7%; to those of antibiotics combined with inhibitors such as piperacillin/tazobactam, amoxicillin/clavulanic acid and cefoperazone/sulbactam were 0～29.4%; to ciprofloxacin and levofloxacin all were 71.4% except E.coli; to imipenem was 97.1% except one strain P.aeruginosa. The susceptible rate of AmpC β-lactamases and AmpC β-lactamases plus ESBLs producing strains to cefepime and amikacin were 97.1% and 64.7%, 66.7% and 26.7% respectively. Conclusion The antibacterial activity of imipenem against AmpC β-lactamases and/or AmpC β-lactamases plus ESBLs producing strains is strong, and also those of ciprofloxacin and levofloxacin are better except E.coli. As to cefepime, the antibacterial activity against which only producing AmpC β-lactamases is also strong, and amikacin has displayed a moderate activity.