下呼吸道感染肠杆菌科细菌产AmpC酶和超广谱β-内酰胺酶的检测

Detection of AmpC and Extended-spectrum β-Lactamases Producing Enterobacteriaceae Strains in Lower Respiratory Tract Infections

目的 探讨下呼吸道感染标本中分离的肠杆菌科细菌去阻遏持续高产 Amp C酶和超广谱 β-内酰胺酶(ESBL s)的发生率。方法 采用纸片扩散法对下呼吸道感染标本中分离的肠杆菌科细菌进行初筛 ,选择出可疑产酶菌株 ,然后以头孢西丁三维试验检测产 Amp C酶菌株 ,以复合纸片法检测产 ESBL s菌株 ,以头孢曲松三维试验检测同时产 Amp C酶和 ESBL s菌株。结果 在下呼吸道感染肠杆菌科细菌初筛为耐药菌株的 2 4 2株细菌中 ,检出单产 Amp C酶、单产 ESBL s及同时产 Am p C酶和 ESBL s细菌分别为 2 1、110、6株 ,总检出率分别为 8.7%、4 5 .5 %、2 .5 % ,其中阴沟肠杆菌 Am p C酶检出率最高 ,为 4 2 .1% ,肺炎克雷伯菌 ESBL s检出率最高 ,为 6 4 .5 %。结论 及时准确地检测产 Am p C酶和 (或 ) ESBL s细菌 ,为临床医师诊断和治疗患者提供依据 ,能早期治疗并控制下呼吸道感染性疾病。

OBJECTIVE To detect AmpC and extended-spectrum β-lactamases producing Enterobacteriaceae strains in lower respiratory tract infections. METHODS Adopting modified three dimensional extract test to detect (AmpC) β-lactamases producing and AmpC β-lactamases combined with ESBLs producing strains. Using method recommended by the National Committee for Clinical Laboratory Standards (NCCLS) to detect ESBLs producing strains. RESULTS Among 242 clinical Enterobacteriaceae isolates, which were resistant to the first-, second- and at least one kind of third-generation cephalosporins, AmpC β-lactamases, ESBLs and AmpC β-lactamases combined with ESBLs producing strains were found in 21, 110, and 6 strains, the incidence being 8.7%, 45.5%, and 2.5%, respectively. AmpC β-lactamases were detected in 42.1% of Enterobacter cloacae and ESBLs detected in 64.5% of Klebsiella pneumoniae. CONCLUSIONS It is important to select proper method to detect AmpC β-lactamases and ESBLs in time.