老年下呼吸道感染患者肺炎克雷伯菌和大肠埃希菌耐药性分析

目的：监测老年下呼吸道感染患者肺炎克雷伯菌和大肠埃希菌的耐药性。为临床合理应用抗生素提供依据。方法：对我院下呼吸道感染患者中分离出的肺炎克雷伯菌和大肠埃希菌240株，以Kirby-Bauer(K-B)琼脂扩散法作药敏试验；以美国临床实验室标准委员会（NCCLS）1999年推荐的表型确认试验检测超广谱β－内酰胺酶（ESBLs）。结果：老年组和非老年组肺炎克雷伯菌和大肠埃希菌对14例抗生素的耐药率分别为阿莫西林93．2％和87．3％，哌拉西林57．1％和42．9％、头孢呋新51．4％和33．3％、头孢噻肟40．1％和17．5％、头孢他啶13．6％和3．2％、头孢曲松39．0％和17．5％、头孢哌酮37．3％和15．9％，头孢吡肟10．2％和3．2％、阿米卡星47．5％和34．9％，环丙沙星54．2％和38．1％、亚胺培南15．9％、头孢吡肟10．2％和3．2％、阿米卡星47．5％和34．9％、环丙沙星54．2％和38．1％，亚胺培南0和0、头孢哌酮／舒巴坦0和0、哌拉西林／三唑巴坦1．1％和0、头孢美唑9．6％和4．8％。78株肺炎克雷伯菌和大肠埃希菌被证实为产ESBLs菌，ESBLs检测出率为32．5％（78／240），其中老年组ESBLs检出率为38．4％（68／177），非老年组ESBLs检出率为15．9％（10／63）。亚胺培南，头孢哌酮／舒巴坦，哌拉西林／三唑巴坦和头孢美唑对产ESBLs菌的耐药率最低，分别为0、0、2．6％和12．8％。结论：老年下呼吸道感染患者肺炎克雷伯菌和大肠埃希菌的耐药率和ESBLs检出率均显著高于非老年患者；亚胺培南，头孢哌酮／舒巴坦、哌拉西林／三唑巴坦和头孢美唑是治疗由产ESBLs菌引起感染的有效抗生素。

Analysis of antibiotic resistance of Klebsiella pneumoniae and Escherichia coli in old patients with lower respiratory tract infections

Objective To investigate antibiotic resistance of Klebsiella pneumoniae and Escherichia coli in old patients with lower respiratory tract infections. Methods Kirby Bauer agar diffusion method was used to evaluate the drug sensitivity in 240 strains of Klebsiella pneumoniae and Escherichia coli isolated from patients with lower respiratory tract infection. Phenotypic confirmatory test recommended by NCCLS1999 was used to detect extended spectrum beta lactamases(ESBLs). Results The resistant rates of Klebsiella pneumoniae and Escherichia coli to 14 antibiotics in old patients and in non old patients with lower respiratory tract infections were amoxicillin 93 2% vs 87 3%, piperacillin 57 1% and 42 9%, cefuroxime 51 4% and 33 3%, cefotaxime 40 1% and 17 5%, ceftazidime 13 6% and 3 2%, ceftriaxone 39 0% and 17 5%, cefoperazone 37 3% and 15 9%, cefepime 10 2% and 3 2%, amikacin 47 5% and 34 9%, ciprofloxacin 54 2% and 38 1%, imipenem 0, cefoperazone/sulbactam 0, piperacillin/tazobactam 1 1% vs 0, and cefmetazole 9 6% and 4 8% respectively. Out of 240 clinical strains of Klebsiella pneumoniae and Escherichia coli, 78(32 5%) were considered ESBLs producers by phenotypic confirmatory test. The prevalence of ESBLs in old patients was 38 4%, which was much higher than that in non old patients(15 9%). The resistant rate of ESBLs producing strains to imipinem, cefoperazone/sulbactam, piperacillin/tazobactam and cefmetazole was the lowest, being 0, 0, 2 6% and 12 8%. Conclusions The resistant rates of Klebsiella pneumoniae and Escherichia coli to most antibiotics and the prevalence of ESBLs in old patients with lower respiratory tract infection were higher than that in non old patients. Imipinem, cefoperazone/sulbactam, piperacillin/tazobactam and cefmetazole were the effective antibiotics to infections caused by ESBLs producing strains.