老年下呼吸道感染患者痰病原菌及其β-内酰胺酶阳性株分析

A clinical investigation of bacteria and their β-lactamase positive strains in senile patients with lower respiratory tract infection

目的 观察住院老年下呼吸道感染患者痰病原菌构成、药敏特点及肺炎克雷伯菌与大肠杆菌超广谱 β 内酰胺酶 (ESBL)的检出率。 方法 应用常规痰细菌培养方法检测病原菌 ,用单纸片扩散法检测药敏 ,以Etest药敏纸条确定ESBL阳性菌株。 结果 (1)老年组痰细菌检出率(36 1% )明显高于非老年组 (2 4 4% )。老年组痰绿脓假单胞菌 (71 7% )、大肠埃希菌 (4 2 % )和肠球菌 (3 6 % )检出率明显高于非老年组 (31 7%、0 3%和 0 8% ) ;(2 )在老年组 ,绿脓假单胞菌对哌拉西林、头孢他啶和亚胺培南的敏感率 (6 6 2 %、6 9 4%和 76 0 % )明显低于非老年组 (92 9%、10 0 0 %和10 0 0 % )。克雷伯菌属对头孢呋肟和环丙沙星的敏感率 (5 9 4%和 6 9 7% )明显低于非老年组 (均为10 0 % ) ,流感嗜血杆菌对氨苄西林敏感率仅 6 2 5 % ,低于非老年组 (10 0 % ) ,不动杆菌属对环丙沙星敏感率 5 9 3% ,低于非老年组 (10 0 % ) ;(3) 97株肺炎克雷伯菌中 ,ESBL阳性株 11株 (11 3% ) ,其中 8株来自老年患者 ;2 2株大肠杆菌中 ,ESBL阳性株 5株 (2 2 7% ) ,均来自老年患者。 结论 老年下呼吸道感染患者痰菌检出率及细菌耐药率明显高于非老年患者 ,肺炎克雷伯菌和大肠杆菌ESBL阳性株绝大部分来自老年患者。

Objective To investigate the difference of the bacteria and the prevalence of the bacteria producing extended spectrum β lactamase (ESBL) between senile and non senile patients with lower respiratory tract infection. Methods The susceptibility to antimicrobial agents was studied with disk diffusion method on Mueller Hinton medium. The Etest ESBL strip confirmed all putative ESBL producing strains. Results (1)The occurrence rate of bacteria in the sputum expectorated by the senile patients was much higher than that by the non senile patients. Pseudomonas aeruginosa, Escherichia coli and Enterococcus were more common in the senile patient group (71 7%,4 2% and 3 6%) than in the non senile patient group (31 7%, 0 3% and 0 8%); (2)Resistant rate of Pseudomonas aeruginosa and Klebsiella pneumonia to the most commonly used antimicrobial agents were significantly higher in the senile than in the non senile patient group. The susceptibility of Haemophilus influenzae to Ampicillin was 62 5% in the senile patient group vs 100% in the non senile patient group; (3) Eleven isolates of 97 Klebsiella pneumonia strains were ESBL positive(11 3%), 8 of the 11 isolates came from the senile patients. Five isolates of 22 Escherichia coli strains were ESBL positive(22 7%), all from the senile patients. Conclusions The constitution of bacteria and their resistance to antimicrobial agents in senile patients with lower respiratory tract infection are quite different from those in non senile patients. ESBL positive trains of Klebsiella pneumonia and Escherichia coli are isolated mostly from senile patients.