临床细菌性眼内炎的病原学分析

目的探讨细菌性眼内炎致病菌的菌属分布及其药物敏感性,为临床诊断与治疗提供依据。方法对1999年1月至2006年12月北京同仁眼科中心临床送检的728份房水和玻璃体标本,进行常规细菌培养鉴定和纸片扩散法药物敏感性试验;对培养阳性菌株的菌属分布及其药物敏感性进行回顾性分析。结果728份房水和玻璃体标本中,细菌培养阳性标本160份,平均培养阳性率为22．0％;共培养出168株细菌,其中革兰阳性球菌96株（57．1％）,革兰阳性杆菌18株（10．7％）,革兰阴性球菌2株（1．2％）,革兰阴性杆菌52株（31．0％）。主要分离菌为表皮葡萄球菌36株（21．4％）,金黄色葡萄球菌19株（11．3％）,铜绿假单胞菌15株（8、9％）。革兰阳性球菌对万古霉素敏感率为93．4％（85／91）、对左旋氧氟沙星为84．4％（81／96）,革兰阴性杆菌对左旋氧氟沙星敏感率为88．2％（45／51）、对氧氟沙星为76．9％（40／52）、对环丙沙星为75．0％（39／52）。前4年（1999年至2002年）与后4年（2003年至2006年）主要致病菌药物敏感性比较,结果发现常用药物的敏感性均有不同程度的下降。结论细菌性眼内炎致病菌谱较广,临床常用抗菌药单一使用时常不能有效覆盖主要致病菌,因此治疗时应考虑联合用药。

Etiological analysis on bacterial endophthalmitis

OBJECTIVE: To investigate the spectrum of organisms causing bacterial endophthalmitis and their sensitivities to commonly used ocular antibiotics. METHODS: A retrospective analysis on microbiological records of 728 intraocular specimens of patients with suspected endophthalmitis from January 1999 to December 2006. Antibiotic susceptibility of these isolates was determined for commonly used ocular antibiotics using the Kirby-Bauer disk-diffusion test. RESULTS: In all, 168 organisms were isolated from 728 intraocular specimens during the study interval. Overall, 96 (57.1%) of 168 isolates were Gram-positive cocci, 52 (31.0%) were Gram-negative bacilli, 18 (10.7%) were Gram-positive bacilli, and 2 (1.2%) were Gram-negative cocci. The most common organisms identified were Staphylococcus epidermidis in 21.4% (36/168), Staphylococcus aureus in 11.3% (19/168), and Pseudomonas aeruginosa in 8.9% (15/168). For Gram-positive cocci, sensitivities were the following: vancomycin 93.4% (85/91), levofloxacin 84.4% (81/96), ofloxacin 68.8% (66/96), ciprofloxacin 59.4% (57/96), gentamicin 56.3% (54/96), and tobramycin 43.8% (42/96). For Gram-negative bacilli, sensitivities were the following: levofloxacin 88.2% (45/51), ofloxacin 76.9% (40/52), ciprofloxacin 75.0% (39/52), gentamicin 49.0% (25/51), and tobramycin 48.1% (25/52). Comparing the data from 2003 to 2006 with the data from 1999 to 2002, the susceptibility of organisms to frequently employed antibiotics was decreasing. CONCLUSIONS: The spectrum of organisms causing bacterial endophthalmitis is complex, and no single antibiotic provided coverage for all of the microbes isolated from intraocular specimens with bacterial endophthalmitis. Combination therapy is recommended as the initial empiric treatment of suspected bacterial endophthalmitis.