骨科感染创面铜绿假单胞菌耐亚胺培南临床分析

目的：探讨骨科感染创面铜绿假单胞菌对亚胺培南耐药的原因和可能机制。方法：检测37株骨科感染创面铜绿假单胞菌外膜蛋白OprD2及金属β-内酰胺酶的表达情况，分析铜绿假单胞菌感染患者临床情况。结果：37株实验菌株中，15株对亚胺培南敏感，22株对亚胺培南耐药，其中有17例与ICU或呼吸内科住院有关，耐药株患者中APACHEⅡ评分达12以上占45．5％，平均住院时间（26．9±7．5）d，2周内有亚胺培南或美罗培南使用史者45．5％（10／22）；敏感株患者中APACHEⅡ评分〉12者6．7％，平均住院时间（13．5±6．6）d，2周内有亚胺培南或美罗培南使用史者0％（0／15）。OprD2相对含量耐亚胺培南菌株组为（2．65±0．54）％，明显低于亚胺培南敏感菌株组的（5．38±0．81）％（P〈0．01）。37株实验菌株中产金属β-内酰胺酶5株（13．5％），并均在耐亚胺培南菌株组中。结论：他科输入、病情危重免疫力低下、住院时间长、碳青霉烯类抗生素使用是骨科感染创面铜绿假单胞菌对亚胺培能耐药的主要原因，而OprD2的含量减少和产金属β-内酰胺酶是骨科感染创面铜绿假单胞菌对亚胺培能耐药的重要机制。

Clinical Analysis of Imipenem Resistance of Pseudomonas Aeruginosa Against Orthopedic Wound Infection

Objective： To investigate the possible mechanism of imipenem resistance of pseudomonas aeruginosa （P. aeruginosa） against orthopedic wound infection. Methods： The expression of pyocyanin ivolucer protein D2 （OprD2） and metallo-β-lactamases （MISLs） in 37 strains of P. aeruginosa were detected from the patients with orthopedic wound infections, and their clinical states were analyzed. Results： 15 of the 37 strains were sensitive to imipenem （the sensitive group）, while the other 22 were resistant to imipenem （the resistant group）, 17 of which were related to the ICU or respiratory department. In the resistant group, 45.5% of the patients with APACHE scoring more than 12 （mean hospital stay： 26.9 ± 7.5 d） were found, while 6.7% （ mean hospital stay was 13.5 ± 6.6 d） in the sensitive group. The ratios of the patients who had taken imipenem or meropenem for 2 weeks were 45.5 % （10/22） and 0% （0/15 ）respectively in the resistant group and sensitive group. The relative amount of OprD2 in the resistant group was （2.65 ± 0.54） % , which was significantly lower than that in the sensitive group （5.38 ±0.81 ） % （P 〈 0.01 ）. The 5 strains （ 13.5% ） that produced MβLs were found in the resistant group. Conclusion： The main reasons of P. aeruginosa resistance to imipenem included admission from other departments, serious diseases with low immunity, long time hospitalization and administration of carbapenems. The deficiency of OprD2 and production of MβLs were important mechanisms of imipenem resistance of P. aeruginosa against the orthopedic wound infection.