摘要
目的观察VSD对感染创面中铜绿似单胞菌生长的影响,并探讨其可能机制。方法选取健康成年雄性C57 BL/6小鼠40只,按照随机数字表法分为对照组和治疗组,每组20只。无菌条件下切除各小鼠背部1cm×1cm的全层皮肤,将细菌荧光素酶目的基因luxCDABE标记的野生型铡绿假单胞菌菌株PA01-lux涂抹于创面,包扎创而24h,制成铜绿假单胞菌感染小鼠模型,治疗组小鼠创向行VSD治疗(负压为-16.625kPa),对照组创面常规换药。分别于治疗前和治疗24h时,刚小动物活体成像系统检测2组小鼠创面PAOI-lux荧光强度,激光多普勒血流成像仪检测创面血流链,以实时荧光定量RT—PCR检测创缘组织IL-1β、血管内皮生长岗子(VEGF)的mRNA表达水平。观察治疗24h时2组小鼠创缘组织病理学特点。对实验数据行t检验。结果(1)治疗前,治疗纰小鼠创面PAOI-lux荧光强度与对照组相近(t=0.03,P=0.98);治疗24h时,治疗绀的荧光强度为(2.69±0.75)光子·秒-1·厘米·单位角度。(photons·s-1·m-2·sr-1),明显低于对照组的(5.18±0.96)Dhotons.s-1·cm-2·sr-1 t=3.54,P=0.02。(2)治疗前,治疗组小鼠创面血流董与对照组相似(t=0.50,P=0.64);治疗24h时,治疗组创面血流量为(96±9)灌注单位,明娃高于对照组的(70±11)灌注单位,t=3.13,P=0.04。(3)治疗前,2组小鼠创缘皮肤组织中IL-1β、VEGFmRNA表达水平接近(t=0.19,P=0.86;t=0.07,P=0.95);治疗24h时,治疗组IL-1β、VEGF mRNA表达水平分别为4.72±0.37、2.68±0.39,均明显高于对照绀的2.24±0.50、1.22±0.13,t值分别为6.90、6.12,P值均为0.00。(4)治疗24h时,治疗组创缘皮肤组织内炎性细胞浸涧数量较对照绀增加约77%。结论与常规换药相比,VSD治疗在小鼠全层皮肤缺损早期即能明显降低创面铜绿假单胞菌含量。其机制叮能与增加创面局部血流量、提高创面组织炎性细胞数龟、促进IL-1β和VEGF的tuRNA表达有关。
Objective To observe the effect of vacuum sealing drainage (VSD) on the proliferation of Pseudomonas aeruginosa (PA) in infected wound, and to explore its possible mechanism. Methods Full-thickness skin wounds each with area of 1cm ×1cm were produced on the back of 40 C57BL/6 mice, and then they were contaminated with wild type PA strains PAO1 marked with target gene of hac.terial luciferase IuxCDABE (PAOI-lux), they were dressed for 24 hours to reproduce PA infection model. Then mice were divided into experiment ~ E, with treatment of VSD ( pressure value at - 16. 625 kPa) ] and cuntrol (C, with treatment of conventional dressing change) groups according to the random number table, with 20 mice in each group. The fluorescence intensity of PAO1-lux and blood fluw in wound was respectively measured by in vivo optical imaging system and laser Doppler perfusion imagcr before treatment and at post treatment hour ( PTH ) 24. The expression levels of IL-1β and vasc.ular endothelial growth factor (VEGF) mRNA in wound edge were determited by real-time fluorescence quantitative RT-PCR befure treatment and at PTH 24. The specimens of wound edge tissue were collected for observation of pathological c.hange at PTH 24. Data were processed with t test. Results There were no obvious difference in fluorescence intensity of PAO1 -lux and blood tlow in wound between E and C groups befnre treatment ( with t value respectively 0.03,0. 50, P values all above 0.05 ). The fluorescence intensity of PAOl-lux and blood flow in wound in E group at PTH 24 [ (2.69 ± 0.75 ) photons · s-1 . cm-2 · sr-land (96 ± 9) PU ] was respectively lower and higher than that in C group [ (5.18 ±0.96) photons ·s-1 · cm-2 · sr-1 and (70 ± 11) PU, with t value respectively 3.54, 3.13, P values all below 0. 05 ]. The expression levels of IL-1β and VEGF mRNA in both groups before treatment were similar (with t value respectively 0.19, 0. 07, P values all above 0. 05). The expression levels of IL-1β and VEGF mRNA in E group at PTH 24 was respectively 4.72 ± 0.37, 2.68±0. 39, all markedly higher than those in C group (2.24 ± 0.50, 1.22 ± 0. 13, with t value respectively 6.90, 6.12, P values all equal to 0.00). The number of inflammatory cell infiltrating the wound edge in E group at PTH 24 was increased by nearly 77% as compared with that in C group. Conclusions Compared with conventional dressing change, VSD can reduce the amount of Pseudomonas aeruginosa in full-thickness skin defect wound at the early stage, it may be related with an increase in blood flow and number of inflammatory cells in wound tissue, promoting expression of IL-1β and VEGF mRNA.
出处
《中华烧伤杂志》
CAS
CSCD
北大核心
2011年第4期255-259,共5页
Chinese Journal of Burns
关键词
负压伤口疗法
假单胞菌
铜绿
感染
活体成像
Negative-pressure wound therapy
Pseudomonas aeruginosa
Infection
In vivo optical imaging system