PhD. Universidade Federal de Minas Gerais - School of Nursing - Department of Basic Nursing - Belo Horizonte (MG), Brazil.
MSc. Universidade Federal de Minas Gerais - School of Nursing - Postgraduate Program - Belo Horizonte (MG), Brazil.
Acta Cir Bras. 2022 Jun 1;37(3):e370306. doi: 10.1590/acb370306. eCollection 2022.
To evaluate a biofilm model of Pseudomonas aeruginosa in excisional cutaneous wound in mice.
Preclinical, translational study conducted with 64 C57BL/6 mice randomly assigned to control and intervention groups. Evaluation was on days D0, D3, D5, D7 and D10 of wound making. The profile of biofilm formation and induction was evaluated using wound closure kinetics, quantitative culture, and evaluation of wounds using transmission electron microscopy (TEM). Clinical evaluation was performed by liver tissue culture, weight variation, and quantification of leukocytes in peripheral blood. Analyses were performed with GraphPad Prism software.
Bacterial load for induction of infection with P. aeruginosa and survival of animals was 104 UFC·mL-1. In D5 (p < 0.0001) and D7 (p < 0.01), animals in the intervention group showed a delay in the healing process and had their wounds covered by necrotic tissue until D10. Statistical differences were observed in wound cultures and weight at D5 and D7 (p < 0.01). Liver cultures and leukocyte quantification showed no statistical differences. No bacteria in planktonic or biofilm form were identified by TEM.
The findings raise questions about the understanding of the ease of formation and high occurrence of biofilm in chronic wounds.
评估铜绿假单胞菌在小鼠切创皮肤模型中的生物膜形成。
本研究为临床前转化研究，纳入 64 只 C57BL/6 小鼠，随机分为对照组和干预组。造模后第 0、3、5、7 和 10 天进行评估。采用伤口闭合动力学、定量培养和透射电子显微镜（TEM）评估生物膜形成和诱导情况。通过肝组织培养、体重变化和外周血白细胞计数进行临床评估。分析采用 GraphPad Prism 软件。
铜绿假单胞菌诱导感染的细菌负荷和动物存活率为 104 UFC·mL-1。在第 5 天（p<0.0001）和第 7 天（p<0.01），干预组动物的愈合过程出现延迟，伤口被坏死组织覆盖，直至第 10 天。第 5 天和第 7 天的伤口培养和体重存在统计学差异（p<0.01）。肝培养和白细胞计数无统计学差异。TEM 未发现浮游或生物膜形式的细菌。
这些发现对慢性伤口中生物膜形成的容易程度和高发生率的理解提出了质疑。
