糖尿病足创面铜绿假单胞菌三型分泌系统和生物膜特点及与抗生素耐药性的关系

The relationship between the characteristics of type 3 secretion system and biofilm of Pseudomonas aeruginosa in diabetic foot wound with antibiotic resistance

目的探讨糖尿病足(diabetic foot,DF)创面中铜绿假单胞菌(Pseudomonas aeruginosa)三型分泌系统、生物膜特点,分析其与抗生素耐药性的关系。方法收集2018年2月1日至2018年12月31日天津医科大学朱宪彝纪念医院糖尿病足科住院DF患者创面中铜绿假单胞菌33株,作为DF组,同时收集非糖尿病创面中铜绿假单胞菌13株,作为对照组。做抗生素敏感试验,检测铜绿假单胞菌三型分泌系统毒力基因exoS、exoU及生物膜形成能力。分析其特点及与抗生素敏感性的关系和临床转归情况。结果两组均以携带exoS的铜绿假单胞菌为主。DF组占90.9%,对照组占84.6%,差异无统计学意义(χ^(2)=0.54,P=0.46)。携带exoS的多重耐药菌株在DF组占16.7%,对照组占18.2%,差异无统计学意义(χ^(2)=0.18,P=0.83)。携带exoU的铜绿假单胞菌共5株,DF组3株,1株多重耐药,对照组2株,无多重耐药株。DF组中生物膜增强的铜绿假单胞菌占57.6%,多重耐药株生物膜增强的占83.3%。两种铜绿假单胞菌产生的生物膜耐药性不同,但均对碳青霉烯类抗生素无效。产生生物膜的DF创面清创次数更多(P<0.01),抗生素使用时间更长(P<0.01),但愈合率在75%~90%。结论DF创面中以分泌exoS铜绿假单胞菌为主。DF创面中铜绿假单胞菌产生生物膜是其产生耐药的原因之一,通过多次清创联合敏感抗生素治疗是清除生物膜的有效方法。

Objective To explore the characteristics of type 3 secretion system and biofilm of Pseudomonas aeruginosa in diabetic foot wound,and to analyze the relationship between these factors,as well as to the antibiotic sensitivity.Methods Thirty-three strains of Pseudomonas aeruginosa were collected from the foot wounds of diabetic foot inpatients in Tianjin Medical University Chu Hsien-I Memorial Hospital from February 1,2018 to December 31,2018.Thirteen strains of Pseudomonas aeruginosa were collected from non-diabetic wounds.All strains were tested for antibiotic sensitivity.The virulence genes exoS or exoU of Pseudomonas aeruginosa and the ability of biofilm formation were tested.The characteristics of exoS or exoU and biofilm of Pseudomonas aeruginosa were analyzed.Patients′clinical outcomes were also analyzed.Results Pseudomonas aeruginosa with exoS gene was the major pathogen,90.9%found in diabetic foot group and 84.6%in control group,with no significant difference(χ^(2)=0.54,P=0.46).The drug-resistant strains of Pseudomonas aeruginosa with exoS accounted for 16.7%in diabetic foot group and 18.2%in control group,also with no significant difference(χ^(2)=0.18,P=0.83).There were 5 strains of Pseudomonas aeruginosa carrying exoU,3 strains in diabetic foot group,of which 1 was resistant,2 in control group,no resistant strain.Pseudomonas aeruginosa increased the ability of biofilm formation in diabetic foot group,accounting for 57.6%,and for resistant strains,83.3%of them increased the biofilm formation ability.Two kinds of Pseudomonas aeruginosa produced different biofilms,but they were effectiveless for carbapenem antibiotics.The times of debridement(P<0.01),time of antibiotic use(P<0.01)were more in biofilm wound,but the healing rate reached 75%-90%.Conclusion Pseudomonas aeruginosa secreting ExoS is the main one in the diabetic foot wound.The ability of Pseudomonas aeruginosa to produce biofilm in DF wound is increased.Biofilm is one reason for its antibiotic resistance.Multiple debridement combined with sensitive antibiotics is an effective method to remove biofilm.