The Infectious Characteristics And Its Relationship With Lower-extremity Vascular Lesions In Patients With Diabetic Foot

Objective:Diabetic foot(DF)has been linked to several risk factors,such as neuropathic and vascular lesions and infection.The symptoms of DF include intermittent claudication,ischemic rest pain,foot ulcers,and gangrene.Older age,male,heart failure,end-stage renal disease,large foot ulcers,peripheral neuropathy,lower-extremity vascular lesions and infection,are all reported to be related with poor prognosis.And the Lower-extremity vascular lesion and infection are the most important factors.Currently,Diabetic foot ulcers(diabetic foot ulcers,DFU)is one of the main causes of hospitalization of diabetic patients.Infection is one of the direct causes of amputation and death in patients with DFU.The bacterial characteristics of DF infection has been reported previously.However,the type of DFU infection and the relationship between bacteria and vascular lesions are still unclear.To investigate the above issues 133 DF patients with infection of whom received bilateral lower limbs CTA as confirmation of vascular lesions were enrolled.Subjects:Between Mar.2009 and Mar.2016,in total of 133 cases of DFU patients(male: n=87;mean age 67.24±11.49 years old;mean duration of diabetes 8.0(3.0,15.0)years;mean duration of DF 1.5(0.5,7.5)months whom confirmed bacteria infection by secretion culture were enrolled in our department.Methods:Patients information were collected,and detailed medical history,physical examination,admission assessment and a preliminary diagnosis and treatment plan were performed and determined by health-care providers in our department.Blood pressure,ABI,TBI,routine blood test,liver and renal function test,serum total and albumin protein,routine urine test,fasting plasma glucose,Hb A1 c,secretion culture and drug susceptibility test of the DF were examined.All patients underwent angiography or 256 row CT(CTA,Philips Brilliance i CT 256 layer),which showed a high degree of consistency.According to the Trans-Atlantic Inter-Society Consensus(TASC),all the patients were further divided into four groups(A,B,C,D),and classified as mild-,moderate-,and severe-infection,or single and mixed infection.Results analysis were performed using SPSS18.0 statistical software.Results:1.Patients were divided into four groups accord to TASC classification(TASC A,n=27;B,n=19;C,n=52;D,n=35).Compared with TASC A and B groups,patients in TASC D group have older age,longer duration of diabetes and neutrophilic granulocyte percentage,while with significantly lower ABI and TBI.G-bacteria infection rate was 44.6% in TASC A and B groups,while in TASC C and D groups the number was 54.2%.The rate of antibiotic resistance was 60.2%(TASC A and B group: 52.2%,C and D groups:64.4%),and there was significant statistically difference between groups(P=0.028).2.All DFU patients were classified into mild-infection(n=39,29.3%),moderate-infection(n=66,49.6%)and severe-infection groups(n=28,21.1%)according to the degree of infection.Significant differences were found in leukocyte and albumin protein,glycosylated hemoglobinand neutrophilic granulocyte percentage among groups.No significant differences were found in the percentage of antibiotic resistance among three groups,of which were 51.3%,69.7% and 71.4%,respectively.The severity of bacteria infection increased significantly in TASC C and D groups(n=66)compared with TASC A and B groups(n=21,P=0.022).3.Constituent ratio of different kinds of bacteria: G+ bacteria infection(36.8%),Gbacteria infection(57.8%),fungal infection(5.4%),and mixed infection(39.1%).Cultured 185 strains of pathogenic bacteria totally,including 35 strains of staphylococcus aureus(18.9%),25 strains of pseudomonas aeruginosa(13.5%)and 14 strains of dung enterococcus(7.5%),and staphylococcus,streptococcus,Klebsiella pneumoniae and Escherichia coli were also commonly seen.Mixed infection ratio were significantly different among TASC groups(P=0.002),with 18.5% in TASC A group,and 26.3%,26.9%,and 60.0% in TASC B,C and D groups respectively.Conclusions:1.The study showed that the DFU infection was commonly related to staphylococcus aureus,pseudomonas aeruginosa,and enterococcus,with mainly G-bacteria and drug-resistant strains.Along with the severity of bacterial infection increased,the rate of drug resistance raised.Therefore,it is not exactly the same as the reported pathogens in domestic or international study,suggesting that diabetic foot ulcers infection was severe and bacteriological characteristics was different from other regions.2.With the deterioration of the lower-extremity vascular lesions,the severity of infection aggravated,and the rate of mixed and G-bacteria infection increased.