Objective:To investigate the risk factors for aggravation of type 2 diabetic foot ulcer and the correlation between the level of infection and the severity of the disease,as well as the association of the detection rate of bacteria and the types of bacteria with disease severity in patients with type 2 diabetic foot ulcer,and to provide individualized guidance for the prevention,diagnosis,and treatment of type 2 diabetic foot.Methods:A retrospective analysis was performed for the data of 150 patients with type 2 diabetic foot who were treated in Department of Endocrinology,The First Affiliated Hospital of Kunming Medical University,from October 2021 to June 2023,and according to the Wagner grade of diabetic foot,these patients were divided into mild group A(35 patients with Wagner grade 2),moderate group B(58 patients with Wagner grade 3),and severe group C(57 patients with Wagner grade 4).The clinical data of the three groups were analyzed.Results:The severity of type 2 diabetic foot ulcer was correlated with white blood cell count,neutrophil count,platelet count,monocyte count,globulin,alkaline phosphatase,neutrophil-lymphocyte ratio,monocyte-lymphocyte ratio,platelet-lymphocyte ratio,high-sensitivity C-reactive protein,procalcitonin,interleukin-6,erythrocyte sedimentation rate,hemoglo-bin,albumin/globulin ratio,lymphocyte count,cholinesterase,albumin,fasting blood glucose,gamma-glutamyl transferase,glycated he-moglobin,blood uric acid,high-density lipoprotein cholesterol,total cholesterol,triglycerides,and low-density lipoprotein cholesterol(P<0.05).The multivariate ordinal logistic regression analysis showed that the neutrophil-lymphocyte ratio and erythrocyte sedi-mentation rate were independent risk factors for the progression of Wagner grade of diabetic foot(P<0.05).For groups A,B,and C,the detection rate of bacteria in foot ulcer secretion tended to increase with the severity of diabetic foot,with the highest detection rate in group C,followed by groups B and A.A total of 31 types of bacteria were detected in the three groups,and the proportion of Gram-positive bacteria was higher than that of Gram-negative bacteria,with Staphylococcus aureus accounting for the highest proportion of 27.72%in all samples.Conclusion:High-sensitivity C-reactive pro-tein,procalcitonin,interleukin-6,and erythrocyte sedimentation rate increase with the progression of the Wagner grade of diabetic foot,and neutrophil-lymphocyte ratio and erythrocyte sedimentation rate are independent risk factors for the progression of the Wagner grade of diabetic foot.The detection rate of bacteria in foot ulcer secretion tends to increase with the Wagner grade of diabetic foot,and Gram-positive bacteria account for a higher proportion than Gram-negative bacteria,with Staphylococcus aureus accounting for the highest proportion.