Distribution of Microbes and Drug Susceptibility in Patients with Diabetic Foot Infections in Southwest China.

Mingxia Wu,Xiaotian Lei,Ziwen Liang,Liu Chen,Weiling Leng,Hang Pan

doi:10.1155/2018/9817308

Abstract

Objective To investigate the microbial distribution and drug susceptibility among diabetic foot ulcers (DFUs) with different Wagner grades and between acute and chronic DFUs. Methods. We enrolled 428 DFU patients who were hospitalized and treated in the Southwest Hospital. We collected deep ulcer secretion for microbial culture and drug susceptibility tests and analyzed the results. We reexamined 67 patients with poor anti-infection efficacy and analyzed microbial species. Results: The 354 positive samples included 201 cases (56.8%) of single-pathogen infections and 153 cases (43.2%) of multiple-pathogen infections before antibiotic therapy. A total of 555 strains were cultivated, including 205 (36.9%) strains of gram-positive organisms (GPOs), 283 (51.0%) gram-negative bacilli (GNB), and 67 (12.1%) fungal strains. In terms of distribution, patients with different Wagner grades had different bacterial composition ratios (P < 0.01). Patients with Wagner grades 3–5 mainly had GNB. The specimens from chronic ulcer wounds were primarily GNB (54.2%), whereas fungi accounted for 14.4% of the infections; the distribution was significantly different from that of acute ulcers (P < 0.01). The susceptibility tests showed that the Staphylococcus genus was more susceptible to vancomycin, linezolid, and tigecycline. Tobramycin was the most effective drug (97%) for the treatment of Escherichia coli, followed by ertapenem (96.4%), imipenem (93.5%), and cefotetan (90%). Most of the remaining GNB were susceptible to antibiotics such as carbapenems, aminoglycosides, fluoroquinolones, ceftazidime, cefepime, and piperacillin-tazobactam (>63.2%). After antibiotic therapy, the positive rate of microbial culture was 52.2%, and the proportion of GNB and fungi increased to 68.9% and 20%. Conclusion The distribution and types of bacteria in diabetic foot infection (DFI) patients varied with the different Wagner classification grades, courses of the ulcers, and antibiotic therapy. Multidrug resistance were increased, and the clinical treatment of DFIs should select the most suitable antibiotics based on the pathogen culture and drug susceptibility test results.

Highlights

Studies from different countries have revealed different diabetic foot infection (DFI)-related microbial compositions and drug susceptibilities [6,7,8], and the ratios of patients associated with multidrug resistance (MDR), methicillin-resistant Staphylococcus (MRS), and extended-spectrum β-lactamase (ESBL) bacterial infections have increased every year, suggesting that administration of empirical anti-infective regimens will increase the chances of treatment failure
China has a large population of DFI patients with a vast geographical distribution and significant variations in the types of bacterial infections found in DFI wounds from different regions
Our results indicated that the DFI-causing bacteria were dominated by gram-negative bacilli (GNB) (51%), which differed from the results of the survey performed in southern China from 2009 to 2014 [13] in which gram-positive organisms (GPOs) accounted for 54% of the infections

Summary

Introduction

Diabetic foot disease is one of the most difficult to treat complications of diabetes and has become an important cause of nontraumatic amputation. The risk of a DFU complicated by a diabetic foot infection (DFI) is high [3]. DFIs extend the average length of the hospital stay, resulting in a huge economic burden [4] and increase the risk of amputation [5], which seriously affects the quality of life and life expectancy of patients with diabetes. Studies from different countries have revealed different DFI-related microbial compositions and drug susceptibilities [6,7,8], and the ratios of patients associated with multidrug resistance (MDR), methicillin-resistant Staphylococcus (MRS), and extended-spectrum β-lactamase (ESBL) bacterial infections have increased every year, suggesting that administration of empirical anti-infective regimens will increase the chances of treatment failure.

Methods

Results

Conclusion