Characterization of microbial agents in diabetic foot infection and its correlation with chronic subclinical inflammation

Abstract

Diabetes mellitus (DM) is a metabolic disorder with chronic physiological complication increased risk of developing Diabetic Foot Infection (DFI) by 25% in diabetics’ patients. The pathophysiological differences between DFI and non-DFI patients may alter microbial compositions in infections. The present study aims at culture based comparative analysis of microbes’ colonized in DFI and non-DFI patients in Bangladesh and explore their correlation with chronic subclinical inflammation (CSI). Pus specimens were collected from 67 DFI and 10 non-DFI patients. Most of them were from rural area; belong to lower middle income group and age between 28-75 years. Enterococcus spp. (9%), and Klebsiella spp. (8%) occurred only in DFI and the other predominant bacteria in DFI over non-DFI patients were Enterobacter spp. (22%) and Bacillus spp. (12%). In contrast, non-DFI patient’s samples predominated Pseudomonas spp. (29%) and Citrobacter spp. (29%). In both cases, Staphylococcus spp. (13%) and Acinetobacter spp. (10%) contained same percentages. The statistical calculation (Comparative bacterial significance analysis: at 90% confidence level) revealed that the rate of occurrence of three organisms; Enterococcus spp. |Z|=2.2125, Klebsiella spp. |Z|= 1.732, Bacillus spp. |Z| =1.9034 is significance in DFI patients compare to non-DFI patients. However in non-DFI patients rate of occurrence of Citrobacter spp. |Z|=14.1901 were significance. Most of the isolates from DFI patients were commonly resistant to cephalosporins (ceftazidime, ceftriaxone, cefuroxime) and monobactam (azteronam) groups of antibiotics. Plasmid profile analysis of the isolates revealed that most of the multidrug resistant (MDR) isolates were plasmid free implicating chromosome mediated MDR properties. A plasmid free, P. studzeri isolated from DFI showed resistant to more than 12 groups of antibiotics. DFI patients had comparatively higher C-reactive protein (CRP) values than non-DFI patients; and there were positive correlation with MDR with CRP values. A significant correlation (p<0.01) were observed between high serum CRP and infection with MDR organism in DFI patients. In conclusion, this investigation showed that there is a clear demarcation of resistant microbiomes composition between DFI and Non-DFI patients’ samples and a positive correlation of CRP values and resistant microbiomes in DFI patients. These results have implication the need for an alternate treatment of DFI patients in Bangladesh.