Fenotypic characteristics of bacteria in diabetic patients

Introduction: Biofilms are microbially derived sessile community characterized by cells that are irreversibly attached to a substratum or interface or to each other. They embedded in a matrix of extracellular polymeric substances that they have produced, and exhibit an altered phenotype with respect to growth rate and gene transcription.Aim: Diabetes mellitus is one of the oldest diseases known to mankind. Diabetic patients tend to have infections due to many factors. Expecially, prevelance of some of soft tissue infections, (necrotizing fasciitis, fournier gangren etc.), Staphylococcus aureus and Gram-negative pneumoniae and asymtomatic bacteriuria are increased than non-diabetic patients. In these events, there are data about defects in diabetic patients? immun system with endotel dysfunction and the surviving properties of the bacteria in different conditions. It is thought that in diabetic patients altering values of glisemia triggers the antibiotic resistance, biofilm production and the other virulan characteristics of bacteria. From this point, in our study we purposed to find differences between biofilm production, virulance factors and antibiotic resistance of same species of bacteria isolated from diabetic and non-diabetic patients.Material and Methods: In this study we examined 100 Escherichia coli obtained from urine and wound cultures of diabetic and non-diabetic patients. The slime production, type1 and p-pili expression of all strains were studied by quantitative microdilution plate method and hemagglütitation method respectively. The antibiotic susceptibility of strains was determined by disc diffusion method as recommended by CLSI. In quantitative microdilution plate method optical density (OD) of well content was determined at 595 nm (OD595) using a microplate reader and strains which? optical density was greater than 0,8 were considered as slime positive. To detect p-pili of the bacteria, the heamgglutitation with sheep erythrocytes in either existence or absence of % 2,5 ? -Methyl-D-mannoside was observed for each strain. The dishaemgglutitation with guinea erythrocytes in existence of % 2,5 ? -methyl-D-mannoside % 2,5 ? -Methyl-D-mannoside and heamgglutitation with absence of % 2,5 ? -Methyl-D-mannoside pointed the type 1 fimbria production of the strain. The antibiotic susceptibility of strains was determined by Kirby- Bauer disk diffusion method as recommended by Clinical and Laboratory Standarts İnstitude (CLSI).Results: At the end of the study, the biofilm production, virulance factors and antibiotic resistance of E. coli strains which isolated from diabetic and non-diabetic patients were investigated and; in diabetic group slime formation was two times higher than non-diabetic group but this result was statistically not significant.Type 1 fimbria expression in diabetic strains was also % 12,2 higher than the non-diabetic strains but this value was statistically not significant either. In correlation between slime forming and antibiotic resistance; antibiotic resistance in slime-forming E. coli was greater than non-slime forming E. coli group but this was statistically not significant. Antibiotic resistance to ampicillin, amoxicillin/clavulanate, ciprofloxacin and co-trimoxazole in slime-forming E. coli strains was greater than non-slime-forming group.Conclusion: In this study we purposed to find differences between biofilm production, virulance factors and antibiotic resistance of same species of bacteria isolated from diabetic and non-diabetic patients. Although, the results were statistically not significant, in diabetic group the greater biofilm production, type 1 fimbria expression and in slime-forming group the greater antibiotic resistance to ampicillin, amoxicillin/clavulanate, ciprofloxacin and co-trimoxazole were observed. These results would assist to develop the follow-up and new treatment modalities of diabetic patients by way of understanding the underlying predisposition mechanisms of infections and pathogenesis of biofilm production. However, numerous comparative studies are required in this subject. Furthermore, our study is the first research which includes the slime production, fimbria expression and the distribution of these findings according to urine and wound cultures beside with antibiotic resistance and the relationships between these virulence factors of E. coli strains obtained from diabetic and non-diabetic patients.Key words: diabetes, biofilm, infection