Abstract

Resistance profile to antibiotics and the occurrence of class-1 integron in 23 bacteria isolated from diabetic foot ulcers (DFUs) were analyzed. Among 23 isolates, 16 elicited resistance to at least two antibiotics and seven were sensitive. Majority of the isolates were resistant to spectinomycin and streptomycin (68.75%) followed by trimethoprim (62.50%) and ampicillin (50%). Among the antibiotics resistant isolates, six exhibited resistance to four different groups of antibiotics and one showed resistance to 11 antibiotics (six antibiotic groups). 17 bacterial strains possessed class-1 integrons with an amplicon size of 0.30 to 2.40 kb which suggested their role in conferring resistance to antibiotics. 2-D gel electrophoresis of proteins extracted from Escherichia coli DF39TA grown with antibiotics revealed significant alteration in total proteome as compared to control culture. Five spots showing four fold up regulation were identified by MALDI TOF MS as OmpX, OmpA, OmpA-OmpF, Omp-tolC and chaperone protein DnaK. Changes in abundance of above proteins following growth with antibiotics may be beneficial for antibiotic resistant bacteria to adapt under adverse environmental conditions. Findings of this study suggest that infection with multiple antibiotic-resistant bacteria is common to DFUs and resistance is mediated by class-1 integrons.

Key words: Diabetic foot ulcer, antibiotic resistance, polymerase chain reaction (PCR), class-I integron, 2-D gel electrophoresis, Escherichia coli.

Abbreviation

DFUs, Diabetic foot ulcers; MDRO, multidrug resistant organisms; MDR, multi drug resistance; PCR, polymerase chain reaction; MR, methyl red; NCBI, National Center for Biotechnology Information; TCA, trichloro acetic acid; IEF, isoelectric focusing; SDS-PAGE, sodium dodecyl sulphate-polyacrylamide gel electrophoresis; MIRSA, methicillin resistant Staphylococcus aureus; ESBL, extended-spectrum β-lactamase.