Determination of antimicrobial effect of protamine by transmission electron microscopy and SDS PAGE on isolates from diabetic foot infection.

OBJECTIVES

Diabetic foot infection is one of the major complications of diabetes leading to lower limb amputations. Isolation and identification of bacteria causing diabetic foot infection, determination of antibiotic resistance, antimicrobial potential of protamine by electron microscopy and SDS-PAGE analysis, arethe aims of this study.

MATERIALS AND METHODS

285 pus samples from diabetic foot infection patients were collected from different hospitals of Karachi and Capital Health Hospital, Halifax, Canada. Clinical history of each patient was recorded. Bacterial isolates were cultured on appropriate media; identification was done by morphology, cultural and biochemical tests. Effect of protamine against multi drug resistant strains of was checked by minimum inhibitory concentration in 96 well micro-titer plates. The isolates were grown in bactericidal concentration of protamine on plates to isolate mutants. Effect of protamine on protein expression was checked by SDS- PAGE and ultra-structural morphological changes by transmission electron microscopy.

RESULTS

Results indicated prevalence of foot infection as 92% in diabetic patients. Major bacterial isolates were 65 (23%), 80 (28.1%), spp. 37 (13%), 79 (27.7%), and 24 (12%). These isolates were highly resistant to different antibiotics. MIC value of protamine was 500 µg/ml against . SDS-PAGE analysis revealed that protamine can suppress expression of various virulence proteins and electron micrographs indicated condensation of cytoplasm and accumulation of protamine in cytoplasm without damaging the cell membrane.

CONCLUSION

. and were the major isolates expressing multi-drug resistance and protamine sulfate represented good antimicrobial potential.