Investigation of antibacterial effect of a recombinant phageendolysin on Acinetobacter baumannii

Background and Aim : A. baumannii infection has become a critical challenge to health caresystems. The most important concern about this bacterium is its increased resistance to differentantibiotics. The prevalence of antibiotic resistant A. baumannii is also high in Iran. One of themethods recently used as an alternative to antibiotic treatment is to use phage endolysin enzymesto specifically eliminate bacteria. In this study, antibacterial effect of recombinant PlyF۳۰۷endolysin was examined on Acinetobacter baumannii.Methods : After synthesis of the endolysin PlyF۳۰۷ gene, the plasmid extracted and transferredto the expression vector pET۲۸a by the enzymatic digestion. The plasmid transferred to E. coliBL۲۱(DE۳) pLysS. Then induced for expression by IPTG. Western blot method was used toconfirm the expression of recombinant protein. Endolysin purified by nickel chromatographycolumn. Then, the protein concentration calculated with Bradford method. To investigate theantibacterial effect of the enzyme, plate lysis assay performed, on Acinetobacter baumannii PTCC۱۸۵۵. Tryptic Soy Agar (TSA) medium was used for antibacterial assay. In summary, ۱.۵×۱۰۸CFU, equivalent to McFarland Turbidity Standard No. ۰.۵, transferred to TSA and ۲۰μl of eachsample was dropped on the medium and then incubated at ۳۷ °C for ۱۸ hours. The initialconcentration of the enzyme was ۶۰۰μg /ml, which was diluted ۱:۲, ۱:۴, ۱:۸ with a suitable buffercontaining ۰.۵ mM EDTA as a membrane permeabilizer.Results : The results showed a ۱۰-۱۵ mm inhibitory zone at the inoculation site of ۱:۴ dilution ofenzyme, which is probably due to the greater accessibility of the enzyme to the bacteria in a dilutedstate.Conclusion : According to the obtained results, the PlyF۳۰۷ endolysin can be candidate asantibacterial drug for Acinetobacter baumannii.

کلیدواژه ها:

Cross Infection ، Acinetobacter baumannii ، Anti-Bacterial Agents ، Bacteriophages ، enzyme.