Evaluation of antibiofilm activity for siderophore produced from rhizospheric Acinetobacter baumannii against of some respiratory tracts bacteria

Abstract

         Siderophore  was extracted from Acinetobacter baumannii  isolated from rhizosphere reigion in Baghdad City . The results appeared the ability  of isolate  (Acinetobacter baumannii 5)  to  produce  Siderophore  with diameter of (15) mm and the condition for production was temperature reached 30 degrees, and the optimum  pH was 7 . Purification  of siderophore  through :  Ion exchange chromatography for  purify more stable form as ferric-siderophore complex and final step through gel filtration.  The activity of  purified siderophore as antibacterial agent was tested against 13 different local clinical bacterial  as follows (Klebsiella pneumoniae ,Pseudomonas aeruginosa ,Acinetobacter baumannii , Escherichia.coli ,Streptococcus pyogenes ,Staph. aureus ,Enterobacter cloacea, Enterobacter aerogenes ,Enterococcus faecalis ,Burkholderia cepacian ,Serratia fiaria ,S. marcescens ,Klebsiella oxytoca ) isolates at concentration 20 mg/ml of free iron siderophore  and the results showed that highest activity of siderophore was reported on Streptococcus.pyogenes with inhibition zone  (26)mm, and on Acinetobacter baumannii, Serratia.marcescens and Escherichia.coli the inhibition zone  was  (20)mm while the lowest effects were on Serratia. fiaria and Klebsiella .oxytoca with inhibition zone (16mm). As well as, the purified siderophore showed good activity as  antibiofilm of pathogenic bacteria. The highest antiadhesive percentage was observed for Escherichia.coli by percentage 64.4%.