Anti-biofilm activityofbiogenicseleniumnanoparticlesandselenium dioxide againstclinicalisolatesof Staphylococcus aureus, Pseudomonas aeruginosa, and Proteus mirabilis

The aimofthepresentstudywastoinvestigatetheanti-biofilmactivityofbiologicallysynthesizedsele- nium nanoparticles(SeNPs)againstthebiofilmproducedbyclinicallyisolatedbacterialstrainscompared to thatofseleniumdioxide.Thirtystrainsof Staphylococcus aureus, Pseudomonas aeruginosa, and Proteus mirabilis were isolatedfromvariousspecimensofthepatientshospitalizedindifferenthospitals(Ker- man, Iran).Quantificationofthebiofilmusingmicrotiterplateassaymethodintroduced30%of S. aureus, 13% of P. aeruginosa and 17%of P. mirabilis isolates asseverelyadherentstrains.Transmissionelectron micrograph (TEM)ofthepurifiedSeNPs(producedby Bacillus sp. MSh-1)showedindividualandspher- ical nano-structureinthesizerangeof80–220nm.Obtainedresultsofthebiofilmformationrevealed that seleniumnanoparticlesinhibitedthebiofilmof S. aureus, P. aeruginosa, and P. mirabilis by 42%,34.3%, and 53.4%,respectively,comparedtothatofthenon-treatedsamples.EffectoftemperatureandpHon the biofilmformationinthepresenceofSeNPsandSeO2 was alsoevaluated