Silver nanoparticles as potential antibiofilm agents against Candida albicans, Candida tropicalis and Candida glabrata

GALERA ILD; PAEZ PL; PARAJE MG

Virtual

Congreso; SAMIGE - SAIB 2020; 2020

SAMIGE

Infections caused by biofilmembeddedpathogensdecreasetheefficacyoftraditionaltreatmentsandincreaseantimicrobialtolerance.Inaddition,mostofthehumanbacterialinfectionsarebiofilm-associated.Candidaalbicansistheyeastmostfrequentlyisolatedinfungalinfections,followedbyCandidaglabrataandCandidatropicalis.Biofilmformationisacomplexprocesswithdifferentgrowthphases(early,intermediate,andmaturation).Nanoparticles(NPs)arepotentialcandidatestoobtainanantifungal(ATF)activity,thuswouldpreventingthefirststagesoffungalcolonizationandavoidingthesubsequentformationofbiofilms.TheobjectiveofthisworkwastoevaluatetheeffectofbiosynthesizedsilverNPs(AgNPs)againstinitialandmatureinC.albicans,C.tropicalisandC.glabratabiofilms.C.albicansSC5314,C.tropicalisNCPF3111,andC.glabrataATCC2001werestudied.Theminimuminhibitoryconcentration(MIC)andtheminimumfungicidalconcentration(MFC)ofAgNPsweredeterminedbythemicrodilutionmethodaccordingtoClinical&LaboratoryStandardsInstituteM27-4thed.Theinhibitoryconcentrationofthebiofilms(%I)wasevaluatedovertheinitialstagesofformation.Theconcentrationofreductionofthebiofilms(%R)wasevaluatedagainstthematurebiofilms(48h),beingexposedtoconcentrationsofAgNPs(supraMIC,MICandsubMIC).Biofilmformationwasachievedthroughtheabilityofmicroorganismstoadheretowellsofflat-bottomed96-wellmicroplates,andquantifiedbyCrystalstaining.Thebiofilmsweredisruptedbysonication(40kHz,60s)inordertore-suspendandrecoverviablesessilecellsanddeterminedbyplatecounting(colony-formingunitspermL,CFUmL-1).ThesameMICandMFCvaluewasfoundforAgNPsinC.albicans3.7x10-2pM,inC.tropicaliswas5.0x10-1pMandfinallyC.glabratashown1.2x10-1pMforAgNPs.The%Iwas61±8(3.7pMAgNPs)forC.albicans,65±3(with38.5pMAgNPs)forC.tropicalis,84±4(12.5pMAgNPs)forC.glabrata.The%Rwas53±3(3.7pMAgNPs)forC.albicans,84±9(38.5pMAgNPs)forC.tropicalis,69±9(77pMAgNPs)forC.glabrata.ExposuretoAgNPsleadstoreductioninmicrobialbiomassandsurvivingsessilecells,reducedbymorethan10%inthethreeCandidaspecies.ThisstudydemonstratedthatAgNPsexertsanantibiofilmeffectagainstseveralCandidaspecies,suggestingitspotentialapplicationasanantibiofilmagentaloneorincombinationwithtraditionalantifungalagents.