CharacterizationofShigatoxin-producingEscherichiacoliO130:H11andO178:H19isolatedfromdairycows

DANIEL FERNÁNDEZ; ALEJANDRA KRÜGER; ROSANA POLIFRONI; ANAV. BUSTAMANTE; A. MARIEL SANSO; ANALÍA I. ETCHEVERRÍA; PAULAM.A. LUCCHESI; ALBERTOE. PARMA; NORAL. PADOLA

Frontiers in cellular and infection microbiology

Frontiers

Año: 2013 vol. 3 p. 1 - 6

2235-2988

Shigatoxin-producingE.coli(STEC)areisolatedfromhumanpatientswithbloodydiarrhea,hemorrhagiccolitis(HC),andhemolyticuremicsyndrome(HUS).Inthelastyears,theinfectionswithnon-O157serotypesareincreasingtheirfrequencyofassociationwithhumandisease.STECproduceShigatoxin(Stx)andothervirulencefactorsthatcouldcontributetohumanpathogenesis.Cattlearethemainreservoirandthetransmissiontohumansisthroughtheconsumptionofundercookedmeat,non-pasteurizeddairyproducts,andvegetablesorwatercontaminatedwithfeces.WehavepreviouslydeterminedthatO130:H11andO178:H19serotypeswerethemostprevalentindairycowsfromArgentina.Inthepresentstudy,37and25STECisolatesfromdairycowsbelongingtoO130:H11andO178:H19serotypes,respectively,werecharacterizedregardingtotheircytotoxicityonVerocells,stxsubtypes,presenceofsabandtypingbymultiple-locusvariable-numbertandemrepeatanalysis(MLVA).Allstrainsdemonstratedacytotoxiceffect,andinO130:H11isolates,stx2EDL933wasthepredominantsubtype.InO178:H19isolatesthemainstx2subtypewasstx2vha.Thesabgenewasdetectedin65and24%oftheisolatesbelongingtoO130:H11andO178:H19,respectively.OnlyoneMLVAprofilewasidentifiedamongtheO130:H11isolatesmeanwhile10MLVAprofilesweredetectedamongtheO178:H19isolateswhichweregroupedintwomainclusters.Inconclusion,ourdatashowthatO130:H11andO178:H19STECisolatesencodevirulencefactorsassociatedwithseverehumandiseaseandbothserotypesshouldbeconsideredforroutinelytesting.Oursubtypingexperimentsshowedthatisolatescouldbedistinguishedbasedonthestx2subtypeandthepresence/absenceofsabgene,andforisolatesbelongingtoO178:H19,alsowhentheMLVAtypewasconsidered.However,MLVAsubtypingofO130:H11isolateswillrequirethedevelopmentofmorespecificmarkers.