Helicobacter bilis/Helicobacter rodentium Co-Infection Associated with Diarrhea in a Colony of scid Mice

摘要

Anoutbreakofdiarrheaspanning3monthsoccurredinabreedingcolonyofscid/Trp53knockoutmice.Approximatelyathirdofthe150micewereclinicallyaffected,withsignsrangingfrommucoidorwaterydiarrheatoseverehemorrhagicdiarrheawithmortality.Helicobacterbilisandthenewlyrecognizedurease-negativeorganismH.rodentiumwereisolatedfrommicroaerobiccultureoffecesorcecalspecimensfromaffectedmice.DualinfectionwithH.bilisandH.rodentiumwereconfirmedbycultureandpolymerasechainreaction(PCR)inseveralanimals.BothHelicobacterspeciesrapidlycolonizedimmunocompetentsentinelmiceexposedtobeddingfromcagescontainingaffectedmice,butthesentinelremainedasymptomatic.Micewithdiarrheahadmultifocaltosegmentalproliferativetyphlitis,colitis,andproctitis.Severalaffectedmicehadmultifocalmucosalnecrosiswithafewfocalulcersinthececum,colon,andrectum.Micewithdiarrheaweretreatedwithantibioticfoodwafers(1.5mgofamoxicillin,0.69mgofmetronidazole,and0.185mgofbismuth/mouseperday)previouslyshowntoeradicateH.hepaticusinimmunocompetentmice.Antibiotictreatmentresultedinresolutionofdiarrhea,butnoteradicationofH.bilisandH.rodentium;micecontinuedtohavepositivePCRresultsaftera2-weektreatmentregimen,andclinicalsignsofdiarrheareturnedinsomemicewhentreatmentwassuspended.Totheauthors'knowledge,thisisthefirstreportofnaturalinfectionwitheitherH.bilisand/orH.rodentiumcausingacutediarrhealdiseaseandsuggeststhatH.bilisand/orH.rodentiumcanbeanimportantpathogenforscidmice.