EVALUATION OF ANTIBIOTIC THERAPIES FOR ERADICATION OF HELICOBACTER-HEPATICUS

The newly recognized murine pathogen Helicobacrer hepaticus is known t o colonize the ceca and colons of several strains of mice from a varie ty of commercial suppliers, Additionally, the organism persistently in fects mice, causes a chronic hepatitis, and is linked to hepatic tumor s in the A/JCr inbred mouse strain. For this reason, eradication of th e organism from infected mouse colonies is desirable, Treatment modali ties for eradication of H. hepaticus from the gastrointestinal system consisted of oral administration of various antibiotic combinations pr eviously evaluated for eradication of experimental H. felis gastric in fection in mice, A/JCr mice (8 to 10 weeks old) naturally infected wit h H. hepaticus were divided into six treatment groups of 10 animals ea ch, Animals received monotherapy of amoxicillin, metronidazole, or tet racycline or triple therapy of amoxicillin-metronidazole-bismuth (AMB) or tetracycline-metronidazole-bismuth (TMB), All medications were adm inistered by oral gavage three times daily for 2 weeks, One month afte r the final treatment, mice were euthanatized and livers, ceca, and co lons were cultured for H. hepaticus. All untreated control animals had H. hepaticus isolated from the cecum and/or colon, H. hepaticus was n ot recovered from the livers, ceca, or colons of the AhlB or TMB treat ment groups, All animals receiving the various antibiotic monotherapie s had H. hepaticus isolated from the cecum and colon, We conclude that at the doses and the route evaluated, AMB and TMB triple therapies ar e effective for eradication of H. hepaticus in 8- to 10-week old A/JCr mice.