USE OF ANTIBIOTICS TO PREVENT HEPATITIS AND TYPHLITIS IN MALE SCID MICE SPONTANEOUSLY INFECTED WITH HELICOBACTER-HEPATICUS

The use of antibiotic combinations to prevent acute and progressive ch ronic hepatitis and proliferative typhlitis associated with Helicobact er hepaticus infection in male scid/NCr mice was evaluated, The drug c ombinations used were amoxicillin-metronidazole bismuth, tetracycline- metronidazole-bismuth, amoxicillin-neomycin, neomycin alone, and amoxi cillin alone, Treatments were administered per os for 14 days beginnin g at 4 weeks of age, All mice remained clinically normal throughout th e study, Specimens from mice were evaluated histologically at 21, 60, 90, and 120 days after initiation of the antibiotic treatments, Result s of histologic examination and use of special stains indicated that t he antibiotic regimens containing amoxicillin prevented progressive ch ronic hepatitis and typhlitis, Helical bacteria were not observed hist ologically in the liver or cecum of amoxicillin-treated mice, Helical bacteria were observed in the liver and cecum of untreated mice and in the cecum of mice treated with antibiotic regimens not containing amo xicillin, Untreated mice and those treated with amoxicillin were evalu ated by culture for presence of H. hepaticus at 60 and 90 days and by polymerase chain reaction at 90 days after initiation of the antibioti c treatment, All untreated mice were test-positive by fecal/cecal cult ure, and three of five were positive by polymerase chain reaction, All mice treated with amoxicillin were negative for H. hepaticus by resul ts of culture and polymerase chain reaction, The oral administration o f amoxicillin to young scid mice via the drinking water prevents hepat itis and typhlitis caused by H. hepaticus.