Prophylaxis against streptococcal endocarditis.

The growth kinetics of Helicobacter pylori after it has been exposed to amoxicillin have been investigated in conjunction with studies of cell morphology. A potent bactericidal effect was observed at concentrations 10-fold higher than the MIC, but this was accompanied by an increase in the residual numbers of coccoid forms observed. In the presence of 10 micrograms of amoxicillin per ml, these forms could be detected as rapidly as 6 h after exposure to the antibiotic. Although the clinical relevance of coccoid forms remains unknown, such forms should be considered when potential anti-Helicobacter agents are tested in vitro.

Amoxicillin↗

PubMed1995

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 chronic hepatitis and proliferative typhlitis associated with Helicobacter hepaticus infection in male scid/NCr mice was evaluated. The drug combinations used were amoxicillin-metronidazole-bismuth, tetracycline-metronidazole-bismuth, amoxicillin-neomycin, neomycin alone, and amoxicillin alone. Treatments were administered per os for 14 days beginning at 4 weeks of age. All mice remained clinically normal throughout the study. Specimens from mice were evaluated histologically at 21, 60, 90, and 120 days after initiation of the antibiotic treatments. Results of histologic examination and use of special stains indicated that the antibiotic regimens containing amoxicillin prevented progressive chronic hepatitis and typhlitis. Helical bacteria were not observed histologically 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 amoxicillin. Untreated mice and those treated with amoxicillin were evaluated by culture for presence of H. hepaticus at 60 and 90 days and by polymerase chain reaction at 90 days after initiation of the antibiotic treatment. All untreated mice were test-positive by fecal/cecal culture, and three of five were positive by polymerase chain reaction. All mice treated with amoxicillin were negative for H. hepaticus by results of culture and polymerase chain reaction. The oral administration of amoxicillin to young scid mice via the drinking water prevents hepatitis and typhlitis caused by H. hepaticus.

Amoxicillin↗