In the present studies, the effect of ampicillin (40 mg intramuscularly twice a day) in combination with water diuresis, produced by the ingestion of 5% dextrose in water, was determined on renal titers of enterococci after intravenous inoculation of 4 x 10(8)-2 x 10(9) enterococci into rats. Ampicillin injections with or without diuresis were started 4 or 21 days after initiation of infection ...

Antibiotics that are excreted into the intestinal tract promote antibiotic resistance by exerting selective pressure on the gut microbiota. Using a beagle dog model, we show that an orally administered targeted recombinant beta-lactamase enzyme eliminates the portion of parenteral ampicillin that is excreted into the small intestine, preventing ampicillin-induced changes to the fecal microbiota...

Bacampicillin is a new oral prodrug which is rapidly converted to ampicillin during absorption from the gastrointestinal tract. High serum peaks of ampicillin are obtained. Bacampicillin orally was compared pharmacokinetically with parenteral ampicillin (intravenously and intramuscularly). A cross-over study on healthy volunteers showed that ampicillin concentrations after equimolar doses of ba...

Despite its relatively good acid stability, ampicillin is absorbed rather poorly from the gastro-intestinal tract, varying from 30 to 50% (8, 10, 12). One of the attempts to achieve better absorption resulted in the development of pivampicillin, the pivaloyloxymethyl ester of ampicillin, which is rapidly hydrolyzed to ampicillin in the body; 15 min after administration, more than 99% of the dru...

Fifty-seven clinical isolates of enterococcus were tested for susceptibility to 10 antibiotics in a microtiter broth dilution system. Amoxicillin, ampicillin, vancomycin, and rifampin inhibited all strains at concentrations easily achievable in blood. Resistance to rifampin developed rapidly. Of the aminoglycosides, gentamicin was most active, followed in decreasing order by tobramycin, amikaci...

Most ampicillin-resistant Shigella are susceptible to cephalexin. Randomized treatment with cephalexin or ampicillin was given to 154 infants and children with acute diarrhea. Rectal swab cultures revealed Shigella in 42%, Salmonella in 6%, enteropathogenic Escherichia coli in 2%, and no pathogen in 50%. Cephalexin failed to eradicate Shigella after 5 days of treatment in 76% of patients as con...

The bactericidal effects of chloramphenicol and three beta-lactams (ampicillin, cefamandole, and penicillin G) were measured for 27 strains of Haemophilus influenzae type b isolated from the blood or cerebrospinal fluid of infected infants. Of the ampicillin-susceptible strains, 75% were killed by less than 2.0 micrograms of each antibiotic per ml; however, the concentration of the beta-lactam ...