title: Antibiotic-induced release of endotoxin in chronically bacteriuric patients.
abstract: A novel in vivo model for the study of antibiotic-induced release of endotoxin from gram-negative bacteria is described. The model uses the chronically colonized urinary tracts of patients whose spinal cords have been injured. At baseline, the organisms were present in the range of 1 x 10(3) to 2 x 10(7) CFU/ml, and the concentration of endotoxin ranged from 2 x 10(-1) to 1 x 10(3) ng/ml in 44 studies. In 10 control studies, the concentration of endotoxin and the numbers of viable gram-negative bacteria over time changed by an average of less than 0.15 log10 units from the baseline values. At 2 h after antibiotic administration, the average decrease in CFU was 0.93 log10 units, and because antibiotics cause the release of endotoxin, an average increase in endotoxin concentration of 0.59 log10 units was noted in 21 studies with susceptible bacteria. Similar changes in response to antibiotic exposure were seen in studies with susceptible Pseudomonas bacteria in comparison with those seen in studies with susceptible members of the family Enterobacteriaceae. These results provide evidence that this novel model may be useful for comparing the effects of antibiotics with different modes of action, both as single agents and in combination, on the concentration of endotoxin in relation to changes in the numbers of bacteria, under conditions of bacterial replication and antibiotic exposure more closely resembling those found in vivo than is possible in other models.
authors.affiliation: Department of Clinical Pharmacology and Therapeutics, Austin Hospital, Heidelberg.
authors.forename: J C
authors.initials: JC
authors.lastname: Hurley
authors.forename: W J
authors.initials: WJ
authors.lastname: Louis
authors.forename: F A
authors.initials: FA
authors.lastname: Tosolini
authors.forename: J B
authors.initials: JB
authors.lastname: Carlin
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001437:Bacteriuria / Q000150:complications / Q000378:metabolism*; D002908:Chronic Disease; D002939:Ciprofloxacin / Q000494:pharmacology; D015169:Colony Count, Microbial; D004731:Endotoxins / Q000378:metabolism*; D004755:Enterobacteriaceae / Q000187:drug effects; D005839:Gentamicins / Q000652:urine; D006801:Humans; D007769:Lactams; D008033:Limulus Test; D008954:Models, Biological; D011549:Pseudomonas / Q000187:drug effects; D013119:Spinal Cord Injuries / Q000150:complications; D014552:Urinary Tract Infections / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D004731:Endotoxins; D005839:Gentamicins; D007769:Lactams; D002939:Ciprofloxacin