title: Alterations in rat gut bacteria and intestinal epithelial cells following experimental exposure of antimicrobials.
abstract: The intestinal bacteria are known to play a significant role in intestinal homoeostasis and the mucosal immune system. In vitro interactions of Ampicillin (0.5-2.0 microg mL(-1)), Amphotericin-B (25-200 microg mL(-1)) and Ciprofloxacin (50-500 ng mL(-1)) with Escherichia coli, Pseudomonas sp. (Gram-negative), Lactobacillus sp., Staphylococcus sp. (Gram-positive), total mixed population of gut bacteria and intestinal epithelial cells were studied. In vitro exposure of Ciprofloxacin showed significant dose-dependent inhibition throughout the growth phase in bacteria. Similar patterns of concentration-dependent changes in membrane transport enzymes and structural constituents, dehydrogenase activity associated with respiratory and energy-producing processes and esterase activity test linked to the general heterotrophic activity of the cell were observed in both bacteria and epithelial cells. The antibiotic effects were in the order of Amphotericin-B<Ampicillin<Ciprofloxacin. Validation studies were conducted using rat intestinal loops filled with different concentrations of antibiotics and incubated for 30 min. In situ changes in epithelial cell membrane enzymes and constituents also indicated similar trends as observed following in vitro exposures. The findings suggest that these antibiotics exert similar cytotoxic effects on intestinal epithelial cells and gut bacteria. Thus, gut bacteria can be used for in vitro screening of gastrointestinal-cellular toxicity caused by antibiotics.
authors.affiliation: Biomembrane Toxicology, Indian Institute of Toxicology Research, Lucknow, India. upretirk@rediffmail.com
authors.forename: Raj K
authors.initials: RK
authors.lastname: Upreti
authors.forename: Ambrose
authors.initials: A
authors.lastname: Kannan
authors.forename: Aditya
authors.initials: A
authors.lastname: Pant
mesh_terms: D000666:Amphotericin B / Q000494:pharmacology; D000667:Ampicillin / Q000494:pharmacology; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002478:Cells, Cultured; D002939:Ciprofloxacin / Q000494:pharmacology; D015169:Colony Count, Microbial; D004064:Digestive System / Q000382:microbiology*; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism / Q000382:microbiology; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification; D006094:Gram-Positive Bacteria / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification; D007422:Intestines / Q000166:cytology / Q000187:drug effects*; D008297:Male; D008826:Microbial Sensitivity Tests; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000900:Anti-Bacterial Agents; D002939:Ciprofloxacin; D000667:Ampicillin; D000666:Amphotericin B