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Scientific article
Open access
English

The human Lactobacillus acidophilus strain LA1 secretes a nonbacteriocin antibacterial substance(s) active in vitro and in vivo

Published inApplied and environmental microbiology, vol. 63, no. 7, p. 2747-2753
Publication date1997
Abstract

The adhering human Lactobacillus acidophilus strain LA1 inhibits the cell association and cell invasion of enteropathogens in cultured human intestinal Caco-2 cells (M. F. Bernet, D. Brassard, J. R. Neeser, and A. L. Servin, Gut 35:483-489, 1994). Here, we demonstrate that strain LA1 developed its antibacterial activity in conventional or germ-free mouse models orally infected by Salmonella typhimurium. We present evidence that the spent culture supernatant of strain LA1 (LA1-SCS) contained antibacterial components active against S. typhimurium infecting the cultured human intestinal Caco-2 cells. The LA1-SCS antibacterial activity was observed in vitro against a wide range of gram-negative and gram-positive pathogens, such as Staphylococcus aureus, Listeria monocytogenes, S. typhimurium, Shigella flexneri, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Enterobacter cloacae. By contrast, no activity was observed against species of the normal gut flora, such as lactobacilli and bifidobacteria. The LA1-SCS antibacterial activity was insensitive to proteases and independent of lactic acid production.

Keywords
  • Animals
  • Anti-Bacterial Agents/metabolism/pharmacology
  • Antibiosis
  • Caco-2 Cells
  • Cells
  • Cultured
  • Endopeptidases/pharmacology
  • Female
  • Germ-Free Life
  • Gram-Negative Bacteria/drug effects
  • Gram-Positive Bacteria/drug effects
  • Humans
  • Lactic Acid/metabolism
  • Lactobacillus acidophilus/metabolism
  • Mice
  • Mice
  • Inbred C3H
  • Microbial Sensitivity Tests
  • Microscopy
  • Electron
  • Salmonella Infections
  • Animal/microbiology
  • Salmonella typhimurium/ultrastructure
Affiliation Not a UNIGE publication
Citation (ISO format)
BERNET-CAMARD, Marie-Françoise et al. The human Lactobacillus acidophilus strain LA1 secretes a nonbacteriocin antibacterial substance(s) active in vitro and in vivo. In: Applied and environmental microbiology, 1997, vol. 63, n° 7, p. 2747–2753.
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Article (Published version)
accessLevelPublic
Identifiers
ISSN of the journal0099-2240
418views
138downloads

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