title: In vitro inhibition of Helicobacter pylori by Enterococcus faecium GM-1.
abstract: A strain of Enterococcus faecium that exhibits antibacterial activity against Helicobacter pylori was isolated from the feces of newborn babies. This strain was selected for its ability to inhibit the growth of H. pylori and to withstand harsh environmental conditions, such as acidic pH and high bile concentration. Biochemical tests and 16S rRNA sequencing specific for Enterococcus faecium GM-1 were used to identify the isolated bacterial strain. In vitro studies were used to investigate the inhibitory effects of E. faecium GM-1 on H. pylori. These results showed that the culture supernatant of E. faecium GM-1 significantly decreased the viability and urease activity of H. pylori. This inhibitory activity remained after adjustment of pH of culture supernatant to neutral. However, treatment with proteolytic enzymes reduced the anti-H. pylori activity of GM-1. Therefore, some substance(s) of E. faecium GM-1 other than pH and lactic acid might be associated with this inhibitory activity. Analysis by electron microscopy also demonstrated that the addition of GM-1 destroyed the cell structure of H. pylori. Additional studies suggested that the binding of H. pylori to human colonial cells decreased in the presence of GM-1.
authors.affiliation: Department of Microbiology, Pukyong National University, Busan, South Korea.
authors.forename: J H
authors.initials: JH
authors.lastname: Kang
authors.forename: M S
authors.initials: MS
authors.lastname: Lee
mesh_terms: D000898:Antibiosis; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D001647:Bile Acids and Salts / Q000494:pharmacology; D002460:Cell Line; D015169:Colony Count, Microbial; D017077:Culture Media, Conditioned / Q000494:pharmacology; D016984:Enterococcus faecium / Q000145:classification / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D005243:Feces / Q000382:microbiology; D016480:Helicobacter pylori / Q000187:drug effects* / Q000254:growth & development*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007231:Infant, Newborn; D046529:Microscopy, Electron, Transmission
chemical_list: D001426:Bacterial Proteins; D001647:Bile Acids and Salts; D017077:Culture Media, Conditioned