title: Lactobacillus acidophilus modulates the virulence of Clostridium difficile.
abstract: Clostridium difficile is a spore-forming, toxin-producing, anaerobic bacterium that colonizes the human gastrointestinal tract. This pathogen causes antibiotic-associated diarrhea and colitis in animals and humans. Antibiotic-associated diseases may be treated with probiotics, and interest is increasing in such uses of probiotics. This study investigated the effect of Lactobacillus strains on the quorum-sensing signals and toxin production of C. difficile. In addition, an in vivo experiment was designed to assess whether Lactobacillus acidophilus GP1B is able to control C. difficile-associated disease. Autoinducer-2 activity was measured for C. difficile using the Vibrio harveyi coupled bioluminescent assay. Cell extract (10μg/mL) of L. acidophilus GP1B exhibited the highest inhibitory activity among 5 to 40μg/mL cell-extract concentrations. Real-time PCR data indicated decreased transcriptional levels in luxS, tcdA, tcdB, and txeR genes in the presence of 10μg/mL of cell extract of L. acidophilus GP1B. Survival rates at 5d for mice given the pathogen alone with L. acidophilus GP1B cell extract or L. acidophilus GP1B were 10, 70, and 80%, respectively. In addition, the lactic acid-produced L. acidophilus GP1B exhibits an inhibitory effect against the growth of C. difficile. Both the L. acidophilus GP1B and GP1B cell extract have significant antipathogenic effects on C. difficile.
authors.affiliation: Division of Animal Science, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 500-757, Korea.
authors.forename: B
authors.initials: B
authors.lastname: Yun
authors.affiliation: Division of Animal Science, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 500-757, Korea. Electronic address: soh@chonnam.ac.kr.
authors.forename: S
authors.initials: S
authors.lastname: Oh
authors.affiliation: Department of Food Science, University of Guelph, Canadian Research Institute for Food Safety, Guelph, ON, N1G 2W1, Canada.
authors.forename: M W
authors.initials: MW
authors.lastname: Griffiths
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001427:Bacterial Toxins / Q000235:genetics / Q000378:metabolism; D016360:Clostridioides difficile / Q000472:pathogenicity*; D003967:Diarrhea / Q000382:microbiology; D015536:Down-Regulation; D004768:Enterotoxins / Q000235:genetics / Q000378:metabolism; D005260:Female; D005506:Food Contamination / Q000032:analysis / Q000517:prevention & control; D005516:Food Microbiology; D041981:Gastrointestinal Tract / Q000382:microbiology*; D006714:Homoserine / Q000031:analogs & derivatives / Q000378:metabolism; D006801:Humans; D007779:Lactobacillus acidophilus / Q000502:physiology*; D007783:Lactones / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D064307:Microbiota; D019936:Probiotics / Q000008:administration & dosage; D012329:RNA, Bacterial / Q000235:genetics; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004768:Enterotoxins; D007783:Lactones; C091088:N-octanoylhomoserine lactone; D012329:RNA, Bacterial; C041348:tcdA protein, Clostridium difficile; C031815:toxB protein, Clostridium difficile; D006714:Homoserine
keywords: Clostridium difficile ribotype 027; Lactobacillus acidophilus GP1B; autoinducer-2; quorum sensing