Open AccessCapacity of Human Nisin- and Pediocin-Producing Lactic Acid Bacteria To Reduce Intestinal Colonization by Vancomycin-Resistant Enterococci
Author(s) -
Mathieu Millette,
Gilbert Cornut,
Claude Dupont,
François Shareck,
Denis Archambault,
Monique Lacroix
Publication year - 2008
Publication title -
applied and environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.552
H-Index - 324
eISSN - 1070-6291
pISSN - 0099-2240
DOI - 10.1128/aem.02150-07
Subject(s) - pediococcus acidilactici , microbiology and biotechnology , nisin , lactococcus lactis , bacteriocin , enterococcus faecium , biology , lactic acid , enterococcus , bacteria , lactobacillus , pediococcus , lactobacillus plantarum , antibiotics , antimicrobial , genetics
This study demonstrated the capacity of bacteriocin-producing lactic acid bacteria (LAB) to reduce intestinal colonization by vancomycin-resistant enterococci (VRE) in a mouse model.Lactococcus lactis MM19 andPediococcus acidilactici MM33 are bacteriocin producers isolated from human feces. The bacteriocin secreted byP. acidilactici is identical to pediocin PA-1/AcH, while PCR analysis demonstrated thatL. lactis harbors the nisin Z gene. LAB were acid and bile tolerant when assayed under simulated gastrointestinal conditions. A well diffusion assay using supernatants from LAB demonstrated strong activity against a clinical isolate of VRE. A first in vivo study was done using C57BL/6 mice that received daily intragastric doses ofL. lactis MM19,P. acidilactici MM33,P. acidilactici MM33A (a pediocin mutant that had lost its ability to produce pediocin), or phosphate-buffered saline (PBS) for 18 days. This study showed thatL. lactis andP. acidilactici MM33A increased the concentrations of total LAB and anaerobes whileP. acidilactici MM33 decreased theEnterobacteriaceae populations. A second in vivo study was done using VRE-colonized mice that received the same inocula as those in the previous study for 16 days. InL. lactis -fed mice, fecal VRE levels 1.73 and 2.50 log10 CFU/g lower than those in the PBS group were observed at 1 and 3 days postinfection. In theP. acidilactici MM33-fed mice, no reduction was observed at 1 day postinfection but a reduction of 1.85 log10 CFU/g was measured at 3 days postinfection. Levels of VRE in both groups of mice treated with bacteriocin-producing LAB were undetectable at 6 days postinfection. No significant difference in mice fed the pediocin-negative strain compared to the control group was observed. This is the first demonstration that humanL. lactis andP. acidilactici nisin- and pediocin-producing strains can reduce VRE intestinal colonization.