Sensitivity of pathogenic and commensal bacteria from the human colon to essential oils

Dinesh Thapa, Riccardo Losa, Beatrice Zweifel, R. John Wallace

Research output: Contribution to journalArticle

33 Citations (Scopus)

Abstract

The microbiota of the intestinal tract plays an important role in colonic health, mediating many effects of dietary components on colonic health and during enteric infections. In the context of the increasing incidence of antibiotic resistance in gut bacteria, complementary therapies are required for the prevention and treatment of enteric infections. Here we report the potential application of essential oils (EO) and pure EO compounds to improve human gut health. Nerolidol, thymol, eugenol and geraniol inhibited growth of the pathogens Escherichia coli O157 : H7(VT(-)), Clostridium difficile DSM1296, Clostridium perfringens DSM11780, Salmonella typhimurium 3530 and Salmonella enteritidis S1400 at a half-maximal inhibitory concentration (IC(50)) varying from 50 to 500 p.p.m. Most EO showed greater toxicity to pathogens than to commensals. However, the beneficial commensal Faecalibacterium prausnitzii was sensitive to EO at similar or even lower concentrations than the pathogens. The EO showed dose-dependent effects on cell integrity, as measured using propidium iodide, of Gram-positive bacteria. These effects were not strongly correlated with growth inhibition, however, suggesting that cell membrane damage occurred but was not the primary cause of growth inhibition. Growth inhibition of Gram-negative bacteria, in contrast, occurred mostly without cell integrity loss. Principal component analysis showed clustering of responses according to bacterial species rather than to the identity of the EO, with the exception that responses to thymol and nerolidol clustered away from the other EO. In conclusion, the selective effects of some EO might have beneficial effects on gut health if chosen carefully for effectiveness against different species
Original languageEnglish
Pages (from-to)2870-2877
Number of pages8
JournalMicrobiology
Volume158
Issue number11
Early online date9 Aug 2012
DOIs
Publication statusPublished - Nov 2012

Fingerprint

Volatile Oils
Colon
Bacteria
Thymol
Health
Growth
Eugenol
Salmonella enteritidis
Clostridium perfringens
Escherichia coli O157
Clostridium difficile
Propidium
Gram-Positive Bacteria
Salmonella typhimurium
Complementary Therapies
Microbial Drug Resistance
Infection
Principal Component Analysis
Gram-Negative Bacteria
Inhibitory Concentration 50

Cite this

Sensitivity of pathogenic and commensal bacteria from the human colon to essential oils. / Thapa, Dinesh; Losa, Riccardo; Zweifel, Beatrice; Wallace, R. John.

In: Microbiology , Vol. 158, No. 11, 11.2012, p. 2870-2877.

Research output: Contribution to journalArticle

Thapa, Dinesh ; Losa, Riccardo ; Zweifel, Beatrice ; Wallace, R. John. / Sensitivity of pathogenic and commensal bacteria from the human colon to essential oils. In: Microbiology . 2012 ; Vol. 158, No. 11. pp. 2870-2877.
@article{82c9550fe3094e47b5618c892e713d17,
title = "Sensitivity of pathogenic and commensal bacteria from the human colon to essential oils",
abstract = "The microbiota of the intestinal tract plays an important role in colonic health, mediating many effects of dietary components on colonic health and during enteric infections. In the context of the increasing incidence of antibiotic resistance in gut bacteria, complementary therapies are required for the prevention and treatment of enteric infections. Here we report the potential application of essential oils (EO) and pure EO compounds to improve human gut health. Nerolidol, thymol, eugenol and geraniol inhibited growth of the pathogens Escherichia coli O157 : H7(VT(-)), Clostridium difficile DSM1296, Clostridium perfringens DSM11780, Salmonella typhimurium 3530 and Salmonella enteritidis S1400 at a half-maximal inhibitory concentration (IC(50)) varying from 50 to 500 p.p.m. Most EO showed greater toxicity to pathogens than to commensals. However, the beneficial commensal Faecalibacterium prausnitzii was sensitive to EO at similar or even lower concentrations than the pathogens. The EO showed dose-dependent effects on cell integrity, as measured using propidium iodide, of Gram-positive bacteria. These effects were not strongly correlated with growth inhibition, however, suggesting that cell membrane damage occurred but was not the primary cause of growth inhibition. Growth inhibition of Gram-negative bacteria, in contrast, occurred mostly without cell integrity loss. Principal component analysis showed clustering of responses according to bacterial species rather than to the identity of the EO, with the exception that responses to thymol and nerolidol clustered away from the other EO. In conclusion, the selective effects of some EO might have beneficial effects on gut health if chosen carefully for effectiveness against different species",
author = "Dinesh Thapa and Riccardo Losa and Beatrice Zweifel and Wallace, {R. John}",
note = "DA - 20121105 IS - 1465-2080 (Electronic) IS - 1350-0872 (Linking) LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't SB - IM",
year = "2012",
month = "11",
doi = "10.1099/mic.0.061127-0",
language = "English",
volume = "158",
pages = "2870--2877",
journal = "Microbiology",
issn = "1350-0872",
publisher = "Society for General Microbiology",
number = "11",

}

TY - JOUR

T1 - Sensitivity of pathogenic and commensal bacteria from the human colon to essential oils

AU - Thapa, Dinesh

AU - Losa, Riccardo

AU - Zweifel, Beatrice

AU - Wallace, R. John

N1 - DA - 20121105 IS - 1465-2080 (Electronic) IS - 1350-0872 (Linking) LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't SB - IM

PY - 2012/11

Y1 - 2012/11

N2 - The microbiota of the intestinal tract plays an important role in colonic health, mediating many effects of dietary components on colonic health and during enteric infections. In the context of the increasing incidence of antibiotic resistance in gut bacteria, complementary therapies are required for the prevention and treatment of enteric infections. Here we report the potential application of essential oils (EO) and pure EO compounds to improve human gut health. Nerolidol, thymol, eugenol and geraniol inhibited growth of the pathogens Escherichia coli O157 : H7(VT(-)), Clostridium difficile DSM1296, Clostridium perfringens DSM11780, Salmonella typhimurium 3530 and Salmonella enteritidis S1400 at a half-maximal inhibitory concentration (IC(50)) varying from 50 to 500 p.p.m. Most EO showed greater toxicity to pathogens than to commensals. However, the beneficial commensal Faecalibacterium prausnitzii was sensitive to EO at similar or even lower concentrations than the pathogens. The EO showed dose-dependent effects on cell integrity, as measured using propidium iodide, of Gram-positive bacteria. These effects were not strongly correlated with growth inhibition, however, suggesting that cell membrane damage occurred but was not the primary cause of growth inhibition. Growth inhibition of Gram-negative bacteria, in contrast, occurred mostly without cell integrity loss. Principal component analysis showed clustering of responses according to bacterial species rather than to the identity of the EO, with the exception that responses to thymol and nerolidol clustered away from the other EO. In conclusion, the selective effects of some EO might have beneficial effects on gut health if chosen carefully for effectiveness against different species

AB - The microbiota of the intestinal tract plays an important role in colonic health, mediating many effects of dietary components on colonic health and during enteric infections. In the context of the increasing incidence of antibiotic resistance in gut bacteria, complementary therapies are required for the prevention and treatment of enteric infections. Here we report the potential application of essential oils (EO) and pure EO compounds to improve human gut health. Nerolidol, thymol, eugenol and geraniol inhibited growth of the pathogens Escherichia coli O157 : H7(VT(-)), Clostridium difficile DSM1296, Clostridium perfringens DSM11780, Salmonella typhimurium 3530 and Salmonella enteritidis S1400 at a half-maximal inhibitory concentration (IC(50)) varying from 50 to 500 p.p.m. Most EO showed greater toxicity to pathogens than to commensals. However, the beneficial commensal Faecalibacterium prausnitzii was sensitive to EO at similar or even lower concentrations than the pathogens. The EO showed dose-dependent effects on cell integrity, as measured using propidium iodide, of Gram-positive bacteria. These effects were not strongly correlated with growth inhibition, however, suggesting that cell membrane damage occurred but was not the primary cause of growth inhibition. Growth inhibition of Gram-negative bacteria, in contrast, occurred mostly without cell integrity loss. Principal component analysis showed clustering of responses according to bacterial species rather than to the identity of the EO, with the exception that responses to thymol and nerolidol clustered away from the other EO. In conclusion, the selective effects of some EO might have beneficial effects on gut health if chosen carefully for effectiveness against different species

U2 - 10.1099/mic.0.061127-0

DO - 10.1099/mic.0.061127-0

M3 - Article

VL - 158

SP - 2870

EP - 2877

JO - Microbiology

JF - Microbiology

SN - 1350-0872

IS - 11

ER -