TY - JOUR
T1 - Ajoene, a sulfur-rich molecule from garlic, inhibits genes controlled by quorum sensing
AU - Jakobsen, Tim Holm
AU - van Gennip, Maria
AU - Phipps, Richard Kerry
AU - Shanmugham, Meenakshi Sundaram
AU - Hultqvist, Louise Dahl
AU - Alhede, Morten
AU - Skindersoe, Mette Eline
AU - Rasmussen, Thomas Bovbjerg
AU - Friedrich, Karlheinz
AU - Uthe, Friedrich
AU - Jensen, Peter Østrup
AU - Moser, Claus
AU - Nielsen, Kristian Fog
AU - Eberl, Leo
AU - Larsen, Thomas Ostenfeld
AU - Tanner, David Ackland
AU - Høiby, Niels
AU - Bjarnsholt, Thomas
AU - Givskov, Michael
AU - Alhede, Maria
PY - 2012/5
Y1 - 2012/5
N2 - In relation to emerging multiresistant bacteria, development of antimicrobials and new treatment strategies of infections should be expected to become a high-priority research area. Quorum sensing (QS), a communication system used by pathogenic bacteria like Pseudomonas aeruginosa to synchronize the expression of specific genes involved in pathogenicity, is a possible drug target. Previous in vitro and in vivo studies revealed a significant inhibition of P. aeruginosa QS by crude garlic extract. By bioassay-guided fractionation of garlic extracts, we determined the primary QS inhibitor present in garlic to be ajoene, a sulfur-containing compound with potential as an antipathogenic drug. By comprehensive in vitro and in vivo studies, the effect of synthetic ajoene toward P. aeruginosa was elucidated. DNA microarray studies of ajoene-treated P. aeruginosa cultures revealed a concentration-dependent attenuation of a few but central QS-controlled virulence factors, including rhamnolipid. Furthermore, ajoene treatment of in vitro biofilms demonstrated a clear synergistic, antimicrobial effect with tobramycin on biofilm killing and a cease in lytic necrosis of polymorphonuclear leukocytes. Furthermore, in a mouse model of pulmonary infection, a significant clearing of infecting P. aeruginosa was detected in ajoene-treated mice compared to a nontreated control group. This study adds to the list of examples demonstrating the potential of QS-interfering compounds in the treatment of bacterial infections.
AB - In relation to emerging multiresistant bacteria, development of antimicrobials and new treatment strategies of infections should be expected to become a high-priority research area. Quorum sensing (QS), a communication system used by pathogenic bacteria like Pseudomonas aeruginosa to synchronize the expression of specific genes involved in pathogenicity, is a possible drug target. Previous in vitro and in vivo studies revealed a significant inhibition of P. aeruginosa QS by crude garlic extract. By bioassay-guided fractionation of garlic extracts, we determined the primary QS inhibitor present in garlic to be ajoene, a sulfur-containing compound with potential as an antipathogenic drug. By comprehensive in vitro and in vivo studies, the effect of synthetic ajoene toward P. aeruginosa was elucidated. DNA microarray studies of ajoene-treated P. aeruginosa cultures revealed a concentration-dependent attenuation of a few but central QS-controlled virulence factors, including rhamnolipid. Furthermore, ajoene treatment of in vitro biofilms demonstrated a clear synergistic, antimicrobial effect with tobramycin on biofilm killing and a cease in lytic necrosis of polymorphonuclear leukocytes. Furthermore, in a mouse model of pulmonary infection, a significant clearing of infecting P. aeruginosa was detected in ajoene-treated mice compared to a nontreated control group. This study adds to the list of examples demonstrating the potential of QS-interfering compounds in the treatment of bacterial infections.
KW - Animals
KW - Anti-Bacterial Agents
KW - Biofilms
KW - Chemical Fractionation
KW - Disulfides
KW - Drug Synergism
KW - Garlic
KW - Gene Expression Regulation, Bacterial
KW - Genes, Reporter
KW - Glycolipids
KW - Mice
KW - Neutrophils
KW - Plant Extracts
KW - Pseudomonas Infections
KW - Pseudomonas aeruginosa
KW - Quorum Sensing
KW - Respiratory Tract Infections
KW - Tobramycin
KW - Virulence Factors
U2 - 10.1128/AAC.05919-11
DO - 10.1128/AAC.05919-11
M3 - Journal article
C2 - 22314537
SN - 0066-4804
VL - 56
SP - 2314
EP - 2325
JO - Antimicrobial Agents and Chemotherapy
JF - Antimicrobial Agents and Chemotherapy
IS - 5
ER -