TY - JOUR
T1 - Antibiofilm effect of plant derived antimicrobials on Listeria monocytogenes
AU - Upadhyay, Abhinav
AU - Upadhyaya, Indu
AU - Kollanoor-Johny, Anup
AU - Venkitanarayanan, Kumar
PY - 2013/10
Y1 - 2013/10
N2 - The present study investigated the efficacy of sub-inhibitory concentrations (SICs, concentrations not inhibiting bacterial growth) and bactericidal concentrations (MBCs) of four, generally recognized as safe (GRAS), plant-derived antimicrobials (PDAs) in inhibiting Listeria monocytogenes (LM) biofilm formation and inactivating mature LM biofilms, at 37, 25 and 4°C on polystyrene plates and stainless-steel coupons. In addition, the effect of SICs of PDAs on the expression of LM genes critical for biofilm synthesis was determined by real-time quantitative PCR. The PDAs and their SICs used for inhibition of biofilm were trans-cinnamaldehyde (TC 0.50, 0.75mM), carvacrol (CR 0.50, 0.65mM), thymol (TY 0.33, 0.50mM), and eugenol (EG 1.8, 2.5mM), whereas the PDA concentrations used for inactivating mature biofilms were 5.0 and 10.0mM (TC, CR), 3.3 and 5.0mM (TY), 18.5 and 25.0mM (EG). All PDAs inhibited biofilm synthesis and inactivated fully formed LM biofilms on both matrices at three temperatures tested (P<0.05). Real-time quantitative PCR data revealed that all PDAs down-regulated critical LM biofilm-associated genes (P<0.05). Results suggest that TC, CR, TY, and EG could potentially be used to control LM biofilms in food processing environments, although further studies under commercial settings are necessary.
AB - The present study investigated the efficacy of sub-inhibitory concentrations (SICs, concentrations not inhibiting bacterial growth) and bactericidal concentrations (MBCs) of four, generally recognized as safe (GRAS), plant-derived antimicrobials (PDAs) in inhibiting Listeria monocytogenes (LM) biofilm formation and inactivating mature LM biofilms, at 37, 25 and 4°C on polystyrene plates and stainless-steel coupons. In addition, the effect of SICs of PDAs on the expression of LM genes critical for biofilm synthesis was determined by real-time quantitative PCR. The PDAs and their SICs used for inhibition of biofilm were trans-cinnamaldehyde (TC 0.50, 0.75mM), carvacrol (CR 0.50, 0.65mM), thymol (TY 0.33, 0.50mM), and eugenol (EG 1.8, 2.5mM), whereas the PDA concentrations used for inactivating mature biofilms were 5.0 and 10.0mM (TC, CR), 3.3 and 5.0mM (TY), 18.5 and 25.0mM (EG). All PDAs inhibited biofilm synthesis and inactivated fully formed LM biofilms on both matrices at three temperatures tested (P<0.05). Real-time quantitative PCR data revealed that all PDAs down-regulated critical LM biofilm-associated genes (P<0.05). Results suggest that TC, CR, TY, and EG could potentially be used to control LM biofilms in food processing environments, although further studies under commercial settings are necessary.
KW - Biofilms
KW - Gene expression
KW - Listeria monocytogenes
KW - Plant derived antimicrobials
UR - http://www.scopus.com/inward/record.url?scp=84878897392&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84878897392&partnerID=8YFLogxK
U2 - 10.1016/j.fm.2013.04.010
DO - 10.1016/j.fm.2013.04.010
M3 - Article
C2 - 23764223
AN - SCOPUS:84878897392
SN - 0740-0020
VL - 36
SP - 79
EP - 89
JO - Food Microbiology
JF - Food Microbiology
IS - 1
ER -