Dual role of pinostrobin-a flavonoid nutraceutical as an efflux pump inhibitor and antibiofilm agent to mitigate food borne pathogens

RSC Advances ◽  
2015 ◽  
Vol 5 (76) ◽  
pp. 61881-61887 ◽  
Author(s):  
Lowrence Rene Christena ◽  
Shankar Subramaniam ◽  
Mohan Vidhyalakshmi ◽  
Vijayalakshmi Mahadevan ◽  
Aravind Sivasubramanian ◽  
...  
Keyword(s):  
Efflux Pump ◽  
Dual Role ◽  
Gram Negative Bacteria ◽  
Efflux Pump Inhibitor ◽  
Gram Negative ◽  
Food Borne Pathogens ◽  
Food Borne

Drastic 128 fold MIC reversal in MRSA stain via EPI effect. Remarkable anti-biofilm effect against gram negative bacteria. Efflux pump other than NorA is involved.

scholarly journals MexAB-OprM Efflux Pump Interaction with the Peptidoglycan of Escherichia coli and Pseudomonas aeruginosa

2021 ◽  
Vol 22 (10) ◽  
pp. 5328
Author(s):  
Miao Ma ◽  
Margaux Lustig ◽  
Michèle Salem ◽  
Dominique Mengin-Lecreulx ◽  
Gilles Phan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Cell Division ◽  
Membrane Proteins ◽  
Outer Membrane ◽  
Efflux Pump ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Active Efflux

One of the major families of membrane proteins found in prokaryote genome corresponds to the transporters. Among them, the resistance-nodulation-cell division (RND) transporters are highly studied, as being responsible for one of the most problematic mechanisms used by bacteria to resist to antibiotics, i.e., the active efflux of drugs. In Gram-negative bacteria, these proteins are inserted in the inner membrane and form a tripartite assembly with an outer membrane factor and a periplasmic linker in order to cross the two membranes to expulse molecules outside of the cell. A lot of information has been collected to understand the functional mechanism of these pumps, especially with AcrAB-TolC from Escherichia coli, but one missing piece from all the suggested models is the role of peptidoglycan in the assembly. Here, by pull-down experiments with purified peptidoglycans, we precise the MexAB-OprM interaction with the peptidoglycan from Escherichia coli and Pseudomonas aeruginosa, highlighting a role of the peptidoglycan in stabilizing the MexA-OprM complex and also differences between the two Gram-negative bacteria peptidoglycans.

The dual role of LBP and CD14 in response to Gram-negative bacteria or Gram-negative compounds

2003 ◽  
Vol 9 (6) ◽  
pp. 381-384 ◽  
Author(s):  
Didier Heumann ◽  
Roger Lauener ◽  
Bernard Ryffel
Keyword(s):  
Dual Role ◽  
Gram Negative Bacteria ◽  
Gram Negative

scholarly journals Antibacterial and Antibiotic Modifying Potential of Crude Extracts, Fractions, and Compounds from Acacia polyacantha Willd. against MDR Gram-Negative Bacteria

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Flora T. Mambe ◽  
Jean Na-Iya ◽  
Ghislain W. Fotso ◽  
Fred Ashu ◽  
Bathélémy Ngameni ◽  
...  
Keyword(s):  
Oleanolic Acid ◽  
Bacterial Infections ◽  
Efflux Pump ◽  
Synergistic Effects ◽  
Bacterial Species ◽  
Gram Negative Bacteria ◽  
Efflux Pump Inhibitor ◽  
Gram Negative ◽  
Acacia Polyacantha

The present study aimed to assess the in vitro antibacterial and antibiotic modifying activities of methanol extracts prepared from the leaf (APL) and bark (APB) of Acacia polyacantha, fractions (APLa-d) and compounds isolated from APL against a panel of multidrug resistant (MDR) Gram-negative bacteria. Leaf extract was subjected to column chromatography for compounds isolation; antibacterial assays were performed on samples alone and with an efflux pump inhibitor (EPI), respectively, and several antibiotics on the tested bacteria. The phytochemical investigation of APL led to the isolation of stigmasterol (1), β-amyrin (2), 3-O-β-D-glucopyranosylstigmasterol (3), 3-O-methyl-D-chiro-inositol (4), epicatechin (5), quercetin-3-O-glucoside (6), 3-O-[β-D-xylopyranosyl-(1→4)-β-D-galactopyranosyl]-oleanolic acid (7), and 3-O-[β-galactopyranosyl-(1→4)-β-D-galactopyranosyl]-oleanolic acid (8). APL and APB had minimal inhibitory concentration (MIC) values ≤ 1024 μg/mL on 73.3% and 46.7% of the tested bacteria, respectively. APLb and APLd were effective against 88.9% of tested bacterial species with compound 8 showing the highest activity inhibiting 88.9% of tested bacteria. The EPI, phenylalanine-arginine-β-naphthylamide (PAßN), strongly improved the activity of APL, APLb, APLd, and compound 8 on all tested bacteria. Synergistic effects were obtained when APL and compounds 7 and 8 were combined with erythromycin (ERY), gentamycin (GEN), ciprofloxacin (CIP), and norfloxacin (NOR). The present study demonstrates the antibacterial potential of Acacia polyacantha and its constituents to combat bacterial infections alone or in combination with EPI.

scholarly journals Comparison of antibacterial effect of seven 1-monoglycerides on food-borne pathogens or spoilage bacteria

2011 ◽  
Vol 80 (1) ◽  
pp. 29-39 ◽  
Author(s):  
Leona Buňková ◽  
František Buňka ◽  
Rahula Janiš ◽  
Jiří Krejčí ◽  
Iva Doležálková ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Growth Rate ◽  
Specific Growth ◽  
Lag Time ◽  
Gram Negative Bacteria ◽  
Inhibitory Effects ◽  
Gram Negative ◽  
Food Borne Pathogens ◽  
Food Borne

The aim of this study was to compare under the same conditionsin vitrothe inhibitory effects of seven 1-monoglycerides (MAG) containing fatty acids with a medium chain on ten strains of food-borne pathogens or spoilage gram-positive and gram-negative bacteria (Bacillus cereus, Bacillus subtilis, Enterococcus faecalis, Micrococcus luteus, Staphylococcus aureus, Citrobacter freundii, Escherichia coli, Proteus mirabilis, Salmonella entericaser.Enteritidis andPseudomonas aeruginosa) and on their growth indicatos. The inhibitory effect of MAGs (monocaprylin, monocaprin, monolaurin, monomyristin, monopalmitin, MAG of undecanoic and 10-undecenoic acids) at a concentration of 25 – 1500 mg·l-1was observed. Growth of bacteria in the presence of MAG was studied by means of optical density of bacteria for 24 h. The data were modelled through a Gompertz equation and the lag-time, the maximum specific growth rate and the maximal value reached were calculated. MAGs inhibited mainly the growth of gram-positive bacteria, which was shown by the extended lag-time, decrease in specific growth rate and decrease in cell density. Inhibitory effects of tested MAGs could be ranked from point of view of the minimum inhibitory concentration: MAG-C12:0 > MAG-C11:0 > MAG-C10:0 > MAG-C14:0 > MAG-C11:1 > MAG-C8:0 > MAG-C16:0.In vitro, no significant inhibitory effects of 1-monoglycerides, with the exception of the highest concentrations applied, on the growth of gram-negative bacteria were detected. The main contribution of this study is to compare the effects of several MAG containing fatty acids with a medium chain under the same conditions on the growth indicators of bacteria.

Inhibition of Food-Borne Pathogens by T1, a Novel Antimicrobial Peptide as a Potential Food Preservative

2008 ◽  
Vol 4 (4) ◽  
Author(s):  
Yali Tang ◽  
Yonghui Shi ◽  
Wei Zhao ◽  
Gang Hao ◽  
Guowei Le
Keyword(s):  
Antimicrobial Peptide ◽  
Gram Negative Bacteria ◽  
Food Preservative ◽  
Recombinant Peptide ◽  
Gram Negative ◽  
Food Borne Pathogens ◽  
Theoretical Design ◽  
Food Borne ◽  
Antimicrobial Mechanism ◽  
Potential Food

An efficient and convenient purifying procedure for recombinant peptide was established. Thereby, the aimed antimicrobial peptide T1 containing the conservative sequences derived from cecropin was successfully expressed and purified. The composition of amino acid of the purified peptide T1 was consistent with that of theoretical design. The significant antimicrobial activity of T1 against gram-positive and gram-negative bacteria was demonstrated, suggesting that the conservative sequences in cecropin play an important role in the antimicrobial mechanism and that antimicrobial peptide T1 has the potential to be used as the food preservative.

Dual role of select plant based nutraceuticals as antimicrobial agents to mitigate food borne pathogens and as food preservatives

RSC Advances ◽  
2015 ◽  
Vol 5 (94) ◽  
pp. 77168-77174 ◽  
Author(s):  
Shankar Subramaniam ◽  
Narendran Rajendran ◽  
Sai brinda Muralidharan ◽  
Gayathri Subramaniam ◽  
Ravikumar Raju ◽  
...  
Keyword(s):  
Therapeutic Effect ◽  
Antimicrobial Agents ◽  
Dual Role ◽  
Food Preservatives ◽  
Food Pathogens ◽  
Food Borne Pathogens ◽  
Food Borne ◽  
Commercially Important

Dual role of commercially important nutraceuticals from plants that potentiate the therapeutic effect of commercial antibiotics to combat food pathogens.

Prevalence and characterization of quinolone resistance in Laribacter hongkongensis from grass carp and Chinese tiger frog

2013 ◽  
Vol 62 (10) ◽  
pp. 1559-1564 ◽  
Author(s):  
Ding-Qiang Chen ◽  
Ling Yang ◽  
Yu-Ting Luo ◽  
Min-Jie Mao ◽  
Yong-Ping Lin ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Efflux Pump ◽  
Quinolone Resistance ◽  
Efflux Pump Inhibitor ◽  
Electrophoretic Patterns ◽  
Food Borne ◽  
Laribacter Hongkongensis ◽  
Resistant Strains

Laribacter hongkongensis is a food-borne bacterium associated with community-acquired gastroenteritis and diarrhoea. Quinolone resistance was recently reported in bacterial isolates from aquatic products, but the molecular mechanisms for resistance were still unknown. In this study, a total of 157 L. hongkongensis strains were isolated from grass carps (n = 443) and Chinese tiger frogs (n = 171). Twenty-one ciprofloxacin-resistant strains were analysed for mutations in quinolone resistance-determining regions (QRDR), acquired quinolone resistance (AQR) genes and the role of efflux pumps in resistance. All QRDR mutations in gyrA (codons 85 and 89) and parC (codons 83 and 231) were found to be closely associated with ciprofloxacin resistance. The AQR gene aac(6′)-Ib-cr was found in 42.9 % (9/21) of the resistant strains, but qnrA, qnrB, qnrC, qnrD, qnrS and qepA were not detected. No significant change of MICs to ciprofloxacin was observed in the presence of an efflux pump inhibitor, indicating the role of efflux pump was probably absent. All 21 ciprofloxacin-resistant strains showed different electrophoretic patterns, which suggested they were not genetically related. These data highlight the importance of QRDR mutations and the AQR gene aac(6′)-Ib-cr during the development of quinolone resistance in a heterogeneous population of L. hongkongensis.

The dual role of LBP and CD14 in response to Gram-negative bacteria or Gram-negative compounds

2003 ◽  
Vol 9 (6) ◽  
pp. 381-384 ◽  
Author(s):  
Didier Heumann ◽  
Roger Lauener ◽  
Bernard Ryffel
Keyword(s):  
Dual Role ◽  
Gram Negative Bacteria ◽  
Gram Negative

Ability of Bdellovibrio bacteriovorus 109J to Lyse Gram-Negative Food-Borne Pathogenic and Spoilage Bacteria

1995 ◽  
Vol 58 (2) ◽  
pp. 160-164 ◽  
Author(s):  
PINA M. FRATAMICO ◽  
RICHARD C. WHITING
Keyword(s):  
Coli Strain ◽  
Gram Negative Bacteria ◽  
Bacterial Strains ◽  
Bdellovibrio Bacteriovorus ◽  
Gram Negative ◽  
E Coli ◽  
Food Borne Pathogens ◽  
Food Borne ◽  
Spoilage Bacteria ◽  
Predatory Bacteria

Bdellovibrios are a group of aerobic, predatory bacteria which attack, penetrate and grow in many species of gram-negative bacteria, causing the lysis of the invaded prey organism. Bdellovibrio bacteriovorus strain 109J varied in its ability to lyse 32 bacterial strains comprising six genera of food-borne pathogens and spoilage organisms. The reduction in the levels of the prey bacteria ranged from 0.1 to 7.7 log-values after 7 h of incubation at 30°C. Escherichia coli strain 2239-69 (pathogenic serotype 026:H11) was lysed most effectively at temperatures between 30 and 37°C, however, lysis also occurred at 12 and 19°C when the incubation period was extended to 24 h. Bdellovibrio bacteriovorus was effective in reducing the level of E. coli 2239-69 at pH 5.6 to 8.6. Increasing the Bdellovibrio: E. coli ratio resulted in a more rapid E. coli reduction. This study demonstrated the potential usefulness of bdellovibrios for the biological control of pathogenic and spoilage organisms in foods.

scholarly journals The Biofilm Inhibitor Carolacton Enters Gram-Negative Cells: Studies Using a TolC-Deficient Strain of Escherichia coli

mSphere ◽  
2017 ◽  
Vol 2 (5) ◽  
Author(s):  
Jannik Donner ◽  
Michael Reck ◽  
Boyke Bunk ◽  
Michael Jarek ◽  
Constantin Benjamin App ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Streptococcus Pneumoniae ◽  
Carbon Atom ◽  
Efflux Pump ◽  
Gram Negative Bacteria ◽  
Rna Seq ◽  
Efflux Pump Inhibitor ◽  
Gram Negative ◽  
Content Type ◽  
E Coli

ABSTRACT The myxobacterial secondary metabolite carolacton inhibits growth of Streptococcus pneumoniae and kills biofilm cells of the caries- and endocarditis-associated pathogen Streptococcus mutans at nanomolar concentrations. Here, we studied the response to carolacton of an Escherichia coli strain that lacked the outer membrane protein TolC. Whole-genome sequencing of the laboratory E. coli strain TolC revealed the integration of an insertion element, IS5, at the tolC locus and a close phylogenetic relationship to the ancient E. coli K-12. We demonstrated via transcriptome sequencing (RNA-seq) and determination of MIC values that carolacton penetrates the phospholipid bilayer of the Gram-negative cell envelope and inhibits growth of E. coli TolC at similar concentrations as for streptococci. This inhibition is completely lost for a C-9 (R) epimer of carolacton, a derivative with an inverted stereocenter at carbon atom 9 [(S) → (R)] as the sole difference from the native molecule, which is also inactive in S. pneumoniae and S. mutans, suggesting a specific interaction of native carolacton with a conserved cellular target present in bacterial phyla as distantly related as Firmicutes and Proteobacteria. The efflux pump inhibitor (EPI) phenylalanine arginine β-naphthylamide (PAβN), which specifically inhibits AcrAB-TolC, renders E. coli susceptible to carolacton. Our data indicate that carolacton has potential for use in antimicrobial chemotherapy against Gram-negative bacteria, as a single drug or in combination with EPIs. Strain E. coli TolC has been deposited at the DSMZ; together with the associated RNA-seq data and MIC values, it can be used as a reference during future screenings for novel bioactive compounds. IMPORTANCE The emergence of pathogens resistant against most or all of the antibiotics currently used in human therapy is a global threat, and therefore the search for antimicrobials with novel targets and modes of action is of utmost importance. The myxobacterial secondary metabolite carolacton had previously been shown to inhibit biofilm formation and growth of streptococci. Here, we investigated if carolacton could act against Gram-negative bacteria, which are difficult targets because of their double-layered cytoplasmic envelope. We found that the model organism Escherichia coli is susceptible to carolacton, similar to the Gram-positive Streptococcus pneumoniae, if its multidrug efflux system AcrAB-TolC is either inactivated genetically, by disruption of the tolC gene, or physiologically by coadministering an efflux pump inhibitor. A carolacton epimer that has a different steric configuration at carbon atom 9 is completely inactive, suggesting that carolacton may interact with the same molecular target in both Gram-positive and Gram-negative bacteria.

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