scholarly journals In vitro synergistic potentials of novel antibacterial combination therapies against Salmonella Typhimurium and Escherichia coli

2019 ◽  
Author(s):  
Md. Akil Hossain ◽  
Hae-Chul Park ◽  
Kwang-jick Lee ◽  
Sung-Won Park ◽  
Seung-Chun Park ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Synergistic Effects ◽  
Clinical Importance ◽  
Blood Stream ◽  
In Vitro Cytotoxicity ◽  
Farm Animals ◽  
Epicatechin Gallate ◽  
E Coli

Abstract Background: The antibiotics generally used in farm animals are rapidly losing their effectiveness all over the world as bacteria develop antibiotic resistance. New strategies are needed to block the development of resistance and to prolong the life of traditional antibiotics. This study aimed to increase the efficacy of existing antibiotics by combining them with the opportunistic phenolic compounds gallic acid (GA), epicatechin, epicatechin gallate, epigallocatechin and hamamelitannin. Fractional inhibitory concentration index (FICI) of phenolic compound-antibiotic combinations against Salmonella enterica serovar Typhimurium (S. Typhimurium) and Escherichia coli (E. coli) were determined. Based on the FICI and clinical importance, 3 combinations were selected to evaluate their effects on the virulence factors of these bacteria. The in vitro cytotoxicity of GA and hamamelitannin in Rattus norvegicus (IEC-6) cell lines were evaluated. Results: Minimum inhibitory concentrations (MICs) of epigallocatechin, GA and hamamelitannin found against different strains were (512–1024), (256–1024) and (512–2048) μg/mL, respectively. Synergistic effects were obtained from combinations of thiamphenicol-GA (FICI: 0.28), erythromycin-hamamelitannin (FICI: 0.38) and thiamphenicol-hamamelitannin (FICI: 0.50) against E. coli, and erythromycin-epicatechin gallate (FICI: 0.50) against S. Typhimurium. Moreover, additive effects were obtained from 33 combinations against S. Typhimurium (FICI: 0.502~0.750) and E. coli (FICI: 0.502~0.625). The time-kill assays and ultrastructural morphology showed that GA-ceftiofur, and hamamelitannin-erythromycin and GA-ampicillin combinations more efficiently inhibited the growth of S. Typhimurium and E. coli, respectively, compared to individual antibiotics. Biofilm viability and swimming and swarming motilities of S. Typhimurium in presence of GA-ceftiofur, and E. coli in presence of hamamelitannin-erythromycin and GA-ampicillin combinations were more competently inhibited than individual antimicrobials. The inhibitory concentrations 50% (IC50) of GA and hamamelitannin in IEC-6 cells were 564.55 μM and 988.54 μM, respectively. Conclusions: This study suggest that GA-ceftiofur combination can be potential medication to treat S. Typhimurium-associated diarrhea and prevent S. Typhimurium-associated blood-stream infections (e.g.: fever) in farm animals. Hamamelitannin-erythromycin and GA-ampicillin combinations can be effective in restricting E. coli contamination in farm animals, and ultimately its transmission from animal to human. Further study to confirm these effects and safety profiles in in vivo system should be undertaken for establishing these combinations as medications.

scholarly journals In vitro synergistic potentials of novel antibacterial combination therapies against Salmonella Typhimurium and Escherichia coli

2020 ◽  
Author(s):  
Md. Akil Hossain ◽  
Hae-Chul Park ◽  
Kwang-jick Lee ◽  
Sung-Won Park ◽  
Seung-Chun Park ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Synergistic Effects ◽  
Clinical Importance ◽  
Blood Stream ◽  
Farm Animals ◽  
Epicatechin Gallate ◽  
E Coli ◽  
Development Of Resistance

Abstract Background: The antibiotics generally used in farm animals are rapidly losing their effectiveness all over the world as bacteria develop antibiotic resistance. New strategies are needed to block the development of resistance and to prolong the life of traditional antibiotics. This study aimed to increase the efficacy of existing antibiotics by combining them with the opportunistic phenolic compounds gallic acid (GA), epicatechin, epicatechin gallate, epigallocatechin and hamamelitannin. Fractional inhibitory concentration index (FICI) of phenolic compound-antibiotic combinations against Salmonella enterica serovar Typhimurium (S. Typhimurium) and Escherichia coli (E. coli) were determined. Based on the FICI and clinical importance, 3 combinations (GA-ampicillin, GA-ceftiofur and hamamelitannin-erythromycin) were selected to evaluate their effects on the virulence factors of these bacteria. Viabilities of Rattus norvegicus (IEC-6) cell in presence of these combination antibacterials were evaluated.Results: Minimum inhibitory concentrations (MICs) of epigallocatechin, GA and hamamelitannin found against different strains were (512–1024), (256–1024) and (512–2048) μg/mL, respectively. Synergistic effects were obtained from combinations of thiamphenicol-GA (FICI: 0.28), erythromycin-hamamelitannin (FICI: 0.38) and thiamphenicol-hamamelitannin (FICI: 0.50) against E. coli, and erythromycin-epicatechin gallate (FICI: 0.50) against S. Typhimurium. Moreover, additive effects were obtained from 33 combinations against S. Typhimurium (FICI: 0.502~0.750) and E. coli (FICI: 0.502~0.625). The time-kill assays and ultrastructural morphology showed that GA-ceftiofur, and hamamelitannin-erythromycin and GA-ampicillin combinations more efficiently inhibited the growth of S. Typhimurium and E. coli, respectively, compared to individual antibiotics. Biofilm viability and swimming and swarming motilities of S. Typhimurium in presence of GA-ceftiofur, and E. coli in presence of hamamelitannin-erythromycin and GA-ampicillin combinations were more competently inhibited than individual antimicrobials. Viabilities of IEC-6 cells were significantly enhanced by GA-ceftiofur, GA-ampicillin combinations than these antibacterials alone. Conclusions: This study suggest that GA-ceftiofur combination can be potential medication to treat S. Typhimurium-associated diarrhea and prevent S. Typhimurium-associated blood-stream infections (e.g.: fever) in farm animals. Hamamelitannin-erythromycin and GA-ampicillin combinations can be effective in restricting E. coli contamination in farm animals, and ultimately its transmission from animal to human. Further in vivo study to confirm these effects and safety profiles in farm animal should be undertaken for establishing these combinations as medications.

scholarly journals In vitro synergistic potentials of novel antibacterial combination therapies against Salmonella Typhimurium and Escherichia coli

2019 ◽  
Author(s):  
Md. Akil Hossain(Former Corresponding Author) ◽  
Hae-Chul Park ◽  
Kwang-jick Lee ◽  
Sung-Won Park ◽  
Seung-Chun Park ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Phenolic Compound ◽  
Clinical Importance ◽  
In Vitro Cytotoxicity ◽  
Hep G2 ◽  
E Coli ◽  
Development Of Resistance ◽  
Different Strains

Abstract Background: Bacteria have remarkable abilities to acquire resistance against antibiotics by several mechanisms. New strategies are needed to block the development of resistance and to prolong the life of traditional antibiotics. This study aimed to increase the efficacy of existing antibiotics by combining them with the opportunistic phenolic compound gallic acid (GA) and its derivatives. Fractional inhibitory concentration (FIC) indexes of phenolic compound-antibiotic combinations against Salmonella enterica serovar Typhimurium ( S. Typhimurium) and Escherichia coli ( E. coli ) were determined. Based on the FIC index values and clinical importance, 3 combinations were selected to evaluate their effects on the virulence factors of these bacteria. The in vitro cytotoxicity of GA and hamamelitannin in human (Hep G2) and Rattus norvegicus (IEC-6) cell lines were evaluated. Results: Phenolic compounds demonstrated considerable antibacterial effects as the minimum inhibitory concentrations (MICs) of epigallocatechin, GA and hamamelitannin found against different strains were (512–1024), (256–1024) and (512–2048) μg/mL, respectively. The FIC indexes of the combined antibacterials against these strains were 0.281–1.016. The time-kill assays and ultrastructural morphology showed that the GA-ceftiofur combination, and hamamelitannin-erythromycin and GA-ampicillin combinations more efficiently inhibited the growth of S. Typhimurium and E. coli , respectively, compared to the individual antibiotics. Biofilm viability and the swimming and swarming motilities of S. Typhimurium in the presence of GA-ceftiofur and E. coli in the presence of the hamamelitannin-erythromycin and GA-ampicillin combinations were more competently inhibited than individual antimicrobials. The inhibitory concentrations 50% (IC 50 ) of GA and hamamelitannin in Hep G2 cells were 1427.34 μM and 2024.97 μM, and in IEC-6 cells were 564.55 μM and 988.54 μM, respectively. Conclusions: We can conclude that these antibacterial combinations can be potential medications to treat S. Typhimurium and E. coli infections. Further study to confirm this effect in in vivo system and to determine the precise mechanism of action should be undertaken to establish these combinations as medications.

scholarly journals In vitro synergistic potentials of novel antibacterial combination therapies against Salmonella enterica serovar Typhimurium

2020 ◽  
Author(s):  
Md. Akil Hossain ◽  
Hae-Chul Park ◽  
Kwang-jick Lee ◽  
Sung-Won Park ◽  
Seung-Chun Park ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Pathogenic Bacteria ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Clinical Importance ◽  
Farm Animals ◽  
Health Concern ◽  
Epicatechin Gallate ◽  
Serovar Typhimurium

Abstract Background: The antibiotics generally used in farm animals are rapidly losing their effectiveness all over the world as bacteria develop antibiotic resistance. Like some other pathogenic bacteria multidrug-resistant strains of Salmonella enterica serovar Typhimurium (S. Typhimurium) are also frequently found in animals and humans which poses a major public health concern. New strategies are needed to block the development of resistance and to prolong the life of traditional antibiotics. Thus, this study aimed to increase the efficacy of existing antibiotics against S. Typhimurium by combining them with opportunistic phenolic compounds gallic acid (GA), epicatechin, epicatechin gallate, epigallocatechin and hamamelitannin. Fractional inhibitory concentration indexes (FICI) of phenolic compound-antibiotic combinations against S. Typhimurium were determined. Based on the FICI and clinical importance, 1 combination (GA and ceftiofur) was selected for evaluating its effects on the virulence factors of this bacterium. Viability of Rattus norvegicus (IEC-6) cell in presence of this antibacterial combination was evaluated.Results: Minimum inhibitory concentrations (MICs) of GA, epigallocatechin and hamamelitannin found against different strains of S. Typhimurium were 256, (512–1024), and (512–1024) μg/mL, respectively. Synergistic antibacterial effect was obtained from the combination of erythromycin-epicatechin gallate (FICI: 0.50) against S. Typhimurium. Moreover, additive effects (FICI: 0.502–0.750) were obtained from 16 combinations against this bacterium. The time-kill assay and ultrastructural morphology showed that GA-ceftiofur combination more efficiently inhibited the growth of S. Typhimurium compared to individual antimicrobials. Biofilm viability, and swimming and swarming motilities of S. Typhimurium in presence of GA-ceftiofur combination were more competently inhibited than individual antimicrobials. Viabilities of IEC-6 cells were more significantly enhanced by GA-ceftiofur combinations than these antibacterials alone.Conclusions: This study suggests that GA-ceftiofur combination can be potential medication to treat S. Typhimurium-associated diarrhea and prevent S. Typhimurium-associated blood-stream infections (e.g.: fever) in farm animals, and ultimately its transmission from animal to human. Further in vivo study to confirm these effects and safety profiles in farm animal should be undertaken for establishing these combinations as medications.

scholarly journals In vitro synergistic potentials of novel antibacterial combination therapies against Salmonella Typhimurium, Escherichia coli and Staphylococcus aureus

2019 ◽  
Author(s):  
Md Akil Hossain ◽  
Hae-Chul Park ◽  
Kwang-jick Lee ◽  
Sung-Won Park ◽  
Seung-Chun Park ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Phenolic Compounds ◽  
Phenolic Compound ◽  
Virulence Factors ◽  
In Vitro Cytotoxicity ◽  
E Coli ◽  
And Staphylococcus Aureus

Abstract Background: Bacteria have remarkable abilities to acquire resistance against antibiotics by several mechanisms. New strategies are needed to block the development of resistance and to prolong the life of traditional antibiotics. This study aimed to increase the efficacy of existing antibiotics by combining them with the opportunistic phenolic compound gallic acid (GA) and its derivatives. Fractional inhibitory concentration (FIC) indexes of phenolic compound-antibiotic combinations against Salmonella enterica serovar Typhimurium, Escherichia coli and Staphylococcus aureus were determined. Based on the FIC indexes and clinical importance, 3 combinations were selected to evaluate their effects on the virulence factors of these bacteria. The in vitro cytotoxicity of GA and hamamelitannin in the Rattus norvegicus (IEC-6) cell line were evaluated. Results: Phenolic compounds demonstrated considerable antibacterial effects as the minimum inhibitory concentrations (MICs) of epigallocatechin, GA and hamamelitannin found against different strains were (32–1024), (128–1024) and (512–≥2048) μg/mL, respectively. The FIC indexes of the combined antibacterials against these strains were 0.281–1.016. The ultrastructural morphology and time-kill assays showed that the GA-ceftiofur combination, and hamamelitannin-erythromycin and GA-ampicillin combinations more efficiently inhibited the growth of S. Typhimurium and E. coli, respectively, compared to the individual antibiotics. Biofilm viability and the swimming and swarming motilities of S. Typhimurium in the presence of GA-ceftiofur and E. coli in the presence of the hamamelitannin-erythromycin and GA-ampicillin combinations were more competently inhibited than individual antimicrobials. The 50% inhibitory concentrations (IC50) of GA and hamamelitannin in IEC-6 cells were 564.55 μM and 988.54 μM, respectively. Conclusions: The phenolic compounds increase the efficacy of existing antibiotics might be by disrupting virulence factors. We can conclude that these antibacterial combinations are safe and can be potential medications to treat S. Typhimurium, E. coli and S. aureus infections in animals and humans. Further study to confirm this effect in in vivo system and to determine the precise mechanism of action should be undertaken to establish these combinations as medications.

scholarly journals Mutual Enhancement of Virulence by Enterotoxigenic and Enteropathogenic Escherichia coli

2006 ◽  
Vol 74 (3) ◽  
pp. 1505-1515 ◽  
Author(s):  
John K. Crane ◽  
Shilpa S. Choudhari ◽  
Tonniele M. Naeher ◽  
Michael E. Duffey
Keyword(s):  
Escherichia Coli ◽  
Host Cell ◽  
Synergistic Effects ◽  
Adenine Nucleotides ◽  
Ussing Chamber ◽  
Atp Release ◽  
T84 Cells ◽  
E Coli

ABSTRACT Enterotoxigenic Escherichia coli (ETEC) and enteropathogenic E. coli (EPEC) are common causes of diarrhea in children in developing countries. Dual infections with both pathogens have been noted fairly frequently in studies of diarrhea around the world. In previous laboratory work, we noted that cholera toxin and forskolin markedly potentiated EPEC-induced ATP release from the host cell, and this potentiated release was found to be mediated by the cystic fibrosis transmembrane conductance regulator. In this study, we examined whether the ETEC heat-labile toxin (LT) or the heat-stable toxin (STa, also known as ST) potentiated EPEC-induced ATP release. We found that crude ETEC culture filtrates, as well as purified ETEC toxins, did potentiate EPEC-induced ATP release in cultured T84 cells. Coinfection of T84 cells with live ETEC plus EPEC bacteria also resulted in enhanced ATP release compared to EPEC alone. In Ussing chamber studies of chloride secretion, adenine nucleotides released from the host by EPEC also significantly enhanced the chloride secretory responses that were triggered by crude ETEC filtrates, purified STa, and the peptide hormone guanylin. In addition, adenosine and LT had additive or synergistic effects in inducing vacuole formation in T84 cells. Therefore, ETEC toxins and EPEC-induced damage to the host cell both enhance the virulence of the other type of E. coli. Our in vitro data demonstrate a molecular basis for a microbial interaction, which could result in increased severity of disease in vivo in individuals who are coinfected with ETEC and EPEC.

scholarly journals In vitro synergistic potentials of novel antibacterial combination therapies against Salmonella enterica serovar Typhimurium

2020 ◽  
Author(s):  
Md. Akil Hossain ◽  
Hae-Chul Park ◽  
Kwang-jick Lee ◽  
Sung-Won Park ◽  
Seung-Chun Park ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Pathogenic Bacteria ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Clinical Importance ◽  
Farm Animals ◽  
Health Concern ◽  
Epicatechin Gallate ◽  
Serovar Typhimurium

Abstract Background: The antibiotics generally used in farm animals are rapidly losing their effectiveness all over the world as bacteria develop antibiotic resistance. Like some other pathogenic bacteria multidrug-resistant strains of Salmonella enterica serovar Typhimurium (S. Typhimurium) are also frequently found in animals and humans which poses a major public health concern. New strategies are needed to block the development of resistance and to prolong the life of traditional antibiotics. Thus, this study aimed to increase the efficacy of existing antibiotics against S. Typhimurium by combining them with the opportunistic phenolic compounds gallic acid (GA), epicatechin, epicatechin gallate, epigallocatechin and hamamelitannin. Fractional inhibitory concentration indexes (FICI) of phenolic compound-antibiotic combinations against S. Typhimurium were determined. Based on the FICI and clinical importance, 1 combination (GA and ceftiofur) was selected to evaluate its effects on the virulence factors of this bacterium. Viability of Rattus norvegicus (IEC-6) cell in presence of this antibacterial combination was evaluated.Results: Minimum inhibitory concentrations (MICs) of GA, epigallocatechin and hamamelitannin found against different strains of S. Typhimurium were 256, (512–1024), and (512–1024) μg/mL, respectively. Synergistic antibacterial effect was obtained from the combination of erythromycin-epicatechin gallate (FICI: 0.50) against S. Typhimurium. Moreover, additive effects (FICI: 0.502–0.750) were obtained from 16 combinations against this bacterium. The time-kill assays and ultrastructural morphology showed that GA-ceftiofur combination more efficiently inhibited the growth of S. Typhimurium compared to individual antimicrobials. Biofilm viability and swimming and swarming motilities of S. Typhimurium in presence of GA-ceftiofur combination were more competently inhibited than individual antimicrobials. Viabilities of IEC-6 cells were significantly enhanced by GA-ceftiofur combinations than these antibacterials alone.Conclusions: This study suggest that GA-ceftiofur combination can be potential medication to treat S. Typhimurium-associated diarrhea and prevent S. Typhimurium-associated blood-stream infections (e.g.: fever) in farm animals, and ultimately its transmission from animal to human. Further in vivo study to confirm these effects and safety profiles in farm animal should be undertaken for establishing these combinations as medications.

scholarly journals Lysyl-tRNA synthetase from Escherichia coli K12. Chromatographic heterogeneity and the lysU-gene product

1987 ◽  
Vol 248 (1) ◽  
pp. 43-51 ◽  
Author(s):  
J Charlier ◽  
R Sanchez
Keyword(s):  
Escherichia Coli ◽  
Gene Product ◽  
Activity Ratio ◽  
Deae Cellulose ◽  
Trna Synthetase ◽  
Trna Synthetases ◽  
E Coli ◽  
Aminoacyl Trna Synthetases

In contrast with most aminoacyl-tRNA synthetases, the lysyl-tRNA synthetase of Escherichia coli is coded for by two genes, the normal lysS gene and the inducible lysU gene. During its purification from E. coli K12, lysyl-tRNA synthetase was monitored by its aminoacylation and adenosine(5′)tetraphospho(5′)adenosine (Ap4A) synthesis activities. Ap4A synthesis was measured by a new assay using DEAE-cellulose filters. The heterogeneity of lysyl-tRNA synthetase (LysRS) was revealed on hydroxyapatite; we focused on the first peak, LysRS1, because of its higher Ap4A/lysyl-tRNA activity ratio at that stage. Additional differences between LysRS1 and LysRS2 (major peak on hydroxyapatite) were collected. LysRS1 was eluted from phosphocellulose in the presence of the substrates, whereas LysRS2 was not. Phosphocellulose chromatography was used to show the increase of LysRS1 in cells submitted to heat shock. Also, the Mg2+ optimum in the Ap4A-synthesis reaction is much higher for LysRS1. LysRS1 showed a higher thermostability, which was specifically enhanced by Zn2+. These results in vivo and in vitro strongly suggest that LysRS1 is the heat-inducible lysU-gene product.

scholarly journals Biological Cost of Single and Multiple Norfloxacin Resistance Mutations in Escherichia coli Implicated in Urinary Tract Infections

2005 ◽  
Vol 49 (6) ◽  
pp. 2343-2351 ◽  
Author(s):  
Patricia Komp Lindgren ◽  
Linda L. Marcusson ◽  
Dorthe Sandvang ◽  
Niels Frimodt-Møller ◽  
Diarmaid Hughes
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Infection Model ◽  
Resistance Mutations ◽  
Topoisomerase Iv ◽  
E Coli ◽  
Tract Infections ◽  
Subsequent Selection

ABSTRACT Resistance to fluoroquinolones in urinary tract infection (UTIs) caused by Escherichia coli is associated with multiple mutations, typically those that alter DNA gyrase and DNA topoisomerase IV and those that regulate AcrAB-TolC-mediated efflux. We asked whether a fitness cost is associated with the accumulation of these multiple mutations. Mutants of the susceptible E. coli UTI isolate Nu14 were selected through three to five successive steps with norfloxacin. Each selection was performed with the MIC of the selected strain. After each selection the MIC was measured; and the regions of gyrA, gyrB, parC, and parE, previously associated with resistance mutations, and all of marOR and acrR were sequenced. The first selection step yielded mutations in gyrA, gyrB, and marOR. Subsequent selection steps yielded mutations in gyrA, parE, and marOR but not in gyrB, parC, or acrR. Resistance-associated mutations were identified in almost all isolates after selection steps 1 and 2 but in less than 50% of isolates after subsequent selection steps. Selected strains were competed in vitro, in urine, and in a mouse UTI infection model against the starting strain, Nu14. First-step mutations were not associated with significant fitness costs. However, the accumulation of three or more resistance-associated mutations was usually associated with a large reduction in biological fitness, both in vitro and in vivo. Interestingly, in some lineages a partial restoration of fitness was associated with the accumulation of additional mutations in late selection steps. We suggest that the relative biological costs of multiple mutations may influence the evolution of E. coli strains that develop resistance to fluoroquinolones.

scholarly journals The Escherichia coli cysG promoter belongs to the ‘extended −10’ class of bacterial promoters

1993 ◽  
Vol 296 (3) ◽  
pp. 851-857 ◽  
Author(s):  
T Belyaeva ◽  
L Griffiths ◽  
S Minchin ◽  
J Cole ◽  
S Busby
Keyword(s):  
Escherichia Coli ◽  
Point Mutations ◽  
Growth Conditions ◽  
Upstream Region ◽  
E Coli ◽  
Run Off ◽  
A Site ◽  
Specific Sequences

The Escherichia coli cysG promoter has been subcloned and shown to function constitutively in a range of different growth conditions. Point mutations identify the -10 hexamer and an important 5′-TGN-3′ motif immediately upstream. The effects of different deletions suggest that specific sequences in the -35 region are not essential for the activity of this promoter in vivo. This conclusion was confirmed by in vitro run-off transcription assays. The DNAase I footprint of RNA polymerase at the cysG promoter reveals extended protection upstream of the transcript start, and studies with potassium permanganate as a probe suggest that the upstream region is distorted in open complexes. Taken together, the results show that the cysG promoter belongs to the ‘extended -10’ class of promoters, and the base sequence is similar to that of the P1 promoter of the E. coli galactose operon, another promoter in this class. In vivo, messenger initiated at the cysG promoter appears to be processed by cleavage at a site 41 bases downstream from the transcript start point.

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