scholarly journals Effects of Gkn1 On Biofilm Formation

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Tova Wasserman-Bruck ◽  
Boger-May Boger-May ◽  
Derek Rubadeux ◽  
Katelyn Ruley-Haase ◽  
David L. Boone
Keyword(s):  
Dose Response ◽  
Response Inhibition ◽  
Biofilm Formation ◽  
Inhibitory Effect ◽  
Protective Role ◽  
Amyloid Formation ◽  
E Coli ◽  
Planktonic Bacteria ◽  
Exact Function ◽  
Gastrokine 1

Background and Objectives: Gastrokine-1 (Gkn1) is a protein produced solely in the stomach and secreted into the lumen of the gut. Gkn1 has a BRICHOS domain which is anti-amyloidogenic. While the exact function of Gkn1 is not yet completely understood, Gkn1 has a protective role against IBD in induced models of colitis. Since microbes secrete amyloid to facilitate biofilm formation, we hypothesized that Gkn1 may play a protective role against IBD by inhibiting amyloid formation by biofilm forming microbes in the gut. We examined the effects of varying concentrations of Gkn1 on known biofilm forming microbes to determine if there was a dose responsive inhibitory effect of Gkn1 on biofilm formation.  Methods: Bacterial colonies from Adherent Invasive E. coli and E. faecalis were cultured and incubated at 37 degrees Celsius overnight. The samples were then diluted 1:100 and inoculated into 96-well costar microassay plates with concentrations of Gkn1 ranging from 0.00075 to 0.025 mg/ml. At 8, 24, or 48 hour time points the plates were then washed to remove planktonic bacteria, and adherent biofilms were stained with crystal violet. Biofilm formation was analyzed by comparing the OD590/OD600 against a control.   Results:  Using a one-way ANOVA, we determined that there is dose response inhibition of biofilm formation with Gkn1, with the greatest inhibition of biofilm formation at concentrations of Gkn1 between 0.00312 and 0.0125 mg/ml.  Conclusions:  A dose response inhibition of Gkn1 on biofilm formation was identified. Since Gkn1 has demonstrated a protective role against IBD in induced colitis, targeting intestinal luminal amyloids may be a potential therapeutic approach for IBD.

scholarly journals Nanoparticles engineered from endophytic fungi (Botryosphaeria rhodina) against ESBL-producing pathogenic multidrug-resistant E. coli

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Tahira Akther ◽  
S. Ranjani ◽  
S. Hemalatha
Keyword(s):  
Biofilm Formation ◽  
Bacterial Resistance ◽  
Klebsiella Oxytoca ◽  
Antibiotic Sensitivity ◽  
Inhibitory Effect ◽  
Positive Control ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Beta Lactam ◽  
E Coli

Abstract Background ESBLs hydrolyze the beta-lactam ring of antibiotics and are not affected by 1st, 2nd, 3rd, and 4th generation antibiotics. There are over 400 ESBL enzymes that have already been investigated globally are present in Enterobacteriaceae species such as Escherichia coli, Klebsiella pneumoniae and Klebsiella oxytoca strains. Prevalence of ESBLs is slowly increased, from 10 to 40% in E. coli and K. pneumonia strains. Microorganisms producing ESBLs are challenging to physicians, clinical microbiologists, and antibiotic researchers. Results In this study, ESBL-producing strains of E. coli were subjected to antibiotic sensitivity screening. The efficacy of myco BR-AgNPs on growth in E. coli ATCC (25922) and clinical isolates of E. coli was determined by well diffusion method. Myco BR-AgNPs reduced the growth as well as inhibited the biofilm formation in ESBL-producing strains of E. coli. MIC and MBC were determined by using serial microdilution and surface drop method. The MICs were 0.078–0.625 µg/ml and MBCs were 0.312–1.25 µg/ml. The biofilm formation was effectively inhibited by myco BR-AgNPs when compared with control. The expression of CTX-M-15 gene was studied in clinical isolates of E. coli treated with antibiotic (positive control), mycosilver nanoparticles (test) and compared with the other positive control (untreated strains). Interestingly, the expression of CTX-M-15 was downregulated in the samples treated with myco BR-AgNPs. Conclusion The use of myco BR-AgNPs and their growth inhibitory effect on ESBL-positive strains were the main focus of this research. ATCC and ESBL strains used in this study were effectively inhibited by myco BR-AgNPs. The effect of myco BR-AgNPs on the expression of a gene encoding CTX-M-15 was tested on a molecular level, and the observed results showed that the gene expression was reduced when compared with control and antibiotic treatment. According to the current research, myco BR-AgNPs synthesized with the aid of endophytic fungal extract could be used to suppress the growth of ESBL-positive strains of E. coli. Myco BR-AgNPs may be an important alternative to various antibiotics in preventing bacterial resistance if optimized and tested for toxicity.

scholarly journals Study of Inhibitory agent produced by Streptococcus thermophilus on growth and Biofilm formation for some pathogenic bacteria

2013 ◽  
Vol 7 (2) ◽  
pp. 24-31
Author(s):  
Jehan A.S. Salman ◽  
Khawlah J. Khalaf ◽  
Mohammed F. Al-Marjani
Keyword(s):  
Escherichia Coli ◽  
Inhibitory Activity ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Streptococcus Thermophilus ◽  
Inhibitory Effect ◽  
E Coli ◽  
Chloroform Methanol ◽  
Klebsiella Spp ◽  
Lipophilic Fraction

Inhibitory activity of Streptococcus thermophilus unconcentrated and concentrated filtrate was studied against some pathogenic bacteria included: Pseudomonas aeruginosa, Klebsiella spp., Staphylococcus aureu, Escherichia coli. Inhibitory activity of protein that extracted from S. thermophilus concentrated filtrate was studied after precipitate by ammonium sulphate and inhibitory activity of lipophilic fraction that extracted from concentrated filtrate with chloroform-methanol (1:1 vol/ vol) was studied against pathogenic bacteria. Also inhibitory activity of biosurfactant produced by S. thermophilus was studied against growth and biofilm formation for pathogenic bacteria. The results showed that unconcentrated and concentrated filtrate had inhibitory activity against all pathogenic bacteria. Also protein and lipophilic fraction had inhibitory effect against pathogenic bacteria, while the biosurfactant show inhibitory activity against growth of all pathogenic bacteria but show inhibitory effect on biofilm formation only for pathogenic bacteria S. aureus and E. coli.

scholarly journals Inhibition of Glucosyltransferase Activity and Glucan Production as an Antibiofilm Mechanism of Lemongrass Essential Oil against Escherichia coli O157:H7

Antibiotics ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 102 ◽  
Author(s):  
Luis A. Ortega-Ramirez ◽  
M. Melissa Gutiérrez-Pacheco ◽  
Irasema Vargas-Arispuro ◽  
Gustavo A. González-Aguilar ◽  
Miguel A. Martínez-Téllez ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Essential Oil ◽  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Inhibitory Effect ◽  
Escherichia Coli O157 ◽  
Cymbopogon Citratus ◽  
Docking Analysis ◽  
E Coli ◽  
Lemongrass Essential Oil

The resistance of Escherichia coli O157:H7 to disinfection is associated with its ability to form biofilms, mainly constituted by glucans produced by glucosyltransferases. Citral and geraniol, terpenes found in the essential oil of Cymbopogon citratus (EO), have proven antibacterial activity against planktonic E. coli; however, no information was found about their efficacy and mode of action against E. coli biofilms. Therefore, the inhibitory effect of C. citratus EO, citral, and geraniol on glucans production and glucosyltransferase activity as anti-biofilm mechanism against E. coli was evaluated. EO, citral, and geraniol inhibited the planktonic growth of E. coli (minimal inhibitory concentration or MIC= 2.2, 1.0, and 3.0 mg/mL, respectively) and the bacterial adhesion (2.0, 2.0, and 4.0 mg/mL, respectively) on stainless steel. All compounds decreased the glucans production; citral and geraniol acted as uncompetitive inhibitors of glucosyltransferase activity (The half maximal inhibitory concentrations or IC50 were 8.5 and 6.5 µM, respectively). The evidence collected by docking analysis indicated that both terpenes could interact with the helix finger of the glucosyltransferase responsible for the polymer production. In conclusion, C. citratus EO, citral, and geraniol inhibited glucosyltransferase activity, glucans production, and the consequent biofilm formation of E. coli O157:H7.

scholarly journals Influence of cell-free extracts of Bifidobacterium bifidum and Lactobacillus reuteri on proliferation and biofilm formation by Escherichia coli and Pseudomonas aeruginosa

2019 ◽  
Vol 10 (2) ◽  
pp. 251-256 ◽  
Author(s):  
O. V. Knysh ◽  
O. Y. Isayenko ◽  
Y. V. Voyda ◽  
O. O. Kizimenko ◽  
Y. M. Babych
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Proliferative Activity ◽  
Lactobacillus Reuteri ◽  
Microtiter Plate ◽  
Inhibitory Effect ◽  
Bifidobacterium Bifidum ◽  
Plate Method ◽  
E Coli ◽  
Test Cultures

The development of new effective preparations for the correction of microecological disorders based on probiotic derivatives requires a comprehensive study of the biological activity of the latter. We studied the proliferative activity and biofilm formation by clinical isolates: Escherichia coli and Pseudomonas aeruginosa under the influence of cell-free extracts containing structural components and metabolites of the Bifidobacterium bifidum and Lactobacillus reuteri probiotic strains. Cell-free extracts were obtained from disintegrates and cultures of probiotics. Disintegrates were prepared by cyclic freezing-thawing of probiotic cell suspensions. The cultures were obtained by cultivating probiotic microorganisms in their own disintegrates. The obtained disintegrates and cultures were filtered. The proliferative activity of the test cultures was studied using the spectrophotometric microtiter plate method after an hour-long exposure in undiluted cell-free extracts and subsequent cultivation in a nutrient medium containing 30%vol of the studied extracts at 37 °C for 24 hours. The biofilm formation of the test cultures was studied with 30% vol content of cell-free extracts in the cultivation medium using the spectrophotometric microtiter plate method. All the studied extracts exerted a similar effect on the proliferative activity and biofilm formation by E. coli and P. aeruginosa. Exposure of the test cultures in all undiluted extracts during an hour led to a significant decrease in the optical density of the test samples: optical density of the test wells ranged from 36.5% to 49.8% of the control wells. The test cultures that were exposed to the extracts: filtrate of L. reuteri disintegrate (L), filtrate of В. bifidum disintegrate (B) and filtrate of В. bifidum culture, grown in В. bifidum disintegrate (MB) after dilution and subsequent cultivation over the next 24 hours completely restored the ability to proliferate. The proliferative activity of the test cultures that were exposed to the extracts: filtrate of L. reuteri culture, grown in L. reuteri disintegrate (ML) and filtrate of L. reuteri culture, grown in L. reuteri disintegrate supplemented with 0.8 M glycerol and 0.4 M glucose (MLG), was significantly inhibited after dilution and subsequent cultivation. The inhibition indices calculated for the ML extract were: 25.9% (E. coli) and 53.0% (P. aeruginosa). Inhibition indices calculated for the MLG extract were: 62.0% (E. coli) and 96.9% (P. aeruginosa). MLG extract had more pronounced inhibitory effect on the proliferation of the test cultures than ML extract. All the studied extracts exerted significant inhibitory effect on the biofilm formation of the test cultures. Analysis of the results of the study shows that cell-free extracts of L. reuteri culture grown in its disintegrate without supplementation or supplemented with glycerol and glucose have the highest antimicrobial activity and can be used as metabiotics to prevent overgrowth of potentially pathogenic bacteria, as well as inoculation and proliferation of pathogenic gram-negative bacteria in the gastrointestinal tract. They can be used alone or in combination with cellular probiotics to enhance their probiotic action. This study encourages further careful investigation of the biochemical composition of cell-free extracts and clarifying the mechanism of their action.

The Inhibition of Platelet Aggregation by an Aorta Intima Extract

1974 ◽  
Vol 32 (02/03) ◽  
pp. 417-431 ◽  
Author(s):  
A. du P Heyns ◽  
D. J van den Berg ◽  
G. M Potgieter ◽  
F. P Retief
Keyword(s):  
Platelet Aggregation ◽  
Degradation Products ◽  
Adenosine Diphosphate ◽  
Inhibitory Effect ◽  
Protective Role ◽  
Vascular Trauma ◽  
Wear And Tear ◽  
Sequential Addition ◽  
Aggregation Activity

SummaryThe platelet aggregating activity of extracts of different layers of the arterial wall was compared to that of Achilles tendon. Arterial media and tendon extracts, adjusted to equivalent protein content as an index of concentration, aggregated platelets to the same extent but an arterial intima extract did not aggregate platelets. Platelet aggregation induced by collagen could be inhibited by mixing with intima extract, but only to a maximum of about 80%. Pre-mixing adenosine diphosphate (ADP) with intima extracts diminished the platelet aggregation activity of the ADP. Depending on the relationship between ADP and intima extract concentrations aggregating activity could either be completely inhibited or inhibition abolished. Incubation of ADP with intima extract and subsequent separation of degradation products by paper chromatography, demonstrated a time-dependent breakdown of ADP with AMP, adenosine, inosine and hypoxanthine as metabolic products; ADP removal was complete. Collagen, thrombin and adrenaline aggregate platelets mainly by endogenous ADP of the release reaction. Results of experiments comparing inhibition of aggregation caused by premixing aggregating agent with intima extract, before exposure to platelets, and the sequential addition of first the intima extract and then aggregating agent to platelets, suggest that the inhibitory effect of intima extract results from ADP breakdown. It is suggested that this ADP degradation by intima extract may play a protective role in vivo by limiting the size of platelet aggregates forming at the site of minimal “wear and tear” vascular trauma.

scholarly journals Myricetin as an Antivirulence Compound Interfering with a Morphological Transformation into Coccoid Forms and Potentiating Activity of Antibiotics against Helicobacter pylori

2021 ◽  
Vol 22 (5) ◽  
pp. 2695
Author(s):  
Paweł Krzyżek ◽  
Paweł Migdał ◽  
Emil Paluch ◽  
Magdalena Karwańska ◽  
Alina Wieliczko ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Biofilm Formation ◽  
Inhibitory Effect ◽  
Morphological Transformation ◽  
High Tendency ◽  
Minimal Inhibitory Concentrations ◽  
Coccoid Form ◽  
Stomach Diseases ◽  
Fold Reduction ◽  
H Pylori

Helicobacter pylori, a gastric pathogen associated with a broad range of stomach diseases, has a high tendency to become resistant to antibiotics. One of the most important factors related to therapeutic failures is its ability to change from a spiral to a coccoid form. Therefore, the main aim of our original article was to determine the influence of myricetin, a natural compound with an antivirulence action, on the morphological transformation of H. pylori and check the potential of myricetin to increase the activity of antibiotics against this pathogen. We observed that sub-minimal inhibitory concentrations (sub-MICs) of this compound have the ability to slow down the process of transformation into coccoid forms and reduce biofilm formation of this bacterium. Using checkerboard assays, we noticed that the exposure of H. pylori to sub-MICs of myricetin enabled a 4–16-fold reduction in MICs of all classically used antibiotics (amoxicillin, clarithromycin, tetracycline, metronidazole, and levofloxacin). Additionally, RT-qPCR studies of genes related to the H. pylori morphogenesis showed a decrease in their expression during exposure to myricetin. This inhibitory effect was more strongly seen for genes involved in the muropeptide monomers shortening (csd3, csd6, csd4, and amiA), suggesting their significant participation in the spiral-to-coccoid transition. To our knowledge, this is the first research showing the ability of any compound to synergistically interact with all five antibiotics against H. pylori and the first one showing the capacity of a natural substance to interfere with the morphological transition of H. pylori from spiral to coccoid forms.

scholarly journals Albizia chinensis bark extract ameliorates the genotoxic effect of cyclophosphamide

2020 ◽  
Vol 44 (1) ◽  
Author(s):  
Marian Nabil ◽  
Entesar E. Hassan ◽  
Neven S. Ghaly ◽  
Fawzia A. Aly ◽  
Farouk R. Melek ◽  
...  
Keyword(s):  
Folk Medicine ◽  
Inhibitory Effect ◽  
Protective Role ◽  
Bark Extract ◽  
Repeated Treatment ◽  
Mouse Bone Marrow ◽  
Sperm Abnormalities ◽  
Wide Range ◽  
Different Doses

Abstract Background The genus Albizia (Leguminoseae) is used in folk medicine for the treatment of a wide range of ailments. Recently, saponins from plant origin have attracted much attention. Saponins are recorded to have a broad range of biological and pharmacological activities. This study was performed to evaluate the protective role of Albizia chinensis bark methanolic extract (MEAC) against the genotoxicity induced by cyclophosphamide (CP) using different mutagenic parameters. Results The results showed that MEAC induced an inhibitory effect against chromosomal aberrations of CP in mouse bone marrow and spermatocytes. Such effect was found to be significant (p < 0.01) with a dose of 100 mg/kg treated once for 24 h and also after repeated treatment at a dose of 25 mg/kg for 7 days. In sperm abnormalities, the protective effect of Albizia extract showed a dose-related relationship. Different doses of MEAC (25, 50, and 100 mg/kg) significantly (p < 0.01) ameliorated sperm abnormalities induced by CP dose-dependently. The percentage of sperm abnormalities was decreased to 5.14 ± 0.72 in the group of animals treated with CP plus MEAC (100 mg/kg) indicating an inhibitory effect of about 50%. Conclusion MEAC at the doses examined was non-genotoxic compared to control (negative) and exhibited a protective role against CP genotoxicity.

scholarly journals Label-free quantitative proteomic analysis of the inhibition effect of Lactobacillus rhamnosus GG on Escherichia coli biofilm formation in co-culture

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Huiyi Song ◽  
Ni Lou ◽  
Jianjun Liu ◽  
Hong Xiang ◽  
Dong Shang
Keyword(s):  
Escherichia Coli ◽  
Proteomic Analysis ◽  
Biofilm Formation ◽  
Lactobacillus Rhamnosus ◽  
Differentially Expressed ◽  
Differentially Expressed Proteins ◽  
Label Free ◽  
Quantitative Proteomic Analysis ◽  
E Coli ◽  
Protein Ubiquitination

Abstract Background Escherichia coli (E. coli) is the principal pathogen that causes biofilm formation. Biofilms are associated with infectious diseases and antibiotic resistance. This study employed proteomic analysis to identify differentially expressed proteins after coculture of E. coli with Lactobacillus rhamnosus GG (LGG) microcapsules. Methods To explore the relevant protein abundance changes after E. coli and LGG coculture, label-free quantitative proteomic analysis and qRT-PCR were applied to E. coli and LGG microcapsule groups before and after coculture, respectively. Results The proteomic analysis characterised a total of 1655 proteins in E. coli K12MG1655 and 1431 proteins in the LGG. After coculture treatment, there were 262 differentially expressed proteins in E. coli and 291 in LGG. Gene ontology analysis showed that the differentially expressed proteins were mainly related to cellular metabolism, the stress response, transcription and the cell membrane. A protein interaction network and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analysis indicated that the differentiated proteins were mainly involved in the protein ubiquitination pathway and mitochondrial dysfunction. Conclusions These findings indicated that LGG microcapsules may inhibit E. coli biofilm formation by disrupting metabolic processes, particularly in relation to energy metabolism and stimulus responses, both of which are critical for the growth of LGG. Together, these findings increase our understanding of the interactions between bacteria under coculture conditions.

scholarly journals A novel bis(pyrazolyl)methane compound as a potential agent against Gram-positive bacteria

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pedro Seguí ◽  
John J. Aguilera-Correa ◽  
Elena Domínguez-Jurado ◽  
Christian M. Sánchez-López ◽  
Ramón Pérez-Tanoira ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Inhibitory Effect ◽  
Eukaryotic Cell ◽  
Liver Carcinoma ◽  
Gram Positive ◽  
Minimal Inhibitory Concentrations ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Therapeutic Compounds ◽  
Toxic Concentrations

AbstractThis study was designed to propose alternative therapeutic compounds to fight against bacterial pathogens. Thus, a library of nitrogen-based compounds bis(triazolyl)methane (1T–7T) and bis(pyrazolyl)methane (1P–11P) was synthesised following previously reported methodologies and their antibacterial activity was tested using the collection strains of Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa. Moreover, the novel compound 2P was fully characterized by IR, UV–Vis and NMR spectroscopy. To evaluate antibacterial activity, minimal inhibitory concentrations (MICs), minimal bactericidal concentrations (MBCs), minimum biofilm inhibitory concentrations (MBICs), and minimum biofilm eradication concentrations (MBECs) assays were carried out at different concentrations (2–2000 µg/mL). The MTT assay and Resazurin viability assays were performed in both human liver carcinoma HepG2 and human colorectal adenocarcinoma Caco-2 cell lines at 48 h. Of all the synthesised compounds, 2P had an inhibitory effect on Gram-positive strains, especially against S. aureus. The MIC and MBC of 2P were 62.5 and 2000 µg/mL against S. aureus, and 250 and 2000 µg/mL against E. faecalis, respectively. However, these values were > 2000 µg/mL against E. coli and P. aeruginosa. In addition, the MBICs and MBECs of 2P against S. aureus were 125 and > 2000 µg/mL, respectively, whereas these values were > 2000 µg/mL against E. faecalis, E. coli, and P. aeruginosa. On the other hand, concentrations up to 250 µg/mL of 2P were non-toxic doses for eukaryotic cell cultures. Thus, according to the obtained results, the 2P nitrogen-based compound showed a promising anti-Gram-positive effect (especially against S. aureus) both on planktonic state and biofilm, at non-toxic concentrations.

Sign in / Sign up

Export Citation Format

Share Document