scholarly journals Quantifying and engineering mucus adhesion of probiotics

2019 ◽  
Author(s):  
Zachary J. S. Mays ◽  
Todd C. Chappell ◽  
Nikhil U. Nair
Keyword(s):  
Binding Capacity ◽  
Probiotic Strain ◽  
Surface Proteins ◽  
Surface Binding ◽  
E Coli ◽  
Wide Range ◽  
Cell Components ◽  
Dose Dependent ◽  
Cell Mucus

ABSTRACTMucus in the gastrointestinal (GI) tract is the primary point-of-interaction between humans and their gut microbiota. This not only intimates that mucus ensures protection against endogenous and ex-ogenous opportunists but provision for the human microbiota to reside and flourish. With the emergence of living therapeutics, engineered microbes can deliver and produce increasingly complex medicine, and controlling the mucoadhesive properties of different microbial chassis can dictate dose-response in a patient. Here we present a redesigned, in vitro, plate-based assay to measure the mucus adhesion of various probiotics. Cell-mucus interactions were isolated by immobilizing mucus to the plate surface. Binding parameters were derived for each probiotic strain by measuring cell adhesion over a wide range of cell concentrations, providing dose-dependent adhesion metrics. Surface proteins and cell components known to influence mucoadhesion were then heterologously expressed or altered in Lactococcus lactis MG1363 and E. coli Nissle 1917 to control mucus-binding capacity, avidity, and cooperativity.

scholarly journals Simonkolleite Coating on Poly(Amino Acids) to Improve Osteogenesis and Suppress Osteoclast Formation in Vitro

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1505 ◽  
Author(s):  
Shuyang Li ◽  
Xingtao Chen ◽  
Xiaomei Wang ◽  
Yi Xiong ◽  
Yonggang Yan ◽  
...  
Keyword(s):  
Amino Acids ◽  
Osteoclast Formation ◽  
Mouse Bone Marrow ◽  
Graft Material ◽  
Dependent Manner ◽  
E Coli ◽  
Ft Ir ◽  
Dose Dependent ◽  
Relative Cell Viability

Zinc can enhance osteoblastic bone formation and stimulate osteogenic differentiation, suppress the differentiation of osteoclast precursor cells into osteoclasts, and inhibit pathogenic bacterial growth in a dose-dependent manner. In this study, simonkolleite, as a novel zinc resource, was coated on poly (amino acids) (PAA) via suspending PAA powder in different concentrations of zinc chloride (ZnCl2) solution, and the simonkolleite-coated PAA (Zn–PAA) was characterized by SEM, XRD, FT-IR and XPS. Zinc ions were continuously released from the coating, and the release behavior was dependent on both the concentration of the ZnCl2 immersing solution and the type of soak solutions (SBF, PBS and DMEM). The Zn–PAA was cultured with mouse bone marrow stem cells (BMSCs) through TranswellTM plates, and the results indicated that the relative cell viability, alkaline phosphatase (ALP) activity and mineralization of BMSCs were significantly higher with Zn–PAA as compared to PAA. Moreover, the Zn–PAA was cultured with RAW264.7 cells, and the results suggested an inhibiting effect of Zn–PAA on the cell differentiation into osteoclasts. In addition, Zn–PAA exhibited an antibacterial activity against both S. aureus and E. coli. These findings suggest that simonkolleite coating with certain contents could promote osteogenesis, suppress osteoclast formation and inhibit bacteria, indicating a novel way of enhancing the functionality of synthetic bone graft material and identifying the underline principles for designing zinc-containing bone grafts.

scholarly journals A Toxic Environment: a Growing Understanding of How Microbial Communities Affect Escherichia coli O157:H7 Shiga Toxin Expression

2020 ◽  
Vol 86 (24) ◽  
Author(s):  
Erin M. Nawrocki ◽  
Hillary M. Mosso ◽  
Edward G. Dudley
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Microbial Interactions ◽  
Severe Illness ◽  
Content Type ◽  
E Coli ◽  
Wide Range ◽  
Lambdoid Prophage

ABSTRACT Enterohemorrhagic Escherichia coli (EHEC) strains, including E. coli O157:H7, cause severe illness in humans due to the production of Shiga toxin (Stx) and other virulence factors. Because Stx is coregulated with lambdoid prophage induction, its expression is especially susceptible to environmental cues. Infections with Stx-producing E. coli can be difficult to model due to the wide range of disease outcomes: some infections are relatively mild, while others have serious complications. Probiotic organisms, members of the gut microbiome, and organic acids can depress Stx production, in many cases by inhibiting the growth of EHEC strains. On the other hand, the factors currently known to amplify Stx act via their effect on the stx-converting phage. Here, we characterize two interactive mechanisms that increase Stx production by O157:H7 strains: first, direct interactions with phage-susceptible E. coli, and second, indirect amplification by secreted factors. Infection of susceptible strains by the stx-converting phage can expand the Stx-producing population in a human or animal host, and phage infection has been shown to modulate virulence in vitro and in vivo. Acellular factors, particularly colicins and microcins, can kill O157:H7 cells but may also trigger Stx expression in the process. Colicins, microcins, and other bacteriocins have diverse cellular targets, and many such molecules remain uncharacterized. The identification of additional Stx-amplifying microbial interactions will improve our understanding of E. coli O157:H7 infections and help elucidate the intricate regulation of pathogenicity in EHEC strains.

scholarly journals Volatile Oils ofNepeta tenuifolia(Jing Jie) as an Alternative Medicine against Multidrug-Resistant Pathogenic Microbes

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Yi-Hsuan Lee ◽  
Chao-Min Wang ◽  
Po-Yu Liu ◽  
Ching-Chang Cheng ◽  
Zong-Yen Wu ◽  
...  
Keyword(s):  
Essential Oils ◽  
In Vitro Study ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Gram Negative ◽  
E Coli ◽  
Wide Range ◽  
Main Component ◽  
Reference Strains

Essential oils from the dried spikes ofNepeta tenuifolia(Benth) are obtained by steam distillation. Pulegone was identified as the main component in the spikes ofN. tenuifoliathrough analysis, with greater than 85% purity obtained in this study. The essential oils are extremely active against all Gram-positive and some Gram-negative reference bacteria, particularlySalmonella enterica,Citrobacter freundii, andEscherichia coli. The minimum inhibitory concentration was found to be between 0.08 and 0.78% (againstS. enterica), 0.39 and 0.78% (againstC. freundii), and 0.097 and 0.39% (againstE. coli), whereas the minimum bactericidal concentration varied in range from 0.097% to 1.04%. In general, the essential oils show a strong inhibitory action against all tested reference strains and clinical isolates. However, the antibacterial activity of EOs against bothPseudomonas aeruginosareference strains and clinical isolates was relatively lower than other Gram-negative pathogens. The essential oils ofN. tenuifoliaalso displayed bactericidal activities (MBC/MIC < 4) in this study. These findings reflect the bactericidal activity of the essential oils against a wide range of multidrug-resistant clinical pathogens in an in vitro study. In addition, we propose the fragmentation pathways of pulegone and its derivatives by LC-ESI-MS/MS in this study.

scholarly journals In Vitro and In Vivo Antibacterial Activities of SM-216601, a New Broad-Spectrum Parenteral Carbapenem

2005 ◽  
Vol 49 (10) ◽  
pp. 4185-4196 ◽  
Author(s):  
Yutaka Ueda ◽  
Katsunori Kanazawa ◽  
Ken Eguchi ◽  
Koji Takemoto ◽  
Yoshiro Eriguchi ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Antibacterial Activities ◽  
Multiresistant Pathogens ◽  
E Coli ◽  
Wide Range ◽  
Agar Dilution ◽  
Resistant Strains ◽  
Mrsa Strains

ABSTRACT SM-216601 is a novel parenteral 1β-methylcarbapenem. In agar dilution susceptibility testing, the MIC of SM-216601 for 90% of the methicillin-resistant Staphylococcus aureus (MRSA) strains tested (MIC90) was 2 μg/ml, which was comparable to those of vancomycin and linezolid. SM-216601 was also very potent against Enterococcus faecium, including vancomycin-resistant strains (MIC90 = 8 μg/ml). SM-216601 exhibited potent activity against penicillin-resistant Streptococcus pneumoniae, ampicillin-resistant Haemophilus influenzae, Moraxella catarrhalis, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis, with MIC90s of less than 0.5 μg/ml, and intermediate activity against Citrobacter freundii, Enterobacter cloacae, Serratia marcescens, and Pseudomonas aeruginosa. The therapeutic efficacy of SM-216601 against experimentally induced infections in mice caused by S. aureus, E. faecium, E. coli, and P. aeruginosa reflected its in vitro activity and plasma level. Thus, SM-216601 is a promising candidate for nosocomial bacterial infections caused by a wide range of gram-positive and gram-negative bacteria, including multiresistant pathogens.

scholarly journals Sensitivity of L. casei and E. сoli to active substances of anti-parasitic preparations

2018 ◽  
Vol 20 (87) ◽  
pp. 65-69
Author(s):  
R.A. Peleno
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Growth Retardation ◽  
Inhibitory Concentration ◽  
Probiotic Strain ◽  
Diffusion Method ◽  
Simultaneous Application ◽  
Minimal Inhibitory Concentrations ◽  
E Coli ◽  
Active Substances

The data of the influence of active substances of anthelmintic and antiprotozoal preparations on the growth of L. casei IMB B-7280 and E. coli 055K59 are provided in the article. Their minimal inhibitory concentrations were determined for these strains of microorganisms and the active substances with which possible simultaneous application of probiotic strain L. casei IMB В-7280 is established. With this aim, the effect on the growth of L. casei IMB B-7280 and E. coli 055K59 and the minimum inhibitory concentration of fenbendazole, levamisole and ivermectin, which are part of the anthelmintic preparations and amprolium, tylosin, sodium sulfadimexone and sodium sulfatyazole, which are active substances of antiprotozoal drugs, were investigated. The determination of the minimum inhibitory concentration of the active substances of antiparasitic agents against these strains of microorganisms was carried out in in vitro experiments by serial dilutions in a dense MRS environment and MPA, and a study of the effect on the growth by diffusion method, followed by measurement of growth retardation zones in millimeters. It is established that among active substances of anthelmintic preparations only phenbendazole caused growth retardation and only relative to L. casei IMB B-7280. Among the active substances of antiprotozoal drugs, sodium sulfatyazole was the most active, which inhibited growth as L. casei IMB-7280 and E. coli 055K59 № 3912/41. Thylosin was effective only in relation to L. casei IMB B-7280 and at the highest concentration of 0.03%, the growth retardation zone was 23.4 ± 0.92 mm. Sodium sulfadimetoxin caused the growth retardation of L. сasei IMB В-7280 only at the highest concentration. The minimum inhibitory concentration of active substances of anti-parasitic drugs was different for strains L. casei IMB B-7280 and E. coli 055K59 № 3912/4. The strongest inhibitory effect was shown by tylosin, which stopped the growth of L. casei IMB B-7280 and E. coli 055K59 № 3912/41 respectively at concentrations of 0.00125 and 50.0 mg/ml. Active substances such as amprolium, levamisole and ivermectin did not significantly inhibit the growth of L. casei, IMB B-7280 and E. coli 055K59 № 3912/41, since their minimal inhibitory concentration was in the range of 4000 to 6000 mg ml.

scholarly journals Binding and neutralization of C. difficile toxins A and B by purified clinoptilolite-tuff

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0252211
Author(s):  
Carmen Ranftler ◽  
Dietmar Nagl ◽  
Andreas Sparer ◽  
Andreas Röhrich ◽  
Michael Freissmuth ◽  
...  
Keyword(s):  
Binding Capacity ◽  
Public Health Problem ◽  
Current Treatment ◽  
Major Public Health Problem ◽  
Toxin Binding ◽  
Clostridioides Difficile ◽  
Wide Range ◽  
Natural Clinoptilolite ◽  
Clinoptilolite Tuff

Clostridioides difficile (C. difficile) infection is a major public health problem worldwide. The current treatment of C. difficile-associated diarrhea relies on the use of antibacterial agents. However, recurrences are frequent. The main virulence factors of C. difficile are two secreted cytotoxic proteins toxin A and toxin B. Alternative research exploring toxin binding by resins found a reduced rate of recurrence by administration of tolevamer. Hence, binding of exotoxins may be useful in preventing a relapse provided that the adsorbent is innocuous. Here, we examined the toxin binding capacity of G-PUR®, a purified version of natural clinoptilolite-tuff. Our observations showed that the purified clinoptilolite-tuff adsorbed clinically relevant amounts of C. difficile toxins A and B in vitro and neutralized their action in a Caco-2 intestinal model. This conclusion is based on four independent sets of findings: G-PUR® abrogated toxin-induced (i) RAC1 glucosylation, (ii) redistribution of occludin, (iii) rarefaction of the brush border as visualized by scanning electron microscopy and (iv) breakdown of the epithelial barrier recorded by transepithelial electrical resistance monitoring. Finally, we confirmed that the epithelial monolayer tolerated G-PUR® over a wide range of particle densities. Our findings justify the further exploration of purified clinoptilolite-tuff as a safe agent in the treatment and/or prevention of C. difficile-associated diarrhea.

scholarly journals 1592. In Vitro Activity of Ceftolozane/Tazobactam (C/T) Against Enterobacteriaceae and Pseudomonas aeruginosa Circulating in Chile

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S581-S581
Author(s):  
Lina M Rivas ◽  
Jose R W Martínez ◽  
Maria Spencer ◽  
Lorena Porte ◽  
Francisco Silva ◽  
...  
Keyword(s):  
Tertiary Care ◽  
Multidrug Resistant ◽  
Global Public Health ◽  
Health Crisis ◽  
Clinical Strains ◽  
E Coli ◽  
Highly Active ◽  
Complex Figure ◽  
Wide Range

Abstract Background The widespread dissemination of carbapenem-resistant (CR) P. aeruginosa and Enterobacteriaceae has created a major global public health crisis. C/T is a recently approved therapeutic which consists of the combination of a novel cephalosporin (ceftolozane) and tazobactam (a β-lactamase inhibitor). C/T has shown good activity against a wide range of multidrug-resistant (MDR) Gram negatives, being particularly interesting as an alternative for MDR P. aeruginosa. We aimed to determine the activity of C/T against clinical strains of Enterobacteriaceae and P. aeruginosa recovered in 4 large clinical centers from Chile. Methods We analyzed 434 isolates of Enterobacteriaceae (347 E. coli, 66 K. pneumoniae, 21 Enterobacter cloacae complex) and 57 P. aeruginosa collected during 2017 from 4 tertiary care institutions in Santiago, Chile. Identification was performed as per each local clinical microbiology lab. Susceptibility testing was performed by broth microdilution using customized Sensititre plates (Trek). Carba-NP was performed to screen for carbapenemase production. Susceptibilities were analyzed as per 2019 CLSI breakpoints. Results The MIC50/90 for C/T against Enterobacteriaceae and P. aeruginosa were 1/4 μg/mL and 2/16 μg/mL, respectively. In Enterobacteriaceae, susceptibility to C/T reached 92% in E. coli (Figure 1A), 91% in E. cloacae complex (Figure 1B) and 70% in K. pneumoniae (Figure 1C). Remarkably, C/T remained active against 58% (33/57) of CR Enterobacteriaceae (Figure 2A). Among Carba-NP-negative CR isolates (46%, 26/57), susceptibility to C/T was 54% (Figure 3 A–C). In P. aeruginosa, the overall susceptibility to C/T was 81% (Figure 1D), maintaining activity against 69% (25/36) of CR strains (Figure 2B). Importantly, susceptibility to C/T in CR P. aeruginosa isolates with a negative Carba-NP (67%, 24/36) was 83% (20/24) (Figure 3D). Conclusion In this multicenter study, we observed that C/T was highly active against clinical isolates of Enterobacteriaceae and P. aeruginosa. Of note, C/T remained active against a large proportion of CR clinical strains. Moreover, the activity of C/T was particularly high against CR P. aeruginosa isolates with a negative Carba-NP. Disclosures All authors: No reported disclosures.

scholarly journals Grapevine extracts and their effect on selected gut-associated microbiota: In vitro study

2020 ◽  
Vol 38 (No. 3) ◽  
pp. 137-143
Author(s):  
Michaela Rollová ◽  
Lucia Gharwalova ◽  
Aleš Krmela ◽  
Věra Schulzová ◽  
Jana Hajšlová ◽  
...  
Keyword(s):  
Inhibitory Concentration ◽  
In Vitro Study ◽  
Probiotic Strain ◽  
Individual Species ◽  
Biofilm Growth ◽  
E Coli ◽  
Bifidobacterium Animalis ◽  
The Individual ◽  
Opportunistic Pathogenic

The biological activity of polyphenol substances contained in food supplements prepared from Vitis vinifera can affect the microorganisms present in the digestive tract in terms of their representation and activity of the individual species. This study deals with resveratrol and two polyphenol-rich extracts (extract from V. vinifera canes and the commercial product Regrapex-R-forte) and their effect on selected gut microbiota (Bifidobacterium animalis subsp. lactis Bb-12, Lactobacillus acidophilus LA-5, Lactobacillus casei Lafti L-26, Citrobacter freundii DBM 3127, Escherichia coli DBM 3125). The effect of the studied agents on planktonic and biofilm growth of the microorganisms was determined as minimum inhibitory concentration (MIC80) and minimum biofilm inhibitory concentration (MBIC80), respectively. The extracts induced metabolic activity as well as total biofilm biomass production in probiotic strain L. acidophilus LA-5 while successfully inhibiting the growth of opportunistic pathogenic microorganisms C. freundii DBM 3127 and E. coli DBM 3125.

THE MOLECULAR BASIS OF DRUG-PLASMA PROTEIN INTERACTION FOR CNS ACTIVE COMPOUNDS

2021 ◽  
Author(s):  
Darija Obradović ◽  
◽  
Milica Radan ◽  
Marija Popović-Nikolić ◽  
Slavica Oljačić ◽  
...  
Keyword(s):  
Plasma Protein ◽  
Protein Interaction ◽  
Negative Impact ◽  
Positive Impact ◽  
Binding Capacity ◽  
Retention Data ◽  
Active Compounds ◽  
Drug Plasma ◽  
Wide Range

The human serum albumin (HSA) is well known for its extraordinary binding capacity for both endogenous and exogenous compounds, including a wide range of drugs. The goal of our investigation was to evaluate the distribution process for 15 CNS active compounds. The drug-plasma protein interaction was evaluated under simulative physiological conditions on the HSA-based stationary phase by using the mixture of Sørensen phosphate buffer (pH 7.40) and acetonitrile modifier as a mobile phase (84:16 v/v). The retention parameters (k) were used to approximate the % of protein-binding by calculating the P(%) values. The results obtained through this study demonstrated that the constitutional properties (e.g. number of total bonds, atoms, carbon atoms) and lipophilicity have a strong positive impact on the HSA-binding affinity. The coefficient of diffusion has a negative impact, while the atoms and sites available for the CYP450 oxidation showed the most significant correlation (r = 0.92). This study provides a basis for further in vitro chromatographical investigations of drug-HSA interaction for CNS active compounds. The correlation between obtained retention data and the availability to enzymes oxidation indicates the application of the tested system in the assessment of the metabolic degradation profile of CNS related drugs.

scholarly journals Characterization and Quantitation of the Pharmacodynamics of Fluconazole in a Neutropenic Murine Disseminated Candidiasis Infection Model

1999 ◽  
Vol 43 (9) ◽  
pp. 2116-2120 ◽  
Author(s):  
D. Andes ◽  
M. van Ogtrop
Keyword(s):  
Time Course ◽  
Infection Model ◽  
Maximal Effect ◽  
Time Curve ◽  
In Vitro Susceptibility ◽  
Disseminated Candidiasis ◽  
Wide Range ◽  
Dosing Intervals ◽  
Dose Dependent

ABSTRACT We determined the pharmacodynamic parameter and the magnitude of that parameter that was predictive of the efficacy of fluconazole in the treatment of disseminated candidiasis. We used a neutropenic murine model of disseminated Candida albicans infection to characterize the time course of activity of fluconazole. Quantitation of colony counts in kidneys after 24 h of therapy with a wide range of doses and three dosing intervals was used to determine the dose required to achieve 50% of the maximal effect (ED50). The ED50 was similar for each of the dosing intervals studied, supporting the area under the concentration-time curve (AUC) MIC ratio as the parameter that predicts the efficacy of fluconazole. Similar studies were performed with C. albicans strains for which fluconazole MICs are in the susceptible-dose-dependent range (MICs, 16 to 32 mg/liter). We found that the magnitude of the AUC/MIC ratio required to reach the ED50 was similar for all three organisms studied, ranging from 12 to 25. When the pharmacokinetics of fluconazole in humans are considered, these AUC/MIC ratios would support in vitro susceptibility breakpoints of 8 mg/liter for dosages of 200 mg/day and susceptibility breakpoints of 16 to 32 mg/liter for dosages of 400 to 800 mg/day.

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