In vitro selection and in vivo confirmation of the antioxidant ability of Lactobacillus brevis MG 000874

2019 ◽  
Vol 126 (4) ◽  
pp. 1221-1232 ◽  
Author(s):  
S. Noureen ◽  
A. Riaz ◽  
M. Arshad ◽  
N. Arshad
Keyword(s):  
In Vitro Selection ◽  
Lactobacillus Brevis ◽  
Antioxidant Ability

scholarly journals Identification of Resistance Determinants for a Promising Antileishmanial Oxaborole Series

2021 ◽  
Vol 9 (7) ◽  
pp. 1408
Author(s):  
Magali Van den Kerkhof ◽  
Philippe Leprohon ◽  
Dorien Mabille ◽  
Sarah Hendrickx ◽  
Lindsay B. Tulloch ◽  
...  
Keyword(s):  
Drug Exposure ◽  
In Vitro Selection ◽  
Selection Procedure ◽  
Cosmid Library ◽  
Neglected Diseases ◽  
Chromosome 2 ◽  
Resistance Determinants ◽  
A Genome

Current treatment options for visceral leishmaniasis have several drawbacks, and clinicians are confronted with an increasing number of treatment failures. To overcome this, the Drugs for Neglected Diseases initiative (DNDi) has invested in the development of novel antileishmanial leads, including a very promising class of oxaboroles. The mode of action/resistance of this series to Leishmania is still unknown and may be important for its further development and implementation. Repeated in vivo drug exposure and an in vitro selection procedure on both extracellular promastigote and intracellular amastigote stages were both unable to select for resistance. The use of specific inhibitors for ABC-transporters could not demonstrate the putative involvement of efflux pumps. Selection experiments and inhibitor studies, therefore, suggest that resistance to oxaboroles may not emerge readily in the field. The selection of a genome-wide cosmid library coupled to next-generation sequencing (Cos-seq) was used to identify resistance determinants and putative targets. This resulted in the identification of a highly enriched cosmid, harboring genes of chromosome 2 that confer a subtly increased resistance to the oxaboroles tested. Moderately enriched cosmids encompassing a region of chromosome 34 contained the cleavage and polyadenylation specificity factor (cpsf) gene, encoding the molecular target of several related benzoxaboroles in other organisms.

scholarly journals Robotic QM/MM-driven maturation of antibody combining sites

2016 ◽  
Vol 2 (10) ◽  
pp. e1501695 ◽  
Author(s):  
Ivan V. Smirnov ◽  
Andrey V. Golovin ◽  
Spyros D. Chatziefthimiou ◽  
Anastasiya V. Stepanova ◽  
Yingjie Peng ◽  
...  
Keyword(s):  
Immune Response ◽  
In Vitro Selection ◽  
Single Point ◽  
Combinatorial Libraries ◽  
Single Point Mutation ◽  
Wild Type ◽  
Selection Of ◽  
Maturation Function

In vitro selection of antibodies from large repertoires of immunoglobulin (Ig) combining sites using combinatorial libraries is a powerful tool, with great potential for generating in vivo scavengers for toxins. However, addition of a maturation function is necessary to enable these selected antibodies to more closely mimic the full mammalian immune response. We approached this goal using quantum mechanics/molecular mechanics (QM/MM) calculations to achieve maturation in silico. We preselected A17, an Ig template, from a naïve library for its ability to disarm a toxic pesticide related to organophosphorus nerve agents. Virtual screening of 167,538 robotically generated mutants identified an optimum single point mutation, which experimentally boosted wild-type Ig scavenger performance by 170-fold. We validated the QM/MM predictions via kinetic analysis and crystal structures of mutant apo-A17 and covalently modified Ig, thereby identifying the displacement of one water molecule by an arginine as delivering this catalysis.

In vitro Selection of a Peptide with High Selectivity for Cardiomyocytes In vivo

2004 ◽  
Vol 342 (1) ◽  
pp. 171-182 ◽  
Author(s):  
Michael J. McGuire ◽  
Kausar N. Samli ◽  
Stephen Albert Johnston ◽  
Kathlynn C. Brown
Keyword(s):  
In Vitro Selection ◽  
High Selectivity ◽  
Selection Of

scholarly journals In-Vitro Selection of Ceftazidime/Avibactam Resistance in OXA-48-Like-Expressing Klebsiella pneumoniae: In-Vitro and In-Vivo Fitness, Genetic Basis and Activities of β-Lactam Plus Novel β-Lactamase Inhibitor or β-Lactam Enhancer Combinations

Antibiotics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1318
Author(s):  
Snehal Palwe ◽  
Yamuna Devi Bakthavatchalam ◽  
Kshama Khobragadea ◽  
Arun S. Kharat ◽  
Kamini Walia ◽  
...  
Keyword(s):  
In Vitro Selection ◽  
Whole Genome Sequence ◽  
Serial Transfer ◽  
Resistance Selection ◽  
Clinical Resistance ◽  
Growth Properties ◽  
Outer Membrane Permeability ◽  
Selection Of

Ceftazidime/avibactam uniquely demonstrates activity against both KPC and OXA-48-like carbapenemase-expressing Enterobacterales. Clinical resistance to ceftazidime/avibactam in KPC-producers was foreseen in in-vitro resistance studies. Herein, we assessed the resistance selection propensity of ceftazidime/avibactam in K. pneumoniae expressing OXA-48-like β-lactamases (n = 10), employing serial transfer approach. Ceftazidime/avibactam MICs (0.25–4 mg/L) increased to 16–256 mg/L after 15 daily-sequential transfers. The whole genome sequence analysis of terminal mutants showed modifications in proteins linked to efflux (AcrB/AcrD/EmrA/Mdt), outer membrane permeability (OmpK36) and/or stress response pathways (CpxA/EnvZ/RpoE). In-vitro growth properties of all the ceftazidime/avibactam-selected mutants were comparable to their respective parents and they retained the ability to cause pulmonary infection in neutropenic mice. Against these mutants, we explored the activities of various combinations of β-lactams (ceftazidime or cefepime) with structurally diverse β-lactamase inhibitors or a β-lactam enhancer, zidebactam. Zidebactam, in combination with either cefepime or ceftazidime, overcame ceftazidime/avibactam resistance (MIC range 0.5–8 mg/L), while cefepime/avibactam was the second best (MIC: 0.5–16 mg/L) in yielding lower MICs. The present work revealed the possibility of ceftazidime/avibactam resistance in OXA-48-like K. pneumoniae through mutations in proteins involved in efflux and/or porins without concomitant fitness cost mandating astute monitoring of ceftazidime/avibactam resistance among OXA-48 genotypes.

scholarly journals In vitro selection of a microbial consortium predictive of synergistic functioning along multiple ecosystem scales

2020 ◽  
Author(s):  
Peter Baas ◽  
Colin Bell ◽  
Lauren Mancini ◽  
Melanie Lee ◽  
Matthew D. Wallenstein ◽  
...  
Keyword(s):  
Plant Growth ◽  
In Vitro Selection ◽  
Bacterial Species ◽  
Microbial Consortia ◽  
Ecosystem Functions ◽  
Emergent Properties ◽  
Form Complex ◽  
Soil P

AbstractSoil microbes form complex interactive networks throughout the soil and plant rhizosphere. These interactions can result in emergent properties for consortia that are not predictable from the phenotypes of constituents in isolation. We used a four-species consortium to assess the capacity of individual microbial species versus different consortia permutations of the four species to contribute to increased P-solubilization using soil incubations and plant growth experiments. We found that as different combinations of bacterial species were assembled into differing consortia, they demonstrated differing abilities to stimulate soil P cycling and plant growth. The combination of all four microbes in the consortia were much more effective at solubilizing P and stimulating plant growth than any of the individual bacterial species alone. This suggests that in vivo functionally synergistic soil microbial consortia can be adept at performing specific ecosystem functions in situ. Improving our understanding of the mechanisms that facilitate synergistic functioning examined in this study is important for maximizing future food production and agroecosystem sustainability.

scholarly journals Drought adaptive prediction in potato (Solanum tuberosum) using in vitro and in vivo approaches

2021 ◽  
Vol 22 (2) ◽  
Author(s):  
JANE KATHRYNE JOLANDA LAISINA ◽  
AWANG MAHARIJAYA ◽  
SOBIR SOBIR ◽  
AGUS PURWITO
Keyword(s):  
Solanum Tuberosum ◽  
Drought Stress ◽  
Plant Height ◽  
Root Length ◽  
In Vitro Selection ◽  
Fresh Weight ◽  
Adaptive Prediction ◽  
Tuber Fresh Weight

Abstract. Laisina JKJ, Maharijaya A, Sobir, Purwito A. 2021. Drought adaptive prediction in potato (Solanum tuberosum) using in vitro and in vivo approaches. Biodiversitas 22: 537-545. Prediction of drought adaptive potatoes requires selection indicators. This study aimed to determine in vitro selection indicators for obtaining drought adaptive potato genotypes in vitro and in vivo. The in vitro study was performed using single-node explants from seven genotypes cultured for six weeks on MS medium added with 0.2 M sorbitol to achieve the research aims. The cultures were partially observed and followed by watering the in vitro tubing medium. For the in vivo study, drought stress was applied for 21 days when the plants reached 25 days after planting (DAP) and for 14 days when the plants reached 50 DAP, then plants were irrigated again until harvesting. The results showed that plant height and root length can be used as selection indicators because they had a relative decrease below 50%, a close relationship and had the same variance with the in vitro number of tubers, in vitro tuber fresh weight and in vivo tuber fresh weight in drought stress at 25 DAP. These characters were determinant characters for the clustering pattern in the heat map cluster analysis. Based on these characters, SSI analysis was also performed and it was found that the PKHT4 was more adaptive than the PKHT6 in vitro, but the two genotypes were classified in the medium adaptive in vivo. In conclusion, plant height and root length were determined as the in vitro selection indicators in predicting drought adaptive genotypes in vivo at the plant age of 25 DAP.

scholarly journals The Antioxidant Capacity In Vitro and In Vivo of Polysaccharides From Bergenia emeiensis

2020 ◽  
Vol 21 (20) ◽  
pp. 7456
Author(s):  
Chen Zeng ◽  
Shiling Feng
Keyword(s):  
Antioxidant Capacity ◽  
Hela Cells ◽  
Carcinoma Cell ◽  
Cellular Level ◽  
Oxygen Species ◽  
Antioxidant Ability ◽  
Cell Level ◽  
C Elegans

Polysaccharides from Bergenia emeiensis (PBE) showed a robust antioxidant ability on scavenging free radicals in vitro. However, the further antioxidant potential in cell level and in vivo was still unknown. Therefore, in this present study, the protective effect of PBE on human cervical carcinoma cell (Hela) cells and Caenorhabditis elegans against oxidative stress was evaluated. The results showed PBE could reduce the reactive oxygen species (ROS) level in Hela cells and promote the mitochondrial membrane potential. Then, the cell apoptosis was reduced. Moreover, PBE could enhance the survival of C. elegans under thermal stress to 13.44%, and significantly reduce the ROS level, which was connected with the overexpression of sod-3 and the increased nuclear localization of daf-16 transcription factor. Therefore, PBE exhibited a strong antioxidant capacity in the cellular level and for a whole organism. Thus, polysaccharides from B. emeiensis have natural potential to be a safe antioxidant.

scholarly journals A Simple Model for Assessment of Anti-Toxin Antibodies

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Alex Skvortsov ◽  
Peter Gray
Keyword(s):  
In Vitro Selection ◽  
Receptor Complex ◽  
Simple Mathematical Model ◽  
Antibody Affinity ◽  
In Vivo Evaluation ◽  
Degree Of Protection ◽  
Protective Antibodies ◽  
Selection Of

The toxins associated with infectious diseases are potential targets for inhibitors which have the potential for prophylactic or therapeutic use. Many antibodies have been generated for this purpose, and the objective of this study was to develop a simple mathematical model that may be used to evaluate the potential protective effect of antibodies. This model was used to evaluate the contributions of antibody affinity and concentration to reducing antibody-receptor complex formation and internalization. The model also enables prediction of the antibody kinetic constants and concentration required to provide a specified degree of protection. We hope that this model, once validated experimentally, will be a useful tool for in vitro selection of potentially protective antibodies for progression to in vivo evaluation.

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