Insights into the antibiotic resistance and inhibition mechanism of aminoglycoside phosphotransferase from Bacillus cereus : In silico and in vitro perspective

2018 ◽  
Vol 119 (11) ◽  
pp. 9444-9461 ◽  
Author(s):  
Rishikesh Satish Parulekar ◽  
Kailas Dashrath Sonawane
Keyword(s):  
Antibiotic Resistance ◽  
Bacillus Cereus ◽  
In Silico ◽  
Inhibition Mechanism ◽  
Aminoglycoside Phosphotransferase

In Silico Appraisal, Synthesis, Antibacterial Screening and DNA Cleavage for 1,2,5-thiadiazole Derivative

2019 ◽  
Vol 15 (5) ◽  
pp. 445-455 ◽  
Author(s):  
Suraj N. Mali ◽  
Sudhir Sawant ◽  
Hemchandra K. Chaudhari ◽  
Mustapha C. Mandewale
Keyword(s):  
Molecular Docking ◽  
Dna Cleavage ◽  
In Silico ◽  
Oral Absorption ◽  
Inhibition Mechanism ◽  
Hydrogen Binding ◽  
Docking Score ◽  
Antibacterial Screening ◽  
Mycobacteria Tuberculosis

Background: : Thiadiazole not only acts as “hydrogen binding domain” and “two-electron donor system” but also as constrained pharmacophore. Methods:: The maleate salt of 2-((2-hydroxy-3-((4-morpholino-1, 2,5-thiadiazol-3-yl) oxy) propyl) amino)- 2-methylpropan-1-ol (TML-Hydroxy)(4) has been synthesized. This methodology involves preparation of 4-morpholino-1, 2,5-thiadiazol-3-ol by hydroxylation of 4-(4-chloro-1, 2,5-thiadiazol-3-yl) morpholine followed by condensation with 2-(chloromethyl) oxirane to afford 4-(4-(oxiran-2-ylmethoxy)-1,2,5-thiadiazol- 3-yl) morpholine. Oxirane ring of this compound was opened by treating with 2-amino-2-methyl propan-1- ol to afford the target compound TML-Hydroxy. Structures of the synthesized compounds have been elucidated by NMR, MASS, FTIR spectroscopy. Results: : The DSC study clearly showed that the compound 4-maleate salt is crystalline in nature. In vitro antibacterial inhibition and little potential for DNA cleavage of the compound 4 were explored. We extended our study to explore the inhibition mechanism by conducting molecular docking, ADMET and molecular dynamics analysis by using Schrödinger. The molecular docking for compound 4 showed better interactions with target 3IVX with docking score of -8.508 kcal/mol with respect to standard ciprofloxacin (docking score= -3.879 kcal/mol). TML-Hydroxy was obtained in silico as non-carcinogenic and non-AMES toxic with good percent human oral absorption profile (69.639%). TML-Hydroxy showed the moderate inhibition against Mycobacteria tuberculosis with MIC 25.00 μg/mL as well as moderate inhibition against S. aureus, Bacillus sps, K. Pneumoniae and E. coli species. Conclusion: : In view of the importance of the 1,2,5-thiadiazole moiety involved, this study would pave the way for future development of more effective analogs for applications in medicinal field.

scholarly journals Safety Assessment of Bacillus subtilis MB40 for Use in Foods and Dietary Supplements

Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 733
Author(s):  
Jessica L. Spears ◽  
Richard Kramer ◽  
Andrey I. Nikiforov ◽  
Marisa O. Rihner ◽  
Elizabeth A. Lambert
Keyword(s):  
Antibiotic Resistance ◽  
Bacillus Subtilis ◽  
Dietary Supplements ◽  
Genome Sequencing ◽  
In Silico ◽  
Safety Assessment ◽  
In Vivo Studies ◽  
Strain Identification ◽  
Consumer Safety

With the growing popularity of probiotics in dietary supplements, foods, and beverages, it is important to substantiate not only the health benefits and efficacy of unique strains but also safety. In the interest of consumer safety and product transparency, strain identification should include whole-genome sequencing and safety assessment should include genotypic and phenotypic studies. Bacillus subtilis MB40, a unique strain marketed for use in dietary supplements, and food and beverage, was assessed for safety and tolerability across in silico, in vitro, and in vivo studies. MB40 was assessed for the absence of undesirable genetic elements encoding toxins and mobile antibiotic resistance. Tolerability was assessed in both rats and healthy human volunteers. In silico and in vitro testing confirmed the absence of enterotoxin and mobile antibiotic resistance genes of safety concern to humans. In rats, the no-observed-adverse-effect level (NOAEL) for MB40 after repeated oral administration for 14 days was determined to be 2000 mg/kg bw/day (equivalent to 3.7 × 1011 CFU/kg bw/day). In a 28 day human tolerability trial, 10 × 109 CFU/day of MB40 was well tolerated. Based on genome sequencing, strain characterization, screening for undesirable attributes and evidence of safety by appropriately designed safety evaluation studies in rats and humans, Bacillus subtilis MB40 does not pose any human health concerns under the conditions tested.

Chemical synthesis and characterization of a new quinazolinedione competitive antagonist for strigolactone receptors with an unexpected binding mode

2019 ◽  
Vol 476 (12) ◽  
pp. 1843-1856 ◽  
Author(s):  
Cyril Hamiaux ◽  
Lesley Larsen ◽  
Hui Wen Lee ◽  
Zhiwei Luo ◽  
Prachi Sharma ◽  
...  
Keyword(s):  
In Silico ◽  
Binding Mode ◽  
Crystal Structure Analysis ◽  
Tolfenamic Acid ◽  
In Vitro Assays ◽  
Inhibition Mechanism ◽  
In Planta ◽  
Competitive Antagonist ◽  
In Silico Docking

Abstract Strigolactones (SLs) are multifunctional plant hormones regulating essential physiological processes affecting growth and development. In vascular plants, SLs are recognized by α/β hydrolase-fold proteins from the D14/DAD2 (Dwarf14/Decreased Apical Dominance 2) family in the initial step of the signaling pathway. We have previously discovered that N-phenylanthranilic acid derivatives (e.g. tolfenamic acid) are potent antagonists of SL receptors, prompting us to design quinazolinone and quinazolinedione derivatives (QADs and QADDs, respectively) as second-generation antagonists. Initial in silico docking studies suggested that these compounds would bind to DAD2, the petunia SL receptor, with higher affinity than the first-generation compounds. However, only one of the QADs/QADDs tested in in vitro assays acted as a competitive antagonist of SL receptors, with reduced affinity and potency compared with its N-phenylanthranilic acid ‘parent’. X-ray crystal structure analysis revealed that the binding mode of the active QADD inside DAD2's cavity was not that predicted in silico, highlighting a novel inhibition mechanism for SL receptors. Despite a ∼10-fold difference in potency in vitro, the QADD and tolfenamic acid had comparable activity in planta, suggesting that the QADD compensates for lower potency with increased bioavailability. Altogether, our results establish this QADD as a novel lead compound towards the development of potent and bioavailable antagonists of SL receptors.

scholarly journals An Overview of Biological and Computational Methods for Designing Mechanism-Informed Anti-biofilm Agents

2021 ◽  
Vol 12 ◽  
Author(s):  
Andy Y. An ◽  
Ka-Yee Grace Choi ◽  
Arjun S. Baghela ◽  
Robert E. W. Hancock
Keyword(s):  
Antibiotic Resistance ◽  
Small Molecules ◽  
In Silico ◽  
Biofilm Formation ◽  
Stringent Response ◽  
Antibiotic Resistant ◽  
Biologically Relevant ◽  
Biofilm Model

Bacterial biofilms are complex and highly antibiotic-resistant aggregates of microbes that form on surfaces in the environment and body including medical devices. They are key contributors to the growing antibiotic resistance crisis and account for two-thirds of all infections. Thus, there is a critical need to develop anti-biofilm specific therapeutics. Here we discuss mechanisms of biofilm formation, current anti-biofilm agents, and strategies for developing, discovering, and testing new anti-biofilm agents. Biofilm formation involves many factors and is broadly regulated by the stringent response, quorum sensing, and c-di-GMP signaling, processes that have been targeted by anti-biofilm agents. Developing new anti-biofilm agents requires a comprehensive systems-level understanding of these mechanisms, as well as the discovery of new mechanisms. This can be accomplished through omics approaches such as transcriptomics, metabolomics, and proteomics, which can also be integrated to better understand biofilm biology. Guided by mechanistic understanding, in silico techniques such as virtual screening and machine learning can discover small molecules that can inhibit key biofilm regulators. To increase the likelihood that these candidate agents selected from in silico approaches are efficacious in humans, they must be tested in biologically relevant biofilm models. We discuss the benefits and drawbacks of in vitro and in vivo biofilm models and highlight organoids as a new biofilm model. This review offers a comprehensive guide of current and future biological and computational approaches of anti-biofilm therapeutic discovery for investigators to utilize to combat the antibiotic resistance crisis.

Synthesis, In silico and Biological Studies of Thiazolyl-2h-chromen-2-one Derivatives as Potent Antitubercular Agents

2020 ◽  
Vol 16 (5) ◽  
pp. 511-522 ◽  
Author(s):  
Bhagwat S. Jadhav ◽  
Ramesh S. Yamgar ◽  
Rajesh S. Kenny ◽  
Suraj N. Mali ◽  
Hemchandra K. Chaudhari ◽  
...  
Keyword(s):  
Schiff Base ◽  
In Silico ◽  
Antitubercular Activity ◽  
Inhibition Mechanism ◽  
Mycobacterium Tuberculosis H37rv ◽  
Schiff Base Derivatives ◽  
Biological Studies ◽  
H37rv Strain ◽  
Modeling Software

Background: A series of new six thiazolyl-2-amine-based Schiff base derivatives (4a-4f) were synthesized by a sequential multistep reaction starting with Salicylaldehyde. Methods: All the Schiff base derivatives were screened in-vitro for their antibacterial activity against Mycobacterium tuberculosis (H37RV strain) ATCC No-27294. The synthesized compounds were characterized by FTIR, 1H-NMR, 13C-NMR and Mass spectrometry. Results: Among the compounds tested, 4c and 4f derivatives exhibited potent antitubercular activity against M. tuberculosis at MIC 6.25 μg/mL. Conclusion: We extended our study to explore the inhibition mechanism by conducting molecular docking analysis by using Schrodinger’s molecular modeling software. All the newly synthesized compounds were found to be in-silico AMES test non-toxic and non-carcinogens. The good Qikprop’s Absorption, Distribution, Metabolism and Excretion (ADMET) would definitely help the researchers in order to make more potent Anti-TB agents.

The Inhibitory Effect of Three Essential Oils on Candida rugosa Lipase: In Vitro and In Silico Studies

2020 ◽  
Vol 10 (3) ◽  
pp. 208-215 ◽  
Author(s):  
Talia Serseg ◽  
Khedidja Benarous ◽  
Mohamed Yousfi
Keyword(s):  
Molecular Docking ◽  
Essential Oils ◽  
In Silico ◽  
Candida Rugosa ◽  
Inhibitory Effect ◽  
Mentha Piperita ◽  
Inhibition Mechanism ◽  
Syzygium Aromaticum ◽  
In Silico Studies

Background: Essential oils have been used for centuries. EOs are gaining increasing interest because of their acceptance by consumers and their safe status. For the first time, the effect of essential oils on the inhibition of lipases has been investigated in this work. Objective: We aimed in this study to investigate in vitro the inhibitory effects of the three essential oils of most used spices: Peppermint (Mentha piperita L.), cinnamon (Cinnamomum zeylanicum L.) and Cloves (Syzygium aromaticum L. Merr. et Perry) against Candida rugose lipase. In silico studies using molecular docking have been achieved to study the inhibition mechanism of major compounds of EO: menthol, carvacrol, eugenol and cinnamylaldehyde toward CRL. Methods: The inhibitory effect of three essential oils were determined by candida rugosa enzyme and pNP-L as substrate using spectrophotometry. Autodock vina was used for molecular docking with 50 runs. Results: We have found that these essential oils have a strong inhibitory effect with IC50 values 1.09, 1.78 and 1.13 mg/ml compared with Orlistat 0.06 mg/ml. The results show competitive inhibition for the three major compounds Menthol, Carvacrol and Eugenol with uncompetitive inhibition for Cinnamaldehyde. Different repetition ratios of hydrogen bonds and hydrophobic interactions were observed. The saved interactions were with His449, Ser209, Gly123, Gly124 and Phe344 for all molecules. Conclusion: These observations support using and considering essential oils and their major compounds as good sources for design new drugs to treat candidiasis and other diseases related to Lipases.

scholarly journals In Silico and In Vitro Evaluation of the Antimicrobial Potential of Bacillus cereus Isolated from Apis dorsata Gut against Neisseria gonorrhoeae

Antibiotics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1401
Author(s):  
Nurdjannah Jane Niode ◽  
Aryani Adji ◽  
Jimmy Rimbing ◽  
Max Tulung ◽  
Mohammed Alorabi ◽  
...  
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Bacillus Cereus ◽  
In Silico ◽  
Pathogenic Bacteria ◽  
Hydrophobic Interactions ◽  
Binding Free Energy ◽  
Dynamics Simulation ◽  
Apis Dorsata ◽  
Associated Bacteria

Antimicrobial resistance is a major public health and development concern on a global scale. The increasing resistance of the pathogenic bacteria Neisseria gonorrhoeae to antibiotics necessitates efforts to identify potential alternative antibiotics from nature, including insects, which are already recognized as a source of natural antibiotics by the scientific community. This study aimed to determine the potential of components of gut-associated bacteria isolated from Apis dorsata, an Asian giant honeybee, as an antibacterial against N. gonorrhoeae by in vitro and in silico methods as an initial process in the stage of new drug discovery. The identified gut-associated bacteria of A. dorsata included Acinetobacter indicus and Bacillus cereus with 100% identity to referenced bacteria from GenBank. Cell-free culture supernatants (CFCS) of B. cereus had a very strong antibacterial activity against N. gonorrhoeae in an in vitro antibacterial testing. Meanwhile, molecular docking revealed that antimicrobial lipopeptides from B. cereus (surfactin, fengycin, and iturin A) had a comparable value of binding-free energy (BFE) with the target protein receptor for N. gonorrhoeae, namely penicillin-binding protein (PBP) 1 and PBP2 when compared with the ceftriaxone, cefixime, and doxycycline. The molecular dynamics simulation (MDS) study revealed that the surfactin remains stable at the active site of PBP2 despite the alteration of the H-bond and hydrophobic interactions. According to this finding, surfactin has the greatest antibacterial potential against PBP2 of N. gonorrhoeae.

scholarly journals Bio-Mechanism of Catechin as Pheromone Signal Inhibitor: Prediction of Antibacterial Agent Action Mode by In Vitro and In Silico Study

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6381
Author(s):  
Dikdik Kurnia ◽  
Zenika Febian Ramadhanty ◽  
Aprilina Mora Ardani ◽  
Achmad Zainuddin ◽  
Hendra Dian Adhita Dharsono ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Binding Energy ◽  
Serine Protease ◽  
In Silico ◽  
Antibacterial Agent ◽  
Antibacterial Agents ◽  
Chemical Structures ◽  
In Silico Study ◽  
And Control

The utilization of medicinal plants has long been explored for the discovery of antibacterial agents and the most effective mechanisms or new targets that can prevent and control the spread of antibiotic resistance. One kind of bacterial cell wall inhibition is the inactivation of the MurA enzyme that contributes to the formation of peptidoglycan. Another approach is to interfere with the cell–cell communication of bacteria called the Quorum sensing (QS) system. The blocking of auto-inducer such as gelatinase biosynthesis-activating pheromone (GBAP) can also suppress the virulence factors of gelatinase and serine protease. This research, in particular, aims to analyze lead compounds as antibacterial and anti-QS agents from Gambir (Uncaria gambir Roxburgh) through protein inhibition by in silico study. Antibacterial agents were isolated by bioactivity-guided isolation using a combination of chromatographic methods, and their chemical structures were determined by spectroscopic analysis methods. The in vitro antibacterial activity was evaluated by disc diffusion methods to determine inhibitory values. Meanwhile, in the in silico analysis, the compound of Uncaria gambir was used as ligand and compared with fosfomycin, ambuic acid, quercetin, and taxifolin as the standard ligand. These ligands were attached to MurA, GBAP, gelatinase, and serine proteases using Autodock Vina in PyRx 0.8 followed by PYMOL for combining the ligand conformation and proteins. plus programs to explore the complex, and visualized by Discovery Studio 2020 Client program. The antibacterial agent was identified as catechin that showed inhibitory activity against Enterococcus faecalis ATCC 29212 with inhibition zones of 11.70 mm at 10%, together with MIC and MBC values of 0.63 and 1.25 μg/mL, respectively. In the in silico study, the molecular interaction of catechin with MurA, GBAP, and gelatinase proteins showed good binding energy compared with two positive controls, namely fosfomycin and ambuic acid. It is better to use catechin–MurA (−8.5 Kcal/mol) and catechin–gelatinase (−7.8 Kcal/mol), as they have binding energies which are not marginally different from quercetin and taxifolin. On the other hand, the binding energy of serine protease is lower than quercetin, taxifolin, and ambuic acid. Based on the data, catechin has potency as an antibacterial through the inhibition of GBAP proteins, gelatinase, and serine protease that play a role in the QS system. This is the first discovery of the potential of catechin as an alternative antibacterial agent with an effective mechanism to prevent and control oral disease affected by antibiotic resistance.

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