scholarly journals The Effect of the plant Adiantum philippense Extracts on Biofilms Formation and Adhesion to Shigella flexneri: A Predictive Modelling Approach

2021 ◽  
Vol 9 (2) ◽  
pp. 34-39
Author(s):  
Garba Uba ◽  
Abdulhadi Yakubu ◽  
Abdussamad M. Baba

In the quest for novel bioactive metabolites, which can also be used as therapeutic agents, Adiantum philippense (A. philippense), an ethnomedically important fern, has become a fascinating herb. In this study, the predictive mathematical modelling of A. philippense crude extract was tested against Shigella flexneri, a common food pathogen for its phytochemical constituents, antagonistic ability, and effect on bacterial adhesion and biofilm formation was calculated. Various kinetics models such as Von Bertalanffy, Baranyi-Roberts, modified Schnute, Modified Richards, Modified Gompertz, Modified Logistics and latest Huang were used to get values for the above kinetic constants or parameters. modified Gompertz of the entire model was found to be the best model with the highest adjusted R2 value and lowest RMSE value. The accuracy and bias factors values were close to unity (1.0). The maximum specific growth rate (mmax (h-1) for S. flexneri treatment with A. philippense extract was significantly much lower (p<0.05) with a value of 0.292 (95% confidence interval of 0.254 to 0.331) compared to control with a value of 0.540 (95% confidence interval of 0.481 to 0.599) indicating potential biofilm inhibition.

2021 ◽  
Vol 10 (11) ◽  
pp. e514101119967
Author(s):  
Ana Lúcia Mendes dos Santos ◽  
Filipe Augusto Matos Araújo ◽  
Érika da Silva Matisui ◽  
Luiz Antonio Mendonça Alves da Costa ◽  
Alexandre José Macêdo ◽  
...  

A low shrub growing in the Amazonian region, Piper marginatum Jacq. has been related to the treatment of a disease variety in folk medicine, however, still lacking scientific support. This study aimed to describe the composition of essential oils obtained from leaves (EOL) and branches (EOB) of P. marginatum and their antimicrobial effects on six relevant pathogenic bacteria. A combination of GC-FID and GC-MS was used to identify the phytochemical constituents. As antimicrobial assays, the oils were screened at the minimum inhibitory concentration (MIC) of 3 µg/ml for planktonic and biofilm inhibition. EOL revealed the presence of trans–nerolidol, o–cymene, spathulenol, elemicin, and α–copaene, while EOB composition was mainly of myristicin, trans-caryophyllene, trans-nerolidol, caryophyllene oxide, α–copaene, γ–muurolene and spathulenol. The strongest inhibition of planktonic growth was achieved against Pseudomonas aeruginosa (EOB) and Escherichia coli (EOB). Overall, Gram negative bacteria were more sensitive to both EOB/EOL showing less ability of growth and biofilm formation. The Gram-positive strains seemed to react to the essential oils by massive adhesion. Our results corroborate the relevance of Piperaceae and indicate the possible use of P. marginatum in future developments of antimicrobials.


2020 ◽  
Vol 21 (4) ◽  
pp. 270-286 ◽  
Author(s):  
Fazlurrahman Khan ◽  
Dung T.N. Pham ◽  
Sandra F. Oloketuyi ◽  
Young-Mog Kim

Background: The establishment of a biofilm by most pathogenic bacteria has been known as one of the resistance mechanisms against antibiotics. A biofilm is a structural component where the bacterial community adheres to the biotic or abiotic surfaces by the help of Extracellular Polymeric Substances (EPS) produced by bacterial cells. The biofilm matrix possesses the ability to resist several adverse environmental factors, including the effect of antibiotics. Therefore, the resistance of bacterial biofilm-forming cells could be increased up to 1000 times than the planktonic cells, hence requiring a significantly high concentration of antibiotics for treatment. Methods: Up to the present, several methodologies employing antibiotics as an anti-biofilm, antivirulence or quorum quenching agent have been developed for biofilm inhibition and eradication of a pre-formed mature biofilm. Results: Among the anti-biofilm strategies being tested, the sub-minimal inhibitory concentration of several antibiotics either alone or in combination has been shown to inhibit biofilm formation and down-regulate the production of virulence factors. The combinatorial strategies include (1) combination of multiple antibiotics, (2) combination of antibiotics with non-antibiotic agents and (3) loading of antibiotics onto a carrier. Conclusion: The present review paper describes the role of several antibiotics as biofilm inhibitors and also the alternative strategies adopted for applications in eradicating and inhibiting the formation of biofilm by pathogenic bacteria.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sirapat Pipattanachat ◽  
Jiaqian Qin ◽  
Dinesh Rokaya ◽  
Panida Thanyasrisung ◽  
Viritpon Srimaneepong

AbstractBiofilm formation on medical devices can induce complications. Graphene oxide/silver nanoparticles (GO/AgNPs) coated nickel-titanium (NiTi) alloy has been successfully produced. Therefore, the aim of this study was to determine the anti-bacterial and anti-biofilm effects of a GO/AgNPs coated NiTi alloy prepared by Electrophoretic deposition (EPD). GO/AgNPs were coated on NiTi alloy using various coating times. The surface characteristics of the coated NiTi alloy substrates were investigated and its anti-biofilm and anti-bacterial effect on Streptococcus mutans biofilm were determined by measuring the biofilm mass and the number of viable cells using a crystal violet assay and colony counting assay, respectively. The results showed that although the surface roughness increased in a coating time-dependent manner, there was no positive correlation between the surface roughness and the total biofilm mass. However, increased GO/AgNPs deposition produced by the increased coating time significantly reduced the number of viable bacteria in the biofilm (p < 0.05). Therefore, the GO/AgNPs on NiTi alloy have an antibacterial effect on the S. mutans biofilm. However, the increased surface roughness does not influence total biofilm mass formation (p = 0.993). Modifying the NiTi alloy surface using GO/AgNPs can be a promising coating to reduce the consequences of biofilm formation.


2008 ◽  
Vol 74 (17) ◽  
pp. 5511-5515 ◽  
Author(s):  
Henny C. van der Mei ◽  
Minie Rustema-Abbing ◽  
Joop de Vries ◽  
Henk J. Busscher

ABSTRACT Transition from reversible to irreversible bacterial adhesion is a highly relevant but poorly understood step in initial biofilm formation. We hypothesize that in oral biofilm formation, irreversible adhesion is caused by bond strengthening due to specific bacterial interactions with salivary conditioning films. Here, we compared the initial adhesion of six oral bacterial strains to salivary conditioning films with their adhesion to a bovine serum albumin (BSA) coating and related their adhesion to the strengthening of the binding forces measured with bacteria-coated atomic force microscopy cantilevers. All strains adhered in higher numbers to salivary conditioning films than to BSA coatings, and specific bacterial interactions with salivary conditioning films were accompanied by stronger initial adhesion forces. Bond strengthening occurred on a time scale of several tens of seconds and was slower for actinomyces than for streptococci. Nonspecific interactions between bacteria and BSA coatings strengthened twofold faster than their specific interactions with salivary conditioning films, likely because specific interactions require a closer approach of interacting surfaces with the removal of interfacial water and a more extensive rearrangement of surface structures. After bond strengthening, bacterial adhesion forces with a salivary conditioning film remained stronger than those with BSA coatings.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Daniel Anokwah ◽  
Evelyn Asante-Kwatia ◽  
Abraham Y. Mensah ◽  
Cynthia Amaning Danquah ◽  
Benjamin K. Harley ◽  
...  

Abstract Background Antimicrobial resistance is a global health challenge. The involvement of bacterial biofilms and efflux pumps in the development of multidrug resistance (MDR) is well established. Medicinal plants have been proposed as alternatives for combating MDR focusing on their bioactive constituents with resistance modulatory activities. This study was aimed at investigating the stem bark of Aidia genipiflora for bioactive constituents with anti-biofilm, efflux pump inhibition and resistance modulatory activities. Method The crude methanol extract was purified by column chromatography and isolated compounds characterized by mass and nuclear magnetic resonance spectrometry. Antibacterial activity was determined by the High-throughput spot culture growth inhibition and the broth micro-dilution assay. The ethidium bromide accumulation assay was used to determine efflux pump inhibition property. Biofilm inhibition was determined in a microplate crystal violet retention assay. Results Purification of the ethyl acetate fraction led to the isolation of oleanonic acid (1), 4-hydroxy cinnamic acid docosyl ester (2), β-stigmasterol/β-sitosterol (mixture 3a/b) and D-mannitol (4). The minimum inhibitory concentrations (MICs) ranged from 250 to > 500 μg/mL for extracts and fractions and from 15 to 250 μg/mL for compounds. In the presence of sub-inhibitory concentrations of the compounds, the MIC of amoxicillin against E. coli (20 μg/mL) and P. aeruginosa (320 μg/mL) was reduced by 32 and 10 folds respectively. The whole extract demonstrated anti-biofilm formation and efflux pump inhibition in E. coli, S. aureus and P. aeruginosa. The sterol mixture (3a/b) at concentration of 100 μg/mL caused the highest inhibition (73%) of biofilm formation in S. aureus. Oleanonic acid (1) demonstrated remarkable efflux pump inhibition at MIC of 7.8 μg/mL in E. coli better than the standard drugs verapamil and chlorpromazine. Conclusion This study confirms the prospects of A. genipiflora as a source of new antibacterial agents and adjuvants that could interact with some resistance mechanisms in bacteria to enhance the activity of hitherto ineffective antibiotics. “A small portion of the study has been presented in a conference in the form of poster”.


RSC Advances ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 3938-3945 ◽  
Author(s):  
Jin-Rong Bai ◽  
Yan-Ping Wu ◽  
Grosu Elena ◽  
Kai Zhong ◽  
Hong Gao

QA effectively inhibitedS. aureusbiofilm formation. The key genes of biofilm inhibition induced by QA wereagrAandsarA.


Author(s):  
Mahinder Partap ◽  
Raghbir Chand Gupta ◽  
Saroj Kumar Pradhan

Objective: Comparative analysis of morphology and phytochemical constituents in different populations and morphotypes of Datura innoxia Mill. and Datura metel L. from Punjab plains.Methods: Morphological analyses of different populations have been done. Methanol extracts of seeds and roots of different populations have been prepared and total phenols, flavonoid contents were measured through spectrophotometry. Antioxidant activity was studied by 2, 2-diphenyl-1- picrylhydrazyl radical scavenging activity and total antioxidant capacity. Two major compounds, caffeic acid and chlorogenic acid were quantified by high-performance thin-layer chromatography (HPTLC) analyses.Results: Two morphotypes of D. metel were reported in the present study. Out of five different populations of D. metel and D. innoxia, the wild populations have more bioactive compound as compared to the cultivated ones from the detailed phytochemical investigation. Pharmacologically important two marker compounds chlorogenic acid and caffeic acid has been identified and quantified by HPTLC technique.Conclusion: Variation in terms of morphology and secondary metabolites exists among the different populations of Datura spp. Among the two plant parts studied, seeds have the maximum amount of bioactive metabolites and antioxidant activity. This study revealed that chlorogenic acid and caffeic acid are the potential polyphenolic compounds in Datura spp. It has been found that the antioxidant activity of plant is due to its polyphenol contents, which provides insight to various researchers to work on it as it imparts health benefit.


2014 ◽  
Vol 21 (9) ◽  
pp. 1206-1214 ◽  
Author(s):  
Lin Yan ◽  
Lei Zhang ◽  
Hongyan Ma ◽  
David Chiu ◽  
James D. Bryers

ABSTRACTNosocomial infections are the fourth leading cause of morbidity and mortality in the United States, resulting in 2 million infections and ∼100,000 deaths each year. More than 60% of these infections are associated with some type of biomedical device.Staphylococcus epidermidisis a commensal bacterium of the human skin and is the most common nosocomial pathogen infecting implanted medical devices, especially those in the cardiovasculature.S. epidermidisantibiotic resistance and biofilm formation on inert surfaces make these infections hard to treat. Accumulation-associated protein (Aap), a cell wall-anchored protein ofS. epidermidis, is considered one of the most important proteins involved in the formation ofS. epidermidisbiofilm. A small recombinant protein vaccine comprising a single B-repeat domain (Brpt1.0) ofS. epidermidisRP62A Aap was developed, and the vaccine's efficacy was evaluatedin vitrowith a biofilm inhibition assay andin vivoin a murine model of biomaterial-associated infection. A high IgG antibody response againstS. epidermidisRP62A was detected in the sera of the mice after two subcutaneous immunizations with Brpt1.0 coadministered with Freund's adjuvant. Sera from Brpt1.0-immunized mice inhibitedin vitroS. epidermidisRP62A biofilm formation in a dose-dependent pattern. After receiving two immunizations, each mouse was surgically implanted with a porous scaffold disk containing 5 × 106CFU ofS. epidermidisRP62A. Weight changes, inflammatory markers, and histological assay results after challenge withS. epidermidisindicated that the mice immunized with Brpt1.0 exhibited significantly higher resistance toS. epidermidisRP62A implant infection than the control mice. Day 8 postchallenge, there was a significantly lower number of bacteria in scaffold sections and surrounding tissues and a lower residual inflammatory response to the infected scaffold disks for the Brpt1.0-immunized mice than for of the ovalbumin (Ova)-immunized mice.


Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2771
Author(s):  
Tobias Wieland ◽  
Julia Assmann ◽  
Astrid Bethe ◽  
Christian Fidelak ◽  
Helena Gmoser ◽  
...  

The increasing rate of antimicrobial resistance (AMR) in pathogenic bacteria is a global threat to human and veterinary medicine. Beyond antibiotics, antimicrobial peptides (AMPs) might be an alternative to inhibit the growth of bacteria, including AMR pathogens, on different surfaces. Biofilm formation, which starts out as bacterial adhesion, poses additional challenges for antibiotics targeting bacterial cells. The objective of this study was to establish a real-time method for the monitoring of the inhibition of (a) bacterial adhesion to a defined substrate and (b) biofilm formation by AMPs using an innovative thermal sensor. We provide evidence that the thermal sensor enables continuous monitoring of the effect of two potent AMPs, protamine and OH-CATH-30, on surface colonization of bovine mastitis-associated Escherichia (E.) coli and Staphylococcus (S.) aureus. The bacteria were grown under static conditions on the surface of the sensor membrane, on which temperature oscillations generated by a heater structure were detected by an amorphous germanium thermistor. Bacterial adhesion, which was confirmed by white light interferometry, caused a detectable amplitude change and phase shift. To our knowledge, the thermal measurement system has never been used to assess the effect of AMPs on bacterial adhesion in real time before. The system could be used to screen and evaluate bacterial adhesion inhibition of both known and novel AMPs.


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