scholarly journals Antibacterial Amphiphilic Copolymers of Dimethylamino Ethyl Methacrylate and Methyl Methacrylate to Control Biofilm Adhesion for Antifouling Applications

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 216
Author(s):  
Shehla Mushtaq ◽  
Nasir M. Ahmad ◽  
Azhar Mahmood ◽  
Mudassir Iqbal

Amphiphilic copolymers are recognized as important biomaterials and used as antibacterial agents due to their effective inhibition of bacterial growth. In current study, the amphiphilic copolymers of P(DMAEMA-co-MMA) were synthesized using free radical polymerization by varying the concentrations of hydrophilic monomer 2-dimethylamino ethylmethacrylate (DMAEMA) and hydrophobic monomer methyl methacrylate (MMA) having PDI value of 1.65–1.93. The DMAEMA monomer, through ternary amine with antibacterial property optimized copolymers, P(DMAEMA-co-MMA), compositions to control biofilm adhesion. Antibacterial activity of synthesized copolymers was elucidated against Gram-positive Staphylococcus aureus (ATCC 6538) and Gram-negative Escherchia coli (ATCC 8739) by disk diffusion method, and zones of inhibition were measured. The desired composition that was PDM1 copolymer had shown good zones of inhibition i.e., 19 ± 0.33 mm and 20 ± 0.33 mm for E. coli and S. aureus respectively. The PDM1 and PDM2 have exhibited significant control over bacterial biofilm adhesion as tested by six well plate method. SEM study of bacterial biofilm formation has illustrated that these copolymers act in a similar fashion like cationic biocide. These compositions viz. PDM1 and PDM2, may be useful in development of bioreactors, sensors, surgical equipment and drug delivery devices.

2017 ◽  
Vol 751 ◽  
pp. 270-276 ◽  
Author(s):  
Warot Prasanseang ◽  
Chaval Sriwong ◽  
Kittisak Choojun

Ag-natural rubber (Ag-NR) hybrid sheets were successfully prepared with a very simple and low cost method. In this method, silver nanoparticles (AgNPs) were firstly synthesized by a rapid and green microwave-assisted using polyvinylpyrroridone (PVP) media. The effect of PVP weight ratios towards the size of AgNPs was also investigated. Then, Ag-NR hybrid sheet samples were prepared by latex mixing-casting method using concentrated natural rubber (NR) latex with the synthesized AgNPs colloids. The characteristic absorption, particles sizes and shapes of the obtained AgNPs were examined through UV-vis, TEM and SAED. Also, the prepared Ag-NR sheet samples were characterized using XRD, FT-IR, SEM and EDS techniques. It was found that the particles sizes of all the synthesized AgNPs had spherical-like shape, and the mean sizes were increased from 29.7 to 90.4 nm upon increasing PVP contents. EDS results showed the AgNPs were well-dispersed and impregnated into the rubber matrix. Moreover, the antibacterial properties of the prepared Ag-NR sheets were tested by agar disk-diffusion method with Gram-positive and Gram-negative bacteria as Staphylococcus aureus(S. aureus) and Escherichia coli(E. coli), respectively. The results showed that the hybrid sheets exhibited excellent antibacterial properties against these bacteria, in which the zones of inhibition were also dependent on the synthesized AgNPs by utilizing the different amounts of PVP.


2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Caroline Suryadi ◽  
Djaja Rusmana ◽  
Endang Evacuasiany

Escherichia coli is the most common bacteria that cause diarrhea. Based on Kurniawati’s research, ethanol extract of tamarind leaves has an antimicrobial effect to Escherichia coli. This study aims to determine the antimicrobial effect using disk diffusion method, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of tamarind leaves infusion against Escherichia coli. This research was done using a real laboratory experimental design with tamarind leaves infusion and Escherichia coli microbes as the research objects. Zones of inhibition were observed using disk diffusion method by putting the tamarind leaves infusion disks on Mueller-Hinton agars with Ampicillin antibiotic for comparison, followed by observing the MIC using macro broth dilution method  and MBC. The result of disk diffusion showed that tamarind leaves infusion had no zone of inhibition, whereas the mean value of the zones of inhibition of ampicillin is 17.2 mm. The MIC of tamarind leaves infusion is 62.5 mg/mL. Average growth of bacteria  for the MBC of tamarind leaves infusion at 125 mg/mL and 62.5 mg/mL concentration are 13 CFU/mL and >300 CFU/mL. It can be concluded that tamarind leaves infusion has antimicrobial activity effect against E.coli and that effect is bacteriostatic. Keywords: Tamarindus indica Linn, Escherichia coli, MIC, MBC


Author(s):  
Pratibha Jinesh Shah

Objective: The present study evaluates the antibacterial effect of aqueous garlic extract (AGE) on beta-lactamase producing Acinetobacter strains isolated from skin and soft tissue infections (SSTIs).Methods: A total of 41 non-duplicate strains of Acinetobacter isolated from SSTIs specimens were tested for their antibiotic susceptibility pattern by Kirby-Bauer disk diffusion method. Ceftazidime-resistant Acinetobacter strains were screened for beta-lactamase production by Phenotypic confirmatory disc diffusion test (PCDDT) and E-test. Antibacterial activity of AGE was examined by the disc diffusion method and the minimum inhibitory concentration (MIC) of AGE and Cefotaxime was determined by the agar dilution technique. The combined activity of AGE and Cefotaxime was evaluated by calculating the fractional inhibitory concentration (FIC) index by the checkerboard method.Results: 21 Acinetobacter strains were confirmed to be beta-lactamase producers, out of which 6 were Metallo-beta-lactamase (MBL) producers, 3 were Ambler Class C (AmpC) and 12 were multiple beta-lactamase producers. AGE exhibited significant antibacterial activity as the observed zones of inhibition ranged from 18 - 31 mm against the test strains. The MIC of AGE was in the range of 0.5% - 2% (2.5 mg/ml – 10 mg/ml) with a mean of 0.86% (4.28 mg/ml). 11 test strains showed synergism, 5 strains exhibited additive and indifferent effect, each. By HPLC analysis the concentration of allicin was found to be 0.20, expressed as percentage w/w.Conclusion: It can be stated that aqueous garlic extract might have therapeutic value against beta-lactamase producing Acinetobacter isolates from SSTIs.


Author(s):  
Kathryn Kelly ◽  
Hannah McColl ◽  
Leandra Hess ◽  
Robert Charvat

The normal intestinal microflora plays pivotal roles in aiding with digestion, stimulating the immune system, and providing protection from enteric pathogens. Despite the importance of these organisms, they are often an innocent bystander, caught in the crossfire during antibiotic treatments intended to target and eliminate invading infectious agents. The collateral damage of antibiotic therapy is a reduction in the population of beneficial bacteria as well as an increased risk for more severe infections, including Clostridium difficile. Additionally, the unpleasant condition termed antibiotic-associated diarrhea is an unfortunate consequence of such treatments. In an attempt to alleviate the intestinal distress, individuals are turning to probiotic supplements, which consist of non-pathogenic bacteria purported to provide various health benefits, such as digestive regularity, prevention of disease, and replenishment of the natural microbiota of the human intestinal tract. However, if the bacterial strains present in the physician-recommended probiotic supplements are overly sensitive to antibiotics, then they would fail to reestablish the intestinal microflora during the course of treatment. The purpose of this project was to test the hypothesis that bacterial strains contained within probiotics are resistant to a variety of common antibiotics. Antibiotic susceptibility was assessed for several over-the-counter probiotic supplements via the Kirby-Bauer Disk Diffusion method on medium specific for lactobacilli propagation. After measuring the zones of inhibition, the probiotics were surprisingly sensitive to two-thirds of the antibiotics tested, with the observed growth inhibition greatly exceeding predetermined standards for susceptibility. These results suggest that concomitantly taking probiotic supplements during a course of antibiotics is likely futile for replenishing the intestinal microbiota. We intend to expand the study to include additional antibiotics and supplements of varying formulations in an attempt to gain insight into which strains may exhibit the least sensitivity and be the most effective for recolonization of the gastrointestinal tract.


2020 ◽  
Vol 66 (3) ◽  
pp. 1-12
Author(s):  
Suneel Prajapati ◽  
Aarti Bhardwaj ◽  
Pankaj Gupta

Abstract Introduction Fungal disseases are the most common opportunistic infection. Objective The main aims of the study were to determine phenolic content and to evaluate the antioxidant and anti-candida activity of the selected Indian-origin plant extracts from the fruit pulp, stem, leaves, and seeds of three plants of Indian origin. Material and methods The extracts from Terminalia chebula, Thuja occidentalic and Syzygium jambolanum were investigated. The total phenolic content, antioxidant potential of different crude extracts was accessed using the free radical, 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). Anti-candida activity was evaluated using disk diffusion method and broth dilution assay against Candida albicans. Results Ethanol and methanol extracts of Indian traditional plants possessed high radical scavenging activity: T. chebula 29.38±0.15, T. occidentalis 6.26±0.24 and S. jambolanum 25.64±0.18 at 0.32 mg/ml. The extracts exhibited good zones of inhibition diameters ranged between: for T. chebula 6.33±0.57 mm and 19.66±1.52 mm in diameter, S. jambolanum 7.00±00 mm and 23.33±1.52 and T. occidentalis 7.66±0.57 and 17.00±1.00 mm. C. albicans were susceptible to all three tested extract at different concentrations. The lowest MIC 1.95 mg/ml was recorded with S. jambolanum while the T. chebula and T. occidentalis inhibited the growth at 3.90 mg/ml, respectively, against the C. albicans. Conclusion The study result paves an overall view on the bioactivities of three traditional Indian medicinal plants crude extracts.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Shehla Mushtaq ◽  
Nasir M. Ahmad ◽  
Habib Nasir ◽  
Azhar Mahmood ◽  
Hussnain A. Janjua

The scope of optical sensors and scanners in aquatic media, fluids, and medical diagnostics has been limited by paucity of transparent shielding materials with antifouling potential. In this research endeavor, facile synthesis, characterization, and bioassay of antifouling transparent functional copolymers are reported. Copolymers of 3-sulfopropyl methacrylate (SPMA) and methyl methacrylate (MMA) were synthesized by free radical polymerization in various proportions. Samples PSM20, PSM30, PSM40, PSM50, and PSM60 contain 20%, 30%, 40%, 50%, and 60% SPMA by weight, respectively. Resultant products were characterized by FTIR and 1H-NMR spectroscopy. The synthesized copolymers have exhibited excellent transparency, i.e., 75% to 88%, as determined by the UV-Vis spectroscopic analysis. Transmittance was decreased from 6% to 2% in these copolymers upon changing the concentration of 3-sulfopropyl methacrylate from 20% to 50% owing to bacterial and algal biofilm formation. Water contact angle values were ranged from 18° to 63° and decreased with the increase in the polarity of copolymers. The surface energy lowest value 58 mJ/m2 and highest value 72 mJ/m2 were calculated for PSM20 and PSM50, respectively, by the Chibowski approach and Young equation. Sample PSM50 has exhibited the highest antibacterial activities, i.e., 18 mm and 19 mm, against Escherichia coli and Staphylococcus aureus, respectively, by the disk diffusion method. Copolymer PSM50 has shown minimum algal adhesion for Dictyosphaerium algae as observed by optical microscopy. This lower bacterial and algal adhesion is attributed to higher concentrations of anionic SPMA monomer that cause electrostatic repulsion between functional groups of the polymer and microorganisms. Thus, the resultant PSM50 product has exhibited good potential for optronics shielding application in aquatic medium and medical diagnostics.


2020 ◽  
Vol 12 (2) ◽  
Author(s):  
Vesna Gojković Cvjetković ◽  
Željka Marjanović-Balabań ◽  
Marijana Kapović-Solomuń ◽  
Ljiljaná́ Stanojevic ◽  
Jelená́ Stanojevic ◽  
...  

The quality of the essential oil obtained from white pine wood greenery from the territory of the Republic of Srpska was analyzed by examining the chemical composi- tion and antimicrobial activity of samples produced by the hydro-distillation process in industrial production conditions. The chemical composition of the essential oil was analyzed by GC/MS and GC/FID analysis. The antimicrobial activity of the ob- tained white pine oil was investigated for its possible use as an antimicrobial agent. The obtained results prove the presence of 37 components in the analyzed sam- ple, which represents 98.5% of the total components present. The most common are monoterpene hydrocarbons, followed by sesquiterpene hydrocarbons, much less represented are monoterpenes containing oxygen and aromatic compounds, while aliphatic esters are found only in traces. Antimicrobial activity was examined using the disk diffusion method. The results showed large zones of inhibition, both for the tested oil sample and for all eight analyzed bacterial strains (from 12.00 ± 0.00 to 17.33 ± 1.15mm), as well as for the fungal strain. The chemical composition and antimicrobial action of essential white pine oiled from plant material originating from the territory of the Republic of Srpska indicates its significant phytomedical potential.


2020 ◽  
Vol 7 (3) ◽  
pp. 463-468
Author(s):  
Hong Thien Van ◽  
Dang Gia Man Nguyen ◽  
Nguyen Tuong An Quynh ◽  
Van Son Le

In this study, the antibacterial activity of ethanolic extract from the leaves of four Rutaceae species, including Acronychia pedunculata, Clausena excavata, Glycosmis pentaphylla and Luvunga scandens, were performed using the agar disk diffusion method for the first time. The ethanolic extracts from the leaves of A. pedunculata and G. pentaphylla were able to resist against all six bacterial strains with zones of inhibition for Bacillus cereus (17.3±2.1 mm, 20.8±1.0 mm) Staphylococcus aureus (8.5±0.5 mm, 17.6±0.3 mm) Escherichia coli (16.7±2.1 mm, 15.3±1.2 mm), Pseudomonas aeruginosa (11.7±0.6 mm, 14.0±1.7 mm), Salmonella enteritidis (22.3±0.6 mm, 24.6±0.5 mm) and Salmonella typhimurium (9.5±0.9 mm, 8.3±0.6 mm). On the other hand, the ethanolic extract of C. excavata leaf was resistant to B. cereus (12.3±0.6 mm), S. aureus (11.6±0.5 mm), E. coli (11.5±2.1 mm), P. aeruginosa (10.6±0.3 mm) while B. cereus (8.2±0.3 mm), S. aureus (9.3±0.6 mm), E. coli (8.5±0.5 mm) and S. typhimurium (8.3±0.6 mm) were inhibited by the ethanolic extract of L. scandens leaf. This study could provide necessary information for further application of these species in medicine.


Author(s):  
Shumaila Shakir ◽  
Sidrah Saleem ◽  
Wajhiah Rizvi ◽  
Waheed Aslam ◽  
Javid Iqbal

Dermatophytosis or tinea is a type of cutaneous infection caused by keratinophilic fungi, infecting the skin, nails and hair. A correct diagnosis is important for epidemiological purposes and initiating appropriate treatment. An increase in the prevalence of fungal infection worldwide is due to abuse of antibiotics, immunosuppressive treatments and numerous medical conditions. Aim: To isolate, identify, and examine the in-vitro antifungal susceptibility of dermatophytes in clinically suspected cases of tinea infections. Methodology: After taking informed consent, we took 65 patients suspected of tinea infection and obtained samples from skin, hair and nail, under aseptic precautions, at Department of Microbiology, University of Health Sciences (UHS), Lahore, Pakistan. The identification of dermatophytes was performed using potassium hydroxide (KOH) mounts and culture on Sabouraud Dextrose Agar (SDA) and Dermatophyte Test Medium (DTM). The cultures were incubated at 30ºC for up to 4 weeks in case of SDA and 2 weeks in case of DTM. Lactophenol cotton blue (LCB) stain was used to identify the species morphologically. Susceptibility test was done by agar diffusion method using antifungal disks and zones of inhibition were measured. Results: More females (55.38%) than males (44.61%) were observed in the study. Most of the cases belonged to the age categories of 1-10 years and 21-30 years. Tinea corporis was the most common clinical type found (27.69%) followed by Tinea capitis (21.53%) and Tinea cruris (12.30%).Trichophyton mentagrophytes was the commonest species isolated (32%)  followed by Trichophyton violaceum (28%) and Trichophyton rubrum (12%). Terbinafine was seen to be the most effective drug against the isolates, followed by clotrimazole. Fluconazole showed least activity. Conclusion: Fungal culture remains the gold standard in identifying the causative species. Terbinafine promises to be a potent antifungal, whereas fluconazole has low efficacy against such organisms. Disk diffusion method adopted for antifungal susceptibility is cost effective and easily performable in small laboratories not having an established mycology bench.


Author(s):  
Rokaya Elamary ◽  
Fawziah Albarakaty ◽  
Wesam Salem

Bacterial biofilms have become a significant and growing threat to human life, nature, and environmental health. The aim of this study is to isolate amylase-producing bacteria from the terrestrial environment (soil) for investigating their general inhibition of some pathogenic human bacterial biofilm. A total of 75 amylase producing isolates were obtained by serial dilution and streaking method. Amylotic activity of these isolates was screened by a starch agar plate method. Isolates were characterized by morphological and biochemical methods. The isolated Bacillus species were B. megaterium (26.7%), B. subtilis (16%), B. cereus (13.3%), B. thuringiesis (10.7%), B. lentus (10.7%), B. mycoides (5.3%), B. alvei (5.3%), B. polymyxa (4%), B. circulans (4%) and Micrococcus roseus (4%). The optimum conditions for amylase production were monitored. Antagonistic activity of these isolates and purified amylase against multidrug-resistant pathogenic human bacteria by agar disk diffusion method. The sensitivity level of some standard antibiotics served as control. Interestingly, it was found that all isolates exhibited great antagonistic activity against the target pathogens. The greatest activity recoded by B. alevi (48 mm) against Staphylococcus aureus (MRSA) and the lowest activity recorded by B. polymyxa (12 mm) against E. coli while low inhibition recorded for amylase. Antibiofilm efficacy of isolates supernatant and purified enzyme also monitored by spectrophotometric methods. The results revealed highly significant inhibition with percentages of 93.6 and 78.8% respectively. So, they represent a good tool for biofilm control in clinical and environmental applications.


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