Antibiofilm Activity Of Extracts Research Articles

Antibacterial and antibiofilm activity of extracts from sponge-associated bacterial endophytes

Sponges forms association with many bacteria that serve as sources of new bioactive compounds. The compounds are produced in response to environmental and nutritional conditions of the environment that enable them to protect their host from colonization. In this study, three sponge bacterial endophytes were isolated, identified, and subjected to solvent extraction processes. The identified bacteria are Bacillus amyloquifaciens, Bacillus paramycoides, and Enterobacter sp. The bacteria were cultured in two different fermentation media with varying nutritional composition for the extraction process. The extracts were evaluated for antibacterial and antibiofilm activity against microfouling bacteria and the chemical composition of each extract was analyzed via gas chromatography-mass spectrometry (GC-MS). The extract from the endophytes shows varying antibacterial and antibiofilm activity against the tested strains. Several compounds were detected from the extracts including some with known antibacterial/antibiofilm activity. The results showed variations in activity and secondary metabolite production between the extracts obtained under different nutritional composition of the media. In conclusion, this study indicated the role of nutrient composition in the activity and secondary metabolites production by bacteria associated with sponge Also, this study confirmed the role of sponge bacterial endophytes as producers of bioactive compounds with potential application as antifouling (AF) agents.

Antibiofilm and Antimicrobial-Enhancing Activity of Chelidonium majus and Corydalis cheilanthifolia Extracts against Multidrug-Resistant Helicobacter pylori.

Helicobacter pylori is a Gram-negative bacterium that colonizes the stomach of about 60% of people worldwide. The search for new drugs with activity against H. pylori is now a hotspot in the effective and safe control of this bacterium. Therefore, the aim of this research was to determine the antibacterial activity of extracts from selected plants of the Papaveraceae family against planktonic and biofilm forms of the multidrug-resistant clinical strain of H. pylori using a broad spectrum of analytical in vitro methods. It was revealed that among the tested extracts, those obtained from Corydalis cheilanthifolia and Chelidonium majus were the most active, with minimal inhibitory concentrations (MICs) of 64 µg/mL and 128 µg/mL, respectively. High concentrations of both extracts showed cytotoxicity against cell lines of human hepatic origin. Therefore, we attempted to lower their MICs through the use of a synergistic combination with synthetic antimicrobials as well as by applying cellulose as a drug carrier. Using checkerboard assays, we determined that both extracts presented synergistic interactions with amoxicillin (AMX) and 3-bromopyruvate (3-BP) (FICI = 0.5) and additive relationships with sertraline (SER) (FICI = 0.75). The antibiofilm activity of extracts and their combinations with AMX, 3-BP, or SER, was analyzed by two methods, i.e., the microcapillary overgrowth under flow conditions (the Bioflux system) and assessment of the viability of lawn biofilms after exposure to drugs released from bacterial cellulose (BC) carriers. Using both methods, we observed a several-fold decrease in the level of H. pylori biofilm, indicating the ability of the tested compounds to eradicate the microbial biofilm. The obtained results indicate that application of plant-derived extracts from the Papaveraceae family combined with synthetic antimicrobials, absorbed into organic BC carrier, may be considered a promising way of fighting biofilm-forming H. pylori.

Antibiofilm Activity of Extract and a Compound Isolated from Triumfetta welwitschii against Pseudomonas aeruginosa.

Triumfetta welwitschii has been used as a traditional medicine in Africa. It is documented as a rich source of phytochemicals with antibacterial activities. To further explore the antibacterial potential of these phytochemical components, the phytochemical profile of the dichloromethane: methanol leaf extract from T. welwitschii was investigated using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Compounds were isolated from the extract using column chromatography and thin-layer chromatography. Compound B1 was isolated from the fraction eluted by 90 hexane:10 ethyl acetate using column chromatography. The antibacterial activity of B1 against Pseudomonas aeruginosa was evaluated in vitro using the broth microdilution method and the iodonitrotetrazolium (INT) colorimetric assay. The antibiofilm activities of the extract and B1 against P. aeruginosa were determined by quantifying the biofilms using crystal violet. The effect of the extract and B1 on capsular polysaccharide and extracellular DNA content of biofilm formed by P. aeruginosa was determined using phenol-sulphuric acid and propidium iodide, respectively. A total of 28 peaks were detected and identified using UPLC-MS/MS. The three most abundant phytochemicals identified were catechin, umbelliferone, and a luteolin derivative. B1 showed antibacterial activity against P. aeruginosa with a minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) value of 25 μg/ml. Only 38% and 6% of the biofilms were formed in the presence of the extract and B1, respectively. The extract and B1 reduced the capsular polysaccharide content in biofilms formed in P. aeruginosa by 40% and 65%, respectively. The extract and B1 significantly reduced the extracellular DNA content of biofilms by 29% and 72%, respectively. The results of this study provide evidence of the antibacterial and antibiofilm activities of B1 and leaf extracts from T. welwitschii. Future work should identify the chemical structure of B1 using nuclear magnetic resonance and mass spectrometry.

Phytochemical and Antibiofilm Activity of Aloe barbadensismiller (Aloe vera) on Candida albicans Isolated from Urinary Catheter

Aims: To screen for phytochemicals present in Aloe barbadensismiller (Aloe vera) growing within the Main Campus of Nasarawa State University Keffi (NSUK), determine biofilm forming ability, and to investigate the antibiofilm activity of the plant extracts on biofilm formed by clinical isolates of Candida isolated from urinary catheters.
 Study Design: The leaf of Aloe vera were collected and maceration method was used to extract the plant materials used for the screening of bioactive components. Swab samples were collected from the surfaces of patients’ urinary catheters presenting at Federal Medical Centre and Nagari Hospital, Keffi respectively, irrespective of their ages and sexes. Biofilm forming ability of the isolates was investigated and the antibiofilm activity of the plant extracts determined. Ordinary one-way ANOVA was used to analyze the data where P = .05.
 Place and Duration of Study: The research was carried out in the Microbiology Laboratory of NSUK, using the Aloe vera plant collected within the University community and the biofilm analysis was conducted at National Veterinary Research Institute, Vom Plateau State, between October 2018 to March 2019.
 Methodology: Both the aqueous and ethanolic extracts were screened for aloin, tannins, saponins, glycosides, flavonoids, phenols, alkaloids etc, and the Candida species were subjected to biofilm formation in a flat bottom 96-well microtiter polystyrene plate using crystal violet assay. Broth microdilution method was used to determine the minimum inhibitory concentrations (MIC) of the extracts whereas, antibiofilm activity of the extracts was investigated by growing biofilms in the presence of Aloe vera leaf extracts.
 Results: The presence of tannin, saponins, phenols, reducing sugars and aloin were found in the leaf aqueous extract while alkaloid, flavonoid, glycoside, tannin, phenols, reducing sugars, terpenoids, quinones and aloin in the ethanolic extract. Clinical isolates of Candida were found to be strong biofilm formers (70%). Both the aqueous and ethanolic extracts had significant effects on initial cell attachment where P = .05, however, none was able to achieve complete biofilm eradication, including the positive control ketoconazole. Ethanolic extract inhibits C. albicans cell attachment by 54.25%, aqueous extract 25.68% and ketoconazole has 48.54% percentage inhibition, respectively. Interestingly, ethanolic extracts showed a better antibiofilm property (37.38%) compared to ketoconazole that had 33.98% biofilm inhibition.
 Conclusion: The leaf extracts of Aloe barbadensismiller has significantly reduced biofilm formed by clinical isolates of Candida. Coating of urinary catheters with A. vera extracts can decrease nosocomial infections, morbidity, and high mortality as well as financial burden, hence, serving as an alternative treatment for urinary tract infections.

Antibiofilm forming, antimicrobial activity and some biochemical properties of Vaccinium vitis idaea leaf and berry extracts on Staphylococcus aureus

Infections caused by Staphylococcus genus bacteria remain a relevant problem due to the high percentage of antibio­tic-resistant biofilm-forming strains of isolates of this genus. Herbs are a promising source for many biologically active compounds with antimicrobial properties. The aim of the research was to study the antimicrobial and antibiofilm formation activity of berry and leaf extracts of Vaccinium vitis-idaea L. upon clinical isolates of S. aureus, and the main biochemical properties of these extracts. For the purpose of analysis, we used S. aureus isolated from the mouth cavities and pharynx of human patients suffering from inflammatory diseases. The plants for the study were gathered in Pylypets, Mizhhiria rayon, Zakarpatska oblast (Transcarpathia). From Vaccinium vitis-idaea L., leaf and berry extracts were produced. To determine the chemical properties of the extracts, the following constituents were investigated: total tannin, flavonoids, total phenols, anthocyanins (by spectrophotometric method), and the total amount of vitamin C in berry extract (chromatographically). The antimicrobial activity was studied by diffusion-into-agar method and determination of minimum inhibitory concentrations. The antibiofilm activity of the extracts was tested in standard 96-well microtitration plates. The main chemical composition of ethyl extracts of Vaccinium vitis-idaea L. berries and leaves was identified. The level of tannins in leaf extracts was established to be higher than in fruit extracts (3.50% and 0.26% per 100 g of extract, respectively). It was shown that extracts of V. vitis-idaea berries and leaves demonstrate high antimicrobial activity against clinical isolates of S. aureus. Further it was established that leaf extracts had high ability to destroy the bacterial biofilm of S. aureus. Leaf extracts were also able to destroy the formed biofilm. Even in the 0.01% concentration, leaf extract inhibited the formation of the biofilm by 69.9% and caused the destruction of the formed biofilm by 62.5%. Thereby, the obtained results show good prospects for the use of V. vitis-idaea leaf extracts as an anti-staphylococcal remedy with antibiofilm forming properties.

The Usefulness of Microalgae Compounds for Preventing Biofilm Infections.

Biofilms play an important role in infectious diseases. It has been estimated that most medical infections are due to bacterial biofilms, and about 60–70% of nosocomial infections are also caused by the formation of a biofilm. Historically, microalgae are an important source of bioactive compounds, having novel structures and potential biological functions that make them attractive for different industries such as food, animal feed, aquaculture, cosmetics, and pharmaceutical. Several studies have described compounds produced by microalgae and cyanobacteria species with antimicrobial activity. However, studies on the antibiofilm activity of extracts and/or molecules produced by these microorganisms are scarce. Quorum-sensing inhibitor and anti-adherent agents have, among others, been isolated from microalgae and cyanobacteria species. The use of tools such as nanotechnology increase their power of action and can be used for preventing and treating biofilm-related infections.

Inhibition of Bacterial and Fungal Biofilm Formation by 675 Extracts from Microalgae and Cyanobacteria.

Bacterial biofilms are complex biological systems that are difficult to eradicate at a medical, industrial, or environmental level. Biofilms confer bacteria protection against external factors and antimicrobial treatments. Taking into account that about 80% of human infections are caused by bacterial biofilms, the eradication of these structures is a great priority. Biofilms are resistant to old-generation antibiotics, which has led to the search for new antimicrobials from different sources, including deep oceans/seas. In this study, 675 extracts obtained from 225 cyanobacteria and microalgae species (11 phyla and 6 samples belonging to unknown group) were obtained from different culture collections: The Blue Biotechnology and Ecotoxicology Culture Collection (LEGE-CC), the Coimbra Collection of Algae (ACOI) from Portugal, and the Roscoff Culture Collection (RCC) from France. The largest number of samples was made up of the microalgae phylum Chlorophyta (270) followed by Cyanobacteria (261). To obtain a large range of new bioactive compounds, a method involving three consecutive extractions (hexane, ethyl acetate, and methanol) was used. The antibiofilm activity of extracts was determined against seven different bacterial species and two Candida strains in terms of minimal biofilm inhibitory concentration (MBIC). The highest biofilm inhibition rates (%) were achieved against Candida albicans and Enterobacter cloacae. Charophyta, Chlorophyta, and Cyanobacteria were the most effective against all microorganisms. In particular, extracts of Cercozoa phylum presented the lowest MBIC50 and MBIC90 values for all the strains except C. albicans.

PHYTOCHEMICAL SCREENING, ANTIOXIDANT, ANTIMICROBIAL, AND ANTIBIOFILM ACTIVITY OF SAUROPUS ANDROGYNUS LEAF EXTRACTS

Objective: The objective of the study was to perform phytochemical screening, and evaluate the antioxidant, antimicrobial, and antibiofilm activities of Sauropus androgynus leaf extract against pathogenic organisms.
 Methods: Sauropus androgynus leaves were shade dried, powdered, and extracted by Soxhlet hot extraction procedure using ethanol or methanol. The aqueous extract was prepared using a rotary shaker. The qualitative phytochemical screening was carried out by gas chromatography-mass spectroscopic (GC-MS) analysis and liquid chromatography-mass spectrometry (LC-MS). The antioxidant activity of plant extracts was estimated by using 2,2-diphenyl-1-picrylhydrazyl (DPPH)-free radical scavenging assay. Antimicrobial and antibiofilm activity of extracts against various pathogens was performed using serial microdilution assay and microtiter plate method, respectively.
 Results: Preliminary phytochemical analysis showed the presence of compounds such as tannins, flavonoids, alkaloids, and phenols. GC-MS studies also revealed the presence of biologically active compounds. Methanolic extract of S. androgynus showed higher DPPH Scavenging activity compared to other extracts. All the extracts were able to inhibit both bacterial growth and biofilm production; however, the methanolic extract showed the highest antibiofilm activity.
 Conclusion: S. androgynus plant extracts possess significant antioxidant, antimicrobial, and antibiofilm activity.

Antibacterial and anti-biofilm activities of crude extracts of Lawsonia inermis against Methicillin Resistant Staphylococcus aureus

Objective:The continuous rise in the prevalence of multi drug resistance pathogens globally is threatening the treatment and management of infectious diseases. Ethno medicine plays a key role in the exploration for novel bioactive compounds. The present study evaluates the antibacterial and antibiofilm activities of the crude extracts of Lawsonia inermis against clinical isolates of methicillin resistant Staphylococcus aureus (MRSA).Materials and methods: Shade dried and finely powdered leaves of the plant were extracted by maceration method using six solvents methanol, acetone, ethyl acetate, chloroform, petroleum ether and n-hexane. Antibacterial and antibiofilm activities of the extracts against MDR MRSA by agar cup diffusion and tube method respectively.Results: Methanol extract showed the highest antibacterial activity of 18mm compared to other extracts. Similarly, petroleum ether extract showed highest biofilm inhibition of 84.7%. Other solvent extracts also exhibited significant biofilm inhibition [n-Hexane-83.6%, Ethyl acetate -79.5%, Chloroform-79.2%, Acetone -77% and Methanol-77%].Conclusion: The leaf extracts of L. inermis have shown promising biofilm inhibitory activity and good antibacterial activity, which can be explored for the development of new drugs for the MDR pathogens. Keywords: Antibioticacivity, Antibiofilm activity, L.inermis, MRSA