Biofilm Degradation Research Articles

Impact of Reactive Sulfur Species on Entamoeba histolytica: Modulating Viability, Motility, and Biofilm Degradation Capacity.

Reactive sulfur species (RSS) like hydrogen sulfide (H2S) and cysteine persulfide (Cys-SSH) emerged as key signaling molecules with diverse physiological roles in the body, depending on their concentration and the cellular environment. While it is known that H2S and Cys-SSH are produced by both colonocytes and by the gut microbiota through sulfur metabolism, it remains unknown how these RSS affect amebiasis caused by Entamoeba histolytica, a parasitic protozoan that can be present in the human gastrointestinal tract. This study investigates H2S and Cys-SSH's impact on E. histolytica physiology and explores potential therapeutic implications. Exposing trophozoites to the H2S donor, sodium sulfide (Na2S), or to Cys-SSH led to rapid cytotoxicity. A proteomic analysis of Cys-SSH-challenged trophozoites resulted in the identification of >500 S-sulfurated proteins, which are involved in diverse cellular processes. Functional assessments revealed inhibited protein synthesis, altered cytoskeletal dynamics, and reduced motility in trophozoites treated with Cys-SSH. Notably, cysteine proteases (CPs) were significantly inhibited by S-sulfuration, affecting their bacterial biofilm degradation capacity. Immunofluorescence microscopy confirmed alterations in actin dynamics, corroborating the proteomic findings. Thus, our study reveals how RSS perturbs critical cellular functions in E. histolytica, potentially influencing its pathogenicity and interactions within the gut microbiota. Understanding these molecular mechanisms offers novel insights into amebiasis pathogenesis and unveils potential therapeutic avenues targeting RSS-mediated modifications in parasitic infections.

Degradation of Listeria monocytogenes biofilm by phages belonging to the genus Pecentumvirus.

Listeria monocytogenes is a pathogenic bacterium that is especially dangerous for children, the elderly, pregnant women, and immune-compromised people. Because of this, the food industry takes its presence in their plants seriously. Food recalls due to L. monocytogenes are common with a high associated economic cost. In food-processing plants, Listeria spp. typically reside in biofilms, which are structures produced by bacteria that shield them from environmental stressors and are often attached to surfaces. The significance of our work is that we show a bacteriophage-a virus-infecting bacteria-can reduce Listeria counts by two orders of magnitude when the bacterial biofilms were grown under simulated dairy processing conditions. This work provides insights into how phages may be tested and used to develop biosanitizers that are effective but are not harmful to the environment or human health.

Pharmacological Potential Effects of Algerian Propolis Against Oxidative Stress, Multidrug-Resistant Pathogens Biofilm and Quorum-Sensing.

This study sought to examine the chemical profile, antioxidant, antimicrobial, antibiofilm, and anti-quorum sensing potential of two propolis ethanolic extracts (PEEs) collected from northeast Algeria. To achieve the main objectives of this study, multiple in vitro tests were employed. The phenolic and flavonoid contents were analyzed, and the chemical composition of both PEE was determined by high-performance liquid chromatography. The antioxidant properties of the propolis extracts were investigated using six complementary tests. The inhibitory effects of propolis extracts were evaluated against multidrug-resistant (MDR) clinical isolates using agar well diffusion and microdilution methods, whereas their antibiofilm and quorum-sensing disruption effects were determined by spectrophotometric microplate methods. The results demonstrated that phenolic and flavonoid contents were higher in propolis from the Guelma (PEEG) region (PEEG; 188.50 ± 0.33 μg GAE/mg E, 144.23 ± 1.03 μg QE/mg E), respectively. Interestingly, different components were identified, and cynarin was the major compound detected. The PEEG sample exhibited potential antioxidant effects in scavenging ABTS•+ radicals with minimal inhibitory concentration values equal to 10.46 ± 1.40 µg/mL. Furthermore, the highest antibacterial activity was recorded by PEEG against Gram-positive Staphylococcus aureus MDR1. Similarly, PEEG effectively inhibited the biofilm formation of S. aureus MDR1 and the degradation of biofilm was up to 60%. In addition, quorum sensing disruption revealed that both extracts have a moderate capacity for violacein inhibition by the Chromobacterium violaceum ATCC 12472 strain in a concentration-dependent manner. These findings indicate that propolis can be regarded as a natural therapeutic agent for health problems associated with MDR bacteria and oxidative stress.

Characterization of Antibiofilm and Antimicrobial Effects of Trigona Stingless Bee Honey Compared to Stinging Bee Centaurea hyalolepis and Citrus Honeys.

The antibiofilm and antimicrobial properties of tropical honey types including Malaysian stingless bee honey remain explicitly unexplored when compared with Apies honey. The antibiofilm and antimicrobial activities of the Malaysian Trigona honey were characterized with two stinging bee honey types (Centaurea hyalolepis and Citrus honeys) from Jordan. The antibiofilm and antimicrobial investigations were conducted on a set of seven microbial strains; five bacterial species of Pseudomonas aeruginosa ATCC 10145, Streptococcus pyogenes ATCC 19615, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 13883, and two fungal strains Candida albicans ATCC 10231 and Candida krusei ATCC 14243. The antimicrobial investigations revealed a broad spectrum activity for Trigona honey against Gram-positive, Gram-negative, and fungal strains over the two honey types. One-way ANOVA showed a significant difference (p < 0.001) in the zone of inhibition ranging from 9 to 25 mm and minimum inhibition activity (MIC) ranged from 9.4-29.6% (w/v) against the microbial strains. Moreover, the addition of honey to established biofilms has induced a degradation activity in the biofilm mass. Two-way ANOVA showed a significant biofilm degradation proportion (p < 0.001) ranging from 1.3% to 91.3% following treatment with Trigona honey and the other honey types in relevance to the concentration ranging from 10% to 50% (w/v). Moreover, the antibiofilm activity was highly consistent with MIC affecting bacterial growth inhibition. In conclusion, a robust antimicrobial and antibiofilm activity for Trigona stingless bee honey over the stinging bee Centaurea hyalolepis and Citrus honeys is noticed which endows the usage of Trigona honey in the antimicrobial industry.

Degradation of Biofilm Formed by Opportunistic Pathogens using Amylase Extracted from Bacillus tequilensis

Degradation of Biofilm Formed by Opportunistic Pathogens using Amylase Extracted from Bacillus tequilensis

Isolation of virulent phages against multidrug-resistant Acinetobacter baumannii recovered from inanimate objects of Jimma Medical Center, Southwest Ethiopia

BackgroundBecause of the multidrug resistance features of Acinetobacter baumannii, endurance to diverse conditions, and causing health fatalities in healthcare settings, the global health system is looking for the development of new antimicrobials for such bacteria. As the new antimicrobial drugs pipeline is running dry, it is imperative to look for eco-friendly bio-control strategies. In this regard, phages are one to combat the biofilm producer and MDR A. baumannii. Thus, the study aimed to isolate and examine the role of phages against biofilm producers and MDR A. baumannii from inanimate objects at Jimma Medical Center (JMC), Ethiopia.MethodInstitution-based cross-sectional study was conducted from June to November 2019. A total of 309 swab samples were collected from inanimate objects and the environment in JMC. Isolation of A. baumannii, antimicrobial susceptibility testing, and biofilm detection were carried out according to standard protocol. Kirby Bauer disk diffusion and microliter plate were methods for AST and biofilm detection, respectively. Specific phage was isolated and characterized from sewage at JMC compound. The data were analyzed by SPSS version 25.0, and chi-square (X2) cross-tabulation was used to determine the correlation of variables. A P-value of < 0.05 was considered a statistically significant association.ResultA. baumannii from inanimate objects and surfaces of different environments at JMC was detected in 6.5% of the samples. From 20 of the isolates, 85% were biofilm producers, and 60% were MDR. The lytic phage isolated specifically against A. baumannii was found host specific, and thermally stable ranging from 10–50°C. The phage was active against 42% of MDR A. baumannii, 40% of both biofilm-producing and MDR A. baumannii (MDRAB), and 35.3% of the biofilm-producing isolates.ConclusionThe good activity of phages towards MDRAB isolates, its biofilm degradation capability, thermal stability, and host specificity in our study encourages viewing the potential use of phages as a bio-control agent besides the routine cleansing agents. Therefore, we recommend isolation of specific phages in the eradication of MDRAB from health facilities with additional efforts to characterize in detail and assess their efficacy in animal models.

Performance and mechanism of the synergistic hexavalent chromium and nitrogen removal in a MABR system

Co-contaminant of hexavalent chromium [Cr(Ⅵ)] and nitrogen in wastewaters produce serious environmental problems. However, it remains little in the way of continuous flow biological reactor to concurrently eliminated Cr(Ⅵ) and nitrogen in wastewater. Here, a single membrane aerated biofilm reactor (MABR) system was employed to achieve synergistic Cr(Ⅵ) and nitrogen removal. Cr(Ⅵ) and nitrogen removal performances, Cr(VI) reduction products, and microorganism functional groups characteristics, as well as microbial community structure and functional genes were investigated. Moreover, we revealed the role of “secretion”, potentially secreted by the biofilm, in nitrogen and Cr(Ⅵ) degradation. Results indicated that the Cr(Ⅵ) removal efficiency and simultaneous nitrification and denitrification (SND) rate reached 90.60 ± 1.45 % and 96.03 ± 1.47 %, respectively, when the influent Cr(Ⅵ) concentration reached 50 mg/L. Cr(Ⅵ) was mainly reduced to Cr(Ⅲ), which was attached to biofilm and secretion surfaces. Microorganism functional groups, including carbonyl (C = O), carboxyl (O-C = O) and hydroxyl (OH–) played an essential role in the adsorption and chelation of Cr(III). Acinetobacter, Lentimicrobium, NS11-12 marine group and Hydrogenophaga were identified as the main Cr(Ⅵ) reducers and denitrifiers. The abundance of genes related to Cr(VI) reduction and nitrogen transformation increased notably in both the biofilm (NasA, ChrR) and secretion (NemA, NfsAB, AzoR) systems under high Cr(VI) stress. The “secretion” played an “secondary system” to enhance nitrogen and Cr(Ⅵ) removal. This study provides new insights into the concurrent Cr(Ⅵ) and nitrogen removal from MABR system by the integrated biofilm and secretion.

The influence of cocoa fruit husk extract on the degradation of eps (extracellular polymeric substance) in Lactobacillus acidophilus biofilm

Introduction: Dental caries is characterized by progressive demineralization and plaque formation by Lactobacillus acidophilus bacteria due to biofilm formation as a microbial defense mechanism that binds to EPS. To address this issue, cocoa fruit husks extract is utilized as it contains active flavonoids with antibacterial properties. Objective: Demonstrate that cocoa fruit husk extract can degrade Lactobacillus acidophilus bacterial EPS biofilm and determine the optimal concentration of cocoa fruit husk extract. Methods: Cocoa Fruit Husk Extract Preparation was followed by Lactobacillus acidophilus bacterial preparation. Dilution was performed to achieve a concentration of 106 Bacteria/mL. Microtiter plates with flat-bottom 24 wells were sealed. They were then divided into two groups: one as a control without cocoa fruit husk extract and the other with cocoa fruit husk extract at concentrations of 1.56%; 3.125%; 4.69%; 6.25%; and 7.8%, and incubated at 35°C for 24 hours. Subsequently, they were aspirated, washed 4 times with phosphate-buffered saline, stained with dextran alexa fluor 647, and rinsed with distilled water. Biofilm sections, 0.5 mm thick, were placed on glass slides, and EPS Biofilm was measured using CLSM at 40x magnification. Results: The division into microtiter plates showed that the 7.8% concentration had the highest potential with a value of X ± SD = 8.3366 ± 1.76364 in degrading EPS biofilm compared to others. This is in line with previous research, indicating that higher extract concentrations lead to better biofilm degradation activity. Conclusion: Cocoa fruit husk extract can degrade Lactobacillus acidophilus bacterial EPS biofilm, with the most optimal concentration being 7.8%.

Recombinant Prevotella melaninogenica α-1,3 glucanase and Capnocytophaga ochracea α-1,6 glucanase as enzymatic tools for in vitro degradation of S. mutans biofilms.

Dental biofilms represent a serious oral health problem playing a key role in the development of caries and other oral diseases. In the present work, we cloned and expressed in E. coli two glucanases, Prevotella melaninogenica mutanase (PmGH87) and Capnocytophaga ochracea dextranase (CoGH66), and characterized them biochemically and biophysically. Their three-dimensional structures were elucidated and discussed. Furthermore, we tested the capacity of the enzymes to hydrolyze mutan and dextran to prevent formation of Streptococcus mutans biofilms, as well as to degrade pre- formed biofilms in low and abundant sugar conditions. The percentage of residual biofilm was calculated for each treatment group in relation to the control, as well as the degree of synergism. Our results suggest that both PmGH87 and CoGH66 are capable of inhibiting biofilm formation grown under limited or abundant sucrose conditions. Degradation of pre-formed biofilms experiments reveal a time-dependent effect for the treatment with each enzyme alone. In addition, a synergistic and dose-dependent effects of the combined enzymatic treatment with the enzymes were observed. For instance, the highest biomass degradation was 95.5% after 30min treatment for the biofilm grown in low sucrose concentration, and 93.8% after 2h treatment for the biofilm grown in sugar abundant condition. Strong synergistic effects were observed, with calculated degree of synergism of 5.54 and 3.18, respectively and their structural basis was discussed. Jointly, these data can pave the ground for the development of biomedical applications of the enzymes for controlling growth and promoting degradation of established oral biofilms.

Investigation of Methicillin-resistant Staphylococcus aureus inhibition with gallic acid and linezolid loaded Poly(Ɛ-caprolactone)-Collagen-Xylitol carrier

Methicillin-resistant Staphylococcus aureus (MRSA) causes serious infections to humans. Combination therapy exhibits good inhibition efficacy against MRSA infections; thus, a natural compound (Gallic acid) and an existing antibiotic drug (Linezolid) combined with Poly(Ɛ-caprolactone)-Collagen-Xylitol (PCX) carrier was designed. Initially, the natural compound was selected from the Natural Product database through molecular docking analysis and the linezolid interaction was investigated against MRSA protein. The binding energies of gallic acid and linezolid was observed as -6.1 kcal/mol and -9.5 kcal/mol against the MRSA (2W9H) strain. The physicochemical characterization confirms the carrier and drug-loaded carrier formation. The biological studies exhibited the potential antibacterial activity of PCXGL against MRSA. PCXGL showed the zone of inhibition and minimum inhibitory concentration of 20 ± 1 mm and 62.5 µg/mL against MRSA, respectively. The minimum bactericidal concentration was obtained as 250 µg/mL, and the ruptured cell morphology was observed through SEM analysis after treating MRSA with PCXGL. It is due to the eradication ability of PCXGL against MRSA. Further, the biofilm inhibition analysis, biofilm dissociation assay, and fluorescence images proved the MRSA biofilm degradation ability of PCXGL. These findings can provide a potential lead for the treatment of MRSA infections.

Digestive exophagy of biofilms by intestinal amoeba and its impact on stress tolerance and cytotoxicity

The human protozoan parasite Entamoeba histolytica is responsible for amebiasis, a disease endemic to developing countries. E. histolytica trophozoites colonize the large intestine, primarily feeding on bacteria. However, in the gastrointestinal tract, bacterial cells form aggregates or structured communities called biofilms too large for phagocytosis. Remarkably, trophozoites are still able to invade and degrade established biofilms, utilizing a mechanism that mimics digestive exophagy. Digestive exophagy refers to the secretion of digestive enzymes that promote the digestion of objects too large for direct phagocytosis by phagocytes. E. histolytica cysteine proteinases (CPs) play a crucial role in the degradation process of Bacillus subtilis biofilm. These proteinases target TasA, a major component of the B. subtilis biofilm matrix, also contributing to the adhesion of the parasite to the biofilm. In addition, they are also involved in the degradation of biofilms formed by Gram-negative and Gram-positive enteric pathogens. Furthermore, biofilms also play an important role in protecting trophozoites against oxidative stress. This specific mechanism suggests that the amoeba has adapted to prey on biofilms, potentially serving as an untapped reservoir for novel therapeutic approaches to treat biofilms. Consistently, products derived from the amoeba have been shown to restore antibiotic sensitivity to biofilm cells. In addition, our findings reveal that probiotic biofilms can act as a protective shield for mammalian cells, hindering the progression of the parasite towards them.

Compatibility of polar organic chemical integrative sampler (POCIS) with compound specific isotope analysis (CSIA) of substituted chlorobenzenes

Compound specific isotope analysis (CSIA) is a powerful technique to demonstrate in situ degradation of traditional groundwater contaminants when concentrations are typically in the mg/L range. Currently, an efficient preconcentration method is lacking to expand CSIA to low aqueous concentration environmental samples. Specially for the H- and N-CSIA of heteroatom-bearing non-traditional compounds, the CSIA analytical detection limits are significantly higher than that of the C-CSIA. This work demonstrates the compatibility of polar organic chemical integrative sampler (POCIS) with C-, H-, and N-CSIA using four nitro- and amino-substituted chlorobenzenes that are common industrial feedstocks for numerous applications and are commonly detected in the environment at mg/L to μg/L range. Using lab experiments, we showed isotopic equilibrium in POCIS was achieved after 30 days with either a negligible (<0.5 ‰) or a constant shift for C (<1 ‰) and N (<2 ‰). Similar negligible (<5 ‰) or constant shift (<20 ‰) was evident for H isotope except for 3,4-dichloroaniline. The method quantification limits for the combined sorbent and membrane of one POCIS were comparable to that of the solid phase extraction (SPE) using 10 L water. Next, we demonstrated the field applicability of POCIS for C- and N-CSIA after a 60-day deployment in a pilot constructed wetland by showing <1 ‰ difference between the δ13C and δ15N obtained from POCIS and SPE. Finally, we evaluated whether the biofilm development on POCIS membrane could affect the isotope signature of the sampled compounds during field deployment. Although a diverse microbial community was identified on the membrane after a 60-day deployment, we did not observe significant isotope fractionation. This was likely due to either slower diffusion in the biofilm or microbial degradation of the sampled compounds. This work demonstrates the potential of using POCIS-CSIA as a simple, fast, and sensitive method for low-concentration contaminants, such as pesticides, pharmaceuticals, and flame-retardants.

Antibacterial activity of peptides and bio-safety evaluation: in vitro and in vivo studies against bacterial and fungal pathogens

BackgroundAntimicrobial peptides are promising alternatives to antibiotics to treat bacterial and fungal infections, especially drug-resistant clinical pathogens. MethodsAntimicrobial peptides (AMPs) were synthesized and antimicrobial activity was assayed. The antibacterial mechanism, ATP production, ROS generation and molecular mechanism were determined. Biofilm inhibition assay was performed in planktonic bacterial cells and biofilm degradation assay was performed using mature biofilm. The synthesized AMP2 was subjected to in vitro and in vivo analysis to analyze the safety. ResultsThe synthesized peptides AMP1, AMP2, AMP3 and AMP4 exhibited antimicrobial activity against Gram-positive and Gram-negative bacteria. The MIC values ranged from 1.5 ± 0.25–12.5 ± 1.25 µM and the MFC values range from 2.25 ± 0.12–25 ± 1.25 µM. F. solani showed fewer MFC values than other fungal strains. Time kill assay was performed and the AMP2 killed about 70 % of Acinetobacter baumannii at 1 × MIC concentration within 10 min incubation and killed 97 % of bacteria at 1 × MBC concentration within 15 min. The antimicrobial peptide AMP2 was highly effective against planktonic A. baumannii and L. monocytogenes. The tested AMP2 showed less toxicity to cell lines and Zebrafish. ConclusionsAntimicrobial peptides have potential antimicrobial properties against Gram-positive and Gram-negative bacteria. The in silico studies of these antimicrobial peptides are useful for eradicating drug-resistant bacteria.

A Multilayered Imaging and Microfluidics Approach for Evaluating the Effect of Fibrinolysis in Staphylococcus aureus Biofilm Formation.

The recognition of microbe and extracellular matrix (ECM) is a recurring theme in the humoral innate immune system. Fluid-phase molecules of innate immunity share regulatory roles in ECM. On the other hand, ECM elements have immunological functions. Innate immunity is evolutionary and functionally connected to hemostasis. Staphylococcus aureus (S. aureus) is a major cause of hospital-associated bloodstream infections and the most common cause of several life-threatening conditions such as endocarditis and sepsis through its ability to manipulate hemostasis. Biofilm-related infection and sepsis represent a medical need due to the lack of treatments and the high resistance to antibiotics. We designed a method combining imaging and microfluidics to dissect the role of elements of the ECM and hemostasis in triggering S. aureus biofilm by highlighting an essential role of fibrinogen (FG) in adhesion and formation. Furthermore, we ascertained an important role of the fluid-phase activation of fibrinolysis in inhibiting biofilm of S. aureus and facilitating an antibody-mediated response aimed at pathogen killing. The results define FG as an essential element of hemostasis in the S. aureus biofilm formation and a role of fibrinolysis in its inhibition, while promoting an antibody-mediated response. Understanding host molecular mechanisms influencing biofilm formation and degradation is instrumental for the development of new combined therapeutic approaches to prevent the risk of S. aureus biofilm-associated diseases.

Fighting Pseudomonas aeruginosa Infections: Antibacterial and Antibiofilm Activity of D-Q53 CecB, a Synthetic Analog of a Silkworm Natural Cecropin B Variant.

Pseudomonas aeruginosa is an opportunistic Gram-negative bacterium responsible for severe nosocomial infections and is considered a critical pulmonary pathogen for both immunocompromised and cystic fibrosis patients. Planktonic cells of P. aeruginosa possess intrinsic and acquired resistances, inactivating several classes of conventional antibiotics. Additionally, this bacterium can grow, forming biofilms, and complex structures, further hampering the action of multiple antibiotics. Here, we report the biological properties of D-Q53 CecB, an all-D enantiomer of the silkworm natural peptide Q53 CecB. Compared to the L-variant, D-Q53 CecB was resistant to in vitro degradation by humans and P. aeruginosa elastases and showed an enhanced bactericidal activity against P. aeruginosa planktonic bacteria. D-Q53 CecB was thermostable and maintained its antimicrobial activity at high salt concentrations and in the presence of divalent cations or fetal-bovine serum, although at reduced levels. Against different types of human cells, D-Q53 CecB showed cytotoxic phenomena at concentrations several folds higher compared to those active against P. aeruginosa. When L- and D-Q53 CecB were compared for their antibiofilm properties, both peptides were active in inhibiting biofilm formation. However, the D-enantiomer was extremely effective in inducing biofilm degradation, suggesting this peptide as a favorable candidate in an anti-Pseudomonas therapy.

Nanodevices based on mesoporous glass nanoparticles enhanced with zinc and curcumin to fight infection and regenerate bone.

Nanotechnology-based approaches are emerging as promising strategies to treat different bone pathologies such as infection, osteoporosis or cancer. To this end, several types of nanoparticles are being investigated, including those based on mesoporous bioactive glasses (MGN) which exhibit exceptional structural and textural properties and whose biological behaviour can be improved by including therapeutic ions in their composition and loading them with biologically active substances. In this study, the bone regeneration capacity and antibacterial properties of MGNs in the SiO2-CaO-P2O5 system were evaluated before and after being supplemented with 2.5% or 4% ZnO and loaded with curcumin. in vitro studies with preosteoblastic cells and mesenchymal stem cells allowed determining the biocompatible MGNs concentrations range. Moreover, the bactericidal effect of MGNs with zinc and curcumin against S. aureus was demonstrated, as a significant reduction of bacterial growth was detected in both planktonic and sessile states and the degradation of a pre-formed bacterial biofilm in the presence of the nanoparticles also occurred. Finally, MC3T3-E1 preosteoblastic cells and S. aureus were co-cultured to investigate competitive colonisation between bacteria and cells in the presence of the MGNs. Preferential colonisation and survival of osteoblasts and effective inhibition of both bacterial adhesion and biofilm formation of S. aureus in the co-culture system were detected. Our study demonstrated the synergistic antibacterial effect of zinc ions combined with curcumin and the enhancement of the bone regeneration characteristics of MGNs containing zinc and curcumin to obtain systems capable of simultaneously promoting bone regeneration and controlling infection. STATEMENT OF SIGNIFICANCE: In search of a new approach to regenerate bone and fight infections, a nanodevice based on mesoporous SiO2-CaO-P2O5 glass nanoparticles enriched with Zn2+ ions and loaded with curcumin was designed. This study demonstrates the synergistic effect of the simultaneous presence of zinc ions and curcumin in the nanoparticles that significantly reduces the bacterial growth in planktonic state and is capable to degrade pre-formed S. aureus biofilms whereas the nanosystem exhibits a cytocompatible behaviour in the presence of preosteoblasts and mesenchymal stem cells. Based on these results, the designed nanocarrier represents a promising alternative for the treatment of acute and chronic infections in bone tissues, while avoiding the significant current problem of bacterial resistance to antibiotics.

Hydrogen peroxide from l-amino acid oxidase of king cobra (Ophiophagus hannah) venom attenuates Pseudomonas biofilms

Because of the high incidence of Pseudomonas aeruginosa biofilms-related nosocomial infections, venoms from common Thai snakes were tested. Although venoms from king cobra (Ophiophagus hannah; OH) and green pit viper (Trimeresurus albolabris) showed the broadest antibacterial spectrum, OH venom demonstrated more profound anti-biofilm activities against P. aeruginosa. Additionally, purified l-amino acid oxidase from OH venom (OH-LAAO), using a three-step chromatography and protein identification, reduced biofilm mass as indicated by the downregulation of several genes, including the genes for biofilm synthesis (algD and pslB) and biofilm regulators (algU, gacA, and siaD). Moreover, OH-LAAO disrupted Pseudomonas-preformed biofilms via upregulation of several genes for biofilm dispersion (nbdA, bdlA, and dipA) and biofilm degradation (endA and pslG), resulting in a reduction of the biofilm biomass. Due to the antimicrobial effects and anti-biofilm activities (reduced production plus increased dispersion) neutralized by catalase, a hydrogen peroxide (H2O2)-degrading enzyme, the enhanced H2O2 by OH venom might be one of the anti-biofilm mechanisms. Hence, OH-LAAO was proposed as a novel agent against Pseudomonas biofilms for either treatment or prevention. More studies are interesting.

The Activities of Torch Ginger Flower (Etlingera elatior) Ethanol Extract on Degradation of Porphyromonas gingivalis Biofilm as Periodontal Pathogen

&#x0D; Introduction: Porphyromonas gingivalis is bacteria that can form biofilms as the main cause of periodontitis. Mouthwash therapy in long term can cause mucositis and even oral cancer. Antibacterial potential of torch ginger flower (Etlingera elatior) can be developed as an alternative adjuvant therapy for periodontitis. Objective: Aims of this research was to determine the effect of torch ginger flower ethanol extract against degradation of P. gingivalis biofilm. Methods: This research used ethanolic extract of torch ginger flower with concentrations 1.56 mg/mL, 3.125 mg/mL, 6.25 mg/mL, 12.5 mg/mL, 25 mg/mL, and 50 mg/mL. Chlorhexidine gluconate 0.2% was used as positive control and DMSO 1% was used as negative control. Measurement of P. gingivalis biofilm degradation used microtiter plate assay with crystal violet 1% staining which reads its optical density at wavelength of 450 nm. Data were analyzed by one way ANOVA and Post hoc LSD. Results: The percentage of P. gingivalis biofilm degradation with torch ginger flower ethanol extract sequentially were 12.47%, 30.56%, 57.12%, 71.36%, and 74.83%. The analysis showed that there was a significant difference (p&lt;0,05) between treatment groups torch ginger flower ethanol extract, as well as between torch ginger flower ethanol extract with DMSO 1% and chlorhexidine gluconate 0.2%. Optimum concentration of ethanol extract of torch ginger flower on P. gingivalis biofilm degradation was 25 mg/mL and showed no significant difference with chlorhexidine gluconate 0,2% (p&gt;0,05). Conclusion: Conclusion of this research is torch ginger flower (Etlingera elatior) ethanol extract has P. gingivalis biofilm degradation activity.biofilm

Formulation and Evaluation of Herbal Toothpaste against Biofilm Producing Staphylococcus aureus

Dental and oral hygiene is essential for overall health and well-being. Tooth brush and dental floss help remove food debris and plaque, while tooth paste and mouth wash are a key part of oral hygiene as they reduce bacterial growth. The use of chemical agents in tooth paste formulations are effective but can have undesirable side effects. The use of herbal extracts instead can be equally effective due to the presence of phytochemicals which render antibacterial and antiseptic properties, with no side effects. In this study we have formulated toothpaste using the extracts of orange peel, tomato peel and Eucalyptus leaves. The extracts were positive for phytochemicals like terpenoids, flavonoids and tannins. The formulated tooth paste demonstrated antibacterial and biofilm degrading activity against Staphylococcus aureus isolated from dental plaques. On comparison with commercially available toothpastes, the herbal formulation was observed to be more effective against the biofilm forming Staphylococcus aureus. Rakhi Bajpai3, Chitranshu Pandey4, Varaprasad Kolla*5

Effectiveness of metal and metal oxide nanoparticles against bacterial biofilms: Perspectives and limitations.

In the last few years, there has been a necessary demand in the pharmaceutical industries for finding a treatment against biofilms formed by different bacterial species. We are aware of the fact that classical processes, which are already there for the removal of bacterial biofilms gives a very low efficiency and consequently antimicrobial resistance makes it even worse. To cope up with the cited problems, scientists from the past few years are inclining toward various types of nanoparticle based treatment procedures as a pharmaceutical agent against bacterial biofilms. Nanoparticles are known for their extremely efficient antimicrobial properties. The current review gives a description of different types of metal oxide nanoparticles and their antibiofilm properties. It also shows a comparative analysis of the nanoparticles and depicts the efficiency rates of biofilm degradation in each of them. It explains the mechanism of the nanoparticles through which the disintegration of bacterial biofilm is carried out. Lastly, the review throws light upon the limitations of different nanoparticles, their safety issues, the mutagenicity, genotoxicity concerns, and toxicity hazards caused by them.