Study of the pathological antibacterial effects of tea extract and its role in reducing hypertension in pregnant women

Aims@#Due to the world's direction of alternative medicine and herbal medication, tea leaves have been employed to inhibit certain bacteria that cause urinary tract infections (UTIs). This study aimed to evaluate the effect of green, red and black tea as antibacterial against UTIs in pregnant women and changes in blood pressure and iron level in the blood of their women.@*Methodology and results@#Forty-eight isolates were isolated from 50 women suffering from urinary tract infections, Staphylococcus aureus (18) 37.5%, Escherichia coli (15) 31.25%, Pseudomonas aeruginosa (8) 16.6%, Klebsiella sp. (5) 10.4% and Enterobacter sp. (2) 4.16%. The sensitivity of bacteria to the antibiotics Amikacin, Amoxicillin/Clavulanic, Ampicillin/Sulbactam, Cefixime, Ceftriaxone, Ciprofloxacin, Imipenem, Nitrofurantion, Penicillin and Tetracycline were tested, while E. coli and P. aeruginosa (8), Enterobacter sp. were resistance for Ceftriaxone and Amoxicillin /Clavulanic (100%). While Enterobacter sp. is sensitive to Nitrofurantoin and Imipenem (100%). The ability of the isolates to form biofilms was tested using the Congo red agar method and the micro titrations plate method. The results showed that not all isolates have the ability to produce biofilms and red tea is the most powerful antibacterial under study. Drinking green tea for two weeks regularly in pregnant women who suffer from high blood pressure showed an improvement in blood pressure, as it became normal 118/78 and with the normal iron level in the blood at a rate of hemoglobin = 11.8, while drinking red tea did not change blood pressure measurements in pregnant women with high blood pressure.@*Conclusion, significance and impact of study@#The effect of red tea extract was stronger than other teas used in the study as an antibacterial against urinary tract bacteria. Regular consumed of green tea helps regulate blood pressure, especially for pregnant women who are at risk of hypertension during pregnancy.

Preparation, characterization and activity evaluation of Spirulina-chitooligosaccharides capable of inhibiting biofilms / 生物工程学报

The biofilms formed by pathogenic microorganisms seriously threaten human health and significantly enhance drug resistance, which urgently call for developing drugs specifically targeting on biofilms. Chitooligosaccharides extracted from shrimp and crab shells are natural alkaline oligosaccharides with excellent antibacterial effects. Nevertheless, their inhibition efficacy on biofilms still needs to be improved. Spirulina (SP) is a microalga with negatively charged surface, and its spiral structure facilitates colonization in the depth of the biofilm. Therefore, the complex of Spirulina and chitooligosaccharides may play a synergistic role in killing pathogens in the depth of biofilm. This research first screened chitooligosaccharides with significant bactericidal effects. Subsequently, Spirulina@Chitooligosaccharides (SP@COS complex was prepared by combining chitooligosaccharides with Spirulina through electrostatic adsorption. The binding of the complex was characterized by zeta potential, z-average size, and fluorescence labeling. Ultraviolet-visible spectroscopy (UV-Vis) showed the encapsulation efficiency and the drug loading efficiency reached up to 90% and 16%, respectively. The prepared SP@COS2 exhibited a profound synergistic inhibition effect on bacterial and fungal biofilms, which was mainly achieved by destroying the cell structure of the biofilm. These results demonstrate the potential of Spirulina-chitooligosaccharides complex as a biofilm inhibitor and provide a new idea for addressing the harm of pathogenic microorganisms.

Evaluation of methanolic crude extract of Linum usitatissimum for the removal of biofilm in diabetic foot isolates / Avaliação do extrato em bruto metanólico de Linum usitatissimum para remoção de biofilmes em isolados diabéticos de pé

Abstract Linum usitatissimum L is a widely used traditionally for multiple ailments. The present research was carried out to explore the antimicrobial, and anti-biofilm activity of crude extract of Linum usitatissimum L (Lu. Cr). Phytochemical and proximate analyses were performed. The bandages of diabetic foot patients were collected from the various hospitals. The bandages were cultured to isolate the bacterial strains present on it. The disc diffusion method was used to identify the antimicrobial potential whereas the minimum inhibitory concentration of the Lu.Cr were also determined. Proximate analysis confirms moisture content 8.33%, ash content 4.33%, crude protein 21.20%, crude fat 49.2% and crude fiber 5.63%. It was revealed that Gram-positive bacteria are most prevalent among all study groups. Lu.Cr possess significant bactericidal potential against S. aureus among all other microbes. Owing to this potential, linseed coated bandages can be used alternatively for the treatment of diabetic foot.

Resumo Linum usitatissimum L é amplamente utilizado tradicionalmente para doenças múltiplas. O presente trabalho foi realizado para explorar a atividade antimicrobiana e antibiofilme do extrato bruto de Linum usitatissimum L (Lu.Cr). Foram realizadas análises fitoquímicas e aproximadas. As ataduras de pacientes diabéticos com pé foram recolhidas nos vários hospitais. As bandagens foram cultivadas para isolar as cepas bacterianas presentes nas mesmas. O método de difusão em disco foi utilizado para identificar o potencial antimicrobiano e a concentração inibitória mínima do Lu.Cr também foi determinada. A análise aproximada confirma o teor de umidade 8,33%, teor de cinzas 4,33%, proteína bruta 21,20%, gordura bruta 49,2% e fibra bruta 5,63%. Foi revelado que as bactérias Gram-positivas são mais prevalentes entre todos os grupos de estudo. Lu.Cr possui potencial bactericida significativo contra S. aureus entre todos os outros micróbios. Devido a esse potencial, as ligaduras revestidas com linhaça podem ser utilizadas alternativamente para o tratamento do pé diabético.

Evaluation of methanolic crude extract of Linum usitatissimum for the removal of biofilm in diabetic foot isolates / Avaliação do extrato em bruto metanólico de Linum usitatissimum para remoção de biofilmes em isolados diabéticos de pé

Linum usitatissimum L is a widely used traditionally for multiple ailments. The present research was carried out to explore the antimicrobial, and anti-biofilm activity of crude extract of Linum usitatissimum L (Lu. Cr). Phytochemical and proximate analyses were performed. The bandages of diabetic foot patients were collected from the various hospitals. The bandages were cultured to isolate the bacterial strains present on it. The disc diffusion method was used to identify the antimicrobial potential whereas the minimum inhibitory concentration of the Lu.Cr were also determined. Proximate analysis confirms moisture content 8.33%, ash content 4.33%, crude protein 21.20%, crude fat 49.2% and crude fiber 5.63%. It was revealed that Gram-positive bacteria are most prevalent among all study groups. Lu.Cr possess significant bactericidal potential against S. aureus among all other microbes. Owing to this potential, linseed coated bandages can be used alternatively for the treatment of diabetic foot.

Linum usitatissimum L é amplamente utilizado tradicionalmente para doenças múltiplas. O presente trabalho foi realizado para explorar a atividade antimicrobiana e antibiofilme do extrato bruto de Linum usitatissimum L (Lu.Cr). Foram realizadas análises fitoquímicas e aproximadas. As ataduras de pacientes diabéticos com pé foram recolhidas nos vários hospitais. As bandagens foram cultivadas para isolar as cepas bacterianas presentes nas mesmas. O método de difusão em disco foi utilizado para identificar o potencial antimicrobiano e a concentração inibitória mínima do Lu.Cr também foi determinada. A análise aproximada confirma o teor de umidade 8,33%, teor de cinzas 4,33%, proteína bruta 21,20%, gordura bruta 49,2% e fibra bruta 5,63%. Foi revelado que as bactérias Gram-positivas são mais prevalentes entre todos os grupos de estudo. Lu.Cr possui potencial bactericida significativo contra S. aureus entre todos os outros micróbios. Devido a esse potencial, as ligaduras revestidas com linhaça podem ser utilizadas alternativamente para o tratamento do pé diabético.

Evaluation of methanolic crude extract of Linum usitatissimum for the removal of biofilm in diabetic foot isolates

Abstract Linum usitatissimum L is a widely used traditionally for multiple ailments. The present research was carried out to explore the antimicrobial, and anti-biofilm activity of crude extract of Linum usitatissimum L (Lu. Cr). Phytochemical and proximate analyses were performed. The bandages of diabetic foot patients were collected from the various hospitals. The bandages were cultured to isolate the bacterial strains present on it. The disc diffusion method was used to identify the antimicrobial potential whereas the minimum inhibitory concentration of the Lu.Cr were also determined. Proximate analysis confirms moisture content 8.33%, ash content 4.33%, crude protein 21.20%, crude fat 49.2% and crude fiber 5.63%. It was revealed that Gram-positive bacteria are most prevalent among all study groups. Lu.Cr possess significant bactericidal potential against S. aureus among all other microbes. Owing to this potential, linseed coated bandages can be used alternatively for the treatment of diabetic foot.

Resumo Linum usitatissimum L é amplamente utilizado tradicionalmente para doenças múltiplas. O presente trabalho foi realizado para explorar a atividade antimicrobiana e antibiofilme do extrato bruto de Linum usitatissimum L (Lu.Cr). Foram realizadas análises fitoquímicas e aproximadas. As ataduras de pacientes diabéticos com pé foram recolhidas nos vários hospitais. As bandagens foram cultivadas para isolar as cepas bacterianas presentes nas mesmas. O método de difusão em disco foi utilizado para identificar o potencial antimicrobiano e a concentração inibitória mínima do Lu.Cr também foi determinada. A análise aproximada confirma o teor de umidade 8,33%, teor de cinzas 4,33%, proteína bruta 21,20%, gordura bruta 49,2% e fibra bruta 5,63%. Foi revelado que as bactérias Gram-positivas são mais prevalentes entre todos os grupos de estudo. Lu.Cr possui potencial bactericida significativo contra S. aureus entre todos os outros micróbios. Devido a esse potencial, as ligaduras revestidas com linhaça podem ser utilizadas alternativamente para o tratamento do pé diabético.

Escherichia coli biofilm formation and control by phenolic compounds from Salvia officinalis L. Extracts

Biofilm is recognized as one of the virulence factors of uropathogenic Escherichia coli. It offers bacteria significantly increased tolerance to antibiotics and makes difficulties in infection eradication. In this study, the biofilm formation ability of clinical isolates of uropathogenic E. coli as well as the antibiofilm activity of the common Garden sage, Salvia officinalis L. extracts were investigated in vitro. The influence of growth conditions (nutrient composition and incubation period) on biofilm formation of E. coli strains was evaluated using crystal violet staining procedure. The tested strains better formed biofilms after a longer incubation period (48 h). In addition, biofilm formation depended on nutrient medium composition. The eight strains were slime producers (Congo red agar assay). The water, ethanol, acetone and diethyl ether S. officinalis extracts were screened for their ability to inhibit the formation and metabolic activity of E. coli biofilms using crystal violet and resazurin assay, respectively. The water extract was not active, while ethanol, acetone and diethyl ether extract exhibited antibiofilm activity (MBIC= 2.5-10 mg/mL). The microscopic visualization of treated E. coli LM1 biofilm has shown morphological and density changes. In addition, the concentrations of phenolic compounds were determined spectrophotometrically. The highest content of total phenolics was found in acetone extract while the flavonoids in water extract

Antifungal and antibiofilm activities of selected plant extracts

Aims@#Candida albicans is a regular member of the human microbiota but also one of the most frequent pathogens with a strong biofilm-forming capacity and prominent resistance to antimycotic drugs. The aim of this investigation was to evaluate the anti-C. albicans biofilm activity of ethanolic and methanolic leaf extracts of spinach, Swiss chard and garden orache.@*Methodology and results@#Antifungal activity was established by determining the minimum inhibitory (MIC) and minimum fungicidal concentrations (MFC) by the broth microdilution method. The antibiofilm activity was tested by the tissue culture plate method, followed by the determination of the biofilm inhibition. Results showed that all extracts exhibit antifungal activity, with the MIC value of 62.50 μg/mL. This is in accordance with the results of antibiofilm activity, where extracts showed the ability to decrease the biofilm-forming capacity at sub-inhibitory concentrations. Overall antibiofilm effect of spinach extracts were narrow, but biofilm inhibition activity was observed at 31.25 μg/mL of ethanolic extract. Considering the dilution range, garden orache extracts had the broadest antibiofilm activity, with a biofilm inhibition of 20.96-38.10% and 12.11-12.97% for ethanolic and methanolic extracts, respectively. Swiss chard ethanolic extract inhibited biofilm from 14.52% to 31.39% and methanolic from 37.66% to 44.70%.@*Conclusion, significance and impact of study@#Study revealed that investigated plant extracts have antifungal and antibiofilm potential against C. albicans, which could be important in light of its emerging resistance to synthetic drugs, as well as the possible toxicity of antimycotics.

Preliminary phytochemical analysis, antibacterial and anti-biofilm activities of Curcuma zedoaria (Christm.) Roscoe extracts

Aims@#Plant extracts are a rich source of natural compounds that have some degree of antimicrobial efficacy and have less side effects compared to antibiotics. The aim of this research was to screen the phytochemical compounds and investigate the potency of Curcuma zedoaria (Christm.) Roscoe rhizome (CZR) extracts to inhibit the growth and biofilm formation of some pathogenic bacteria.@*Methodology and results@#Antimicrobial and antibiofilm effects of CZR extracts in different solvents were examined by agar well diffusion and the broth microdilution method after phytochemical screening. The 95% ethanolic extract of CZR exhibited broad-spectrum antibacterial properties against Gram-negative and Gram-positive bacteria with inhibition zones of 7.25 ± 0.58-12.00 ± 0.26 mm and MIC values ranging from 50-200 mg/mL. The extract also showed rapid bacteriostatic and bactericidal activities towards Enterococcus faecalis DMST 4736 and Staphylococcus aureus ATCC 25923 by time-kill assays. Moreover, the 95% ethanolic extracts of CZR also acted as a potent anti-biofilm agent against E. faecalis DMST 4736, S. aureus ATCC 25923, S. epidermidis, Escherichia coli ATCC 25922, Klebsiella pneumoniae, Pseudomonas aeruginosa ATCC 27853 and Proteus mirabilis DMST 8212 (54.62 ± 0.30-71.25 ± 0.20% inhibition of biofilm formation). The bioactive potency of compounds of the crude 95% ethanolic extract (tannins, flavonoids, cardiac glycosides, steroids, terpenoids and alkaloids) play important roles in the observed antibacterial and anti-biofilm activities.@*Conclusion, significance and impact of study@#Curcuma zedoaria (Christm.) Roscoe extract had broad-spectrum antibacterial activity. The ethanolic CZR extract revealed bacteriostatic and bactericidal capacities, depending on time of exposure and concentration of the extracts. Thus, the present results indicate that C. zedoaria (Christm.) Roscoe rhizomes are a potential natural alternative antibacterial agent for preventing bacterial diseases.

Potencial antimicrobiano e antibiofilme do extrato hidroetanólico da folha de Spondias mombin L e de suas frações frente a microrganismos superinfectantes do meio ambiente bucal / Antimicrobial and antibiofilm potential of the hydroethanolic extract of Spondias mombin L leaf and its fractions against superinfecting microorganisms in the oral environment

O controle químico do biofilme bucal atua como método auxiliar do controle mecânico para fins de manutenção e/ou restabelecimento da saúde bucal, agindo também nos demais microrganismos que não são residentes locais da microbiota bucal. Nesse contexto, a literatura já relata que muitos microrganismos superinfectantes podem estar presentes no biofilme bucal e assim, contribuir para a ocorrência de infecções sistêmicas mais graves. Assim sendo, os fitoterápicos têm demonstrado uma ampla variedade de atividades biológicas, em especial a atividade antimicrobiana. Diante disso, o presente estudo buscou avaliar a ação antimicrobiana e antibiofilme do extrato hidroetanólico da folha de Spondias mombin L. (cajá) e de suas frações de flavonóides, taninos e ácidos fenólicos, frente aos microrganismos superinfectantes (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli e Enterococcus faecalis) do ambiente bucal. Para isso, foram investigadas a Concentração Inibitória Mínima (CIM) pela Técnica de Disco-Difusão e pela Técnica da Microdiluição em Caldo, a Concentração Inibitória Mínima de Aderência (CIMA), a Cinética Bactericida e a Atividade Antibiofilme do extrato hidroetanólico da folha Spondias mombin L. e de suas frações sobre a formação de biofilme e em biofilmes pré-formados, utilizando como controle o digluconato de clorexidina a 0,12%, em triplicata. Além da interpretação descritiva, foram aplicados no presente estudo as análises estatísticas do Teste de Tukey e Two-Way ANOVA. Os resultados demonstraram que: para a CIM pela Técnica de Disco-Difusão, o extrato hidroetanólico da folha Spondias mombin L. foi estatisticamente superior ao digluconato de clorexidina 0,12% (p<0,05) para as concentrações de 500µg/mL e250µg/mLe foi estatisticamente superior também às frações estudadas (p<0,05); para a CIM pela Técnica da Microdiluição em Caldo, foi observado que o extrato hidroetanólico da folha Spondias mombin L. foi superior às frações estudadas e semelhante ao grupo controle; para a CIMA, tanto o extrato hidroetanólico da folha de Spondias mombin L., quanto as frações estudadas e o grupo controle exibiram atividade antiaderente; para a Cinética Bactericida, foi verificado que o extrato hidroetanólico, as frações estudadas e o grupo controle possuem atividade bactericida iniciando nas primeiras duas horas de contato com o microrganismo e para a Atividade Antibiofilme, foi observado que, sobre a formação de biofilme e em biofilmes pré-formados, em diferentes concentrações, o extrato hidroetanólico da folha Spondias mombin L. foi estatisticamente superior ao grupo controle (p<0,05), sendo também estatisticamente superior às frações estudadas (p<0,05). Dessa forma, pode-se concluir que o extrato hidroetanólico da folha Spondias mombin L., em diferentes concentrações, se apresentou estatisticamente superior que o digluconato de clorexidina 0,12%, exibindo assim, ação antimicrobiana e atividade antibiofilme. As frações do extrato, porém, exibiram ação antimicrobiana e atividade antibiofilme inferiores ao extrato hidroetanólico e ao digluconato de clorexidina 0,12% (AU).

The chemical control of oral biofilm acts as an auxiliary method of mechanical control for the maintenance and/or restoration of oral health, also acting on other microorganisms that are not local residents of the oral microbiota. In this context, the literature already reports that many superinfecting microorganisms can be present in the oral biofilm and thus contribute to the occurrence of more serious systemic infections. Therefore, herbal medicines have demonstrated a wide variety of biological activities, especially antimicrobial activity. Therefore, this study aimed to evaluate the antimicrobial and antibiofilm action of the hydroethanolic extract of the leaf of Spondias mombin L. (cajá) and its fractions of flavonoids, tannins and phenolic acids, against superinfecting microorganisms (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecalis) from the oral environment. For this purpose, the Minimum Inhibitory Concentration (MIC) by the Disc-Diffusion Technique and the Broth Microdilution Technique, the Minimum Inhibitory Concentration of Adhesion (MICA), the Bactericidal Kinetics and the Antibiofilm Activity of the hydroethanolic extract of the Spondias mombin L. leaf were investigated and its fractions on biofilm formation and in preformed biofilms, using 0.12% chlorhexidine gluconate as a control, in triplicate. In addition to descriptive interpretation, statistical analyzes of the Tukey Test and Two-Way ANOVA were applied in this study. The results showed that: for MIC by the Disc-Diffusion Technique, the hydroethanolic extract of the Spondias mombin L. leaf was statistically superior to 0.12% chlorhexidine gluconate (p<0.05) for the concentrations of 500µg/mL and 250µg/mL and it was also statistically superior to the studied fractions (p<0.05); for the MIC by the Broth Microdilution Technique, it was observed that the hydroethanolic extract of the Spondias mombin L. leaf was superior to the studied fractions and similar to the control group; for MICA, both the hydroethanolic extract of the leaf of Spondias mombin L., the studied fractions and the control group exhibited antiadherent activity; for Bactericidal Kinetics, it was verified that the hydroethanolic extract, the studied fractions and the control group have bactericidal activity starting in the first two hours of contact with the microorganism and for the Antibiofilm Activity, it was observed that, on the formation of biofilm and in biofilms preformed, at different concentrations, the hydroethanolic extract of the Spondias mombin L. leaf was statistically superior to the control group (p<0.05), being also statistically superior to the studied fractions (p<0.05). Thus, it can be concluded that the hydroethanolic extract of the Spondias mombin L. leaf, at different concentrations, was statistically superior to 0.12% chlorhexidine gluconate, thus exhibiting antimicrobial action and antibiofilm activity. The extract fractions, however, exhibited lower antimicrobial and antibiofilm activity than hydroethanolic extract and 0.12% chlorhexidine gluconate (AU).

Antimicrobial and antibiofilm activities of aqueous extracts of Cucurbita pepo L / Atividades antimicrobiana e antibiofilme de extratos aquosos de Cucurbita pepo L

Introduction: Cucurbita pepo L. is an herbaceous plant belonging to the family Cucurbitaceae. The species is popularly used in different countries for the treatment of diabetes and parasitic diseases. Objective: This study evaluated the antimicrobial and antibiofilm potential of aqueous extracts of leaves and seeds of C. pepo. Methodology: the extracts were tested in vitro against strains of Streptococcus pyogenes, Candida albicans and Candida krusei. The antimicrobial activity was performed by the microtiter method and the antibiofilm activity by the violet crystal method. Results: the results demonstrated that the extracts tested showed antibacterial and antibiofilm actions against S. pyogenes, but it was not possible to determine the minimum inhibitory concentration (MIC). The extracts inhibited the growth of C. albicans and C. krusei with MIC of 0.03 mg/mL. The antibiofilm activity of these species did not present either a dose dependence relationship or a synergistic effect when associated with the antifungal Fluconazole®. Conclusion: although there are indications of antimicrobial and inhibitory action in the formation of biofilm, additional studies are necessary to characterize the possible pharmacological effects of the analyzed specie.

Introdução: Cucurbita pepo L. é uma planta herbácea pertencente à família Cucurbitaceae. A espécie é usada popularmente em diferentes países para tratamento de diabetes e parasitoses. Objetivo: esse trabalho objetivou avaliar o potencial antimicrobiano e antibiofilme de extratos aquosos de folhas e sementes de C. pepo. Metodologia: os extratos foram testados in vitro contra cepas de Streptococcus pyogenes, Candida albicans e Candida krusei. A atividade antimicrobiana foi realizada pelo método de microtitulação e a atividade antibiofilme pelo método de cristal de violeta. Resultados: os resultados demonstraram que os extratos testados apresentaram ação contra S. pyogenes, tanto em relação ao controle do crescimento bacteriano como inibição de formação de biofilme, mas não foi possível determinar a concentração inibitória mínima (CIM). Os extratos inibiram o crescimento C. albicans e C. krusei com CIM de 0.03 mg/mL. A atividade antibiofilme dessas espécies não apresentou relação de dose dependência nem de efeito sinérgico quando associado ao antifúngico Fluconazol®. Conclusão: Embora haja indicativos de ação antimicrobiana e inibitória na formação de biofilme, são necessários estudos adicionais para a caracterização dos possíveis efeitos farmacológicos da espécie analisada.

Antibacterial and Antibiofilm Activities of Crude Extract of Lasiodiplodia pseudotheobromae IBRL OS-64 against Foodborne Bacterium, Yersinia enterocolitica

The antibacterial and antibiofilm activities of crude extract of Lasiodiplodia pseudotheobromaeIBRL OS-64 was studied and tested against a foodborne pathogenic bacterium, Yersinia enterocolitica. The ethylacetate extract exhibited favorable antibacterial activity with the zone of inhibition was 20.3±0.6 mm compared to dichloromethane (15.0±0.3 mm) and butanol (9.0±0.3 mm) extracts. Minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) values of the extract were 125 and 250 μg/mL, respectively. Structural degeneration studies through scanning electron microscopy (SEM) and transmission electron microscope (TEM) micrographs exhibited major abnormalities that occurred on thebacterial cells after exposureto the extract were complete alterations in their morphology and collapsed of the cells beyond repair. The findings showed that the extract possesses antibiofilm activity against the initial and preformed biofilm of Y. enterocoliticawith the highest inhibition value of 69.12% and 58.70%, respectively The results also revealed the initial biofilm was more susceptible to the extract as compared to pre-formed biofilm. The light microscopy (LM) and SEM photomicrographs proved that thefungal extract significantly eliminates extracellular polysaccharide (EPS) matrices and hinder the attachment of the bacterial cells for biofilm formation. Therefore, the current study suggested the ethyl acetate crude extract from an endophytic fungus, L. pseudotheobromae IBRL OS-64 may be an effective antibacterial and anti-biofilm agent to treat foodborne pathogens

Evaluation of anti-biofouling potential of Viburnum opulus extracts / Evaluación del potencial anti bioincrustante de extractos de Viburnum opulus

In this study the in vitro investigation of the inhibitory effect of ethanol extract of Viburnum opulus L. bark sample on Streptococcus mutans planctonic cells and biofilm has been intended. A Scanning electron microscopy analysis has been performed in order to investigate the inhibitory effect of the extract on Streptococcus mutans biofilms. Furthermore, the Exopolysaccharide and dextran production of this bacteria have been identified in the presence of the extract. It has been found out that the bark extract with the concentration of 2,5 mg/mL is able to inhibit more than 50% of the cells in the different times development phases. According to this, the exopolymeric matrix on the biofilm surface disperses and the Exopolysaccharide and dextran production get lowered in the presence of bark extract compared to the control group. It is considered that this extract can be used as an alternative approach for the new chemotherapeutic strategies against tooth decay.

En este estudio se investigó el efecto inhibitorio in vitro del extracto de etanólico de una muestra de corteza de Viburnum opulus L. en biopelículas de células planctónicas de Streptococcus mutans. Se realizó un análisis de microscopía electrónica de barrido para investigar el efecto inhibitorio del extracto sobre las biopelículas de Streptococcus mutans. Además, se identificó la producción de exopolisacárido y dextrano de esta bacteria en presencia del extracto. Se descubrió que el extracto de corteza con una concentración de 2,5 mg/ml inhibió más del 50% de las células en las diferentes fases de desarrollo. Consecuentemente, la matriz exopolimérica en la superficie de la biopelícula se dispersa y la producción de exopolisacárido y dextrano se reduce en presencia de extracto de corteza en comparación con el grupo de control. Se sugiere que este extracto puede ser usado como un enfoque alternativo para las nuevas estrategias quimioterapéuticas contra la carie dental.

Antimicrobial, Antioxidant and Antibiofilm Potential of Peppermint (Mentha piperita) Essential Oil for Application in Meat Products

The current study was carried out to examine in-vitro antimicrobial, antioxidant and antibiofilm efficacy of Peppermint essential oil (PEO) for its potential application in meat products. Antimicrobial activity was measured by using zone inhibition assay (ZOI) and Minimum Inhibitory Concentration (MIC) against ten food borne pathogens including four Gram-positive viz. Listeria monocytogenes, Enterococcus faecalis, Bacillus cereus and Staphylococcus aureus and six Gram-negative viz. Proteus mirabilis, Salmonella enterica serovar Typhi, Klebsiella pneumonia, Shigella flexneri, Escherichia coli and Pseudomonas aeruginosa whereas antioxidant assay was measured using 1,1 diphenyl-2 picrylhydrazyl (DPPH) and 2-2- azinobis-3 ethylbenthiazoline-6-sulphonic acid (ABTS) radical scavenging activity. Maximum zone size was observed for Proteus mirabilis whereas, MIC values ranged from 5000-20000 ppm for all tested organisms. The oil was found to be more effective against Pseudomonas aeruginosa and Salmonella enterica serovar Typhi. Antibiofilm activity (%) was also performed against pure cultures of two pathogens i.e. Listeria monocytogenes and Proteus mirabilis as positive control. The results exhibited that with application of PEO, biofilm formation of both Listeria monocytogenes and Proteus mirabilis was inhibited by 45.80% and 73.01%, respectively in contrast to their respective controls. ABTS and DPPH radical scavenging activity of PEO was measured at five different concentrations and values were ranging from 17.24-49.07% for ABTS whereas 35.16 – 60.70% for DPPH under investigation. It can be concluded that peppermint essential oil possesses potent antimicrobial, antioxidant and antibiofilm activity and can be further used as a natural alternative for preservation in meat industry

Antibiofilm activity of alpha-mangostin loaded nanoparticles against Streptococcus mutans

Objective: To investigate the antibiofilm activity of alpha- mangostin (AMG) loaded nanoparticle (nanoAMG) against dental caries pathogen Streptococcus mutans. Methods: AMG was isolated from the peels of Garcinia mangostana L. using silica gel columns and chemically analysed by high performance liquid chromatography and nuclear magnetic resonance. NanoAMG was prepared using the solvent evaporation method combined with high-speed homogenization. The nanoparticles were characterized using dynamic light scattering, field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared spectroscopy (FTIR). The toxicity of nanoAMG in fibroblast NIH/3T3 cell line was determined using MTT method. The antibiofilm effect of nanoAMG was determined through the evaluation of biofilm formation by Streptococcus mutans using a 96-well plate. Biofilm biomass was quantified using crystal violet. Cell viability was observed under confocal microscopy using LIVE/DEAD BacLight staining. Moreover, gene expression was determined by quantitative real-time PCR and membrane permeabilization activity by measuring the uptake of o-nitrophenol- β-D-galactoside. Results: NanoAMG size was in a range of 10-50 nm with a polydispersity index of < 0.3 and zeta potential value of -35.2 mV The size and the incorporation of AMG in the nanoparticles were confirmed by FE-SEM and FTIR analyses. The IC

Current progress in antimicrobial peptides against bacterial biofilms / 生物工程学报

Microbial biofilm, a consortium of microbial cells protected by a self-produced polymer matrix, is considered as one main cause of current bacterial drug resistance. As a new type of antimicrobial agents, antimicrobial peptides provide a new strategy for the treatment of antibiotic resistant bacteria biofilm infections. Antimicrobial peptides have shown unique advantages in preventing microbial colonization of surfaces, killing bacteria in biofilms or disrupting the mature biofilm structure. This review systemically analyzes published data in the recent 30 years to summarize the possible anti-biofilm mechanisms of antimicrobial peptides. We hope that this review can provide reference for the treatment of infectious diseases by pathogenic microbial biofilm.

Antibiofilm activity of alpha-mangostin loaded nanoparticles against Streptococcus mutans

Objective: To investigate the antibiofilm activity of alpha-mangostin (AMG) loaded nanoparticle (nanoAMG) against dental caries pathogen Streptococcus mutans. Methods: AMG was isolated from the peels of Garcinia mangostana L. using silica gel columns and chemically analysed by high performance liquid chromatography and nuclear magnetic resonance. NanoAMG was prepared using the solvent evaporation method combined with high-speed homogenization. The nanoparticles were characterized using dynamic light scattering, field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared spectroscopy (FTIR). The toxicity of nanoAMG in fibroblast NIH/3T3 cell line was determined using MTT method. The antibiofilm effect of nanoAMG was determined through the evaluation of biofilm formation by Streptococcus mutans using a 96-well plate. Biofilm biomass was quantified using crystal violet. Cell viability was observed under confocal microscopy using LIVE/DEAD BacLight staining. Moreover, gene expression was determined by quantitative real-time PCR and membrane permeabilization activity by measuring the uptake of o-nitrophenol-β-D-galactoside. Results: NanoAMG size was in a range of 10-50 nm with a polydispersity index of < 0.3 and zeta potential value of -35.2 mV. The size and the incorporation of AMG in the nanoparticles were confirmed by FE-SEM and FTIR analyses. The IC50 values of the test agents on NIH/3T3 cells were (9.80 ± 0.63) μg/mL for AMG and (8.70 ± 0.81) μg/mL for nanoAMG, while no toxicity was generated from excipients used to prepare nanoparticles. In the early stage of biofilm formation, treatment with 6.25 μmol/L nanoAMG caused a reduction in biofilm biomass up to 49.1％, compared to 33.4％ for AMG. In contrast, biofilms at the late stage were more resistant to the test agents. At 96 μmol/L (= 10 × MIC), nanoAMG reduced only 20.7％ of biofilm biomass while AMG did not show any effect. Expressions of gtfB and gtfC genes involved in biofilm formation were down-regulated 3.3 and 12.5 folds, respectively, compared to AMG (2.4 and 7.6 folds, respectively). LIVE/DEAD BacLight fluorescence staining and microscopy observation indicated that biofilm cells were killed by both nanoAMG andAMG at 48 μmol/L (= 5 × MIC). In addition, membrane permeabilization activity was increased in a time dependent manner and higher in nanoAMG treated cells compared toAMG.Conclusions: AMG coated nanoparticle can enhance AMG bioactivity and can be used as a new and promising antibiofilm agent.

Antimicrobial and Antibiofilm Activity of Essential Oil of Cymbopogon citratus against Oral Microflora Associated with Dental Plaque

Aims: Dental biofilms are complex, multi-species microorganism communities that inhabit the oral cavity in the form of dental plaque which causes dental caries and periodontal diseases. The present study aims to explore the potential of Lemon Grass Essential Oil (LGEO) extracted from Cymbopogon citratus as antimicrobial and antibiofilm agent against the microorganisms responsible for dental plaque. Study Design: Observational and comparison study. Place and Duration of Study: Research centre, Department of Microbiology, Abasaheb Garware college, Pune, India, between Dec 2012 to Jan 2017. Methodology: Three bacterial species primarily responsible for the biofilm formation were isolated from dental plaque and identified using 16S ribosomal RNA sequences. Five most primary colonizer of dental plaque organisms were acquired from the Microbial Type Culture Collection cultures. Antimicrobial as well as antibiofilm activity of LGEO, was determined against these eight biofilm forming microorganism. The antibiofilm activity of LGEO was evaluated against oral flora individually, as well as in consortium. Results: LGEO displayed excellent antimicrobial activity against eight test organisms associated with dental plaque, representing four genera namely Streptococcus, Staphylococcus, Lactobacillus and Candida. MIC of LGEO for all test organisms was determined as 1.5% (v/v). The LGEO was found to exhibit as high as 76% biofilm inhibitory activity even in the consortium, where the biofilm formation sometimes has been noted to be comparatively more than that of the individual organism, making LGEO a very promising antibiofilm agent. Conclusion: LGEO present in rampantly grown plant, Cymbopogon citratus, has remarkable antimicrobial and antibiofilm activity against the dental plaque organism and thus can be the economical, convenient, natural and nontoxic herbal material to effectively control the oral microflora associated with dental plaque.

Chitosan Nanoparticles As Drug Delivery System For Cephalexin And Its Antimicrobial Activity Against Multiidrug Resistent Bacteria

Objective: The evolution of antimicrobial resistance is a universal obstacle that necessities the innovation of more effective and safe antimicrobial alternatives with synergistic properties. The purpose of this study was to investigate the possible improvement of cephalexin antimicrobial treatments by loading into chitosan-based nanoparticles, then evaluate their antibacterial and antibiofilm activities as well as determination of its cytotoxicity. Methods: Chitosan nanoparticles (CSNPs) were prepared by ionic gelation method. Parameters were studied to optimize the particle size of CSNPs including pH, stirring rate, homogenization and ultra-sonication time. Size was measured by transmission electron microscope (TEM) and Zeta sizer, morphology seen by scanning electron microscope (SEM). Entrapment efficiency, drug loading and drug content were calculated. Stability of both plain and loaded chitosan Nano-carriers, Drug release and Kinetics also compatibilities were studied. Antimicrobial activity of CSNPs and cephalexin loaded CSNPs were evaluated against 4 Gram-positive and 4 Gram-negative standard and clinical isolates by microdilution method, also assessment of antibiofilm activity of both formulas was investigated against two biofilm producers clinical isolates by tube assay in addition to determination of their cytotoxicity by MTT(3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Results: Chitosan nanoparticles and its loaded antibiotics proved compatible combination with small Zeta size, suitable Zeta potential, maximum EE% and drug-loading capacity, sustained controlled release properties followed diffusion kinetic model and six month stability studies. Cephalexin loaded CSNPs showed better antimicrobial activity than plain CSNPs. Synergistic effects were found against S. aureus (ATCC 25923), B. subtilis (ATCC 9372), S. epidermidis, E. faecalis, P. aeruginosa (ATCC 29853) in addition to two carbapenem resistant isolates k. pneumoniae and E. coli. Also cephalexin loaded CSNPs exhibited antibiofilm activity against E. faecalis clinical isolate. Even though, cephalexin loaded CSNPs exhibited significant antibacterial activity, it showed less toxicity against mammalian cells, it had IC50 equal to 231.893 and did not exhibit any cytotoxicity against the WI-38 fibroblast cells at concentration 23.4 µg/ml. Conclusion: Cephalexin loaded CSNPs possessed good stability and sustained release effect in addition to its antimicrobial, antibiofilm activities and reduced cytotoxicity.

Elucidating the effect of anti-biofilm activity of bioactive compounds extracted from plants

Biofilms are dense population of sessile bacterial cells that adhere to the surface, forming a matrix composed ofexopolysaccharide, proteins and DNA. This matrix is termed as extracellular polymeric substance and provides stability tothe cells adhering to it to form biofilms. It also provides nutrients and thus helps in the pathogenesis of biofilm-associatedinfections and resistance. Biofilms promote bacterial persistence by resisting host immune responses and antibiotic treatment. Antibiotics are rendered ineffective when biofilms form due to their relative impermeability, the variable physiological status of microorganisms, and subpopulations of persistent strains. Another factor that results in the development ofantibiotic resistance within the biofilm is the adaptations that take place within the genes present in the cells dwelling withinthe biofilm. These adaptations decrease the sensitivity of the bacterial cells toward the antibiotics and develop resistance.Hence, an alternative antimicrobial strategy of making use of plant-based products has been observed to be useful to curevarious ailments, as compared to conventional therapy. In this review, we have listed the various biofilm-forming bacteriaand the bioactive compounds being produced from the aerial parts of plants having antibiofilm activity and evaluated themagainst different biofilm-producing bacterial strains.

Antimicrobial and antibiofilm activities of phenolic compounds extracted from Populus nigra and Populus alba buds (Algeria)

The interest of this work is the discovery of new antimicrobial agents of plant origin to inhibit the formation of microbial biofilms. The present research was conducted to identify and quantify the phenolic compounds extracted from Populus nigra and Populus alba buds harvested in the area of Tizi-Ouzou (Algeria), and to evaluate their antimicrobial and antibiofilm activity. High performance liquid chromatography (HPLC) was performed to identify the phenolic compounds in the ethyl acetate fraction of P. nigra and the methanolic extracts of P. nigra and P. alba. The antimicrobial activity of the crude extracts and the fractions of these two species was tested against 11 microorganisms, using the disk diffusion method, while the antibiofilm effect of certain extracts was carried out in a 96-well microplate and on a biomaterial (catheter). HPLC analysis revealed the presence of 10 bioactive compounds. The main phenolic compounds identified in the three extracts were p-coumaric acid, ellagic acid, and Kaempferol. This study was able to demonstrate that the extracts of P. nigra and P. alba buds have interesting antimicrobial properties, with diameters ranging from 6.6 to 21.3 mm. In addition, extracts of P. nigra exhibited antibiofilm effects greater than 70%. Our results provide evidence for the antimicrobial and antibiofilm potential of bud extracts from both poplar species. Thus, these results will pave the way for further research on these two plants.