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Evolution of Biofilm and Its Effect on Microstructure of Mortar Surfaces in Simulated Seawater
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作者 荣辉 YU Chenglong 张颖 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第1期234-243,共10页
To explore the role of biofilm formation on the corrosion of marine concrete structures, we investigated the attachment of biofilm on mortar surfaces in simulated seawater and the influence of biofilm on the microstru... To explore the role of biofilm formation on the corrosion of marine concrete structures, we investigated the attachment of biofilm on mortar surfaces in simulated seawater and the influence of biofilm on the microstructure of mortar surfaces. The results show that the evolution of biofilm on mortar surfaces in simulated seawater is closely related to the corrosion suffered by the mortar, and the process of biofilm attachment and shedding is continuous and cyclical. It is found that the specimens in the absence of biofilm attachment are more severely eroded internally by the corrosive medium in simulated seawater than those in the presence of biofilm attachment. For the specimens without biofilm attachment, after 60 days, gypsum forms,and after 120 days, the number of pores in the mortar is reduced. In contrast, for the specimens in the presence of biofilm attachment, gypsum could only be detected after 90 days, and fewer pores are filled. Therefore, the formation of biofilm could delay the invasion of the corrosive medium into the interior of mortar during the evolution of biofilm on mortar surfaces, mitigating the corrosion of mortars in seawater. 展开更多
关键词 biofilm attachment MORTAR sulfur-oxidizing bacteria GYPSUM simulated seawater MICROSTRUCTURE
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Staphylococcus aureus and biofilms:transmission, threats, and promising strategies in animal husbandry
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作者 Mengda Song Qi Tang +8 位作者 Yakun Ding Peng Tan Yucheng Zhang Tao Wang Chenlong Zhou Shenrui Xu Mengwei Lyu Yueyu Bai Xi Ma 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2024年第4期1408-1423,共16页
Staphylococcus aureus(S. aureus) is a common pathogenic bacterium in animal husbandry that can cause diseases such as mastitis, skin infections, arthritis, and other ailments. The formation of biofilms threatens and e... Staphylococcus aureus(S. aureus) is a common pathogenic bacterium in animal husbandry that can cause diseases such as mastitis, skin infections, arthritis, and other ailments. The formation of biofilms threatens and exacerbates S. aureus infection by allowing the bacteria to adhere to pathological areas and livestock product surfaces, thus triggering animal health crises and safety issues with livestock products. To solve this problem, in this review, we provide a brief overview of the harm caused by S. aureus and its biofilms on livestock and animal byproducts(meat and dairy products). We also describe the ways in which S. aureus spreads in animals and the threats it poses to the livestock industry. The processes and molecular mechanisms involved in biofilm formation are then explained. Finally, we discuss strategies for the removal and eradication of S. aureus and biofilms in animal husbandry, including the use of antimicrobial peptides, plant extracts, nanoparticles, phages, and antibodies. These strategies to reduce the spread of S. aureus in animal husbandry help maintain livestock health and improve productivity to ensure the ecologically sustainable development of animal husbandry and the safety of livestock products. 展开更多
关键词 Animal husbandry biofilm MASTITIS Mitigation strategies Staphylococcus aureus
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Structural insights on anti-biofilm mechanism of heated slightly acidic electrolyzed water technology against multi-resistant Staphylococcus aureus biofilm on food contact surface
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作者 Pianpian Yan Ramachandran Chelliah +7 位作者 Kyoung Hee Jo Xiuqin Chen Akanksha Tyagi Hyeon Yeong Jo Fazle Elahi Nam Chan Woo Min Seung Wook Deog Hwan Oh 《Food Science and Human Wellness》 SCIE CSCD 2024年第3期1556-1566,共11页
Slightly acidic electrolyzed water(SAEW)has proven to be an efficient and novel sanitizer in food and agriculture field.This study assessed the efficacy of SAEW(30 mg/L)at 40℃on the inactivation of foodbome pathogens... Slightly acidic electrolyzed water(SAEW)has proven to be an efficient and novel sanitizer in food and agriculture field.This study assessed the efficacy of SAEW(30 mg/L)at 40℃on the inactivation of foodbome pathogens and detachment of multi-resistant Staphylococcus aureus(MRSA)biofilm.Furthermore.the underlying mechanism of MRS A biofilm under heated SAEW at 40℃treatment on metabolic profiles was investigated.The results showed that the heated SAEW at 40℃significantly effectively against foodbome pathogens of 1.96-7.56(lg(CFU/g))reduction in pork,chicken,spinach,and lettuce.The heated SAEW at 40℃treatment significantly reduced MRS A biofilm cells by 2.41(lg(CFU/cm^(2))).The synergistic effect of SAEW treatment showed intense anti-biofilm activity in decreasing cell density and impairing biofilm cell membranes.Global metabolic response of MRSA biofilms,treated by SAEW at 40℃,revealed the alterations of intracellular metabolites,including amino acids,organic acid,fatty acid,and lipid.Moreover,signaling pathways involved in amino acid metabolism,energy metabolism,nucleotide synthesis,carbohydrate metabolites,and lipid biosynthesis were functionally disrupted by the SAEW at 40℃treatment.As per our knowledge,this is the first research to uncover the potential mechanism of heated SAEW treatment against MRSA biofilm on food contact surface. 展开更多
关键词 Multi-resistant Staphylococcus aureus Metabolic profile SAEW biofilm Hurdle technology Electrode material
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Contemporary strategies and approaches for characterizing composition and enhancing biofilm penetration targeting bacterial extracellular polymeric substances
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作者 Lan Lu Yuting Zhao +4 位作者 Mingxing Li Xiaobo Wang Jie Zhu Li Liao Jingya Wang 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2024年第4期506-524,共19页
Extracellular polymeric substances(EPS)constitutes crucial elements within bacterial biofilms,facili-tating accelerated antimicrobial resistance and conferring defense against the host's immune cells.Developing pr... Extracellular polymeric substances(EPS)constitutes crucial elements within bacterial biofilms,facili-tating accelerated antimicrobial resistance and conferring defense against the host's immune cells.Developing precise and effective antibiofilm approaches and strategies,tailored to the specific charac-teristics of EPS composition,can offer valuable insights for the creation of novel antimicrobial drugs.This,in turn,holds the potential to mitigate the alarming issue of bacterial drug resistance.Current analysis of EPS compositions relies heavily on colorimetric approaches with a significant bias,which is likely due to the selection of a standard compound and the cross-interference of various EPS compounds.Considering the pivotal role of EPS in biofilm functionality,it is imperative for EPS research to delve deeper into the analysis of intricate compositions,moving beyond the current focus on polymeric materials.This ne-cessitates a shift from heavy reliance on colorimetric analytic methods to more comprehensive and nuanced analytical approaches.In this study,we have provided a comprehensive summary of existing analytical methods utilized in the characterization of EPS compositions.Additionally,novel strategies aimed at targeting EPS to enhance biofilm penetration were explored,with a specific focus on high-lighting the limitations associated with colorimetric methods.Furthermore,we have outlined the challenges faced in identifying additional components of EPS and propose a prospective research plan to address these challenges.This review has the potential to guide future researchers in the search for novel compounds capable of suppressing EPS,thereby inhibiting biofilm formation.This insight opens up a new avenue for exploration within this research domain. 展开更多
关键词 Analytic strategies and approaches Composition characterization Extracellular polymeric substances(EPS) Promoting biofilm penetration
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Antimicrobial Activities of Extracts of Macrosphyra longistyla against Gram-Positive Oral Biofilm-Formers from School Children in Southwestern Nigeria and Toxicity Studies Using Brine Shrimps
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作者 Chukwuemeka Emmanuel Nwankwo Onikepe Folarin Adeleke Osho 《Advances in Microbiology》 CAS 2024年第3期163-174,共12页
The world will benefit from more effective antimicrobial agents against oral conditions arising from the actions of biofilm forming bacteria. Also, information is lacking on the oral biofilm-forming bacterial diversit... The world will benefit from more effective antimicrobial agents against oral conditions arising from the actions of biofilm forming bacteria. Also, information is lacking on the oral biofilm-forming bacterial diversity in Southwestern Nigeria. In this study, we isolate and characterize oral biofilm producing bacteria in the oral cavities of schoolchildren in Southwestern Nigeria. We also investigate the antimicrobial properties of Macrosphyra longistyla extracts against the biofilm-formers and the toxicity of potent extracts. Samples were obtained from 109 schoolchildren aged 4 - 14 years from Lagos, Oyo and Osun States. Agar well diffusion technique was used in the antimicrobial susceptibility testing. Toxicity testing was done using brine shrimps (Artemia salina). Biofilm-formers in this study are Klebsiella sp., Streptococcus sp., Staphylococcus sp., and Micrococcus sp. Ethanol leaf extracts had the highest activity against all biofilm-producing bacteria. Ethanol stem bark extract, which elicited activity against Klebsiella only, was found to be less toxic than the ethanol leaf extract. Staphylococcus showed >10 mm susceptibility to the ethanol and aqueous extracts of Macrosphyra longistyla. Streptococcus and Micrococcus were susceptible to the antimicrobial actions of the ethanolic leaf extracts. Although the ethanol extracts of the leaves had lower minimum inhibitory concentrations than the ethanol extracts of the stem bark, toxicity studies showed ethanol extracts of the stem-bark to be more toxic than the ethanol extracts of the leaves. In conclusion, ethanolic extracts of Macrosphyra longistyla show potential as sources of antimicrobials against gram-positive, oral biofilm-forming bacteria. 展开更多
关键词 biofilms Plant Extracts Toxicity Bacteria Susceptibility ANTIMICROBIAL
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Bacterial Exofactors Modulate Biofilm Growth and Resistivity to Antimicrobial Drugs
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作者 Van Nguyen# Bea Penaredondo# Girdhari Rijal 《Advances in Microbiology》 CAS 2024年第1期11-24,共14页
Some bacteria have the ability to co-exist, proliferate and survive in a multicellular community, biofilm. Each participating bacteria can form its colonies and encases itself by a self-produced insoluble extracellula... Some bacteria have the ability to co-exist, proliferate and survive in a multicellular community, biofilm. Each participating bacteria can form its colonies and encases itself by a self-produced insoluble extracellular matrix substance (EPS). Microcolonies within biofilm are held together by interactions and bonding of the substances present in the EPS with their separation from the water channels. Similar to insoluble EPS, bacterial microcolonies release soluble exofactors that have direct impacts on the survivability, growth and antibacterial resistivity of other microcolonies made of single- or multi-species bacteria in the same biofilm. How the exofactors of microcolonies of one-type bacteria impact on microcolonies of other-type bacteria is still unclear. We studied about the role of exofactors released from Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa, which are common biofilm-forming pathogenic bacteria. Exofactors facilitate to transform the microenvironment where bacteria can acquire alternative lifestyle with a long survival period and resistivity to certain antimicrobial drugs. 展开更多
关键词 biofilm Exofactors Antimicrobial Drugs GROWTH Extracellular Matrix Substance Microcolonies
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Numerical Modeling of Mass Transfer in the Interaction between River Biofilm and a Turbulent Boundary Layer
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作者 Falilou Coundoul Evrad M. D. Ngom Frédéric Y. Moulin 《Open Journal of Fluid Dynamics》 2024年第1期1-23,共23页
In this article dedicated to the modeling of vertical mass transfers between the biofilm and the bulk flow, we have, in the first instance, presented the methodology used, followed by the presentation of various resul... In this article dedicated to the modeling of vertical mass transfers between the biofilm and the bulk flow, we have, in the first instance, presented the methodology used, followed by the presentation of various results obtained through analyses conducted on velocity fields, different fluxes, and overall transfer coefficients. Due to numerical constraints (resolution of relevant spatial scales), we have restricted the analysis to low Schmidt numbers (S<sub>c</sub><sub></sub>=0.1, S<sub>c</sub></sub>=1, and S<sub>c</sub></sub>=10) and a single roughness Reynolds number (Re<sub>*</sub>=150). The analysis of instantaneous concentration fields from various simulations revealed logarithmic concentration profiles above the canopy. In this zone, the concentration is relatively homogeneous for longer times. The analysis of results also showed that the contribution of molecular diffusion to the total flux depends on the Schmidt number. This contribution is negligible for Schmidt numbers S<sub>c</sub></sub>≥0.1, but nearly balances the turbulent flux for S<sub>c</sub></sub>=0.1. In the canopy, the local Sherwood number, given by the ratio of the total flux (within or above the canopy) to the molecular diffusion flux at the wall, also depends on the Schmidt number and varies significantly between the canopy and the region above. The exchange velocity, a purely hydrodynamic parameter, is independent of the Schmidt number and is on the order of 10% of in the present case. This study also reveals that nutrient absorption by organisms near the wall depends on the Schmidt number. Such absorption is facilitated by lower Schmidt numbers. 展开更多
关键词 Epilithic biofilm Passive Scalar Transport Direct Numerical Simulation NAVIER-STOKES
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Biofilm analyses and exoproduct release by clinical and environmental isolates of Burkholderia pseudomallei from Brazil
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作者 Glaucia Morgana de Melo Guedes Crister JoséOcadaque +7 位作者 Alyne Soares Freitas Rodrigo Machado Pinheiro Giovanna Barbosa Riello Silviane Praciano Bandeira Rossana de Aguiar Cordeiro Marcos Fábio Gadelha Rocha JoséJúlio Costa Sidrim Débora de Souza Collares Maia Castelo-Branco 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2023年第7期321-328,共8页
Objective:To characterize biofilm production by clinical(n=21)and environmental(n=11)isolates of Burkholderia pseudomallei and evaluate the production of proteases,hemolysins and siderophores.Methods:Initially,the 32 ... Objective:To characterize biofilm production by clinical(n=21)and environmental(n=11)isolates of Burkholderia pseudomallei and evaluate the production of proteases,hemolysins and siderophores.Methods:Initially,the 32 strains were evaluated for biofilm production in Müller-Hinton broth-1%glucose(MH-1%glucose)and BHI broth-1%glucose,using the crystal violet staining technique.Subsequently,growing(48 h)and mature(72 h)biofilms were evaluated by confocal microscopy.Finally,the production of proteases,hemolysins and siderophores by planktonic aggregates,growing biofilms and mature biofilms was evaluated.Results:All isolates produced biofilms,but clinical isolates had significantly higher biomass in both MH-1%glucose(P<0.001)and BHI-glucose 1%(P=0.005).The structural analyses by confocal microscopy showed thick biofilms,composed of multiple layers of cells,homogeneously arranged,with mature biofilms of clinical isolates presenting higher biomass(P=0.019)and thickness of the entire area(P=0.029),and lower roughness coefficient(P=0.007)than those of environmental isolates.Protease production by growing biofilms was significantly greater than that of planktonic(P<0.001)and mature biofilms(P<0.001).Hemolysin release by planktonic aggregates was higher than that of biofilms(P<0.001).Regarding siderophores,mature biofilms presented higher production than growing biofilms(P<0.001)and planktonic aggregates(P<0.001).Conclusions:Clinical isolates have higher production of biofilms than their environmental counterparts;protease and siderophores seem important for growth and maintenance of Burkholderia pseu­domallei biofilms. 展开更多
关键词 MANGOSTEEN Burkholderia pseudomallei biofilms Proteases HEMOLYSINS SIDEROPHORES
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Biofilm removal mediated by Salmonella phages from chicken-related source
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作者 Zhenzhen Ning Lingling Zhang +3 位作者 Linlin Cai Xinglian Xu Ying Chen Huhu Wang 《Food Science and Human Wellness》 SCIE CSCD 2023年第5期1799-1808,共10页
Salmonella and their biofilm formation are the primary bacterial causes of foodborne outbreaks and crosscontamination. The objective of the study was to investigate the potential of Salmonella phages as an alternative... Salmonella and their biofilm formation are the primary bacterial causes of foodborne outbreaks and crosscontamination. The objective of the study was to investigate the potential of Salmonella phages as an alternative technology for biofilm removal. In this work, 21 Salmonella phages were isolated from a chicken farm and slaughter plant and the phage(CW1)with the broadest spectrum was characterized. Complete genome sequence analysis revealed that the genomes of phage CW1 is composed of 41 763 bp with 58 open reading frames(ORFs)and a holin-endolysin system and it does not encode any virulence or lysogeny. A phage cocktail consisted of CW1(with the broadest spectrum of 70.49%)and CW11, M4 and M10(with a high lytic activity of more than 67.11%)was established. Treatment with the cocktail reduced the cells in the developing biofilm and mature biofilm by 0.79 lg(CFU/cm~2)and 0.4 lg(CFU/cm~2), respectively. More dead cells and scattered extracellular polymeric substances(EPS)were observed by confocal laser scanning microscopy and scanning electron microscopy. Raman analysis found that carbohydrates and proteins were the identification receptors for scattered EPS. This finding suggests that this phage cockta il has potential applications for the sterilization of Salmonella biofilm during meat processing. 展开更多
关键词 CHICKEN SALMONELLA PHAGE biofilm REMOVAL
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Temporal characteristics of algae-denitrifying bacteria co-occurrence patterns and denitrifier assembly in epiphytic biofilms on submerged macrophytes in Caohai Lake,SW China
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作者 Pinhua XIA Guoqing LI +3 位作者 Xianfei HUANG Lei SHI Xin DU Tao LIN 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第6期2276-2291,共16页
Denitrifying bacteria in epiphytic biofilms play a crucial role in nitrogen cycle in aquatic habitats.However,little is known about the connection between algae and denitrifying bacteria and their assembly processes i... Denitrifying bacteria in epiphytic biofilms play a crucial role in nitrogen cycle in aquatic habitats.However,little is known about the connection between algae and denitrifying bacteria and their assembly processes in epiphytic biofilms.Epiphytic biofilms were collected from submerged macrophytes(Patamogeton lucens and Najas marina L.)in the Caohai Lake,Guizhou,SW China,from July to November 2020 to:(1)investigate the impact of abiotic and biotic variables on denitrifying bacterial communities;(2)investigate the temporal variation of the algae-denitrifying bacteria co-occurrence networks;and(3)determine the contribution of deterministic and stochastic processes to the formation of denitrifying bacterial communities.Abiotic and biotic factors influenced the variation in the denitrifying bacterial community,as shown in the Mantel test.The co-occurrence network analysis unveiled intricate interactions among algae to denitrifying bacteria.Denitrifying bacterial community co-occurrence network complexity(larger average degrees representing stronger network complexity)increased continuously from July to September and decreased in October before increasing in November.The co-occurrence network complexity of the algae and nirS-encoding denitrifying bacteria tended to increase from July to November.The co-occurrence network complexity of the algal and denitrifying bacterial communities was modified by ammonia nitrogen(NH_(4)^(+)-N)and total phosphorus(TP),pH,and water temperature(WT),according to the ordinary least-squares(OLS)model.The modified stochasticity ratio(MST)results reveal that deterministic selection dominated the assembly of denitrifying bacterial communities.The influence of environmental variables to denitrifying bacterial communities,as well as characteristics of algal-bacterial co-occurrence networks and the assembly process of denitrifying bacterial communities,were discovered in epiphytic biofilms in this study.The findings could aid in the appropriate understanding and use of epiphytic biofilms denitrification function,as well as the enhancement of water quality. 展开更多
关键词 denitrifying bacteria epiphytic biofilms co-occurrence networks submerged macrophytes community assembly
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Biofilm formation under high temperature causes the commensal bacteria Bacillus cereus WPySW2 to shift from friend to foe in Neoporphyra haitanensis in vitro model
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作者 Qiqin LIU Rui YANG +2 位作者 Xiaoxiao SUN Xinqian ZHOU Haimin CHEN 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第1期229-240,共12页
Although biofilm formation may promote growth,biofilms are not always beneficial to their hosts.The biofilm formation characteristics of Bacillus cereus WPySW2 and its changes at different temperatures were studied.Re... Although biofilm formation may promote growth,biofilms are not always beneficial to their hosts.The biofilm formation characteristics of Bacillus cereus WPySW2 and its changes at different temperatures were studied.Results show that B.cereus WPySW2 promoted the growth of Neoporphyra haitanensis(an economically cultivated seaweed)at 20℃ but accelerated algal rot at 28℃.Thicker B.cereus WPySW2 biofilms covered the surface of N.haitanensis thalli at 28℃,which hindered material exchange between the algae and surrounding environment,inhibited algal photosynthesis and respiration,and accelerated algal decay.Compared with planktonic bacteria,mature biofilm cells had lower energy consumption and metabolic levels.The biofilm metabolic characteristics of B.cereus WPySW2 changed significantly with temperature.High temperature accelerated biofilm maturation,which made it thicker and more stable,allowing the bacteria to easily adapt to environmental changes and obtain greater benefits from their host.High temperature did not affect the production or increased the abundance of toxic metabolites,indicating that the negative effects of B.cereus WPySW2 on algae were not caused by toxins.This study shows that increased temperature can transform a harmless bacterium into a detrimental one,demonstrating that temperature may change the ecological function of phycospheric bacteria by affecting their morphology and metabolism. 展开更多
关键词 bacterial biofilm Bacillus cereus WPySW2 Pyropia function transformation metabolize
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Anti-Biofilm, Anti-Quorum Sensing, and Anti-Proliferative Activities of Methanolic and Aqueous Roots Extracts of Carica papaya L. and Cocos nucifera L.
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作者 Wendkouni Leila Marie Esther Belem-Kabré Vincent Ouédraogo +7 位作者 Bagora Bayala Alimata Bancé Estelle Ouédraogo Boubacar Yaro Lazare Belemnaba Moussa Compaoré Martin Kiendrébeogo Noufou Ouédraogo 《Advances in Microbiology》 CAS 2023年第4期165-180,共16页
Objective: This study focused on the antibacterial and anti-proliferative activity of extracts from Carica papaya and Cocos nucifera roots. Methodology: The minimum inhibitory concentration and the minimum bactericida... Objective: This study focused on the antibacterial and anti-proliferative activity of extracts from Carica papaya and Cocos nucifera roots. Methodology: The minimum inhibitory concentration and the minimum bactericidal concentration of the extracts on Escherichia coli, Pseudomonas aeruginosa, Streptococcus mutans, and Staphylococcus aureus were deduced by the microdilution method. The anti-biofilm activity was determined on all four strains and anti-quorum sensing activity by inhibition of violacein production in Chromobacterium violaceum. Anti-proliferative activity on prostate cultured cancer cells was evaluated by MTT assay. Sterols and triterpenes were also assayed in this study. Results: The methanolic extract of Carica papaya showed the best anti-biofilm effect with a percentage inhibition of 66.10 ± 1.79. The methanolic extract of Cocos nucifera had the strongest inhibition on the production of quorum sensing (61.42 ± 0.28). In addition, the methanolic extract of Cocos nucifera roots showed the best cytotoxic effect on prostate cancer LNCaP cell lines (IC<sub>50</sub> = 26.98 ± 2.6 μg/mL) and Carica papaya on the PC-3 lines (IC<sub>50</sub> = 127.20 ± 5.99 μg/mL). The extracts were also rich in triterpenes and sterols. Conclusion: This study provides support for the ethnomedical use of Carica papaya and Cocos nucifera roots as an antimicrobial and anticancer. 展开更多
关键词 Triterpenes and Sterols Content Antibacterial biofilm Quorum Sensing ANTI-PROLIFERATIVE Medicinal Plants
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Virulence Factors and Biofilm Formation in Vancomycin Resistant Enterococcus faecalis and Enterococcus faecium Isolates in Brazil
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作者 Bárbara de Azevedo Ramos Marília Manta Manta +7 位作者 Sivoneide Maria da Silva Rafael Artur Queiroz Cavalcanti de Sá Natália Lira de Souza Henrique Douglas Melo Coutinho Márcia Vanusa da Silva Túlio Diego da Silva Maria Tereza dos Santos Correia Maria Betânia Melo de Oliveira 《Advances in Microbiology》 2023年第6期299-314,共16页
In this work, we evaluated biofilm formation of Vancomycin Resistant of E. faecalis and E. faecium (VRE) in different culture media and adhesion substrate, as well as cellular hydrophobicity and presence of virulence ... In this work, we evaluated biofilm formation of Vancomycin Resistant of E. faecalis and E. faecium (VRE) in different culture media and adhesion substrate, as well as cellular hydrophobicity and presence of virulence genes. For this, 35 isolates were collected from a public hospital in Recife, Pernambuco, Brazil and identified by the Matrix-Assisted Laser Desorption Ionization - Time-of-flight - Mass Spectrometry (MALDI-TOF-MS) technique. Biofilm formation was analyzed by the Crystal Violet (CV) method and fluorescence microscopy, cellular hydrophobicity by hydrocarbon interaction and the presence of gelE, esp and asa1 genes by Polymerase Chain Reaction (PCR). 12 isolates were identified as E. faecalis and 23 as E. faecium. Most were obtained in Coronary Units (40.0%) and Intensive Care Unit (31.4%). E. faecium isolates were more resistant to the antibiotics tested than E. faecalis;however, E. faecalis stood out as a biofilm producer. Regarding the presence and gene frequency, it was observed that gelE (54.3%) and esp (54.3%) were the most prevalent, followed by asa1 (22.9%). When comparing the gene frequency, it was observed that gelE and esp were predominant (48.6% for both species), while asa1 was more frequent in E. faecalis (20.0%). The data presented here are worrying, because they reveal the virulence potential of isolates VRE, which contributes to the dissemination and persistence of these pathogens in the hospital environment. 展开更多
关键词 biofilm Cellular Hydrophobicity GRAM-POSITIVE Hospital Environment Virulence Genes
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The clinical impact of bacterial biofilms 被引量:50
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作者 Niels Hoiby Oana Ciofu +7 位作者 Helle Krogh Johansen Zhi-jun Song Claus Moser Peter Ostrup Jenser Soren Molin Michael Givskov Tim Tolker-Nieisen Thomas Bjamsholt 《International Journal of Oral Science》 SCIE CAS CSCD 2011年第2期55-65,共11页
Bacteria survive in nature by forming biofilms on surfaces and probably most, if not all, bacteria (and fungi) are capable of forming biofilms. A biofilm is a structured consortium of bacteria embedded in a self-pro... Bacteria survive in nature by forming biofilms on surfaces and probably most, if not all, bacteria (and fungi) are capable of forming biofilms. A biofilm is a structured consortium of bacteria embedded in a self-produced polymer matrix consisting of polysaccharide, protein and extracellular DNA. Bacterial biofilms are resistant to antibiotics, disinfectant chemicals and to phagocytosis and other components of the innate and adaptive inflammatory defense system of the body. It is known, for example, that persistence of staphylococcal infections related to foreign bodies is due to biofilm formation. Likewise, chronic Pseudomonas aeruginosa lung infections in cystic fibrosis patients are caused by biofilm growing mucoid strains. Gradients of nutrients and oxygen exist from the top to the bottom of biofilms and the bacterial cells located in nutrient poor areas have decreased metabolic activity and increased doubling times. These more or less dormant cells are therefore responsible for some of the tolerance to antibiotics. Biofilm growth is associated with an increased level of mutations. Bacteria in biofilms communicate by means of molecules, which activates certain genes responsible for production of virulence factors and, to some extent, biofilm structure. This phenomenon is called quorum sensing and depends upon the concentration of the quorum sensing molecules in a certain niche, which depends on the number of the bacteria. Biofilms can be prevented by antibiotic prophylaxis or early aggressive antibiotic therapy and they can be treated by chronic suppressive antibiotic therapy. Promising strategies may include the use of compounds which can dissolve the biofilm matrix and quorum sensing inhibitors, which increases biofilm susceptibility to antibiotics and phagocytosis. 展开更多
关键词 bacterial biofilm biofilm infection antibiotic resistance quorum sensing
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Bacterial Biofilm Degradation Using Extracellular Enzymes Produced by <i>Penicillium janthinellum</i>EU2D-21 under Submerged Fermentation 被引量:1
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作者 Anil Kumar Nagraj Digambar Gokhale 《Advances in Microbiology》 2018年第9期687-698,共12页
Bacterial biofilms are the bacterial aggregates that are embedded in the self-produced matrix of extracellular polymeric substances (EPS) that cause persistent bacterial infections posing significant medical challenge... Bacterial biofilms are the bacterial aggregates that are embedded in the self-produced matrix of extracellular polymeric substances (EPS) that cause persistent bacterial infections posing significant medical challenges. They are recalcitrant to antibiotics and host defenses which make the treatments difficult and costly. Penicillium janthinellum mutant EU2D-21 was found to produce extracellular enzyme complex (amylase, cellulase, protease) under submerged fermentation. Maximum specific enzyme activities were found to be 3.04 IU/mg, 2.61 IU/mg and 3.39 IU/mg for alpha-amylase, cellulase and protease respectively, after 8 days of incubation at 30?C. We evaluated the enzyme complex for its ability to target and degrade the biofilms of different bacteria. We found that it degraded biofilms of Escherichia coli (85.5%), Salmonella enterica (79.72%), Pseudomonas aeruginosa (88.76%) and Staphyloccus aureus (87.42%) within 1 h of incubation at 50?C. The scanning electron microscopy (SEM), quantitation of biofilm removal assay and Crystal violet assay demonstrated that the enzyme complex detached the biofilm exo-polysaccharide matrix and bacteria from the cell surface. These results illustrate the feasibility and benefits of using this enzyme complex as anti-biofilm therapeutics to eradicate biofilms. This can also be used as a promising strategy to improve treatment of multidrug resistant bacterial infections. 展开更多
关键词 PENICILLIUM janthinellum CELLULASE biofilm DEGRADATION Bacterial biofilms
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温度对改良后Atmosphere-exposed Biofilm系统处理特性的影响
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作者 王颖 聂冬 金明姬 《科学技术与工程》 北大核心 2018年第17期332-336,共5页
研究利用改良后Atmosphere-exposed Biofilm系统处理了模拟废水,调查分析了温度对改良后系统处理性能的影响。同时,通过菲尔普斯公式探求了改良后系统的温度系数。结果,在10~35℃温度范围内,改良后Atmosphere-exposed Biofilm系统的COD... 研究利用改良后Atmosphere-exposed Biofilm系统处理了模拟废水,调查分析了温度对改良后系统处理性能的影响。同时,通过菲尔普斯公式探求了改良后系统的温度系数。结果,在10~35℃温度范围内,改良后Atmosphere-exposed Biofilm系统的COD、TN及TP出水浓度呈下降趋势,去除率及去除速率呈上升趋势,与改良前相比系统在低温及高温阶段TN、TP的处理具有一定耐温性。改良后系统的COD、TN及TP温度系数分别为1.007 3、1.029 7及1.030 6,温度对TP的影响最大。 展开更多
关键词 Atmosphere-exposed biofilm 改良 温度 处理特性 温度系数
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Research Development and Application of Nitrogen and Phosphorus Removal in Sequencing Batch Biofilm Reactor
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作者 Cao Shan Cao Xiuqin 《Meteorological and Environmental Research》 CAS 2014年第3期1-3,6,共4页
Frequent variations of the wastewater quality and quantity and other uncertain factors are the challenges faced by many wastewater treatment plants during the operation. Sequencing batch biofilm reactor( SBBR) proce... Frequent variations of the wastewater quality and quantity and other uncertain factors are the challenges faced by many wastewater treatment plants during the operation. Sequencing batch biofilm reactor( SBBR) process provides a new idea for an effective solution to this problem. This paper introduces the basic processes and characteristics of the sequencing batch biofilm reactor( SBBR) process,and summarizes the research status of this process in wastewater treatment. Factors affecting the nitrogen and phosphorus removal effect of the SBBR process are also analyzed. 展开更多
关键词 Sequencing batch biofilm reactor Wastewater treatment Nitrogen and phosphorus removal FILLER biofilm China
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Inhibition of Biofilms by Non-Thermal Plasma Treated Novel Solutions
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作者 Utku K. Ercan Siddharth S. Joshi +5 位作者 Adam Yost Natalie Gogotsi Sean O’Toole Michelle Paff Eric Melchior Suresh G. Joshi 《Advances in Microbiology》 2014年第16期1188-1196,共9页
Biofilms act as a reservoir of infection, and periodically release cells in vicinity that are capable of developing new biofilm colonies and disseminate infection. Many chronic bacterial infections are serious that ar... Biofilms act as a reservoir of infection, and periodically release cells in vicinity that are capable of developing new biofilm colonies and disseminate infection. Many chronic bacterial infections are serious that are associated with biofilms and have high morbidity and mortality, partly due to their higher resistance to antimicrobial agents, and partly due to lack of strong biocides which can efficiently treat and inhibit biofilm formation. We recently demonstrated that nonequilibrium non-thermal dielectric-barrier discharge plasma (Plasma) can also be applied to control pathogens via applying treated-liquids, and these liquids acquire broad-spectrum antimicrobial properties. In present studies we demonstrated a range of plasma-activated simple chemical solutions which significantly inhibited biofilm formation by multidrug-resistant bacterial pathogens. Plasma-activated methionine solution exhibited strong inhibitory activity against the biofilms of car-bapenem-resistant Acinetobacter baumannii, methicillin-resistant Staphylococcus aureus, metal-lo-β-lactamase (NDM1)-positive Klebsiella pneumoniae, and Enterococcus faecalis, and prevented the formation of biofilms by about 70% as compared to untreated controls in single exposure. In addition to inhibition of biofilm formation, a complete inactivation of biofilm-embedded bacterial cells was observed in less than 30 minute’s exposure to candidate plasma-activated methionine solution. These findings suggest that plasma-activated solutions have a potential to prevent biofilm formation, and as biofilm inhibitor. 展开更多
关键词 ACINETOBACTER BAUMANNII ANTIBACTERIAL Solution ANTIbiofilm Agent biofilm MRSA Nonthermal Plasma
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水力负荷对Atmosphere-Exposed Biofilm(AEB)净化效果的影响 被引量:2
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作者 王必胜 金明姬 +1 位作者 徐明哲 齐书亭 《西南农业学报》 CSCD 北大核心 2016年第12期2971-2974,共4页
本文采用Atmosphere-Exposed Biofilm(AEB)处理模拟废水,调查分析了水力负荷(4.3、8.5、12.7、17.0、21.3rn/d)对系统处理特性的影响。结果表明,水力负荷对COD、TN、TP具有不同程度的影响,COD、TN、TP最佳去除率分别出现17... 本文采用Atmosphere-Exposed Biofilm(AEB)处理模拟废水,调查分析了水力负荷(4.3、8.5、12.7、17.0、21.3rn/d)对系统处理特性的影响。结果表明,水力负荷对COD、TN、TP具有不同程度的影响,COD、TN、TP最佳去除率分别出现17.0、17.0、21.3m/d。在17.0~21.3m/d负荷范围内,COD、TN出水浓度满足了《城镇污水处理厂污染物排放标准》一级A标准,TP满足一级B标准。在所有运行范围内,系统COD、TN、TP去除速率相对恒定。系统水力负荷与进出水浓度比(C/C0)拟合结果,水力负荷与系统处理特性具有一定相关性。综合水力负荷对系统处理特性的影响,水力负荷为17.0m/d时,Atmosphere.Exposed Biofilm(AEB)系统处理效果较优。 展开更多
关键词 Atmosphere—Exposed biofilm 水力负荷 处理特性 去除速率
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Determination of the Anti-Adhesive and Anti-Biofilm Capacity of a Wheat Extract on <i>Staphylococcus aureus</i>in Farms
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作者 Maria Angeles Calvo Torras Esteban Leonardo Arosemena Angulo +1 位作者 Susana Martin Orúe Xavier Torras Bombardó 《Journal of Materials Science and Chemical Engineering》 2021年第9期11-21,共11页
The formation of biofilm by pathogenic microorganisms has become a problem in the livestock industry since it is considered a potential source of infection for farm animals while increasing microbial resistance to phy... The formation of biofilm by pathogenic microorganisms has become a problem in the livestock industry since it is considered a potential source of infection for farm animals while increasing microbial resistance to physical and chemical agents. Some plant extracts, such as soluble wheat extract, have been shown to be effective in inhibiting or destroying the biofilm of certain micro-organisms under specific conditions. The objective of this study is to evaluate the capacity of the pathogen to form biofilm on different surfaces used in livestock, as well as to evaluate the anti-biofilm capacity of the soluble wheat extract against <i>S. aureus</i> on these surfaces. The inhibition potential of inhibition or destruction of biofilm was tested in vitro. Wheat extract at a concentration of 0.29 mg/100mL showed anti-biofilm activity on <i>S. aureus</i>, inhibiting its formation, as well as destroying it greatly after a contact time of 24 hours, on those surfaces where the microorganism presents more adhesion capacity. 展开更多
关键词 Microbiology biofilm Anti-biofilm Wheat Extract Staphylococcus Aureus
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