Biofilms最新文献

{"title":"Action of ciprofloxacin on planktonic bacteria and biofilm of Proteus mirabilis","authors":"V. Aiassa, A. I. Barnes, I. Albesa","doi":"10.1017/S1479050507002086","DOIUrl":"https://doi.org/10.1017/S1479050507002086","url":null,"abstract":"","PeriodicalId":87392,"journal":{"name":"Biofilms","volume":"3 1","pages":"11-17"},"PeriodicalIF":0.0,"publicationDate":"2006-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/S1479050507002086","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57038157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of smectite clay on biofilm formation by microorganisms","authors":"A. Alimova, M. Roberts, A. Katz, E. Rudolph, J. Steiner, R. Alfano, P. Gottlieb","doi":"10.1017/S1479050507002128","DOIUrl":"https://doi.org/10.1017/S1479050507002128","url":null,"abstract":"We have investigated the role of smectite clay particles in biofilm formation by several different species of bacteria ( Pseudomonas syringae, Escherichia coli , Staphylococcus aureus and Bacillus subtilis ). We observed that the presence of clay particles enhances the formation of biofilms and, after 24 h, the bacterial populations in the clay mixtures were greater than the respective populations in media without clay. Smectite-bearing clay slurries uniformly develop bacteria–clay aggregates with a substantial biofilm component within 24 h, while the exclusively bacterial suspensions do not develop any observable biofilm component. The biofilm–clay aggregates vary in size from tens of micrometers to several millimeters. Biofilm formation was evaluated by phase contrast microscopy and fluorescence staining. Biofilm promotion by smectite clays may indicate the importance of transport of bacteria by aerosol dust particles.","PeriodicalId":87392,"journal":{"name":"Biofilms","volume":"3 1","pages":"47-54"},"PeriodicalIF":0.0,"publicationDate":"2006-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/S1479050507002128","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57038218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adaptation of microbial communities in soil contaminated with polychlorinated biphenyls, leading to the transformation of more highly chlorinated congeners in biofilm communities","authors":"A. Macêdo, T. Neu, U. Kuhlicke, W. Abraham","doi":"10.1017/S1479050507002116","DOIUrl":"https://doi.org/10.1017/S1479050507002116","url":null,"abstract":"A site polluted for many years with polychlorinated biphenyls (PCB) was used to elucidate the metabolic adaptation of microbial communities to these xenobiotics. Soil samples taken along a gradient of PCB-pollution at this site were used to grow biofilm communities on PCB oil. The biofilm communities originating from the non-polluted soil formed rather uniform and thin bacterial layers on PCB oil, while the biofilms originating from contaminated soil samples formed agglomerated structures on the PCB droplets. Biofilm communities were very diverse but those from highly polluted soil were dominated by Burkholderia species, a genus known for degrading several PCBs. All biofilm communities could transform low to medium chlorinated PCB congeners but a strong increase in the rate and degree of PCB transformation in communities from heavily polluted soil was observed. Notably, pentachlorinated congeners were transformed only by biofilms derived from the highly polluted soil but at the same time the content of trichlorinated congeners did not decrease. It is assumed that biofilms from the highly contaminated soil reductively dechlorinated PCB, converting pentachlorinated congeners to trichlorinated congeners in the spherical biofilm aggregates by diffusing to the surface of the aggregates, where aerobic transformation took place.","PeriodicalId":87392,"journal":{"name":"Biofilms","volume":"3 1","pages":"37-46"},"PeriodicalIF":0.0,"publicationDate":"2006-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/S1479050507002116","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57038205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bacterial adhesion to stainless steel is reduced by aqueous fish extract coatings","authors":"N. Bernbom, R. L. Jørgensen, Y. Y. Ng, R. Meyer, P. Kingshott, R. M. Vejborg, P. Klemm, F. Besenbacher, L. Gram","doi":"10.1017/S1479050507002104","DOIUrl":"https://doi.org/10.1017/S1479050507002104","url":null,"abstract":"Microbial adhesion and biofilm formation on surfaces pose major problems and risks to human health. One way to circumvent this problem is to coat surfaces (in this report stainless steel) with a non-toxic fish extract that generates an abiotic surface with less bacterial attachment than uncoated surfaces or surfaces coated with, for example, tryptone soy broth. The bacteria grow well in the fish extract; hence a general bacteriocidal effect is not the reason for the antifouling effect. Bacterial attachment was quantified by different methods including (a) direct fluorescence microscopy, (b) removal by ultrasound and subsequent quantification of the adhered bacteria, and (c) regrowth of the adhered bacteria measured by indirect conductometry. Surprisingly, the bacterial counts on surfaces coated with aqueous fish extract were 10‐100 times lower than on surfaces coated with laboratory broths when surfaces were submerged in bacterial suspensions. The effect was seen for Pseudomonas fluorescens AH2, Pseudomonas aeruginosa PAO1, Escherichia coli MG1655, Vibrio anguillarum 90-11-287 and Aeromonas salmonicida Jno 3175/88. It lasted for at least 7 days. Atomic force microscopy showed that steel surfaces conditioned with fish extract were covered by a thin layer of spherical, nanosized particles. Chemical analysis of the surfaces coated with adsorbed fish extract using X-ray photoelectron spectroscopy revealed that the layer was proteinaceous and had a thickness less than 2nm. Numerous protein bands/peaks were also detected by sodium dodecyl sulphate‐polyacrylamide gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry techniques. We conclude that coating the stainless steel surface with fish extract results in a thin protein layer that reduces bacterial adhesion significantly.","PeriodicalId":87392,"journal":{"name":"Biofilms","volume":"3 1","pages":"25-36"},"PeriodicalIF":0.0,"publicationDate":"2006-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/S1479050507002104","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57038194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of oxygen and growth medium on in vitro biofilm formation by Escherichia coli","authors":"L. A. Bjergbæk, J. Haagensen, A. Reisner, S. Molin, P. Roslev","doi":"10.1017/S1479050507002074","DOIUrl":"https://doi.org/10.1017/S1479050507002074","url":null,"abstract":"The effects of oxygen availability on in vitro biofilm formation by an Escherichia coli K-12 strain and 13 clinical E. coli strains were compared. All E. coli strains were capable of forming monospecies biofilm on polystyrene in aerobic media. The K-12 strain produced biofilm in both aerobic glucose minimal medium (ABTG), and aerobic trypticase soy broth (TSB) whereas the majority of the clinical strains produced significant biofilm only in aerobic TSB (9 of 13). In anaerobic media, E. coli K-12 and 9 of the 13 clinical strains were capable of forming biofilm in vitro . Only three clinical strains formed biofilm in anaerobic TSB whereas six clinical strains produced detectable biofilm in anaerobic ABTG. None of the strains tested were capable of forming biofilm in both anaerobic ABTG and anaerobic TSB. Strains that were good biofilm formers in aerobic ABTG also produced the highest amount of biofilm in anaerobic ABTG ( R 2 = 0.90). Image analysis revealed notable differences in architecture for biofilms grown in the presence and in the absence of oxygen. In aerobic ABTG, the biofilm was dominated by tall, mushroom-shaped microcolonies with pores and channels whereas biofilm in anaerobic ABTG was thinner and less heterogeneous, resulting in reduced maximum thickness and biovolume. Analysis of phospholipid fatty acid (PLFA) profiles from E. coli K-12 and three clinical strains did not reveal a specific pattern associated with the biofilm phenotypes. Interestingly, the clinical E. coli strains adjusted their PLFA composition much more than did E. coli K-12 in response to changes in growth regimens. Collectively, the results indicate that oxygen availability may affect E. coli biofilm formation in minimal and complex media. The results confirm that E. coli K-12 and some clinical E. coli strains are capable of forming in vitro biofilm under anaerobic conditions. However, the data also suggest that this attribute is highly strain dependent and may vary significantly among clinical isolates.","PeriodicalId":87392,"journal":{"name":"Biofilms","volume":"1 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2006-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/S1479050507002074","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57038145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Carbon substrate utilization as a method of studying biofilm development","authors":"D. Spratt, J. Pratten","doi":"10.1017/S1479050506002006","DOIUrl":"https://doi.org/10.1017/S1479050506002006","url":null,"abstract":"The aim of this work was to study the community level physiological profile of a developing oral biofilm. Mixed-species biofilms, derived from human saliva, were grown in a constant-depth film fermentor for up to 240 h. Biolog GP2 microplates were inoculated with saliva or homogenized biofilms and incubated at 37°C. The results showed that a biofilm community could utilize a range of substrates more diverse than those of their planktonic counterparts. Following the construction of dendrograms, a temporal relationship was demonstrated between the inoculum and biofilms, and the difference in communities over time was also resolved by using an eight-digit code of positive carbon sources. The diversity of the populations could be determined through the use of the community level physiological profile and the treatment of the data may augment the interpretation of the results. Methods such as community level physiological profiling may provide a valuable insight into the composition of biofilm communities associated with oral health and disease. © 2006 Cambridge University Press.","PeriodicalId":87392,"journal":{"name":"Biofilms","volume":"2 1","pages":"239-243"},"PeriodicalIF":0.0,"publicationDate":"2005-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/S1479050506002006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57037100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure and rheological behaviour of the extracellular polymeric substance network of mucoid Pseudomonas aeruginosa biofilms","authors":"M. Wloka, H. Rehage, H. Flemming, J. Wingender","doi":"10.1017/S1479050506002031","DOIUrl":"https://doi.org/10.1017/S1479050506002031","url":null,"abstract":"A rheological study was performed on biofilms of mucoid Pseudomonas aeruginosa strains producing high molecular weight alginate as the major polysaccharide component of the extracellular polymeric substances (EPS). Environmental strain SG81 and clinical strain FRD1 produced O -acetylated alginate, and mutant FRD1153 derived from strain FRD1 was defective in alginate acetylation. Confluent biofilms were prepared by cultivating the bacteria at 36 °C for 24 h on membrane filters placed on Pseudomonas isolation agar. The rheological properties of these pure culture biofilms attached to the membrane filters were analysed using a rotating disc rheometer. The biofilms of all mucoid strains showed viscoelastic properties, with polymer (alginate) cross-linking caused predominantly by physical interactions in the form of entanglements. In dynamic frequency-sweep tests, we observed time-dependent plateau regimens, describing the dynamics of network structures. From these data, we could derive the concentration of elastically effective polymer chains as 5 (±1) x 10 19 chains/l (limits are standard deviation) for 24 h old biofilms of P. aeruginosa SG81. Relaxation processes predicted an average lifetime of junction points of the order of 16 (±10) s. Pseudomona aeruginosa FRD1 revealed a more elastic polymer network when compared with the acetylation-defective strain FRD1153, which had a more viscous biofilm structure. With calcium (10 mmol/l) added to the growth medium, enhanced biofilm stability was observed, which was based mainly on Coulomb interactions between divalent calcium ions and the carboxylate groups of alginate, with entanglements making only minor contributions. The calcium-induced increase in polymer network stability was greater in biofilms of P. aeruginosa FRD1 than in the acetylation-defective strain FRD1153. These results indicate that acetyl groups as low molecular weight substituents of alginate polymers strongly influence the rheological behaviour of mucoid P. aeruginosa biofilms and are involved in the stabilization of polymer networks of the EPS matrix in both the absence and the presence of calcium ions.","PeriodicalId":87392,"journal":{"name":"Biofilms","volume":"2 1","pages":"275-283"},"PeriodicalIF":0.0,"publicationDate":"2005-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/S1479050506002031","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57037130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal variation of an initial marine biofilm community and its effects on larval settlement and metamorphosis of the tubeworm Hydroides elegans","authors":"Nicholas J. Shikuma, M. Hadfield","doi":"10.1017/S1479050506002018","DOIUrl":"https://doi.org/10.1017/S1479050506002018","url":null,"abstract":"Planktonic larvae of many sessile marine invertebrates settle and metamorphose preferentially on surfaces covered by bacterial biofilms. The polychaete tubewormHydroides elegansis induced to settle by biofilms and is the primary colonizer of newly submerged surfaces in the succession of macrofouling invertebrates in Pearl Harbor, Hawaii, USA. This study examines the succession of bacterial community composition and cell density of marine biofilms, and how temporal changes in biofilms affect settlement of H. elegans. Settlement assays of H. elegans were conducted on naturally formed biofilms of increasing age from Pearl Harbor. Denaturing gradient gel electrophoresis and epifluoresence microscopy were used to identify community composition and densities of bacterial cells in biofilms. Results of this study suggest that increasing densities of a stable community, rather than a shift in dominant species composition of biofilm bacteria, are probably responsible for the primary colonization of submerged surfaces by H. elegans in Pearl Harbor. However, the current data leave open the question of why larvae of other biofouling invertebrate species known to settle in response to biofilms recruit to surfaces only at later times.","PeriodicalId":87392,"journal":{"name":"Biofilms","volume":"2 1","pages":"231-238"},"PeriodicalIF":0.0,"publicationDate":"2005-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/S1479050506002018","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57037112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Susceptibility of Pseudomonas aeruginosa biofilm to UV-A illumination over photocatalytic and non-photocatalytic surfaces","authors":"J. Gage, T. Roberts, J. Duffy","doi":"10.1017/S1479050505001857","DOIUrl":"https://doi.org/10.1017/S1479050505001857","url":null,"abstract":"The susceptibility of Pseudomonas aeruginosa (PA01) bacteria to ultraviolet-A (UV-A) light in photocatalytic and non-photocatalytic systems was investigated. Thin films of TiO 2 were deposited on glass slides using a dip-coating method. Disinfection of both planktonic and biofilm bacterial cells was studied over both coated and uncoated slides exposed to low intensity (1.0 mW/cm 2 ) UV-A irradiation. Photocatalytic treatment of planktonic PA01 cultures pro-vided a 4-log reduction in the number of viable cells in 3 h whereas UV light alone produced a 1-log reduction. For biofilm bacteria, photocatalytic treatment did not enhance killing relative to UV treatment alone; however, the UV illumination resulted in a 2- to 3-log reduction in viable cells as compared with non-illuminated controls. Possible explanations for the discrepancy between susceptibility of planktonic and biofilm bacteria to photocatalytic oxidation are discussed.","PeriodicalId":87392,"journal":{"name":"Biofilms","volume":"2 1","pages":"155-163"},"PeriodicalIF":0.0,"publicationDate":"2005-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/S1479050505001857","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57037027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Qualitative and quantitative changes in marine biofilms as a function of temperature and salinity in summer and winter","authors":"J. M. Chiu, V. Thiyagarajan, M. Tsoi, P. Qian","doi":"10.1017/S147905050500195X","DOIUrl":"https://doi.org/10.1017/S147905050500195X","url":null,"abstract":"This study examined quantitative (dry weight, chlorophyll a content and C:N ratio) and qualitative (community compositions of bacteria and diatoms) changes in marine biofilms as a function of season (summer 2003 and winter 2004), temperature (16, 23 and 30 ◦ C) and salinity (20‰ ,2 7‰ and 34‰) underlaboratoryconditions.Biofilmswereallowedtodevelopfor20daysinthe laboratory,usingnaturalseawatercollectedfromPortShelter,HongKong.The following results were obtained: (1) biofilm dry weight was greater in summer than in winter, and greater at 34‰ than at 20‰; (2) biofilm chlorophyll a content was affected by all three factors (season, temperature and salinity), with significant interactive effects among the three factors; and (3) C:N ratio was affected by season (winter >summer) and temperature (30 ◦ C >16 ◦ Ci n summer), but not by salinity. Bacterial community composition was analyzed by terminal restriction-fragment length polymorphism of polymerase chain reaction-amplified 16S rRNA genes. In summer, community compositions of both bacteria and diatoms were strongly affected by salinity. In addition, natural summer biofilms that developed at three field sites, where different salinities were found, harbored appreciably different bacterial and diatom community compositions. In contrast, in winter, temperature exerted a major influence on community compositions. The present study adds to the growing evidence that environmental factors are important determinants of both the quality and quantity of marine biofilms.","PeriodicalId":87392,"journal":{"name":"Biofilms","volume":"54 1","pages":"183-195"},"PeriodicalIF":0.0,"publicationDate":"2005-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/S147905050500195X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57037077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}