scholarly journals Initial Phases of Biofilm Formation in Shewanella oneidensis MR-1

2004 ◽  
Vol 186 (23) ◽  
pp. 8096-8104 ◽  
Author(s):  
Kai M. Thormann ◽  
Renée M. Saville ◽  
Soni Shukla ◽  
Dale A. Pelletier ◽  
Alfred M. Spormann

ABSTRACT Shewanella oneidensis MR-1 is a facultative Fe(III)- and Mn(IV)-reducing microorganism and serves as a model for studying microbially induced dissolution of Fe or Mn oxide minerals as well as biogeochemical cycles. In soil and sediment environments, S. oneidensis biofilms form on mineral surfaces and are critical for mediating the metabolic interaction between this microbe and insoluble metal oxide phases. In order to develop an understanding of the molecular basis of biofilm formation, we investigated S. oneidensis biofilms developing on glass surfaces in a hydrodynamic flow chamber system. After initial attachment, growth of microcolonies and lateral spreading of biofilm cells on the surface occurred simultaneously within the first 24 h. Once surface coverage was almost complete, biofilm development proceeded with extensive vertical growth, resulting in formation of towering structures giving rise to pronounced three-dimensional architecture. Biofilm development was found to be dependent on the nutrient conditions, suggesting a metabolic control. In global transposon mutagenesis, 173 insertion mutants out of 15,000 mutants screened were identified carrying defects in initial attachment and/or early stages in biofilm formation. Seventy-one of those mutants exhibited a nonswimming phenotype, suggesting a role of swimming motility or motility elements in biofilm formation. Disruption mutations in motility genes (flhB, fliK, and pomA), however, did not affect initial attachment but affected progression of biofilm development into pronounced three-dimensional architecture. In contrast, mutants defective in mannose-sensitive hemagglutinin type IV pilus biosynthesis and in pilus retraction (pilT) showed severe defects in adhesion to abiotic surfaces and biofilm formation, respectively. The results provide a basis for understanding microbe-mineral interactions in natural environments.

2008 ◽  
Vol 190 (8) ◽  
pp. 2759-2766 ◽  
Author(s):  
V. S. R. K. Maddula ◽  
E. A. Pierson ◽  
L. S. Pierson

ABSTRACT Pseudomonas chlororaphis strain 30-84 is a plant-beneficial bacterium that is able to control take-all disease of wheat caused by the fungal pathogen Gaeumannomyces graminis var. tritici. The production of phenazines (PZs) by strain 30-84 is the primary mechanism of pathogen inhibition and contributes to the persistence of strain 30-84 in the rhizosphere. PZ production is regulated in part by the PhzR/PhzI quorum-sensing (QS) system. Previous flow cell analyses demonstrated that QS and PZs are involved in biofilm formation in P. chlororaphis (V. S. R. K. Maddula, Z. Zhang, E. A. Pierson, and L. S. Pierson III, Microb. Ecol. 52:289-301, 2006). P. chlororaphis produces mainly two PZs, phenazine-1-carboxylic acid (PCA) and 2-hydroxy-PCA (2-OH-PCA). In the present study, we examined the effect of altering the ratio of PZs produced by P. chlororaphis on biofilm formation and pathogen inhibition. As part of this study, we generated derivatives of strain 30-84 that produced only PCA or overproduced 2-OH-PCA. Using flow cell assays, we found that these PZ-altered derivatives of strain 30-84 differed from the wild type in initial attachment, mature biofilm architecture, and dispersal from biofilms. For example, increased 2-OH-PCA production promoted initial attachment and altered the three-dimensional structure of the mature biofilm relative to the wild type. Additionally, both alterations promoted thicker biofilm development and lowered dispersal rates compared to the wild type. The PZ-altered derivatives of strain 30-84 also differed in their ability to inhibit the fungal pathogen G. graminis var. tritici. Loss of 2-OH-PCA resulted in a significant reduction in the inhibition of G. graminis var. tritici. Our findings suggest that alterations in the ratios of antibiotic secondary metabolites synthesized by an organism may have complex and wide-ranging effects on its biology.


RSC Advances ◽  
2019 ◽  
Vol 9 (56) ◽  
pp. 32453-32461
Author(s):  
Yan-Ping Wu ◽  
Xiao-Yan Liu ◽  
Jin-Rong Bai ◽  
Hong-Chen Xie ◽  
Si-Liang Ye ◽  
...  

3-p-trans-Coumaroyl-2-hydroxyquinic acid (CHQA), a natural phenolic compound, prevented Staphylococcus aureus biofilm formation due to the inhibition of the initial attachment stage of biofilm development by targeting sortase A.


2008 ◽  
Vol 58 (6) ◽  
pp. 1221-1229 ◽  
Author(s):  
D. H. Dusane ◽  
Y. V. Nancharaiah ◽  
V. P. Venugopalan ◽  
A. R. Kumar ◽  
S. S. Zinjarde

Biofilm formation by Yarrowia lipolytica, a biotechnologically important fungus in microtitre plates, on glass slide surfaces and in flow cell was investigated. In microtitre plates, there was a short lag phase of adhesion followed by a period of rapid biofilm growth. The fungus formed extensive biofilms on glass slides, whereas in flow-cells a multicellular, three-dimensional microcolony structure was observed. The isolate formed biofilms in seawater and in fresh water media at neutral pH when grown in microtitre plates. The carbon sources differentially affected formation of biofilms in microtitre plates. Lactic acid, erythritol, glycerol, glucose and edible oils supported the formation of biofilms, while alkanes resulted in sub-optimal biofilm development. A variation in the morphology of the fungus was observed with different carbon sources. The results point to the possible existence of highly structured biofilms in varied ecological niches from where the yeast is isolated.


2007 ◽  
Vol 73 (8) ◽  
pp. 2690-2696 ◽  
Author(s):  
Leonardo De La Fuente ◽  
Emilie Montanes ◽  
Yizhi Meng ◽  
Yaxin Li ◽  
Thomas J. Burr ◽  
...  

ABSTRACT Xylella fastidiosa, a bacterium responsible for Pierce's disease in grapevines, possesses both type I and type IV pili at the same cell pole. Type IV pili facilitate twitching motility, and type I pili are involved in biofilm development. The adhesiveness of the bacteria and the roles of the two pili types in attachment to a glass substratum were evaluated using a microfluidic flow chamber in conjunction with pilus-defective mutants. The average adhesion force necessary to detach wild-type X. fastidiosa cells was 147 ± 11 pN. Mutant cells possessing only type I pili required a force of 204 ± 22 pN for removal, whereas cells possessing only type IV pili required 119 ± 8 pN to dislodge these cells. The experimental results demonstrate that microfluidic flow chambers are useful and convenient tools for assessing the drag forces necessary for detaching bacterial cells and that with specific pilus mutants, the role of the pilus type can be further assessed.


2008 ◽  
Vol 76 (11) ◽  
pp. 4944-4951 ◽  
Author(s):  
John J. Varga ◽  
Blair Therit ◽  
Stephen B. Melville

ABSTRACT The predominant organizational state of bacteria in nature is biofilms. Biofilms have been shown to increase bacterial resistance to a variety of stresses. We demonstrate for the first time that the anaerobic gram-positive pathogen Clostridium perfringens forms biofilms. At the same concentration of glucose in the medium, optimal biofilm formation depended on a functional CcpA protein. While the ratio of biofilm to planktonic growth was higher in the wild type than in a ccpA mutant strain in middle to late stages of biofilm development, the bacteria shifted from a predominantly biofilm state to planktonic growth as the concentration of glucose in the medium increased in a CcpA-independent manner. As is the case in some gram-negative bacteria, type IV pilus (TFP)-dependent gliding motility was necessary for efficient biofilm formation, as demonstrated by laser confocal and electron microscopy. However, TFP were not associated with the bacteria in the biofilm but with the extracellular matrix. Biofilms afforded C. perfringens protection from environmental stress, including exposure to atmospheric oxygen for 6 h and 24 h and to 10 mM H2O2 for 5 min. Biofilm cells also showed 5- to 15-fold-increased survival over planktonic cells after exposure to 20 μg/ml (27 times the MIC) of penicillin G for 6 h and 24 h, respectively. These results indicate C. perfringens biofilms play an important role in the persistence of the bacteria in response to environmental stress and that they may be a factor in diseases, such as antibiotic-associated diarrhea and gas gangrene, that are caused by C. perfringens.


2018 ◽  
Vol 87 (1) ◽  
Author(s):  
David R. Danforth ◽  
Gaoyan Tang-Siegel ◽  
Teresa Ruiz ◽  
Keith P. Mintz

ABSTRACTPeriodontitis is an inflammatory disease caused by polymicrobial biofilms. The periodontal pathogenAggregatibacter actinomycetemcomitansdisplays two proteinaceous surface structures, the fimbriae and the nonfimbrial extracellular matrix binding protein A (EmaA), as observed by electron microscopy. Fimbriae participate in biofilm biogenesis and the EmaA adhesins mediate collagen binding. However, in the absence of fimbriae,A. actinomycetemcomitansstill retains the potential to form robust biofilms, suggesting that other surface macromolecules participate in biofilm development. Here, isogenic mutant strains lacking EmaA structures, but still expressing fimbriae, were observed to have reduced biofilm potential. In strains lacking both EmaA and fimbriae, biofilm mass was reduced by 80%. EmaA enhanced biofilm formation in different strains, independent of the fimbriation state or serotype. Confocal microscopy revealed differences in cell density within microcolonies between the EmaA positive and mutant strains. EmaA-mediated biofilm formation was found to be independent of the glycosylation state and the precise three-dimensional conformation of the protein, and thus this function is uncorrelated with collagen binding activity. The data suggest that EmaA is a multifunctional adhesin that utilizes different mechanisms to enhance bacterial binding to collagen and to enhance biofilm formation, both of which are important forA. actinomycetemcomitanscolonization and subsequent infection.


Author(s):  
Katrin Schilcher ◽  
Alexander R. Horswill

SUMMARY In many natural and clinical settings, bacteria are associated with some type of biotic or abiotic surface that enables them to form biofilms, a multicellular lifestyle with bacteria embedded in an extracellular matrix. Staphylococcus aureus and Staphylococcus epidermidis, the most frequent causes of biofilm-associated infections on indwelling medical devices, can switch between an existence as single free-floating cells and multicellular biofilms. During biofilm formation, cells first attach to a surface and then multiply to form microcolonies. They subsequently produce the extracellular matrix, a hallmark of biofilm formation, which consists of polysaccharides, proteins, and extracellular DNA. After biofilm maturation into three-dimensional structures, the biofilm community undergoes a disassembly process that leads to the dissemination of staphylococcal cells. As biofilms are dynamic and complex biological systems, staphylococci have evolved a vast network of regulatory mechanisms to modify and fine-tune biofilm development upon changes in environmental conditions. Thus, biofilm formation is used as a strategy for survival and persistence in the human host and can serve as a reservoir for spreading to new infection sites. Moreover, staphylococcal biofilms provide enhanced resilience toward antibiotics and the immune response and impose remarkable therapeutic challenges in clinics worldwide. This review provides an overview and an updated perspective on staphylococcal biofilms, describing the characteristic features of biofilm formation, the structural and functional properties of the biofilm matrix, and the most important mechanisms involved in the regulation of staphylococcal biofilm formation. Finally, we highlight promising strategies and technologies, including multitargeted or combinational therapies, to eradicate staphylococcal biofilms.


2014 ◽  
Vol 27 (10) ◽  
pp. 1132-1147 ◽  
Author(s):  
German Dunger ◽  
Cristiane R. Guzzo ◽  
Maxuel O. Andrade ◽  
Jeffrey B. Jones ◽  
Chuck S. Farah

Bacterial type IV pili (T4P) are long, flexible surface filaments that consist of helical polymers of mostly pilin subunits. Cycles of polymerization, attachment, and depolymerization mediate several pilus-dependent bacterial behaviors, including twitching motility, surface adhesion, pathogenicity, natural transformation, escape from immune system defense mechanisms, and biofilm formation. The Xanthomonas citri subsp. citri strain 306 genome codes for a large set of genes involved in T4P biogenesis and regulation and includes several pilin homologs. We show that X. citri subsp. citri can exhibit twitching motility in a manner similar to that observed in other bacteria such as Pseudomonas aeruginosa and Xylella fastidiosa and that this motility is abolished in Xanthomonas citri subsp. citri knockout strains in the genes coding for the major pilin subunit PilAXAC3241, the ATPases PilBXAC3239 and PilTXAC2924, and the T4P biogenesis regulators PilZXAC1133 and FimXXAC2398. Microscopy analyses were performed to compare patterns of bacterial migration in the wild-type and knockout strains and we observed that the formation of mushroom-like structures in X. citri subsp. citri biofilm requires a functional T4P. Finally, infection of X. citri subsp. citri cells by the bacteriophage (ΦXacm4-11 is T4P dependent. The results of this study improve our understanding of how T4P influence Xanthomonas motility, biofilm formation, and susceptibility to phage infection.


2021 ◽  
Author(s):  
Raquel Martínez-Méndez ◽  
Diego A. Camacho-Hernández ◽  
Elizabeth Sulvarán-Guel ◽  
David Zamorano-Sánchez

Vibrio parahaemolyticus cells transit from free swimming to surface adapted lifestyles, such as swarming colonies and three-dimensional biofilms. These transitions are regulated by sensory modules and regulatory networks that involve the second messenger cyclic dimeric guanosine monophosphate (c-di-GMP). In this work, we show that a previously uncharacterized c-di-GMP phosphodiesterase (VP1881) from V. parahaemolyticus plays an important role in modulating the c-di-GMP pool. We found that the product of VP1881 promotes its own expression when the levels of c-di-GMP are low or when the phosphodiesterase is catalytically inactive. This behavior has been observed in a class of c-di-GMP receptors called Trigger phosphodiesterases, hence we named the product of VP1881 TpdA, for Trigger phosphodiesterase A. The absence of tpdA showed a negative effect on swimming motility while its overexpression from an IPTG inducible promoter showed a positive effect on both swimming and swarming motility, and a negative effect on biofilm formation. Changes in TpdA abundance altered the expression of representative polar and lateral flagellar genes as well as the biofilm related gene cpsA. Our results also revealed that autoactivation of the native PtpdA promoter is sufficient to alter c-di-GMP signaling responses such as swarming and biofilm formation in V. parahaemolyticus, an observation that could have important implications in the dynamics of these social behaviors. IMPORTANCE C-di-GMP trigger phosphodiesterases (PDEs) could play a key role in controlling the heterogeneity of biofilm-matrix composition, a property that endows characteristics that are potentially relevant for sustaining integrity and functionality of biofilms in a variety of natural environments. Trigger PDEs are not always easy to identify based on their sequence, hence not many examples of these type of signaling proteins have been reported in the literature. Here we report on the identification of a novel trigger PDE in V. parahaemolyticus and provide evidence suggesting that its autoactivation could play an important role in the progression of swarming motility and biofilm formation, multicellular behaviors that are important for the survival and dissemination of this environmental pathogen.


Biofilms ◽  
2005 ◽  
Vol 2 (4) ◽  
pp. 245-273

The effect of growth and detachment on formation of large-scale biofilm structureBiofilm cohesive energy density determination using a novel atomic force microscopy methodologyFluorescence correlation spectroscopy under two-photon excitation for the study of diffusion and reactivity of bacteriophage inside bacterial biofilmsBiothermodynamic characterization and dynamic analysis of biofilms using calorimetryBiomimetic antifouling coatings for sensor surfaces for water monitoring: performance control in defined biofilm cultures and under real environmental conditionsThe contribution of rpos to formation of Escherichia coli biofilmsSynergistic effects in mixed Escherichia coli biofilms: conjugative plasmid transfer drives biofilm expansionThe universal stress protein PA3309 in Pseudomonas aeruginosa is induced in biofilmsExtracellular polymeric substances from biofilms on membranes in waste-water treatment plantsBiofilm-to-planktonic cell yield: a strategy for proliferationPhysiological and phylogenetic characterization of the dispersed and loosely attached fraction of activated sludge flocsTowards a deterministic model of biofilm detachment: an experimental studyEffect of backwash on the characteristics of biofilm in a biological activated filter reactor using elemental sulfur particlesProcess performance and biomass properties in membrane-aerated bioreactorsBioaugmentation via conjugation in biofilms treating 3-chloroaniline: effects of selective pressureEffect of phosphorus on biofilm growth in a completely mixed biofilm reactorImpacts of biofilm development on reactive transport in porous media under variable flow regimensInfluence of biofilms on colloid mobility in the subsurfaceBiofilms in amendable in situ microcosms indicate relevant electron acceptor processes at a BTEX-contaminated aquiferFunctional biodiversity of complex biofilms grown on polychlorinated biphenyl oilIdentification and characterization of biofilm formation phenotypes of several clinically relevant Streptococcus pyogenes serotype strainsSelected probiotic bacteria disrupt biofilm development of vancomycin-resistant Enterococcus faeciumComparison of the extracellular polymeric substances of Candida albicans and Candida dubliniensis biofilmsInfluence of quorum-sensing regulated production of an antimicrobial component by Serratia plymuthica on establishment of dual species biofilms with Escherichia coliBiofilm formation by the thermophilic and cellulolytic actinomycete Thermobifida fuscaBiomonitoring of bacterial contamination on different surfaces of food-processing machinesRole of the flagella during the adhesion of Listeria monocytogenes EGD-e to inert surfaces after cultivation at different pHs and temperaturesAdhesion of Saccharomyces cerevisiae to stainless steel: influence of surface propertiesInvestigating the mechanical strength of biofilms with fluid dynamic gaugingThree-dimensional biofilm model with individual cells and continuum extracellular polymeric substances matrixA three-dimensional computer model analysis of four hypothetical biofilm detachment mechanismsModelling biofilm growth, detachment and fluid flow in a cross-section of tube reactorsBiofilm games


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