scholarly journals A temperature-dependent translational switch controls biofilm development in Vibrio cholerae

2020 ◽  
Author(s):  
Teresa del Peso Santos ◽  
Jonathon Blake ◽  
Brandon Sit ◽  
Alyson R. Warr ◽  
Vladimir Benes ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Translational Control ◽  
Low Temperatures ◽  
Biofilm Formation ◽  
Common Mechanism ◽  
Seasonal Temperature ◽  
Temperature Dependent ◽  
Regulatory Cascade ◽  
Biofilm Development

AbstractThe gastrointestinal pathogen Vibrio cholerae frequently forms biofilms during its life cycle. Biofilm formation is vital for protection against environmental stresses and is thought to facilitate intestinal colonization. Adaptation to temperature is crucial for V. cholerae survival, as the pathogen is exposed to seasonal temperature variations in the aquatic environment, and temperature fluctuations during host-environment transitions. Here, we show that V. cholerae strains naturally lacking the master biofilm transcriptional regulator HapR are unable to develop colony rugosity at low temperatures. We find that BipA, a ribosome-associated GTPase, accounts for this temperature-dependent control of biofilm formation by repressing translation of the primary biofilm transcriptional activators VpsR and VpsT at low temperatures. In vitro studies demonstrate that low temperatures influence BipA structural conformation and decrease its sensitivity to proteolysis. Proteomic analyses reveal that BipA exerts temperature-dependent control over >200 proteins in V. cholerae involved in a multitude of cell processes, including biofilm assembly. Our study reveals a remarkable new facet of the complex V. cholerae biofilm regulatory cascade and suggests that combined transcriptional-translational control could be a common mechanism by which bacteria adapt to environmental flux.

scholarly journals Bacterial lipopolysaccharides variably modulate in vitro biofilm formation of Candida species

2010 ◽  
Vol 59 (10) ◽  
pp. 1225-1234 ◽  
Author(s):  
H. M. H. N. Bandara ◽  
O. L. T. Lam ◽  
R. M. Watt ◽  
L. J. Jin ◽  
L. P. Samaranayake
Keyword(s):  
Biofilm Formation ◽  
Laser Scanning ◽  
Significant Inhibition ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Dependent Manner ◽  
Bacterial Lipopolysaccharides ◽  
Species Specific ◽  
Biofilm Development

The objective of this study was to evaluate the effect of the bacterial endotoxin LPS on Candida biofilm formation in vitro. The effect of the LPS of Pseudomonas aeruginosa, Klebsiella pneumoniae, Serratia marcescens and Salmonella typhimurium on six different species of Candida, comprising Candida albicans ATCC 90028, Candida glabrata ATCC 90030, Candida krusei ATCC 6258, Candida tropicalis ATCC 13803, Candida parapsilosis ATCC 22019 and Candida dubliniensis MYA 646, was studied using a standard biofilm assay. The metabolic activity of in vitro Candida biofilms treated with LPS at 90 min, 24 h and 48 h was quantified by XTT reduction assay. Viable biofilm-forming cells were qualitatively analysed using confocal laser scanning microscopy (CLSM), while scanning electron microscopy (SEM) was employed to visualize the biofilm structure. Initially, adhesion of C. albicans was significantly stimulated by Pseudomonas and Klebsiella LPS. A significant inhibition of Candida adhesion was noted for the following combinations: C. glabrata with Pseudomonas LPS, C. tropicalis with Serratia LPS, and C. glabrata, C. parapsilosis or C. dubliniensis with Salmonella LPS (P<0.05). After 24 h of incubation, a significant stimulation of initial colonization was noted for the following combinations: C. albicans/C. glabrata with Klebsiella LPS, C. glabrata/C. tropicalis/C. krusei with Salmonella LPS. In contrast, a significant inhibition of biofilm formation was observed in C. glabrata/C. dubliniensis/C. krusei with Pseudomonas LPS, C. krusei with Serratia LPS, C. dubliniensis with Klebsiella LPS and C. parapsilosis/C. dubliniensis /C. krusei with Salmonella LPS (P<0.05). On further incubation for 48 h, a significant enhancement of biofilm maturation was noted for the following combinations: C. glabrata/C. tropicalis with Serratia LPS, C. dubliniensis with Klebsiella LPS and C. glabrata with Salmonella LPS, and a significant retardation was noted for C. parapsilosis/C. dubliniensis/C. krusei with Pseudomonas LPS, C. tropicalis with Serratia LPS, C. glabrata/C. parapsilosis/C. dubliniensis with Klebsiella LPS and C. dubliniensis with Salmonella LPS (P<0.05). These findings were confirmed by SEM and CLSM analyses. In general, the inhibition of the biofilm development of LPS-treated Candida spp. was accompanied by a scanty architecture with a reduced numbers of cells compared with the profuse and densely colonized control biofilms. These data are indicative that bacterial LPSs modulate in vitro Candida biofilm formation in a species-specific and time-dependent manner. The clinical and the biological relevance of these findings have yet to be explored.

scholarly journals Effects of CO2laser irradiation on matrix-rich biofilm development formation–an in vitro study

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2458 ◽  
Author(s):  
Bruna Raquel Zancopé ◽  
Vanessa B. Dainezi ◽  
Marinês Nobre-dos-Santos ◽  
Sillas Duarte ◽  
Vanessa Pardi ◽  
...  
Keyword(s):  
Contact Angle ◽  
Biofilm Formation ◽  
Dental Enamel ◽  
In Vitro Study ◽  
Dry Weight ◽  
Vitro Study ◽  
Enamel Surface ◽  
Control Group ◽  
Biofilm Development

BackgroundA carbon dioxide (CO2) laser has been used to morphologically and chemically modify the dental enamel surface as well as to make it more resistant to demineralization. Despite a variety of experiments demonstrating the inhibitory effect of a CO2laser in reduce enamel demineralization, little is known about the effect of surface irradiated on bacterial growth. Thus, this in vitro study was preformed to evaluate the biofilm formation on enamel previously irradiated with a CO2laser (λ = 10.6 µM).MethodsFor this in vitro study, 96 specimens of bovine enamel were employed, which were divided into two groups (n = 48): 1) Control-non-irradiated surface and 2) Irradiated enamel surface. Biofilms were grown on the enamel specimens by one, three and five days under intermittent cariogenic condition in the irradiated and non-irradiated surface. In each assessment time, the biofilm were evaluated by dry weigh, counting the number of viable colonies and, in fifth day, were evaluated by polysaccharides analysis, quantitative real time Polymerase Chain Reaction (PCR) as well as by contact angle. In addition, the morphology of biofilms was characterized by fluorescence microscopy and field emission scanning electron microscopy (FESEM). Initially, the assumptions of equal variances and normal distribution of errors were conferred and the results are analyzed statistically by t-test and Mann Whitney test.ResultsThe mean of log CFU/mL obtained for the one-day biofilm evaluation showed that there is statistical difference between the experimental groups. When biofilms were exposed to the CO2laser, CFU/mL and CFU/dry weight in three day was reduced significantly compared with control group. The difference in the genes expression (Glucosyltransferases (gtfB) and Glucan-binding protein (gbpB)) and polysaccharides was not statically significant. Contact angle was increased relative to control when the surface was irradiated with the CO2laser. Similar morphology was also visible with both treatments; however, the irradiated group revealed evidence of melting and fusion in the specimens.ConclusionIn conclusion, CO2laser irradiation modifies the energy surface and disrupts the initial biofilm formation.

scholarly journals Role of the Streptococcus mutans irvA Gene in GbpC-Independent, Dextran-Dependent Aggregation and Biofilm Formation

2009 ◽  
Vol 75 (22) ◽  
pp. 7037-7043 ◽  
Author(s):  
Min Zhu ◽  
Dragana Ajdić ◽  
Yuan Liu ◽  
David Lynch ◽  
Justin Merritt ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Growth Conditions ◽  
Parental Background ◽  
A Cell ◽  
Major Surface ◽  
Biofilm Development ◽  
Small Aggregation

ABSTRACT Dextran-dependent aggregation (DDAG) of Streptococcus mutans is an in vitro phenomenon that is believed to represent a property of the organism that is beneficial for sucrose-dependent biofilm development. GbpC, a cell surface glucan-binding protein, is responsible for DDAG in S. mutans when cultured under defined stressful conditions. Recent reports have described a putative transcriptional regulator gene, irvA, located just upstream of gbpC, that is normally repressed by the product of an adjacent gene, irvR. When repression of irvA is relieved, there is a resulting increase in the expression of GbpC and decreases in competence and synthesis of the antibiotic mutacin I. This study examined the role of irvA in DDAG and biofilm formation by engineering strains that overexpressed irvA (IrvA+) on an extrachromosomal plasmid. The IrvA+ strain displayed large aggregation particles that did not require stressful growth conditions. A novel finding was that overexpression of irvA in a gbpC mutant background retained a measure of DDAG, albeit very small aggregation particles. Biofilms formed by the IrvA+ strain in the parental background possessed larger-than-normal microcolonies. In a gbpC mutant background, the overexpression of irvA reversed the fragile biofilm phenotype normally associated with loss of GbpC. Real-time PCR and Northern blot analyses found that expression of gbpC did not change significantly in the IrvA+ strain but expression of spaP, encoding the major surface adhesin P1, increased significantly. Inactivation of spaP eliminated the small-particle DDAG. The results suggest that IrvA promotes DDAG not only by GbpC, but also via an increase in P1.

scholarly journals Searching Hit Potential Antimicrobials in Natural Compounds Space against Biofilm Formation

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5334
Author(s):  
Roberto Pestana-Nobles ◽  
Jorge A. Leyva-Rojas ◽  
Juvenal Yosa
Keyword(s):  
Natural Products ◽  
Biofilm Formation ◽  
Caulobacter Crescentus ◽  
Resistant Bacteria ◽  
Chronic Infections ◽  
Aconitic Acid ◽  
Starting Point ◽  
In Silico Studies ◽  
Biofilm Development

Biofilms are communities of microorganisms that can colonize biotic and abiotic surfaces and thus play a significant role in the persistence of bacterial infection and resistance to antimicrobial. About 65% and 80% of microbial and chronic infections are associated with biofilm formation, respectively. The increase in infections by multi-resistant bacteria instigates the need for the discovery of novel natural-based drugs that act as inhibitory molecules. The inhibition of diguanylate cyclases (DGCs), the enzyme implicated in the synthesis of the second messenger, cyclic diguanylate (c-di-GMP), involved in the biofilm formation, represents a potential approach for preventing the biofilm development. It has been extensively studied using PleD protein as a model of DGC for in silico studies as virtual screening and as a model for in vitro studies in biofilms formation. This study aimed to search for natural products capable of inhibiting the Caulobacter crescentus enzyme PleD. For this purpose, 224,205 molecules from the natural products ZINC15 database, have been evaluated through molecular docking and molecular dynamic simulation. Our results suggest trans-Aconitic acid (TAA) as a possible starting point for hit-to-lead methodologies to obtain new inhibitors of the PleD protein and hence blocking the biofilm formation.

scholarly journals Early Biofilm Formation on UV Light Activated Nanoporous TiO2SurfacesIn Vivo

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Nagat Areid ◽  
Eva Söderling ◽  
Johanna Tanner ◽  
Ilkka Kangasniemi ◽  
Timo O. Närhi
Keyword(s):  
Titanium Alloy ◽  
Biofilm Formation ◽  
Uv Light ◽  
Antibacterial Properties ◽  
Mutans Streptococci ◽  
Human Gingival Fibroblast ◽  
Gingival Fibroblast ◽  
Biofilm Development

Purpose. To explore earlyS. mutansbiofilm formation on hydrothermally induced nanoporous TiO2surfacesin vivoand to examine the effect of UV light activation on the biofilm development.Materials and Methods. Ti-6Al-4V titanium alloy discs (n = 40) were divided into four groups with different surface treatments: noncoated titanium alloy (NC); UV treated noncoated titanium alloy (UVNC); hydrothermally induced TiO2coating (HT); and UV treated titanium alloy with hydrothermally induced TiO2coating (UVHT).In vivoplaque formation was studied in 10 healthy, nonsmoking adult volunteers. Titanium discs were randomly distributed among the maxillary first and second molars. UV treatment was administered for 60 min immediately before attaching the discs in subjects’ molars. Plaque samples were collected 24h after the attachment of the specimens. Mutans streptococci (MS), non-mutans streptococci, and total facultative bacteria were cultured, and colonies were counted.Results. The plaque samples of NC (NC + UVNC) surfaces showed over 2 times more oftenS. mutanswhen compared to TiO2surfaces (HT + UVHT), with the number of colonized surfaces equal to 7 and 3, respectively.Conclusion. Thisin vivostudy suggested that HT TiO2surfaces, which we earlier showed to improve blood coagulation and encourage human gingival fibroblast attachmentin vitro, do not enhance salivary microbial (mostly mutans streptococci) adhesion and initial biofilm formation when compared with noncoated titanium alloy. UV light treatment provided Ti-6Al-4V surfaces with antibacterial properties and showed a trend towards less biofilm formation when compared with non-UV treated titanium surfaces.

scholarly journals Extracellular DNA and Type IV Pilus Expression Regulate the Structure and Kinetics of Biofilm Formation by Nontypeable Haemophilus influenzae

mBio ◽  
2017 ◽  
Vol 8 (6) ◽  
Author(s):  
Jayajit Das ◽  
Elaine Mokrzan ◽  
Vinal Lakhani ◽  
Lucia Rosas ◽  
Joseph A. Jurcisek ◽  
...  
Keyword(s):  
Middle Ear ◽  
In Silico ◽  
Biofilm Formation ◽  
Rational Design ◽  
Bacterial Biofilm ◽  
Confocal Imaging ◽  
Extracellular Dna ◽  
Fractal Structures ◽  
Biofilm Development

ABSTRACT Biofilms formed in the middle ear by nontypeable Haemophilus influenzae (NTHI) are central to the chronicity, recurrence, and refractive nature of otitis media (OM). However, mechanisms that underlie the emergence of specific NTHI biofilm structures are unclear. We combined computational analysis tools and in silico modeling rooted in statistical physics with confocal imaging of NTHI biofilms formed in vitro during static culture in order to identify mechanisms that give rise to distinguishing morphological features. Our analysis of confocal images of biofilms formed by NTHI strain 86-028NP using pair correlations of local bacterial densities within sequential planes parallel to the substrate showed the presence of fractal structures of short length scales (≤10 μm). The in silico modeling revealed that extracellular DNA (eDNA) and type IV pilus (Tfp) expression played important roles in giving rise to the fractal structures and allowed us to predict a substantial reduction of these structures for an isogenic mutant (ΔcomE) that was significantly compromised in its ability to release eDNA into the biofilm matrix and had impaired Tfp function. This prediction was confirmed by analysis of confocal images of in vitro ΔcomE strain biofilms. The fractal structures potentially generate niches for NTHI survival in the hostile middle ear microenvironment by dramatically increasing the contact area of the biofilm with the surrounding environment, facilitating nutrient exchange, and by generating spatial positive feedback to quorum signaling. IMPORTANCE NTHI is a major bacterial pathogen for OM, which is a common ear infection in children worldwide. Chronic OM is associated with bacterial biofilm formation in the middle ear; therefore, knowledge of the mechanisms that underlie NTHI biofilm formation is important for the development of therapeutic strategies for NTHI-associated OM. Our combined approach using confocal imaging of NTHI biofilms formed in vitro and mathematical tools for analysis of pairwise density correlations and agent-based modeling revealed that eDNA and Tfp expression were important factors in the development of fractal structures in NTHI biofilms. These structures may help NTHI survive in hostile environments, such as the middle ear. Our in silico model can be used in combination with laboratory or animal modeling studies to further define the mechanisms that underlie NTHI biofilm development during OM and thereby guide the rational design of, and optimize time and cost for, benchwork and preclinical studies. IMPORTANCE NTHI is a major bacterial pathogen for OM, which is a common ear infection in children worldwide. Chronic OM is associated with bacterial biofilm formation in the middle ear; therefore, knowledge of the mechanisms that underlie NTHI biofilm formation is important for the development of therapeutic strategies for NTHI-associated OM. Our combined approach using confocal imaging of NTHI biofilms formed in vitro and mathematical tools for analysis of pairwise density correlations and agent-based modeling revealed that eDNA and Tfp expression were important factors in the development of fractal structures in NTHI biofilms. These structures may help NTHI survive in hostile environments, such as the middle ear. Our in silico model can be used in combination with laboratory or animal modeling studies to further define the mechanisms that underlie NTHI biofilm development during OM and thereby guide the rational design of, and optimize time and cost for, benchwork and preclinical studies.

scholarly journals Architectural transitions in Vibrio cholerae biofilms at single-cell resolution

2016 ◽  
Vol 113 (14) ◽  
pp. E2066-E2072 ◽  
Author(s):  
Knut Drescher ◽  
Jörn Dunkel ◽  
Carey D. Nadell ◽  
Sven van Teeffelen ◽  
Ivan Grnja ◽  
...  
Keyword(s):  
Single Cell ◽  
Vibrio Cholerae ◽  
Biofilm Formation ◽  
Bacterial Species ◽  
Bacterial Biomass ◽  
Biofilm Growth ◽  
Glass Substrates ◽  
Critical Transitions ◽  
Cell Shapes ◽  
Biofilm Development

Many bacterial species colonize surfaces and form dense 3D structures, known as biofilms, which are highly tolerant to antibiotics and constitute one of the major forms of bacterial biomass on Earth. Bacterial biofilms display remarkable changes during their development from initial attachment to maturity, yet the cellular architecture that gives rise to collective biofilm morphology during growth is largely unknown. Here, we use high-resolution optical microscopy to image all individual cells in Vibrio cholerae biofilms at different stages of development, including colonies that range in size from 2 to 4,500 cells. From these data, we extracted the precise 3D cellular arrangements, cell shapes, sizes, and global morphological features during biofilm growth on submerged glass substrates under flow. We discovered several critical transitions of the internal and external biofilm architectures that separate the major phases of V. cholerae biofilm growth. Optical imaging of biofilms with single-cell resolution provides a new window into biofilm formation that will prove invaluable to understanding the mechanics underlying biofilm development.

Biofilm Formation by Candida Species on Silicone Surfaces and Latex Pacifier Nipples: An in vitro Study

2009 ◽  
Vol 33 (3) ◽  
pp. 235-240 ◽  
Author(s):  
Luiz Cezar da Silveira ◽  
Senda Charone ◽  
Lucianne Cople Maia ◽  
Rosangela Maria de Araújo Soares ◽  
Maristela Barbosa Portela
Keyword(s):  
Candida Species ◽  
Biofilm Formation ◽  
In Vitro Study ◽  
Reduction Reaction ◽  
Fungal Colonization ◽  
Candida Spp ◽  
Biofilm Growth ◽  
Species Analysis ◽  
Biofilm Development

The present study assessed the growth and development of biofilm formation by isolates of C. albicans, C. glabrata and C. parapsilosis on silicone and latex pacifier nipples. The silicone and latex surfaces were evaluated by scanning electronic microscopy (SEM). The plastic component of the nipple also seems to be an important factor regarding the biofilm formation by Candida spp. The biofilm growth was measured using the MTT reduction reaction. C. albicans was found to have a slightly greater capacity of forming biofilm compared to the other Candida species. Analysis of the pattern of biofilm development by C. albicans,C. glabrata and C. parapsilosis on latex and silicon pacifier shields showed an increased biofilm formation regarding the latter substrate. Silicone was shown to be more resistant to fungal colonization, particularly in the case of C. parapsilosis, despite the lack of any statistically significant differences (P &gt; 0.05). In addition, silicone has a smoother surface compared to latex, whose surface was found to be rugose and irregular

scholarly journals The Sodium-Driven Flagellar Motor Controls Exopolysaccharide Expression in Vibrio cholerae

2004 ◽  
Vol 186 (15) ◽  
pp. 4864-4874 ◽  
Author(s):  
Crystal M. Lauriano ◽  
Chandradipa Ghosh ◽  
Nidia E. Correa ◽  
Karl E. Klose
Keyword(s):  
Vibrio Cholerae ◽  
Gene Transcription ◽  
Biofilm Formation ◽  
Diarrheal Disease ◽  
Response Regulator ◽  
Gene Clusters ◽  
Signaling Cascade ◽  
Genes Encoding ◽  
Life Threatening

ABSTRACT Vibrio cholerae causes the life-threatening diarrheal disease cholera. This organism persists in aquatic environments in areas of endemicity, and it is believed that the ability of the bacteria to form biofilms in the environment contributes to their persistence. Expression of an exopolysaccharide (EPS), encoded by two vps gene clusters, is essential for biofilm formation and causes a rugose colonial phenotype. We previously reported that the lack of a flagellum induces V. cholerae EPS expression. To uncover the signaling pathway that links the lack of a flagellum to EPS expression, we introduced into a rugose flaA strain second-site mutations that would cause reversion back to the smooth phenotype. Interestingly, mutation of the genes encoding the sodium-driven motor (mot) in a nonflagellated strain reduces EPS expression, biofilm formation, and vps gene transcription, as does the addition of phenamil, which specifically inhibits the sodium-driven motor. Mutation of vpsR, which encodes a response regulator, also reduces EPS expression, biofilm formation, and vps gene transcription in nonflagellated cells. Complementation of a vpsR strain with a constitutive vpsR allele likely to mimic the phosphorylated state (D59E) restores EPS expression and biofilm formation, while complementation with an allele predicted to remain unphosphorylated (D59A) does not. Our results demonstrate the involvement of the sodium-driven motor and suggest the involvement of phospho-VpsR in the signaling cascade that induces EPS expression. A nonflagellated strain expressing EPS is defective for intestinal colonization in the suckling mouse model of cholera and expresses reduced amounts of cholera toxin and toxin-coregulated pili in vitro. Wild-type levels of virulence factor expression and colonization could be restored by a second mutation within the vps gene cluster that eliminated EPS biosynthesis. These results demonstrate a complex relationship between the flagellum-dependent EPS signaling cascade and virulence.

Cl- regulates cryoglobulin structure: a new hypothesis for the physiopathological mechanism of temperature non-dependent cryoprecipitation

2004 ◽  
Vol 42 (6) ◽  
Author(s):  
Enrico Di Stasio ◽  
Patrizia Bizzarri ◽  
Milvia Casato ◽  
Antonio Galtieri ◽  
Massimo Fiorilli ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Clinical Signs ◽  
Cold Temperature ◽  
Pathogenetic Mechanism ◽  
Temperature Dependent ◽  
Temperature Changes ◽  
Significant Temperature ◽  
Neoplastic Disorders ◽  
New Hypothesis

AbstractCryoglobulins are pathological cold-precipitable immunoglobulins associated with a number of infectious, autoimmune and neoplastic disorders. Patients, when exposed to low temperatures, show symptoms related to intravascular precipitation of such immunoglobulins. The formation of cryoaggregates induced by exposure to cold temperature is the key pathogenetic mechanism. The subsequent intravascular precipitation can account for some clinical signs of peripheral vasculitis, but fails to explain the precipitation of cryoglobulins in regions where no significant temperature changes take place. We studied, in vitro, the activity of different ions on temperature-dependent aggregation of cryoglobulins and found that the concentration of Cl

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