scholarly journals Biofilm formation displays intrinsic offensive and defensive features of Bacillus cereus

2019 ◽  
Author(s):  
Caro-Astorga Joaquin ◽  
Frenzel Elrike ◽  
Perkins James Richard ◽  
Antonio de Vicente ◽  
Juan A.G. Ranea ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Amino Acids ◽  
Cell Wall ◽  
Bacillus Cereus ◽  
Biofilm Formation ◽  
Bacterial Species ◽  
Physiological Changes ◽  
Effective Strategy ◽  
Abiotic Surfaces ◽  
The Individual

AbstractBackgroundBiofilm formation is a strategy of many bacterial species to adapt to a variety of stresses and has become a part of infections, contaminations or beneficial interactions. We previously observed that B. cereus ATCC 14579 (CECT148), formed a thick biomass of cells firmly adhered to abiotic surfaces.ResultsIn this study, we combined two techniques, RNAseq and iTRAQ mass spectrometry, to demonstrate the profound physiological changes that permit Bacillus cereus to switch from a floating to a sessile lifestyle, to undergo further maturation of the biofilm, and to differentiate into offensive or defensive populations. The rearrangement of nucleotides, sugars, amino acids and energy metabolism lead to changes promoting reinforcement of the cell wall, activation of ROS detoxification strategies or secondary metabolite production, all oriented to defend biofilm cells from external aggressions. However, floating cells maintain a fermentative metabolic status along with a higher aggressiveness against hosts, evidenced by the production of toxins and other virulent factors.ConclusionsWe show that biofilm-associated cells seem to direct the energy to the individual and global defense against external aggressions and competitors. By contrary, floating cells are more aggressive against hosts. The maintenance of the two distinct subpopulations is an effective strategy to face changeable environmental conditions found in the life cycle of B. cereus.

Archaeal biofilms: widespread and complex

2013 ◽  
Vol 41 (1) ◽  
pp. 393-398 ◽  
Author(s):  
Sabrina Fröls
Keyword(s):  
Biofilm Formation ◽  
Extracellular Polymeric Substances ◽  
Bacterial Species ◽  
Surface Adhesion ◽  
Form Complex ◽  
Abiotic Surfaces ◽  
Archaeal Species ◽  
Physical And Chemical ◽  
Insight Into ◽  
Mixed Communities

Biofilms or multicellular structures become accepted as the dominant microbial lifestyle in Nature, but in the past they were only studied extensively in bacteria. Investigations on archaeal monospecies cultures have shown that many archaeal species are able to adhere on biotic and abiotic surfaces and form complex biofilm structures. Biofilm-forming archaea were identified in a broad range of extreme and moderate environments. Natural biofilms observed are mostly mixed communities composed of archaeal and bacterial species of various abundances. The physiological functions of the archaea identified in such mixed communities suggest a significant impact on the biochemical cycles maintaining the flow and recycling of the nutrients on earth. Therefore it is of high interest to investigate the characteristics and mechanisms underlying the archaeal biofilm formation. In the present review, I summarize and discuss the present investigations of biofilm-forming archaeal species, i.e. their diverse biofilm architectures in monospecies or mixed communities, the identified EPSs (extracellular polymeric substances), archaeal structures mediating surface adhesion or cell–cell connections, and the response to physical and chemical stressors implying that archaeal biofilm formation is an adaptive reaction to changing environmental conditions. A first insight into the molecular differentiation of cells within archaeal biofilms is given.

scholarly journals Quorum-Sensing Mutations Affect Attachment and Stability of Burkholderia cenocepacia Biofilms

2005 ◽  
Vol 71 (9) ◽  
pp. 5208-5218 ◽  
Author(s):  
Kerry L. Tomlin ◽  
Rebecca J. Malott ◽  
Gordon Ramage ◽  
Douglas G. Storey ◽  
Pamela A. Sokol ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Biofilm Formation ◽  
Bacterial Species ◽  
Cell Mass ◽  
Sodium Dodecyl ◽  
Burkholderia Cenocepacia ◽  
Structural Defects ◽  
Expression Vectors ◽  
Structural Development ◽  
The Individual

ABSTRACT Biofilm formation in Burkholderia cenocepacia has been shown to rely in part on acylhomoserine lactone-based quorum sensing. For many other bacterial species, it appears that both the initial adherence and the later stages of biofilm maturation are affected when quorum sensing pathways are inhibited. In this study, we examined the effects of mutations in the cepIR and cciIR quorum-sensing systems of Burkholderia cenocepacia K56-2 with respect to biofilm attachment and antibiotic resistance. We also examined the role of the cepIR system in biofilm stability and structural development. Using the high-throughput MBEC assay system to produce multiple equivalent biofilms, the biomasses of both the cepI and cepR mutant biofilms, measured by crystal violet staining, were less than half of the value observed for the wild-type strain. Attachment was partially restored upon providing functional gene copies via multicopy expression vectors. Surprisingly, neither the cciI mutant nor the double cciI cepI mutant was deficient in attachment, and restoration of the cciI gene resulted in less attachment than for the mutants. Meanwhile, the cciR mutant did show a significant reduction in attachment, as did the cciR cepIR mutant. While there was no change in antibiotic susceptibility with the individual cepIR and cciIR mutants, the cepI cciI mutant biofilms were more sensitive to ciprofloxacin. A significant increase in sensitivity to removal by sodium dodecyl sulfate was seen for the cepI and cepR mutants. Flow cell analysis of the individual cepIR mutant biofilms indicated that they were both structurally and temporally impaired in attachment and development. These results suggest that biofilm structural defects might be present in quorum-sensing mutants of B. cenocepacia that affect the stability and resistance of the adherent cell mass, providing a basis for future studies to design preventative measures against biofilm formation in this species, an important lung pathogen of cystic fibrosis patients.

scholarly journals Antibacterial Activity of Copper and Cobalt Amino Acids Complexes

2011 ◽  
Vol 39 (2) ◽  
pp. 124 ◽  
Author(s):  
ANDREEA STĂNILĂ ◽  
Cornelia BRAICU ◽  
Sorin STĂNILĂ ◽  
Raluca M. POP
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Antibacterial Activity ◽  
Bacillus Cereus ◽  
Copper Complexes ◽  
Micrococcus Luteus ◽  
Bacterial Species ◽  
Free Ligand ◽  
Antibacterial Properties ◽  
Moderate Activity

The antibacterial properties of differently copper and cobalt amino acids complexes on agar plates was investigated in the present study. The antibacterial activity of amino acid complexes was evaluated against on three bacteria strains (Escherichia coli, Bacillus cereus, Micrococcus luteus). Generally, the amino acids complexes were mainly active against gram-positive organisms, species like Micrococcus luteus being the most susceptible strain tested. It was registered a moderate antibacterial activity against Bacillus cereus. The microorganisms Escherichia coli, which are already known to be multi-resistant to drugs, were also resistant to the amino acids complexes but also to the free salts tested. Escherichia coli were susceptible only to the CoCl2 and copper complex with phenylalanine. The complexes with leucine and histidine seem to be more active than the parent free ligand against one or more bacterial species. Moderate activity was registered in the case of complexes with methionine and phenylalanine. From the complexes tested less efficient antibacterial activity was noted in the case of complexes with lysine and valine. These results show that cobalt and copper complexes have an antibacterial activity and suggest their potential application as antibacterial agents.

scholarly journals Characterization of the mechanism of action of the Enterococcus faecalis bacteriocin EntV on Candida albicans

2021 ◽  
Vol 3 (12) ◽  
Author(s):  
Giuseppe Buda De Cesare ◽  
Yasmin Chebaro ◽  
Shantanu Guha ◽  
Melissa Cruz ◽  
Danielle Garsin ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Enterococcus Faecalis ◽  
Biofilm Formation ◽  
Bacterial Species ◽  
Positive Bacterium ◽  
Hyphal Morphogenesis ◽  
Target Layer ◽  
Further Development

Candida albicans shares communal niches with multiple bacterial species. Previous work from our group demonstrated that the Gram-positive bacterium Enterococcus faecalis, a normal constituent of the oral and gut microbiome that is often co-isolated with C. albicans, antagonizes hyphal morphogenesis, biofilm formation, and virulence in C. albicans. These effects are mediated by EntV, a bacteriocin and antimicrobial peptide produced by E. faecalis. The main aim of this work is to unveil the molecular mechanism behind the activity of EntV on C. albicans. Using fluorescence microscopy, we determined that EntV binds to the cell walls of several Candida species, including both yeast and hyphae of C. albicans. Contrary to other antimicrobial peptides, it does not cause cell lysis and does not synergize with cell wall damaging agents. Moreover, we screened a library of C. albicans mutants for strains with altered susceptibility to the peptide; most of the positive hits had functions related to cell wall maintenance and were further screened to ascertain changes in the staining patterns. Furthermore, to identify the target layer on the cell wall, pull-down assays were performed. Mannan was identified as the major wall component able to bind the peptide. Finally, live imaging of macrophages incubated with Candida was carried out in order to assess any change in the phagocytic behaviour in presence of the peptide. Identifying the molecular target of EntV in regard to the anti-virulence mechanisms of C. albicans is an important step in its further development as a therapeutic addition to the classical antifungal agents.

scholarly journals D-Amino acids inhibit biofilm formation in Staphylococcus epidermidis strains from ocular infections

2014 ◽  
Vol 63 (10) ◽  
pp. 1369-1376 ◽  
Author(s):  
Miriam L. Ramón-Peréz ◽  
Francisco Diaz-Cedillo ◽  
J. Antonio Ibarra ◽  
Azael Torales-Cardeña ◽  
Sandra Rodríguez-Martínez ◽  
...  
Keyword(s):  
Amino Acids ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Inhibitory Effect ◽  
Ocular Infection ◽  
Healthy Skin ◽  
Ocular Infections ◽  
Abiotic Surfaces ◽  
Surgical Devices ◽  
First Time

Biofilm formation on medical and surgical devices is a major virulence determinant for Staphylococcus epidermidis. The bacterium S. epidermidis is able to produce biofilms on biotic and abiotic surfaces and is the cause of ocular infection (OI). Recent studies have shown that d-amino acids inhibit and disrupt biofilm formation in the prototype strains Bacillus subtilis NCBI3610 and Staphylococcus aureus SCO1. The effect of d-amino acids on S. epidermidis biofilm formation has yet to be tested for clinical or commensal isolates. S. epidermidis strains isolated from healthy skin (n = 3), conjunctiva (n = 9) and OI (n = 19) were treated with d-Leu, d-Tyr, d-Pro, d-Phe, d-Met or d-Ala and tested for biofilm formation. The presence of d-amino acids during biofilm formation resulted in a variety of patterns. Some strains were sensitive to all amino acids tested, while others were sensitive to one or more, and one strain was resistant to all of them when added individually; in this way d-Met inhibited most of the strains (26/31), followed by d-Phe (21/31). Additionally, the use of d-Met inhibited biofilm formation on a contact lens. The use of l-isomers caused no defect in biofilm formation in all strains tested. In contrast, when biofilms were already formed d-Met, d-Phe and d-Pro were able to disrupt it. In summary, here we demonstrated the inhibitory effect of d-amino acids on biofilm formation in S. epidermidis. Moreover, we showed, for the first time, that S. epidermidis clinical strains have a different sensitivity to these compounds during biofilm formation.

scholarly journals Role of DLP12 lysis genes in Escherichia coli biofilm formation

Microbiology ◽  
2011 ◽  
Vol 157 (6) ◽  
pp. 1640-1650 ◽  
Author(s):  
Faustino A. Toba ◽  
Mitchell G. Thompson ◽  
Bryan R. Campbell ◽  
Lauren M. Junker ◽  
Karl-Gustav Rueggeberg ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cell Wall ◽  
Biofilm Formation ◽  
Wall Stress ◽  
Wild Type ◽  
Lambda Phage ◽  
Kinase Gene ◽  
Abiotic Surfaces ◽  
K 12 ◽  
Biofilm Development

Phages have recently been implicated as important in biofilm development, although the mechanisms whereby phages impact biofilms remain unclear. One defective lambdoid phage carried by Escherichia coli K-12 is DLP12. Among the genes found in DLP12 are essD, ybcS and rzpD/rzoD, which are homologues of the Lambda phage genes encoding cell-lysis proteins (S, R and Rz/Rz1). The role that these DLP12 lysis genes play in biofilm formation was examined in deletion mutants of E. coli PHL628, a curli-overproducing, biofilm-forming K-12 derivative. Strains lacking essD, ybcS and rzpD/rzoD were unable to form wild-type biofilms. While all mutants were compromised in attachment to abiotic surfaces and aggregated less well than the wild-type, the effect of the essD knockout on biofilm formation was less dramatic than that of deleting ybcS or rzpD/rzoD. These results were consistent with electron micrographs of the mutants, which showed a decreased number of curli fibres on cell surfaces. Also consistent with this finding, we observed that expression from the promoter of csgB, which encodes the curli subunits, was downregulated in the mutants. As curli production is transcriptionally downregulated in response to cell wall stress, we challenged the mutants with SDS and found them to be more sensitive to the detergent than the wild-type. We also examined the release of 14C-labelled peptidoglycan from the mutants and found that they did not lose labelled peptidoglycan to the same extent as the wild-type. Given that curli production is known to be suppressed by N-acetylglucosamine 6-phosphate (NAG-6P), a metabolite produced during peptidoglycan recycling, we deleted nagK, the N-acetylglucosamine kinase gene, from the lysis mutants and found that this restored curli production. This suggested that deletion of the lysis genes affected cell wall status, which was transduced to the curli operon by NAG-6P via an as yet unknown mechanism. These observations provide evidence that the S, R and Rz/Rz1 gene homologues encoded by DLP12 are not merely genetic junk, but rather play an important, though undefined, role in cell wall maintenance.

scholarly journals CwpFM (EntFM) Is a Bacillus cereus Potential Cell Wall Peptidase Implicated in Adhesion, Biofilm Formation, and Virulence

2010 ◽  
Vol 192 (10) ◽  
pp. 2638-2642 ◽  
Author(s):  
Seav-Ly Tran ◽  
Elisabeth Guillemet ◽  
Michel Gohar ◽  
Didier Lereclus ◽  
Nalini Ramarao
Keyword(s):  
Cell Wall ◽  
Epithelial Cells ◽  
Bacillus Cereus ◽  
Biofilm Formation ◽  
New Information ◽  
A Cell

ABSTRACT Bacillus cereus EntFM displays an NlpC/P60 domain, characteristic of cell wall peptidases. The protein is involved in bacterial shape, motility, adhesion to epithelial cells, biofilm formation, vacuolization of macrophages, and virulence. These data provide new information on this, so far, poorly studied toxin and suggest that this protein is a cell wall peptidase, which we propose to rename CwpFM.

scholarly journals High Biofilm Formation of Non-Smooth Candida parapsilosis Correlates with Increased Incorporation of GPI-Modified Wall Adhesins

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 493
Author(s):  
Ana Esther Moreno-Martínez ◽  
Emilia Gómez-Molero ◽  
Pablo Sánchez-Virosta ◽  
Henk L. Dekker ◽  
Albert de Boer ◽  
...  
Keyword(s):  
Cell Wall ◽  
Biofilm Formation ◽  
Candida Parapsilosis ◽  
Surface Expression ◽  
Growth Conditions ◽  
Clinical Isolates ◽  
Abiotic Surfaces ◽  
Abundance And Diversity ◽  
Cellular Phenotypes ◽  
Comprehensive Study

Candida parapsilosis is among the most frequent causes of candidiasis. Clinical isolates of this species show large variations in colony morphotype, ranging from round and smooth to a variety of non-smooth irregular colony shapes. A non-smooth appearance is related to increased formation of pseudohyphae, higher capacity to form biofilms on abiotic surfaces, and invading agar. Here, we present a comprehensive study of the cell wall proteome of C. parapsilosis reference strain CDC317 and seven clinical isolates under planktonic and sessile conditions. This analysis resulted in the identification of 40 wall proteins, most of them homologs of known Candida albicans cell wall proteins, such as Gas, Crh, Bgl2, Cht2, Ecm33, Sap, Sod, Plb, Pir, Pga30, Pga59, and adhesin family members. Comparative analysis of exponentially growing and stationary phase planktonic cultures of CDC317 at 30 °C and 37 °C revealed only minor variations. However, comparison of smooth isolates to non-smooth isolates with high biofilm formation capacity showed an increase in abundance and diversity of putative wall adhesins from Als, Iff/Hyr, and Hwp families in the latter. This difference depended more strongly on strain phenotype than on the growth conditions, as it was observed in planktonic as well as biofilm cells. Thus, in the set of isolates analyzed, the high biofilm formation capacity of non-smooth C. parapsilosis isolates with elongated cellular phenotypes correlates with the increased surface expression of putative wall adhesins in accordance with their proposed cellular function.

Sidrophore Production and Phosphate Solubilization by Bacillus cereus and Pseudomonas fluorescens Isolated from Iraqi Soils and Soil Characterization

2018 ◽  
Vol 9 (4) ◽  
Author(s):  
Zaid Raad Abbas ◽  
Aqeel Mohammed Majeed Al-Ezee ◽  
Sawsan H
Keyword(s):  
Bacillus Cereus ◽  
Pseudomonas Fluorescens ◽  
Phosphate Solubilization ◽  
Bacterial Species ◽  
Nutrient Status ◽  
Bacterial Count ◽  
Soil Samples ◽  
Phosphate Solubilizing Bacteria ◽  
Clear Zone ◽  
Zone Formation

This study was conducted to explore the ability of Pseudomonas fluorescens and Bacillus cereus to solubilizing a phosphate in soil for enhancing the planting growth and, its relation with soill characterization. The isolates were identified as P.fluorescens and B. cereus using convential analysis and, its phosphate solubilization ability and sidrophore was shown by the clear zone formation on National Botanical Research Institute���s Phosphate medium. Moreover, Pseudomonas fluorescens isolates (n = 9) and three of B. cereus isolated from agricultural area in Baghdad university, Mustansiriyah university and Diyala bridge. Results displayed that bacterial count were varied in soil samples according to their region, and ranging from 30 to 60 *10 2 CFU/g in Baghdad university soil to 10���20 *10 2 CFU/g in Mustansiriyah university soil, the Baghdad soil macronutrient which included: NH4, NO3, P, and K were, 8.42, 20.53, 19.09, 218.73 respectively, While the physio analysis revealed that the mean of pH was 7.3 and EC was 8.63. on the other hand the micronutrient analysis indicated that the soil samples were included Ca, Fe, Mn, Zn and Cu which gave their mean 5025.9, 8.9, 4.9, 0.5 and 1.5 respectevily. Results revealed that all isolated bacteria (9 isolates of P.fluorescens and three isolates of B. cereus gave ahalo zone which mean their ability to be phosphate solubilizing bacteria at 100%. Results revealed that all isolated bacteria were detected a ability to produce high levels from chelating agents (siderophores)) by P.fluorescens and. B cereus at 100%, when appeared ahalo clear zone. Furthermore, the high levels of phosphate solubilization and siderophore production were grouped in bacterial species isolated from Iraqi soils. might be attributed to many soil factors such as soil nutrient status, soil acidity, water content, organic matter and soil enzyme activities.

Bacterial Peptidoglycan Stapling with Functionalized D-Amino Acids

2019 ◽  
Author(s):  
Sylvia L. Rivera ◽  
Akbar Espaillat ◽  
Arjun K. Aditham ◽  
Peyton Shieh ◽  
Chris Muriel-Mundo ◽  
...  
Keyword(s):  
Cell Wall ◽  
Clinical Success ◽  
Bacterial Species ◽  
Enzymatic Reaction ◽  
Amino Acid Derivative ◽  
Wall Structure ◽  
Live Bacteria ◽  
Cross Links ◽  
Osmotic Lysis ◽  
Bacterial Peptidoglycan

Transpeptidation reinforces the structure of cell wall peptidoglycan, an extracellular heteropolymer that protects bacteria from osmotic lysis. The clinical success of transpeptidase-inhibiting β-lactam antibiotics illustrates the essentiality of these cross-linkages for cell wall integrity, but the presence of multiple, seemingly redundant transpeptidases in many bacterial species makes it challenging to determine cross-link function precisely. Here we present a technique to covalently link peptide strands by chemical rather than enzymatic reaction. We employ bio-compatible click chemistry to induce triazole formation between azido- and alkynyl-D-alanine residues that are metabolically installed in the cell walls of Gram-positive and Gram-negative bacteria. Synthetic triazole cross-links can be visualized by substituting azido-D-alanine with azidocoumarin-D-alanine, an amino acid derivative that undergoes fluorescent enhancement upon reaction with terminal alkynes. Cell wall stapling protects the model bacterium Escherichia coli from β-lactam treatment. Chemical control of cell wall structure in live bacteria can provide functional insights that are orthogonal to those obtained by genetics.<br>

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