scholarly journals Development of Biofilms for Antimicrobial Resistance

2020 ◽  
Author(s):  
Asma Bashir ◽  
Neha Farid ◽  
Kashif Ali ◽  
Kiran Fatima
Keyword(s):  
Antimicrobial Resistance ◽  
Quorum Sensing ◽  
Microbial Communities ◽  
Biofilm Formation ◽  
Genetic Transfer ◽  
Microbial Cells ◽  
Resistant Genes ◽  
Area Unit ◽  
Biofilm Development

Biofilms are a unit referred to as assemblage of microbial cells growing as surface-attached microbial communities within the natural surroundings. Their genetic and physiological aspects are widely studied. Biofilm development involves the assembly of extracellular compound substances that forms the most bailiwick network. Quorum sensing is one more crucial development specifically connected with biofilm formation in several microorganism species. In ecological purpose, the biofilm offers protection against unfavorable conditions and provides a platform for the genetic transfer. A biofilm-forming bacterium area unit is medically necessary, as they are resistant to several antibiotics and might spread resistant genes. This chapter provides the summary of microorganism biofilm formation and its significance in ecology.

scholarly journals Antimicrobial Resistance and Biofilm Formation of Pseudomonas aeruginosa

10.3823/846 ◽  
2020 ◽  
Vol 10 (2) ◽  
Author(s):  
Abdelraouf A Elmanama ◽  
Suhaila Al-Sheboul ◽  
Renad I Abu-Dan
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Antimicrobial Resistance ◽  
Quorum Sensing ◽  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Developmental Stages ◽  
Infection Site ◽  
Major Virulence Factor

Abstract Pseudomonas aeruginosa threatens patient’s care. It is considered as the most complicated health care associated pathogen to be eliminated from infection site. The biofilm forming ability of P. aeruginosa, being a major virulence factor for most pathogenic microorganism, protects it from host immunity and contribute to antibiotic resistance of this organism. It is estimated that about 80% of infectious diseases are due to biofilm mode of growth. Biofilm forming ability of bacteria imparts antimicrobial resistance that leads to many persistent and chronic bacterial infections. The world is becoming increasingly under the threat of entering the “post-antibiotic era”, an era in which the rate of death from bacterial infections is higher than from cancer. This review focus on P. aeruginosa biofilm forming ability; definition, developmental stages, and significance. In addition, the quorum sensing and the antibiotic resistance of this pathogen is discussed. Keywords: Biofilm; bacterial adhesion; Pseudomonas aeruginosa; antimicrobial resistance; quorum sensing.

scholarly journals Quorum Sensing Influences Burkholderia thailandensis Biofilm Development and Matrix Production

2016 ◽  
Vol 198 (19) ◽  
pp. 2643-2650 ◽  
Author(s):  
Boo Shan Tseng ◽  
Charlotte D. Majerczyk ◽  
Daniel Passos da Silva ◽  
Josephine R. Chandler ◽  
E. Peter Greenberg ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Biofilm Formation ◽  
Bacterial Species ◽  
Matrix Material ◽  
Close Relative ◽  
Wild Type ◽  
Flow Conditions ◽  
Burkholderia Thailandensis ◽  
Content Type ◽  
Biofilm Development

ABSTRACTMembers of the genusBurkholderiaare known to be adept at biofilm formation, which presumably assists in the survival of these organisms in the environment and the host. Biofilm formation has been linked to quorum sensing (QS) in several bacterial species. In this study, we characterizedBurkholderia thailandensisbiofilm development under flow conditions and sought to determine whether QS contributes to this process.B. thailandensisbiofilm formation exhibited an unusual pattern: the cells formed small aggregates and then proceeded to produce mature biofilms characterized by “dome” structures filled with biofilm matrix material. We showed that this process was dependent on QS.B. thailandensishas three acyl-homoserine lactone (AHL) QS systems (QS-1, QS-2, and QS-3). An AHL-negative strain produced biofilms consisting of cell aggregates but lacking the matrix-filled dome structures. This phenotype was rescued via exogenous addition of the three AHL signals. Of the threeB. thailandensisQS systems, we show that QS-1 is required for proper biofilm development, since abtaR1mutant, which is defective in QS-1 regulation, forms biofilms without these dome structures. Furthermore, our data show that the wild-type biofilm biomass, as well as the material inside the domes, stains with a fucose-binding lectin. ThebtaR1mutant biofilms, however, are negative for fucose staining. This suggests that the QS-1 system regulates the production of a fucose-containing exopolysaccharide in wild-type biofilms. Finally, we present data showing that QS ability during biofilm development produces a biofilm that is resistant to dispersion under stress conditions.IMPORTANCEThe saprophyteBurkholderia thailandensisis a close relative of the pathogenic bacteriumBurkholderia pseudomallei, the causative agent of melioidosis, which is contracted from its environmental reservoir. Since most bacteria in the environment reside in biofilms,B. thailandensisis an ideal model organism for investigating questions inBurkholderiaphysiology. In this study, we characterizedB. thailandensisbiofilm development and sought to determine if quorum sensing (QS) contributes to this process. Our work shows thatB. thailandensisproduces biofilms with unusual dome structures under flow conditions. Our findings suggest that these dome structures are filled with a QS-regulated, fucose-containing exopolysaccharide that may be involved in the resilience ofB. thailandensisbiofilms against changes in the nutritional environment.

scholarly journals Quorum-Sensing Genes in Pseudomonas aeruginosa Biofilms: Their Role and Expression Patterns

2001 ◽  
Vol 67 (4) ◽  
pp. 1865-1873 ◽  
Author(s):  
Teresa R. De Kievit ◽  
Richard Gillis ◽  
Steve Marx ◽  
Chris Brown ◽  
Barbara H. Iglewski
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Biofilm Formation ◽  
Fluorescent Protein ◽  
Expression Patterns ◽  
Homoserine Lactone ◽  
Lower Percentage ◽  
Spatial Studies ◽  
Green Fluorescent ◽  
Biofilm Development

ABSTRACT Acylated homoserine lactone molecules are used by a number of gram-negative bacteria to regulate cell density-dependent gene expression by a mechanism known as quorum sensing (QS). InPseudomonas aeruginosa, QS or cell-to-cell signaling controls expression of a number of virulence factors, as well as biofilm differentiation. In this study, we investigated the role played by the las and rhl QS systems during the early stages of static biofilm formation when cells are adhering to a surface and forming microcolonies. These studies revealed a marked difference in biofilm formation between the PAO1 parent and the QS mutants when glucose, but not citrate, was used as the sole carbon source. To further elucidate the contribution of lasI andrhlI to biofilm maturation, we utilized fusions to unstable green fluorescent protein in concert with confocal microscopy to perform real-time temporal and spatial studies of these genes in a flowing environment. During the course of 8-day biofilm development,lasI expression was found to progressively decrease over time. Conversely, rhlI expression remained steady throughout biofilm development but occurred in a lower percentage of cells. Spatial analysis revealed that lasI andrhlI were maximally expressed in cells located at the substratum and that expression decreased with increasing biofilm height. Because QS was shown previously to be involved in biofilm differentiation, these findings have important implications for the design of biofilm prevention and eradication strategies.

scholarly journals Trp-Containing Antibacterial Peptides Impair Quorum Sensing and Biofilm Development in Multidrug-Resistant Pseudomonas aeruginosa and Exhibit Synergistic Effects With Antibiotics

2021 ◽  
Vol 12 ◽  
Author(s):  
Dejing Shang ◽  
Xue Han ◽  
Wanying Du ◽  
Zhiru Kou ◽  
Fengquan Jiang
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Efflux Pump ◽  
Synergistic Effects ◽  
Multidrug Resistant ◽  
Biofilm Development ◽  
Antibiotic Efflux

Pseudomonas aeruginosa uses quorum sensing (QS) to control virulence, biofilm formation and antibiotic efflux pump expression. The development of effective small molecules targeting the QS system and biofilm formation represents a novel attractive strategy. In this present study, the effects of a series of Trp-containing peptides on the QS-regulated virulence and biofilm development of multidrug-resistant P. aeruginosa, as well as their synergistic antibacterial activity with three classes of traditional chemical antibiotics were investigated. The results showed that Trp-containing peptides at low concentrations reduced the production of QS-regulated virulence factors by downregulating the gene expression of both the las and rhl systems in the strain MRPA0108. Biofilm formation was inhibited in a concentration-dependent manner, which was associated with extracellular polysaccharide production inhibition by downregulating pelA, algD, and pslA transcription. These changes correlated with alterations in the extracellular production of pseudomonal virulence factors and swarming motility. In addition, the combination of Trp-containing peptides at low concentration with the antibiotics ceftazidime and piperacillin provided synergistic effects. Notably, L11W and L12W showed the highest synergy with ceftazidime and piperacillin. A mechanistic study demonstrated that the Trp-containing peptides, especially L12W, significantly decreased β-lactamase activity and expression of efflux pump genes OprM, MexX, and MexA, resulting in a reduction in antibiotic efflux from MRPA0108 cells and thus increasing the antibacterial activity of these antibiotics against MRPA0108.

scholarly journals AbaM Regulates Quorum Sensing, Biofilm Formation and Virulence in Acinetobacter baumannii

2021 ◽  
Author(s):  
Mario López-Martín ◽  
Jean-Frédéric Dubern ◽  
Morgan R. Alexander ◽  
Paul Williams
Keyword(s):  
Quorum Sensing ◽  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Plant Pathogens ◽  
Galleria Mellonella ◽  
Homoserine Lactone ◽  
Infection Model ◽  
Wild Type ◽  
Surface Motility ◽  
Biofilm Development

Acinetobacter baumannii possesses a single divergent luxR/luxI-type quorum sensing (QS) locus named abaR/abaI. This locus also contains a third gene located between abaR and abaI which we term abaM that codes for an uncharacterized member of the RsaM protein family known to regulate N-acylhomoserine lactone (AHL) dependent QS in other β- and γ-proteobacteria. Here we show that disruption of abaM via a T26 insertion in A. baumannii strain AB5075 resulted in increased production of N-(3-hydroxydodecanoyl)-L-homoserine lactone (OHC12) and enhanced surface motility and biofilm formation. In contrast to the wild type and abaI::T26 mutant, the virulence of the abaM::T26 mutant was completely attenuated in a Galleria mellonella infection model. Transcriptomic analysis of the abaM::T26 mutant revealed that AbaM differentially regulates at least 76 genes including the csu pilus operon and the acinetin 505 lipopeptide biosynthetic operon, that are involved in surface adherence, biofilm formation and virulence. A comparison of the wild type, abaM::T26 and abaI::T26 transcriptomes, indicates that AbaM regulates ∼21% of the QS regulon including the csu operon. Moreover, the QS genes (abaI/abaR) were among the most upregulated in the abaM::T26 mutant. A. baumannii lux-based abaM reporter gene fusions revealed that abaM expression is positively regulated by QS but negatively auto-regulated. Overall, the data presented in this work demonstrates that AbaM plays a central role in regulating A. baumannii QS, virulence, surface motility and biofilm formation. Importance Acinetobacter baumanni is a multi-antibiotic resistant pathogen of global healthcare importance. Understanding Acinetobacter virulence gene regulation could aid the development of novel anti-infective strategies. In A. baumannii, the abaR and abaI genes that code for the receptor and synthase components of an N-acylhomoserine (AHL) lactone-dependent quorum sensing system (QS) are separated by abaM. Here we show that although mutation of abaM increased AHL production, surface motility and biofilm development, it resulted in the attenuation of virulence. AbaM was found to control both QS-dependent and QS-independent genes. The significance of this work lies in the identification of AbaM, an RsaM ortholog known to control virulence in plant pathogens, as a modulator of virulence in a human pathogen.

The versatile effect of L- and D-Cateslytin on bacteria and yeast biofilms according to configuration, medium and dose

2020 ◽  
Author(s):  
Lydie Ploux ◽  
Min Jin ◽  
Sophie Hellé ◽  
Cosette Betscha ◽  
Jean-Marc Strub ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Antimicrobial Properties ◽  
P Value ◽  
Microbial Cells ◽  
Response System ◽  
Stress Response System ◽  
Biofilm Development ◽  
The Impact

<p>L- and D-Cateslytin (CTL) are antimicrobial peptides (AMP) derived from chromogranin A, a protein of the stress response system. Their antimicrobial properties have been thoroughly characterized and already exploited in biomaterials. However, effects on biofilms of yeast and bacteria have never been specifically addressed. We have investigated the impact of both L and D configurations of CTL on the growth of biofilms formed by Candida albicans, Escherichia coli or Staphylococcus aureus microorganisms.</p> <p>The study was conducted in different media and two strategies of treatment were tested, consisting of administrating the peptide either just at the beginning of biofilm development i.e. on just adhering pioneer microbial cells or on a biofilm already allowed to develop for 24h. We also considered whether the peptide was modified in contact with the medium or/and microbial metabolites. Planktonic and sessile populations of microbial cells were analyzed by spectrophotometry, crystal violet staining, MTT and confocal microscopy with staining by Syto9Ò and propidium iodide. Identification of the peptides and their derived fragments was investigated by HPLC and Mass-Spectroscopy.</p> <p>In general, CTL-D exhibited higher antibiofilm performances than CTL-L. In addition, concentrations necessary to inhibit biofilm formation were found to vary from ten to eighty times the MICs determined in planktonic cultures. Nevertheless, the results also demonstrate that sessile microorganisms and biofilms are sensitive to CTL (L and D conformations) differently that planktonic populations. Significant (p-value < 0.01) effects were observed on both sessile and planktonic populations and with both strategies of treatments, but they highly varied with medium, species and CTL configuration. Typically, better antibiofilm effect than common antibiotics was reached in some specific conditions, while enhancement of aggregation or biofilm formation occurred in another medium and for other doses. Nevertheless,</p> <p>Finally, this confirms the quality of CTL peptides as new antimicrobial agents and reveals their anti-biofilm properties. This also specifies the conditions of use necessary to benefit of the highest performances.</p>

scholarly journals Inhibition of Candida albicans Biofilm Formation by Farnesol, a Quorum-Sensing Molecule

2002 ◽  
Vol 68 (11) ◽  
pp. 5459-5463 ◽  
Author(s):  
Gordon Ramage ◽  
Stephen P. Saville ◽  
Brian L. Wickes ◽  
José L. López-Ribot
Keyword(s):  
Candida Albicans ◽  
Quorum Sensing ◽  
Biofilm Formation ◽  
Northern Blot Analysis ◽  
Adherent Cell ◽  
Naturally Occurring ◽  
Biofilm Development ◽  
Further Development ◽  
Quorum Sensing Molecule

ABSTRACT Farnesol is a quorum-sensing molecule that inhibits filamentation in Candida albicans. Both filamentation and quorum sensing are deemed to be important factors in C. albicans biofilm development. Here we examined the effect of farnesol on C. albicans biofilm formation. C. albicans adherent cell populations (after 0, 1, 2, and 4 h of adherence) and preformed biofilms (24 h) were treated with various concentrations of farnesol (0, 3, 30, and 300 μM) and incubated at 37°C for 24 h. The extent and characteristics of biofilm formation were then assessed microscopically and with a semiquantitative colorimetric technique based on the use of 2,3-bis(2-methoxy-4-nitro-5-sulfo-phenyl)-2H-tetrazolium-5-carboxanilide. The results indicated that the effect of farnesol was dependent on the concentration of this compound and the initial adherence time, and preincubation with 300 μM farnesol completely inhibited biofilm formation. Supernatant media recovered from mature biofilms inhibited the ability of planktonic C. albicans to form filaments, indicating that a morphogenetic autoregulatory compound is produced in situ in biofilms. Northern blot analysis of RNA extracted from cells in biofilms indicated that the levels of expression of HWP1, encoding a hypha-specific wall protein, were decreased in farnesol-treated biofilms compared to the levels in controls. Our results indicate that farnesol acts as a naturally occurring quorum-sensing molecule which inhibits biofilm formation, and we discuss its potential for further development and use as a novel therapeutic agent.

scholarly journals Role of the luxS Quorum-Sensing System in Biofilm Formation and Virulence of Staphylococcus epidermidis

2006 ◽  
Vol 74 (1) ◽  
pp. 488-496 ◽  
Author(s):  
Lin Xu ◽  
Hualin Li ◽  
Cuong Vuong ◽  
Viveka Vadyvaloo ◽  
Jianping Wang ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Mutant Strain ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Bacterial Pathogens ◽  
Sensing System ◽  
Autoinducer 2 ◽  
Enhanced Production ◽  
Quorum Sensing System ◽  
Biofilm Development

ABSTRACT Nosocomial infections caused by Staphylococcus epidermidis are characterized by biofilm formation on implanted medical devices. Quorum-sensing regulation plays a major role in the biofilm development of many bacterial pathogens. Here, we describe luxS, a quorum-sensing system in staphylococci that has a significant impact on biofilm development and virulence. We constructed an isogenic ΔluxS mutant strain of a biofilm-forming clinical isolate of S. epidermidis and demonstrated that luxS signaling is functional in S. epidermidis. The mutant strain showed increased biofilm formation in vitro and enhanced virulence in a rat model of biofilm-associated infection. Genetic complementation and addition of autoinducer 2-containing culture filtrate restored the wild-type phenotype, demonstrating that luxS repressed biofilm formation through a cell-cell signaling mechanism based on autoinducer 2 secretion. Enhanced production of the biofilm exopolysaccharide polysaccharide intercellular adhesin in the mutant strain is presumably the major cause of the observed phenotype. The agr quorum-sensing system has previously been shown to impact biofilm development and biofilm-associated infection in a way similar to that of luxS, although by regulation of different factors. Our study indicates a general scheme of quorum-sensing regulation of biofilm development in staphylococci, which contrasts with that observed in many other bacterial pathogens.

scholarly journals Quorum Sensing in Staphylococcus aureus Biofilms

2004 ◽  
Vol 186 (6) ◽  
pp. 1838-1850 ◽  
Author(s):  
Jeremy M. Yarwood ◽  
Douglas J. Bartels ◽  
Esther M. Volper ◽  
E. Peter Greenberg
Keyword(s):  
Staphylococcus Aureus ◽  
Quorum Sensing ◽  
Biofilm Formation ◽  
Time Lapse ◽  
Confocal Scanning Laser Microscopy ◽  
Accessory Gene ◽  
Fluorescent Reporter ◽  
Accessory Gene Regulator ◽  
Confocal Scanning Laser ◽  
Biofilm Development

ABSTRACT Several serious diseases are caused by biofilm-associated Staphylococcus aureus, infections in which the accessory gene regulator (agr) quorum-sensing system is thought to play an important role. We studied the contribution of agr to biofilm development, and we examined agr-dependent transcription in biofilms. Under some conditions, disruption of agr expression had no discernible influence on biofilm formation, while under others it either inhibited or enhanced biofilm formation. Under those conditions where agr expression enhanced biofilm formation, biofilms of an agr signaling mutant were particularly sensitive to rifampin but not to oxacillin. Time lapse confocal scanning laser microscopy showed that, similar to the expression of an agr-independent fluorescent reporter, biofilm expression of an agr-dependent reporter was in patches within cell clusters and oscillated with time. In some cases, loss of fluorescence appeared to coincide with detachment of cells from the biofilm. Our studies indicate that the role of agr expression in biofilm development and behavior depends on environmental conditions. We also suggest that detachment of cells expressing agr from biofilms may have important clinical implications.

scholarly journals Safety of Food and Water Supplies in the Landscape of Changing Climate

2019 ◽  
Vol 7 (10) ◽  
pp. 469 ◽  
Author(s):  
Aliyar Cyrus Fouladkhah ◽  
Brian Thompson ◽  
Janey Smith Camp
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Quorum Sensing ◽  
Microbial Communities ◽  
Biofilm Formation ◽  
Processing Conditions ◽  
Water Supplies ◽  
Changing Climate ◽  
Transfer Mechanisms

In response to evolving environmental, production, and processing conditions, microbial communities have tremendous abilities to move toward increased diversity and fitness by various pathways such as vertical and horizontal gene transfer mechanisms, biofilm formation, and quorum sensing [...]

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