Effects of inducer levels on a recombinant bacterial biofilm formation and gene expression

1994 ◽  
Vol 16 (9) ◽  
pp. 903-908 ◽  
Author(s):  
Ching-Tsan Huang ◽  
Steven W. Peretti ◽  
James D. Bryers
Keyword(s):  
Gene Expression ◽  
Biofilm Formation ◽  
Bacterial Biofilm

scholarly journals purL gene expression affects biofilm formation and symbiotic persistence of Photorhabdus temperata in the nematode Heterorhabditis bacteriophora

Microbiology ◽  
2011 ◽  
Vol 157 (9) ◽  
pp. 2595-2603 ◽  
Author(s):  
Ruisheng An ◽  
Parwinder S. Grewal
Keyword(s):  
Gene Expression ◽  
Metabolic Pathway ◽  
Biofilm Formation ◽  
Heterorhabditis Bacteriophora ◽  
Bacterial Biofilm ◽  
Infective Juvenile ◽  
Plant Interactions ◽  
Symbiotic Interaction ◽  
The Impact ◽  
Photorhabdus Temperata

Extensive studies of the well-known legume and rhizobium symbiosis model system suggest that the purine metabolic pathway plays a key role in microbe–plant interactions, although the exact mechanism is unknown. Here, we report the impact of a key purine metabolic gene, purL, on the symbiotic interaction between the bacterium Photorhabdus temperata and its nematode partner Heterorhabditis bacteriophora. Real-time PCR assays showed that the purL gene was upregulated in P. temperata in the nematode infective juvenile compared with artificial media. Mutation of the purL gene by in-frame deletion dramatically decreased the capacity of the bacterium to persist in infective juveniles and its ability to form biofilm in vitro. It was further demonstrated that purL gene expression was positively related to bacterial biofilm formation and the symbiotic persistence of the bacterium in nematode infective juveniles. A ΔpurL mutant lost the ability to support infective juvenile formation in the media which weakly supported biofilm formation, suggesting that a critical level of biofilm formation is required by the bacteria to support infective juvenile formation and thus establish their partnership. In addition, the defects in both biofilm formation and symbiotic ability due to the disruption of the purL gene could be partially restored by the addition of 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR), an intermediate of the purine biosynthesis pathway. Overall, these data indicate that the purine metabolic pathway is important in microbe–animal symbioses, and that it may influence symbiotic interactions at the level of biofilm formation.

scholarly journals Hybrid histidine kinase BinK represses Vibrio fischeri biofilm signaling at multiple developmental stages

2021 ◽  
Author(s):  
Denise A. Ludvik ◽  
Katherine M. Bultman ◽  
Mark J. Mandel
Keyword(s):  
Gene Expression ◽  
Gene Regulation ◽  
Histidine Kinase ◽  
Biofilm Formation ◽  
Vibrio Fischeri ◽  
Bacterial Biofilm ◽  
Negative Regulator ◽  
Light Organ ◽  
Host Colonization ◽  
Hybrid Histidine Kinase

ABSTRACTThe symbiosis between the Hawaiian bobtail squid, Euprymna scolopes, and its exclusive light-organ symbiont, Vibrio fischeri, provides a natural system in which to study host-microbe specificity and gene regulation during the establishment of a mutually-beneficial symbiosis. Colonization of the host relies on bacterial biofilm-like aggregation in the squid mucus field. Symbiotic biofilm formation is controlled by a two-component signaling (TCS) system consisting of regulators RscS-SypF-SypG, which together direct transcription of the Syp symbiotic polysaccharide. TCS systems are broadly important for bacteria to sense environmental cues and then direct changes in behavior. Previously, we identified hybrid histidine kinase BinK as a strong negative regulator of V. fischeri biofilm regulation, and here we further explore the function of BinK. To inhibit biofilm formation, BinK requires the predicted phosphorylation sites in both the histidine kinase (H362) and receiver (D794) domains. Furthermore, we show that a strain lacking BinK yields RscS non-essential for host colonization, and imaging of aggregate size revealed no benefit to the presence of RscS in a background lacking BinK. Strains lacking RscS still suffered in competition, suggesting another function for the protein. Finally, we show that BinK functions to inhibit biofilm gene expression in the light organ crypts, providing evidence for biofilm gene regulation at later stages of host colonization. Overall, this study provides direct evidence for opposing activities of RscS and BinK and yields novel insights into biofilm regulation during the maturation of a beneficial symbiosis.IMPORTANCEBacteria are often in a biofilm state, and transitions between planktonic and biofilm lifestyles are important for pathogenic, beneficial, and environmental microbes. The critical nature of biofilm formation during Vibrio fischeri colonization of the Hawaiian bobtail squid light organ provides an opportunity to study development of this process in vivo using a combination of genetic and imaging approaches. The current work refines the signaling circuitry of the biofilm pathway in V. fischeri, provides evidence that biofilm regulatory changes occur in the host, and identifies BinK as one of the regulators of that process. This study provides information about how bacteria regulate biofilm gene expression in an intact animal host.

scholarly journals Hybrid histidine kinase BinK represses Vibrio fischeri biofilm signaling at multiple developmental stages

2021 ◽  
Author(s):  
Denise A. Ludvik ◽  
Katherine M. Bultman ◽  
Mark J. Mandel
Keyword(s):  
Gene Expression ◽  
Gene Regulation ◽  
Histidine Kinase ◽  
Biofilm Formation ◽  
Vibrio Fischeri ◽  
Bacterial Biofilm ◽  
Negative Regulator ◽  
Light Organ ◽  
Host Colonization ◽  
Hybrid Histidine Kinase

The symbiosis between the Hawaiian bobtail squid, Euprymna scolopes, and its exclusive light-organ symbiont, Vibrio fischeri, provides a natural system in which to study host-microbe specificity and gene regulation during the establishment of a mutually-beneficial symbiosis. Colonization of the host relies on bacterial biofilm-like aggregation in the squid mucus field. Symbiotic biofilm formation is controlled by a two-component signaling (TCS) system consisting of regulators RscS-SypF-SypG, which together direct transcription of the Syp symbiotic polysaccharide. TCS systems are broadly important for bacteria to sense environmental cues and then direct changes in behavior. Previously, we identified hybrid histidine kinase BinK as a strong negative regulator of V. fischeri biofilm regulation, and here we further explore the function of BinK. To inhibit biofilm formation, BinK requires the predicted phosphorylation sites in both the histidine kinase (H362) and receiver (D794) domains. Furthermore, we show that RscS is not essential for host colonization when binK is deleted from strain ES114, and imaging of aggregate size revealed no benefit to the presence of RscS in a background lacking BinK. Strains lacking RscS still suffered in competition. Finally, we show that BinK functions to inhibit biofilm gene expression in the light organ crypts, providing evidence for biofilm gene regulation at later stages of host colonization. Overall, this study provides direct evidence for opposing activities of RscS and BinK and yields novel insights into biofilm regulation during the maturation of a beneficial symbiosis. IMPORTANCE Bacteria are often in a biofilm state, and transitions between planktonic and biofilm lifestyles are important for pathogenic, beneficial, and environmental microbes. The critical nature of biofilm formation during Vibrio fischeri colonization of the Hawaiian bobtail squid light organ provides an opportunity to study development of this process in vivo using a combination of genetic and imaging approaches. The current work refines the signaling circuitry of the biofilm pathway in V. fischeri, provides evidence that biofilm regulatory changes occur in the host, and identifies BinK as one of the regulators of that process. This study provides information about how bacteria regulate biofilm gene expression in an intact animal host.

Molecular Basis of Tobacco-Induced Bacterial Biofilms

2012 ◽  
Vol 147 (5) ◽  
pp. 876-884 ◽  
Author(s):  
Marcelo B. Antunes ◽  
John J. Chi ◽  
Zhi Liu ◽  
Natalia Goldstein-Daruech ◽  
James N. Palmer ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Tobacco Smoke ◽  
Biofilm Formation ◽  
Smoke Exposure ◽  
Bacterial Biofilm ◽  
Tobacco Smoke Exposure ◽  
University Of Pennsylvania ◽  
Biofilm Growth

Objective To evaluate changes in the expression of biofilm-related genes when exposed to tobacco smoke and oxidative stress. Study Design Experimental, in vitro. Setting Laboratories of Rhinology and Microbiology, University of Pennsylvania. Subjects and Methods Bacterial biofilm mass was measured using crystal violet staining and measurement of the optical density. Biofilm-related genes of the Pseudomonas aeruginosa PAO1 strain ( pilF, flgK, lasI, lasB, rhlA, and algC) were studied following repetitive exposure to exogenous tobacco smoke and hydrogen peroxide. This was done using a reporter plasmid. Results After 1 exposure to smoke, there was no change in biofilm formation. However, after 2 and 3 exposures, the biofilm formed had an increased mass ( P < .05). With respect to oxidative stress in the form of H2O2, bacterial cultures demonstrated a dose- and time-dependent induction of biofilm formation compared with control conditions. Gene expression following repetitive smoke exposure demonstrated an increase in expression of pilF, flgK, algC, and lasI genes ( P < .05); a decrease in rhlA ( P < .05); and no significant change in the lasB gene ( P = 0.1). Gene expression following H2O2 exposure demonstrated an increase in pilF ( P < .05), whereas the other genes failed to demonstrate a statistical change. Conclusions Repetitive tobacco smoke exposure leads to molecular changes in biofilm-related genes, and exposure to oxidative stress in the form of H2O2 induces biofilm growth in PAO1. This could represent adaptative changes due to oxidative stress or chemically mediated through any of the several chemicals encountered in tobacco smoke and may explain increased biofilm formation in microbes isolated from smokers.

scholarly journals Escherichia coli O157:H7 Strains Isolated from High-Event Period Beef Contamination Have Strong Biofilm-Forming Ability and Low Sanitizer Susceptibility, Which Are Associated with High pO157 Plasmid Copy Number

2016 ◽  
Vol 79 (11) ◽  
pp. 1875-1883 ◽  
Author(s):  
RONG WANG ◽  
BRANDON E. LUEDTKE ◽  
JOSEPH M. BOSILEVAC ◽  
JOHN W. SCHMIDT ◽  
NORASAK KALCHAYANAND ◽  
...  
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Biofilm Formation ◽  
Copy Number ◽  
Plasmid Copy Number ◽  
Bacterial Biofilm ◽  
Escherichia Coli O157 ◽  
Plasmid Copy ◽  
E Coli ◽  
High Event

ABSTRACT In the meat industry, a high-event period (HEP) is defined as a time period when beef processing establishments experience an increased occurrence of product contamination by Escherichia coli O157:H7. Our previous studies suggested that bacterial biofilm formation and sanitizer resistance might contribute to HEPs. We conducted the present study to further characterize E. coli O157:H7 strains isolated during HEPs for their potential to cause contamination and to investigate the genetic basis for their strong biofilm-forming ability and high sanitizer resistance. Our results show that, compared with the E. coli O157:H7 diversity control panel strains, the HEP strains had a significantly higher biofilm-forming ability on contact surfaces and a lower susceptibility to common sanitizers. No difference in the presence of disinfectant-resistant genes or the prevalence of antibiotic resistance was observed between the HEP and control strains. However, the HEP strains retained significantly higher copy numbers of the pO157 plasmid. A positive correlation was observed among a strain's high plasmid copy number, strong biofilm-forming ability, low sanitizer susceptibility, and high survival and recovery capability after sanitization, suggesting that these specific phenotypes could be either directly correlated to gene expression on the pO157 plasmid or indirectly regulated via chromosomal gene expression influenced by the presence of the plasmid. Our data highlight the potential risk of biofilm formation and sanitizer resistance in HEP contamination by E. coli O157:H7, and our results call for increased attention to proper and effective sanitization practices in meat processing facilities.

scholarly journals Effect of garlic on bacterial biofilm formation on orthodontic wire

2011 ◽  
Vol 81 (5) ◽  
pp. 895-900 ◽  
Author(s):  
Heon-Jin Lee ◽  
Hyo-Sang Park ◽  
Kyo-Han Kim ◽  
Tae-Yub Kwon ◽  
Su-Hyung Hong
Keyword(s):  
Gene Expression ◽  
Biofilm Formation ◽  
Agar Plate ◽  
Oral Bacteria ◽  
Bacterial Attachment ◽  
Bacterial Biofilm ◽  
Garlic Extract ◽  
Cell Counting ◽  
Orthodontic Wires ◽  
Orthodontic Wire

Abstract Objective: To examine the effect of garlic extract on the biofilm formation by Streptococcus mutans on orthodontic wire and on glucosyltransferase gene expression. Materials and Methods: Growth inhibition of oral bacteria was tested after 50 µL of garlic extract was placed on an agar plate. The minimum inhibitory concentration (MIC) of garlic extract on S mutans growth was first determined. After cultivating streptococci in biofilm medium (BM)-sucrose with garlic extract and orthodontic wire, adenosine triphosphate (ATP) measurement and viable cell counting was performed from the bacteria attached on the wire. Scanning electron microscopy (SEM) analysis of morphology was observed on bacterial cells attached to orthodontic wire. The effect of garlic extract on gene expression was evaluated using quantitative real-time polymerase chain reaction (PCR) of glucosyltransferase. Results: Though garlic extract had a clear antibacterial effect on all microorganisms, it also enhanced S mutans attachment on orthodontic wire. Low concentration of garlic extract also increased glucosyltransferase gene expression of S mutans. Conclusions: Despite its antibacterial function, garlic extract increases biofilm formation by S mutans to orthodontic wire, likely through upregulation of glucosyltransferase expression. Garlic extract may thus play an important role in increased bacterial attachment to orthodontic wires.

Bacterial biofilm behavior in water-supply lines of dental units

1992 ◽  
Vol 50 (1) ◽  
pp. 882-883
Author(s):  
B.D. Tall ◽  
K.S. George ◽  
R. T. Gray ◽  
H.N. Williams
Keyword(s):  
Water Supply ◽  
Medical Devices ◽  
Biofilm Formation ◽  
Bacterial Biofilm

Studies of bacterial behavior in many environments have shown that most organisms attach to surfaces, forming communities of microcolonies called biofilms. In contaminated medical devices, biofilms may serve both as reservoirs and as inocula for the initiation of infections. Recently, there has been much concern about the potential of dental units to transmit infections. Because the mechanisms of biofilm formation are ill-defined, we investigated the behavior and formation of a biofilm associated with tubing leading to the water syringe of a dental unit over a period of 1 month.

Inhibition of Bacterial Biofilm Formation by Phytotherapeutics with Focus on Overcoming Antimicrobial Resistance

2020 ◽  
Vol 26 (24) ◽  
pp. 2807-2816 ◽  
Author(s):  
Yun Su Jang ◽  
Tímea Mosolygó
Keyword(s):  
Antimicrobial Resistance ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Bacterial Biofilm ◽  
Experimental Investigations ◽  
Resistant Bacteria ◽  
Salmonella Spp ◽  
Food Borne ◽  
High Prevalence ◽  
Scientific Attention

: Bacteria within biofilms are more resistant to antibiotics and chemical agents than planktonic bacteria in suspension. Treatment of biofilm-associated infections inevitably involves high dosages and prolonged courses of antimicrobial agents; therefore, there is a potential risk of the development of antimicrobial resistance (AMR). Due to the high prevalence of AMR and its association with biofilm formation, investigation of more effective anti-biofilm agents is required. : From ancient times, herbs and spices have been used to preserve foods, and their antimicrobial, anti-biofilm and anti-quorum sensing properties are well known. Moreover, phytochemicals exert their anti-biofilm properties at sub-inhibitory concentrations without providing the opportunity for the emergence of resistant bacteria or harming the host microbiota. : With increasing scientific attention to natural phytotherapeutic agents, numerous experimental investigations have been conducted in recent years. The present paper aims to review the articles published in the last decade in order to summarize a) our current understanding of AMR in correlation with biofilm formation and b) the evidence of phytotherapeutic agents against bacterial biofilms and their mechanisms of action. The main focus has been put on herbal anti-biofilm compounds tested to date in association with Staphylococcus aureus, Pseudomonas aeruginosa and food-borne pathogens (Salmonella spp., Campylobacter spp., Listeria monocytogenes and Escherichia coli).

Antibiotics Application Strategies to Control Biofilm Formation in Pathogenic Bacteria

2020 ◽  
Vol 21 (4) ◽  
pp. 270-286 ◽  
Author(s):  
Fazlurrahman Khan ◽  
Dung T.N. Pham ◽  
Sandra F. Oloketuyi ◽  
Young-Mog Kim
Keyword(s):  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Extracellular Polymeric Substances ◽  
Quorum Quenching ◽  
Resistance Mechanisms ◽  
Bacterial Biofilm ◽  
Bacterial Cells ◽  
High Concentration ◽  
Biofilm Inhibition ◽  
Abiotic Surfaces

Background: The establishment of a biofilm by most pathogenic bacteria has been known as one of the resistance mechanisms against antibiotics. A biofilm is a structural component where the bacterial community adheres to the biotic or abiotic surfaces by the help of Extracellular Polymeric Substances (EPS) produced by bacterial cells. The biofilm matrix possesses the ability to resist several adverse environmental factors, including the effect of antibiotics. Therefore, the resistance of bacterial biofilm-forming cells could be increased up to 1000 times than the planktonic cells, hence requiring a significantly high concentration of antibiotics for treatment. Methods: Up to the present, several methodologies employing antibiotics as an anti-biofilm, antivirulence or quorum quenching agent have been developed for biofilm inhibition and eradication of a pre-formed mature biofilm. Results: Among the anti-biofilm strategies being tested, the sub-minimal inhibitory concentration of several antibiotics either alone or in combination has been shown to inhibit biofilm formation and down-regulate the production of virulence factors. The combinatorial strategies include (1) combination of multiple antibiotics, (2) combination of antibiotics with non-antibiotic agents and (3) loading of antibiotics onto a carrier. Conclusion: The present review paper describes the role of several antibiotics as biofilm inhibitors and also the alternative strategies adopted for applications in eradicating and inhibiting the formation of biofilm by pathogenic bacteria.

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