scholarly journals Kaurenoic Acid fromAralia continentalisInhibits Biofilm Formation ofStreptococcus mutans

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Seung-Il Jeong ◽  
Beom-Su Kim ◽  
Ki-Suk Keum ◽  
Kwang-Hee Lee ◽  
Sun-Young Kang ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Biofilm Formation ◽  
Acid Production ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Pcr Analysis ◽  
Dependent Manner ◽  
Kaurenoic Acid

We isolated a single chemical compound fromA. continentalisand identified it to be kaurenoic acid (KA) and investigated the influence of anticariogenic properties. Inhibitory effects of KA on cariogenic properties such as growth, acid production, biofilm formation, and the adherence ofS. mutanswere evaluated. Furthermore, real-time PCR analysis was performed to evaluate the influence of KA on the genetic expression of virulence factors. KA significantly inhibited the growth and acid production ofS. mutansat 2–4 μg/mL and 4 μg/mL of KA, respectively. Furthermore, the adherence onto S-HAs was inhibited at 3-4 μg/mL of KA and biofilm formation was significantly inhibited when treated with 3 μg/mL KA and completely inhibited at 4 μg/mL. Also, the inhibitory effect of KA on biofilm formation was confirmed by SEM. In confocal laser scanning microscopy, bacterial viability gradually decreased by KA in a dose dependent manner. Real-time PCR analysis showed that the expressions ofgtfB, gtfC, gbpB, spaP, brpA, relA, andvicRwere significantly decreased inS. mutanswhen it was treated with KA. These results suggest that KA fromA. continentalismay be a useful agent for inhibiting the cariogenic properties ofS. mutans.

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 Inhibition of Quorum Sensing and Biofilm Formation of Esculetin on Aeromonas Hydrophila

2021 ◽  
Vol 12 ◽  
Author(s):  
Bing Sun ◽  
Huaizhi Luo ◽  
Huan Jiang ◽  
Zhennan Wang ◽  
Aiqun Jia
Keyword(s):  
Quorum Sensing ◽  
Aeromonas Hydrophila ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Pcr Analysis ◽  
Swarming Motility ◽  
Gene Expression Levels ◽  
Good Agreement

Quorum sensing (QS) and biofilm formation inhibition activity of esculetin on Aeromonas hydrophila SHAe 115 were evaluated. Exposure to esculetin at 25, 50, and 100μg/ml significantly inhibited the production of protease and hemolysin, the formation of biofilms and attenuated the swarming motility of A. hydrophila SHAe 115. Biofilm forming inhibition was also observed through confocal laser scanning microscopy and scanning electron microscope. Quantitative real-time PCR analysis indicated that genes positively related to QS and biofilm formation were downregulated to varying degrees, while gene (litR) negatively related to biofilm formation was significantly upregulated. The phenotypic results were in good agreement with gene expression levels. These results indicated that esculetin would be a potential QS inhibitor for A. hydrophila.

scholarly journals Effect of Cinnamon Oil on icaA Expression and Biofilm Formation by Staphylococcus epidermidis

2009 ◽  
Vol 75 (21) ◽  
pp. 6850-6855 ◽  
Author(s):  
Titik Nuryastuti ◽  
Henny C. van der Mei ◽  
Henk J. Busscher ◽  
Susi Iravati ◽  
Abu T. Aman ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Antimicrobial Agents ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Pcr Analysis ◽  
Minimal Bactericidal Concentration ◽  
Cinnamon Oil ◽  
Broth Microdilution Method

ABSTRACT Staphylococcus epidermidis is notorious for its biofilm formation on medical devices, and novel approaches to prevent and kill S. epidermidis biofilms are desired. In this study, the effect of cinnamon oil on planktonic and biofilm cultures of clinical S. epidermidis isolates was evaluated. Initially, susceptibility to cinnamon oil in planktonic cultures was compared to the commonly used antimicrobial agents chlorhexidine, triclosan, and gentamicin. The MIC of cinnamon oil, defined as the lowest concentration able to inhibit visible microbial growth, and the minimal bactericidal concentration, the lowest concentration required to kill 99.9% of the bacteria, were determined using the broth microdilution method and plating on agar. A checkerboard assay was used to evaluate the possible synergy between cinnamon oil and the other antimicrobial agents. The effect of cinnamon oil on biofilm growth was studied in 96-well plates and with confocal laser-scanning microscopy (CLSM). Biofilm susceptibility was determined using a metabolic 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Real-time PCR analysis was performed to determine the effect of sub-MIC concentrations of cinnamon oil on expression of the biofilm-related gene, icaA. Cinnamon oil showed antimicrobial activity against both planktonic and biofilm cultures of clinical S. epidermidis strains. There was only a small difference between planktonic and biofilm MICs, ranging from 0.5 to 1% and 1 to 2%, respectively. CLSM images indicated that cinnamon oil is able to detach and kill existing biofilms. Thus, cinnamon oil is an effective antimicrobial agent to combat S. epidermidis biofilms.

scholarly journals Inhibition of Cronobacter Sakazakii Biofilm Formation and Expression of Virulence Factors by Coenzyme Q0

2020 ◽  
Author(s):  
Ning Guan ◽  
Yiqi Shi ◽  
Haoyu Tong ◽  
Yanpeng Yang ◽  
Jiahui Li ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Laser Scanning ◽  
Coenzyme Q ◽  
Polymerase Chain Reaction Analysis ◽  
Laser Scanning Microscopy ◽  
Raw 264.7 Cells ◽  
Confocal Laser ◽  
Dependent Manner ◽  
Cronobacter Sakazakii ◽  
And Control

Abstract Objectives：Here, we investigated the inhibitory effects of coenzyme Q0 (CoQ0) on biofilm formation and the expression of virulence genes by Cronobacter sakazakii. Results：We found that the minimum inhibitory concentration of CoQ0 against C. sakazakii strains ATCC29544 and ATCC29004 was 100 μg/mL, while growth curve assays showed that sub-inhibitory concentrations (SICs) of CoQ0 for both strains were 6.4, 3.2, 1.6 and 0.8 μg/mL. Assays exploring the inhibition of specific biofilm formation showed that SICs of CoQ0 inhibited biofilm formation by C. sakazakii in a dose-dependent manner, which was confirmed by scanning electron microscopy and confocal laser scanning microscopy analyses. CoQ0 inhibited the swimming and swarming motility of C. sakazakii and reduced its ability to adhere to and invade HT-29 cells. In addition, CoQ0 impeded the ability of C. sakazakii to survive and replicate within RAW 264.7 cells. Finally, real time polymerase chain reaction analysis confirmed that nine C. sakazakii genes associated with biofilm formation and virulence were down-regulated in response to CoQ0 treatment. Conclusion：Overall, our findings suggest that CoQ0 is a promising antibiofilm agent and provide new insights for the prevention and control of infections caused by C. sakazakii.

scholarly journals Antibacterial Activity ofRhus javanicaagainst Methicillin-ResistantStaphylococcus aureus

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Yong-Ouk You ◽  
Na-Young Choi ◽  
Sun-Young Kang ◽  
Kang-Ju Kim
Keyword(s):  
Laser Scanning ◽  
Ethanol Extract ◽  
Bactericidal Effect ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Pcr Analysis ◽  
Phytochemical Analysis ◽  
Dependent Manner ◽  
High Concentration ◽  
Inhibited Acid

In the present study, the leaves ofRhus javanica(R. javanica) were extracted with ethanol, and we investigated the antimicrobial activity of the ethanol extract ofR. javanicaagainst methicillin-resistantStaphylococcus aureus(MRSA). Control groups were treated with media containing 0.1% DMSO. The ethanol extract ofR. javanicainhibited the growth of MRSA at concentrations ranging from 0.05 to 0.2 mg/mL and inhibited acid production at concentrations higher than 0.1 mg/mL (P<0.05). MRSA biofilm formation was determined by scanning electron microscopy and safranin staining. The ethanol extract ofR. javanicainhibited the formation of MRSA biofilms at concentrations higher than 0.05 mg/mL. In confocal laser scanning microscopy, high concentration (0.4–1.6 mg/mL) ofR. javanicaextract showed bactericidal effect in a dose-dependent manner. In real-time PCR analysis,R. javanicaextract showed the inhibition of the genetic expression of virulence factors such asmecA,sea,agrA, andsarAin MRSA. Preliminary phytochemical analysis revealed the strong presence of phenolics. These results suggest thatR. javanicamay be a useful medicinal plant for inhibiting MRSA, which may be related to the presence of phenolics in theR. javanicaextract.

scholarly journals Colonization of Pythium oligandrum in the Tomato Rhizosphere for Biological Control of Bacterial Wilt Disease Analyzed by Real-Time PCR and Confocal Laser-Scanning Microscopy

2008 ◽  
Vol 98 (2) ◽  
pp. 187-195 ◽  
Author(s):  
Shigehito Takenaka ◽  
Hiroyuki Sekiguchi ◽  
Kazuhiro Nakaho ◽  
Motoaki Tojo ◽  
Akira Masunaka ◽  
...  
Keyword(s):  
Real Time ◽  
Confocal Laser Scanning Microscopy ◽  
Bacterial Wilt ◽  
Real Time Pcr ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Confocal Laser ◽  
Pythium Oligandrum ◽  
Rhizosphere Population

It recently has been reported that the non-plant-pathogenic oomycete Pythium oligandrum suppresses bacterial wilt caused by Ralstonia solanacearum in tomato. As one approach to determine disease-suppressive mechanisms of action, we analyzed the colonization of P. oligandrum in rhizospheres of tomato using real-time polymerase chain reaction (PCR) and confocal laser-scanning microscopy. The real-time PCR specifically quantified P. oligandrum in the tomato rhizosphere that is reliable over a range of 0.1 pg to 1 ng of P. oligandrum DNA from 25 mg dry weight of soil. Rhizosphere populations of P. oligandrum from tomato grown for 3 weeks in both unsterilized and sterilized field soils similarly increased with the initial application of at least 5 × 105 oospores per plant. Confocal microscopic observation also showed that hyphal development was frequent on the root surface and some hyphae penetrated into root epidermis. However, rhizosphere population dynamics after transplanting into sterilized soil showed that the P. oligandrum population decreased with time after transplanting, particularly at the root tips, indicating that this biocontrol fungus is rhizosphere competent but does not actively spread along roots. Protection over the long term from root-infecting pathogens does not seem to involve direct competition. However, sparse rhizosphere colonization of P. oligandrum reduced the bacterial wilt as well as more extensive colonization, which did not reduce the rhizosphere population of R. solanacearum. These results suggest that competition for infection sites and nutrients in rhizosphere is not the primary biocontrol mechanism of bacterial wilt by P. oligandrum.

Star Anise (Illicium verum Hook. f.) as Quorum Sensing and Biofilm Formation Inhibitor on Foodborne Bacteria: Study in Milk

2016 ◽  
Vol 80 (4) ◽  
pp. 645-653 ◽  
Author(s):  
MD Ramim Tanver Rahman ◽  
Zaixiang Lou ◽  
Jun Zhang ◽  
Fuhao Yu ◽  
Yakindra Prasad Timilsena ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Health Hazard ◽  
Group Behavior ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Dependent Manner ◽  
Star Anise ◽  
Synthetic Chemicals

ABSTRACT Bacteria use quorum sensing (QS) systems to communicate with each other and regulate microbial group behavior, such as the secretion of virulence factors, including biofilm formation. In order to explore safe, edible agents, the potential of star anise (SA) as an anti-QS and antibiofilm agent and its possible application in milk safety were investigated. Staphylococcus aureus, Salmonella Typhimurium, Pseudomonas aeruginosa, and biosensor strain Chromobacterium violaceum were selected as test strains for QS, biofilm, and exopolysaccharide assays. The percent acidities and total plate counts were determined to evaluate the quality of biofilm-inoculated and noninoculated milk. The yield of SA extraction was 25.90% ± 0.2% (w/w). At sub-MIC, SA extract did not show any effect on bacterial growth. The production of violacein was inhibited by 89% by SA extract. The extract also inhibited the formation of biofilm by up to 87% in a dose-dependent manner. Inhibition rates of 70.45%, 42.82%, and 35.66% were found for exopolysaccharide production. The swarming motility of S. aureus was reduced by about 95.9% by SA extract. Confocal laser scanning microscopy analysis confirmed that the development of biofilm architecture was hampered. It was found that SA extract could delay the spoilage of milk. In the endeavor to avoid drug resistance, pathogenesis, and resistance to biocides while improving food safety and avoiding health hazard issues arising from synthetic chemicals, SA extract could be used as a potential QS and biofilm inhibitor.

scholarly journals Mucosa-Associated Bacterial Diversity in Relation to Human Terminal Ileum and Colonic Biopsy Samples

2007 ◽  
Vol 73 (22) ◽  
pp. 7435-7442 ◽  
Author(s):  
Shakil Ahmed ◽  
George T. Macfarlane ◽  
Alemu Fite ◽  
Andrew J. McBain ◽  
Peter Gilbert ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Real Time ◽  
Large Intestine ◽  
Terminal Ileum ◽  
Real Time Pcr ◽  
Large Bowel ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Descending Colon

ABSTRACT Little is known about bacterial communities that colonize mucosal surfaces in the human gastrointestinal tract, but they are believed to play an important role in host physiology. The objectives of this study were to investigate the compositions of these populations in the distal small bowel and colon. Healthy mucosal tissue from either the terminal ileum (n = 6) or ascending (n = 8), transverse (n = 8), or descending colon (n = 4) of 26 patients (age, 68.5 ± 1.2 years [mean ± standard deviation]) undergoing emergency resection of the large bowel was used to study these communities. Mucosa-associated eubacteria were characterized by using PCR-denaturing gradient gel electrophoresis (DGGE), while real-time PCR was employed for quantitative analysis. Mucosal communities were also visualized in situ using confocal laser scanning microscopy. DGGE banding profiles from all the gut regions exhibited at least 45% homology, with five descending colon profiles clustering at ca. 75% concordance. Real-time PCR showed that mucosal bacterial population densities were highest in the terminal ileum and that there were no significant differences in overall bacterial numbers in different parts of the colon. Bifidobacterial numbers were significantly higher in the large bowel than in the terminal ileum (P = 0.006), whereas lactobacilli were more prominent in the distal large intestine (P = 0.019). Eubacterium rectale (P = 0.0004) and Faecalibacterium prausnitzii (P = 0.001) were dominant in the ascending and descending colon. Site-specific colonization in the gastrointestinal tract may be contributory in the etiology of some diseases of the large intestine.

Confocal and SEM imaging to demonstrate food pathogen- biofilm biocontrol by pyocyanin from Pseudomonas aeruginosa BTRY1

2016 ◽  
Vol 6 (01) ◽  
pp. 5218
Author(s):  
Laxmi Mohandas ◽  
Anju T. R. ◽  
Sarita G. Bhat*
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Antibiofilm Activity ◽  
Opportunistic Pathogens ◽  
Redox Active ◽  
Sem Imaging ◽  
The Impact

An assortment of redox-active phenazine compounds like pyocyanin with their characteristic blue-green colour are synthesized by Pseudomonas aeruginosa, Gram-negative opportunistic pathogens, which are also considered one of the most commercially valuable microorganisms. In this study, pyocyanin from Pseudomonas aeruginosa BTRY1 from food sample was assessed for its antibiofilm activity by micro titer plate assay against strong biofilm producers belonging to the genera Bacillus, Staphylococcus, Brevibacterium and Micrococcus. Pyocyanin inhibited biofilm activity in very minute concentrations. This was also confirmed by Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM). Both SEM and CLSM helped to visualize the biocontrol of biofilm formation by eight pathogens. The imaging and quantification by CLSM also established the impact of pyocyanin on biofilm-biocontrol mainly in the food industry.

scholarly journals Vacuolar-type H+-ATPase regulates cytoplasmic pH in Toxoplasma gondii tachyzoites

1998 ◽  
Vol 330 (2) ◽  
pp. 853-860 ◽  
Author(s):  
N. J. Silvia MORENO ◽  
Li ZHONG ◽  
Hong-Gang LU ◽  
Wanderley DE SOUZA ◽  
Marlene BENCHIMOL
Keyword(s):  
Plasma Membrane ◽  
Toxoplasma Gondii ◽  
Laser Scanning ◽  
Membrane Surface ◽  
Surface Proteins ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Dependent Manner ◽  
Cytoplasmic Ph ◽  
Bafilomycin A1

Cytoplasmic pH (pHi) regulation was studied in Toxoplasma gondii tachyzoites by using the fluorescent dye 2ʹ,7ʹ-bis-(2-carboxyethyl)-5(6)-carboxyfluorescein. Their mean baseline pHi (7.07±0.06; n = 5) was not significantly affected in the absence of extracellular Na+, K+ or HCO3- but was significantly decreased in a dose-dependent manner by low concentrations of N,Nʹ-dicyclohexylcarbodi-imide (DCCD), N-ethylmaleimide (NEM) or bafilomycin A1. Bafilomycin A1 also inhibited the recovery of tachyzoite pHi after an acid load with sodium propionate. Similar concentrations of DCCD, NEM and bafilomycin A1 produced depolarization of the plasma membrane potential as measured with bis-(1,3-diethylthiobarbituric)trimethineoxonol (bisoxonol), and DCCD prevented the hyperpolarization that accompanies acid extrusion after the addition of propionate, in agreement with the electrogenic nature of this pump. Confocal laser scanning microscopy indicated that, in addition to being located in cytoplasmic vacuoles, the vacuolar (V)-H+-ATPase of T. gondii tachyzoites is also located in the plasma membrane. Surface localization of the V-H+-ATPase was confirmed by experiments using biotinylation of cell surface proteins and immunoprecipitation with antibodies against V-H+-ATPases. Taken together, the results are consistent with the presence of a functional V-H+-ATPase in the plasma membrane of these intracellular parasites and with an important role of this enzyme in the regulation of pHi homoeostasis in these cells.

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