scholarly journals Autoinducer 2 Affects Biofilm Formation by Bacillus cereus

2006 ◽  
Vol 72 (1) ◽  
pp. 937-941 ◽  
Author(s):  
Sandrine Auger ◽  
Evelyne Krin ◽  
Stéphane Aymerich ◽  
Michel Gohar
Keyword(s):  
Bacillus Cereus ◽  
Biofilm Formation ◽  
Inhibitory Effect ◽  
Strain Atcc ◽  
Photorhabdus Luminescens ◽  
Autoinducer 2 ◽  
Exogenous Addition

ABSTRACT Cell-free supernatants from growing Bacillus cereus strain ATCC 10987 induced luminescence in a Photorhabdus luminescens ΔluxS mutant, indicating the production of functional autoinducer 2 (AI-2). The exogenous addition of in vitro synthesized AI-2 had an inhibitory effect on biofilm formation by B. cereus and promoted release of the cells from a preformed biofilm.

Effect of Thymus ciliatus oil-based disinfectant solutions against bio-films formed by Bacillus cereus strains isolated from pasteurized-milk processing lines in Algeria

2018 ◽  
Vol 8 (1) ◽  
pp. 01-12
Author(s):  
Amina Kalai ◽  
Fadila Malek ◽  
Leila Bousmaha-Marroki
Keyword(s):  
Essential Oil ◽  
Organic Acids ◽  
Bacillus Cereus ◽  
Biofilm Formation ◽  
Chemical Cleaning ◽  
Pasteurized Milk ◽  
Thyme Oil ◽  
Milk Processing ◽  
Planktonic Growth

Bacillus cereus is a foodborne pathogen that often persists in dairy environments and is associated with food poisoning and spoilage. This spore-forming bacterium has a high propensity to develop biofilms onto dairy processing equipment and resists to chemical cleaning and disinfecting. This study deals with the in vitro application of thyme oil-based sanitizer solutions against biofilms formed by B. cereus genotypes which persist in pasteurized-milk processing lines. The effect of Thymus ciliatus essential oil on B. cereus planktonic cells and biofilms was assessed. The oil was tested alone and in combination with organic acids or industrial cleaning agents, in order to improve the removal of B. cereus recurrent genotypes. Minimal inhibitory concentrations of planktonic growth (MICs), biofilm formation (MBIC) and biofilm eradication (MBEC) of oil and organic acids were evaluated by microdilution assays. Thyme oil was more effective than organic acids against B. cereus planktonic growth, biofilm formation and established bio-films. High values of MICs were obtained for the three organic acids tested (3.5-4.5%) in comparison with those of essential oil (0.082-0.088%). The combination of oil with other antimicrobials as acetic acid, NaOH or HNO3 improves their effectiveness against B. cereus biofilms. These oil-based sanitizer solutions allow complete B. cereus biofilm eradication and should be an attractive candidate for the control and removal of biofilms in the dairy envi-ronment.

scholarly journals Antimicrobial and anti-biofilm potencies of dermcidin-derived peptide DCD-1L against Acinetobacter baumannii: an in vivo wound healing model

2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Zahra Farshadzadeh ◽  
Maryam Pourhajibagher ◽  
Behrouz Taheri ◽  
Alireza Ekrami ◽  
Mohammad Hossein Modarressi ◽  
...  
Keyword(s):  
Wound Healing ◽  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Histopathological Examination ◽  
Inhibitory Effect ◽  
Bacterial Attachment ◽  
Burn Wound ◽  
Conventional Antibiotics

Abstract Background The global emergence of Acinetobacter baumannii resistance to most conventional antibiotics presents a major therapeutic challenge and necessitates the discovery of new antibacterial agents. The purpose of this study was to investigate in vitro and in vivo anti-biofilm potency of dermcidin-1L (DCD-1L) against extensively drug-resistant (XDR)-, pandrug-resistant (PDR)-, and ATCC19606-A. baumannii. Methods After determination of minimum inhibitory concentration (MIC) of DCD-1L, in vitro anti-adhesive and anti-biofilm activities of DCD-1L were evaluated. Cytotoxicity, hemolytic activity, and the effect of DCD-1L treatment on the expression of various biofilm-associated genes were determined. The inhibitory effect of DCD-1L on biofilm formation in the model of catheter-associated infection, as well as, histopathological examination of the burn wound sites of mice treated with DCD-1L were assessed. Results The bacterial adhesion and biofilm formation in all A. baumannii isolates were inhibited at 2 × , 4 × , and 8 × MIC of DCD-1L, while only 8 × MIC of DCD-1L was able to destroy the pre-formed biofilm in vitro. Also, reduce the expression of genes involved in biofilm formation was observed following DCD-1L treatment. DCD-1L without cytotoxic and hemolytic activities significantly reduced the biofilm formation in the model of catheter-associated infection. In vivo results showed that the count of A. baumannii in infected wounds was significantly decreased and the promotion in wound healing by the acceleration of skin re-epithelialization in mice was observed following treatment with 8 × MIC of DCD-1L. Conclusions Results of this study demonstrated that DCD-1L can inhibit bacterial attachment and biofilm formation and prevent the onset of infection. Taking these properties together, DCD-1L appears as a promising candidate for antimicrobial and anti-biofilm drug development.

scholarly journals Evaluating the thermoresistance of Bacillus cereus strains isolated from wheat flour

2021 ◽  
Vol 10 (6) ◽  
pp. e2510615268
Author(s):  
Eliandra Mirlei Rossi ◽  
Suelen Caroline Mahl ◽  
Ana Carolina Spaniol ◽  
Jéssica Fernanda Barreto Honorato ◽  
Tauany Rocha
Keyword(s):  
Bacillus Cereus ◽  
Wheat Flour ◽  
Food Products ◽  
Thermal Treatments ◽  
Strain Atcc ◽  
Baked Goods ◽  
Confectionery Products ◽  
Wheat Flours

Wheat flour is often used to prepare confectionery and baked goods, however, it can be contaminated by aporulating microorganisms contaminated during harvest or improper storage. The aim of this study was to isolate Bacillus cereus strains from different wheat flour brands and to evaluate their thermoresistance in different confectionery products. It was done in order to investigate the risks posed by food prepared with flour contaminated with B. cereus to consumers’ health. The investigation of B.cereus was realized in five brands of different wheat flours were collected and named A to E. The isolated strains were subjected to boiling tests in vitro to evaluate their thermoresistance. In addition, confectionery products were prepared with flour contaminated with B. cereus strains. These products were subjected to different cooking and B. cereus strain ATCC®30301™ was used as control. Flour brands were contaminated with B. cereus; and counts ranged from 0.25 to 1.57 log CFU/g. The strains presented higher thermoresistance in the confectionery products than in the test conducted in vitro. Based on our results, it was concluded that B. cereus strains are thermoresistant. Moreover, if the flour is contaminated with this bacterium, food products subjected to thermal treatments may remain contaminated. In addition, it is suggested that there is some mechanism (not observed in our study) that could directly influence the thermoresistance of strains found in food.

scholarly journals Inhibitory effect of propafenone derivatives on pseudomonas aeruginosa biofilm and pyocyanin production

2020 ◽  
Vol 148 (3-4) ◽  
pp. 196-202
Author(s):  
Snjezana Petrovic ◽  
Jasmina Basic ◽  
Zoran Mandinic ◽  
Dragana Bozic ◽  
Marina Milenkovic ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Laboratory Strain ◽  
Inhibitory Effect ◽  
Negative Control ◽  
Clinical Strains ◽  
Control Value ◽  
Essential Components ◽  
Pyocyanin Production

Introduction/Objective. Biofilm and pyocyanin production are essential components of Pseudomonas aeruginosa virulence and antibiotic resistance. Our objective was to examine inhibitory effect of synthetized propafenone derivatives 3-(2-Fluorophenyl)- 1-(2- (2-hydroxy-3-propylamino-propoxy)-phenyl)-propan-1-one hydrochloride (5OF) and3-(2- Trifluoromethyl-phenyl)-1-(2-(2-hydroxy-3-propylamino-propoxy)-phenyl)-propan-1-one hydrochloride (5CF3) on biofilm and pyocyanin in Pseudomonas aeruginosa clinical strains. Methods. Effects were tested on nine clinical isolates and one control laboratory strain of P. aeruginosa. In vitro analysis of biofilm growing was performed by incubating bacteria (0.5 McFarland) with 5OF and 5CF3 (500?31.2 ?g/ml) and measuring optical density (OD) at 570 nm. Bacteria in medium without compounds were positive control. Blank medium (an uninoculated medium without test compounds) was used as negative control. Pyocyanin production was estimated by OD at 520 nm, after bacteria incubated with 5CF3 and 5OF (250 and 500 ?g/ml), treated with chloroform, and chloroform layer mixed with HCl. Results. A total of 500 ?g/ml of 5OF and 5CF3 completely inhibited biofilm formation in 10/10 and 4/10 strains, respectively. A total of 250 ?g/ml of 5OF and 5CF3 strongly inhibited biofilm formation in 7/10 strains, while inhibition with 125 ?g/ml of 5OF and 5CF3 was moderate. Lower concentrations had almost no effect on biofilm production. Pyocyanin production was reduced to less than 40% of the control value in 6/9, and less than 50% of the control in 7/9 strains with 500 ?g/ml of 5OF and 5CF3, respectively. At 250 ?g/ml 5OF and 5CF3, most strains had pyocyanin production above 50% of the control value. Conclusion. Synthetized propafenone derivatives, 5OF and 5CF3, inhibited biofilms and pyocyanin production of Pseudomonas aeruginosa clinical strains. Presented results suggest that propafenone derivatives are potential lead-compounds for synthesis of novel antipseudomonal drugs.

Inhibitory activity of isoniazid and ethionamide against Cryptococcus biofilms

2015 ◽  
Vol 61 (11) ◽  
pp. 827-836 ◽  
Author(s):  
Rossana de Aguiar Cordeiro ◽  
Rosana Serpa ◽  
Francisca Jakelyne de Farias Marques ◽  
Charlline Vládia Silva de Melo ◽  
Antonio José de Jesus Evangelista ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Biofilm Formation ◽  
Inhibitory Effect ◽  
Cell Membrane Permeability ◽  
Planktonic Cells ◽  
Fungal Cell ◽  
Antituberculosis Drugs ◽  
Opportunistic Mycoses ◽  
Cryptococcus Spp

In recent years, the search for drugs to treat systemic and opportunistic mycoses has attracted great interest from the scientific community. This study evaluated the in vitro inhibitory effect of the antituberculosis drugs isoniazid and ethionamide alone and combined with itraconazole and fluconazole against biofilms of Cryptococcus neoformans and Cryptococcus gattii. Antimicrobials were tested at defined concentrations after susceptibility assays with Cryptococcus planktonic cells. In addition, we investigated the synergistic interaction of antituberculosis drugs and azole derivatives against Cryptococcus planktonic cells, as well as the influence of isoniazid and ethionamide on ergosterol content and cell membrane permeability. Isoniazid and ethionamide inhibited both biofilm formation and viability of mature biofilms. Combinations formed by antituberculosis drugs and azoles proved synergic against both planktonic and sessile cells, showing an ability to reduce Cryptococcus biofilms by approximately 50%. Furthermore, isoniazid and ethionamide reduced the content of ergosterol in Cryptococcus spp. planktonic cells and destabilized or permeabilized the fungal cell membrane, leading to leakage of macromolecules. Owing to the paucity of drugs able to inhibit Cryptococcus biofilms, we believe that the results presented here might be of interest in the designing of new antifungal compounds.

scholarly journals The Anti-biofilm Activity of Nanometric Zinc doped Bioactive Glass against Putative Periodontal Pathogens: An in vitro Study

2018 ◽  
Vol 4 (1) ◽  
pp. 95-107
Author(s):  
Nasrin Esfahanizadeh ◽  
Mohammad Reza Nourani ◽  
Abbas Bahador ◽  
Nasrin Akhondi ◽  
Mostafa Montazeri
Keyword(s):  
Biofilm Formation ◽  
Sol Gel ◽  
Antimicrobial Properties ◽  
In Vitro Study ◽  
Inhibitory Effect ◽  
Antibiofilm Activity ◽  
Periodontal Pathogens ◽  
Microplate Reader ◽  
45S5 Bioglass

Abstract Colonization of periodontal pathogens on the surgical sites is one of the primary reasons for the failure of regenerative periodontal therapies. Bioactive glasses (BGs) owing to their favorable structural and antimicrobial properties have been proposed as promising materials for the reconstruction of periodontal and peri-implant bone defects. This study aimed to investigate the antibiofilm activity of zinc-doped BG (Zn/BG) compared with 45S5 Bioglass® (BG®) on putative periodontal pathogens. In this in vitro experimental study, the nano BG doped with 5-mol% zinc and BG® were synthesized by sol-gel method. Mono-species biofilms of Aggregatibacter actinomycetemcomitans (A. a), Porphyromonas gingivalis (P. g), and Prevotella intermedia (P. i)were prepared separately in a well-containing microplate. After 48 hours of exposure to generated materials at 37°C, the anti-biofilm potential of the samples was studied by measuring the optical density (OD) at 570nm wavelengths with a microplate reader. Two-way ANOVA then analyzed the results. Both Zn/BG and BG® significantly reduced the biofilm formation ability of all examined strains after 48 hours of incubation (P=0.0001). Moreover, the anti-biofilm activity of Zn/BG was significantly stronger than BG® (P=0.0001), which resulted in the formation of a weak biofilm (OD<1) compared with a moderately adhered biofilm observed with BG® (1<OD<2). Zn/BG showed a significant inhibitory effect on the biofilm formation of all examined periodontal pathogens. Given the enhanced regenerative and anti-biofilm properties of this novel biomaterial, further investigations are required for its implementation in clinical situations.

scholarly journals Effects of Hsp90 Inhibitor Ganetespib on Inhibition of Azole-Resistant Candida albicans

2021 ◽  
Vol 12 ◽  
Author(s):  
Rui Yuan ◽  
Jie Tu ◽  
Chunquan Sheng ◽  
Xi Chen ◽  
Na Liu
Keyword(s):  
Drug Resistance ◽  
Candida Albicans ◽  
Biofilm Formation ◽  
Efflux Pump ◽  
Inhibitory Effect ◽  
Hsp90 Inhibitor ◽  
Pcr Analysis ◽  
Fungal Hypha

Candida albicans is the most common fungal pathogen. Recently, drug resistance of C. albicans is increasingly severe. Hsp90 is a promising antifungal target to overcome this problem. To evaluate the effects of Hsp90 inhibitor ganetespib on the inhibition of azole-resistant C. albicans, the microdilution checkerboard method was used to measure the in vitro synergistic efficacy of ganetespib. The XTT/menadione reduction assay, microscopic observation, and Rh6G efflux assay were established to investigate the effects of ganetespib on azole-resistant C. albicans biofilm formation, filamentation, and efflux pump. Real-time RT-PCR analysis was employed to clarify the mechanism of antagonizing drug resistance. The in vivo antifungal efficacy of ganetespib was determined by the infectious model of azole-resistant C. albicans. Ganetespib showed an excellent synergistic antifungal activity in vitro and significantly inhibited the fungal biofilm formation, whereas it had no inhibitory effect on fungal hypha formation. Expression of azole-targeting enzyme gene ERG11 and efflux pump genes CDR1, CDR2, and MDR1 was significantly down-regulated when ganetespib was used in combination with FLC. In a mouse model infected with FLC-resistant C. albicans, the combination of ganetespib and FLC effectively reversed the FLC resistance and significantly decreased the kidney fungal load of mouse.

Biosurfactants of Lactobacillus helveticus for biodiversity inhibit the biofilm formation of Staphylococcus aureus and cell invasion

2019 ◽  
Vol 14 (13) ◽  
pp. 1133-1146 ◽  
Author(s):  
Xinpeng Jiang ◽  
Xin Yan ◽  
Shanshan Gu ◽  
Yan Yang ◽  
Lili Zhao ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Host Cell ◽  
Biofilm Formation ◽  
Lactobacillus Helveticus ◽  
Real Time Quantitative Pcr ◽  
Autoinducer 2 ◽  
New Strategy ◽  
Better Than

Aim: This study aimed to evaluate the differences of biosurfactants produced by two Lactobacillus helveticus strains against the biofilm formation of Staphylococcus aureus in vitro and in vivo. Materials & methods: Scanning electron microscopy, Real time-quantitative PCR (RT-qPCR) and cell assay were used to analyze the inhibiting effect of biosurfactants against biofilm formation. Results & conclusion: Results showed that the biosurfactants have anti-adhesive and inhibiting effects on biofilm formation in vivo and in vitro. The biofilm-formative genes and autoinducer-2 signaling regulated these characteristics, and the biosurfactant L. helveticus 27170 is better than that of 27058. Host cell adhesion and invasion results indicated that the biosurfactants L. helveticus prevented the S. aureus invading the host cell, which may be a new strategy to eliminate biofilms.

Inhibitory Effect of Pomegranate Oil on Biofilm Formation-An In vitro Study

2018 ◽  
Vol 11 (2) ◽  
pp. 521
Author(s):  
M. Vaishali ◽  
R.V. Geetha ◽  
Pradeep Kumar Rathinavelu
Keyword(s):  
Biofilm Formation ◽  
In Vitro Study ◽  
Inhibitory Effect ◽  
Vitro Study
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