Features of formation of Yersinia enterocolitica biofilms

Aim: The work aimed to study the morphology of colonies and their comparison by features of the formation of Yersinia enterocolitica biofilms. Materials and Methods: Bacteria were cultured on a Yersinia Selective Agar medium ("CIN-agar") at 28°C for 24 h. The microorganisms were grown in meat-peptone broth with 1.0% glucose to measure the absolute values of the optical density of the culture. The optical density of the liquid was determined in a microplate photometric analyzer Immunochem-2100 (HTI, USA) at a wavelength of 490 nm. For the study of biofilms, the specimens were fixed for 3-5 h in pairs of 25.0% solution of glutaraldehyde (according to DV), and pairs of a 1.0% aqueous solution of osmic acid (OSO4) were used for contrasting for 2-3 min. The specimens were examined with stereoscopic microscopy "BIOMED MS-1 Stereo" (Russia) and scanning electron microscope "TM 3030 plus" (Holland). Results: With stereoscopic microscopy of the colonies of Y. enterocolitica, the S-forms had an elevated intensely colored center, radial striation along the periphery, smooth edges, d ≤ 1.0 mm. R-form colonies had a dark color and a dry surface, were tuberous and had a dense center with a peripheral ridge, rugged edges, d ≥ 1.5 mm. The optical density of the Y. enterocolitica S-form showed that this type of microorganism belongs to the moderate producers of biofilms since the optical density of the sample (density of the sample - Ds) exceeded the optical density of control (density of the control - Dc) by 3 times. In Y. enterocolitica R-form (D ≤ 0.197) weakly produced biofilms, the optical density of the sample exceeded the optical density of the control by <2 times. Conclusion: The ability to form biofilms, the variability of phenotypic features, and the multiplicity of virulence factors of bacteria significantly reduce the effectiveness of diagnostic studies. The development of accelerated methods of detection and differentiation of the virulent properties of pathogenic bacteria will allow scientifically to substantiate and develop a set of measures aimed at preventing animal diseases and obtaining safe livestock products to prevent human diseases. Thus, we need to pay attention to which forms of colonies do Y. enterocolitica form on solid nutrient media: S- or R-forms. Through this study, we know that bacteria-forming S-shaped colonies are more capable of forming biofilms than R-forms. It means that they are more pathogenic and can cause persistent infections due to adhesion and biofilm formation.

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METHODOLOGICAL APPROACHES TO THE STUDY OF FORMATION OF BIOFILMS BY CONDITIONALLY PATHOGENIC AND PATHOGENIC ENTEROSBACTERIES

Problems of Veterinary Sanitation, Hygiene and Ecology ◽

10.36871/vet.san.hyg.ecol.201801008 ◽

2018 ◽

Vol 1 (1) ◽

pp. 50-58

Author(s):

A. B. Kononenko ◽

◽

I. B. Pavlova ◽

D. A. Bannikova ◽

S. V. Britova ◽

...

Keyword(s):

Electron Microscopy ◽

Nutrient Medium ◽

Biofilm Formation ◽

Pathogenic Bacteria ◽

Osmic Acid ◽

Liquid Nutrient Medium ◽

Petri Dishes ◽

Peptone Broth ◽

Scanning Electron

To study the process of biofilm formation, microorganisms were cultured in 96-well plates, on meat-peptone broth, stained with a 0,1% solution of crystalline violet for 10...15 minutes, after which the unbound dye was washed off. The quantitative accounting of the bound dye was carried out by spectrophotometry at a wavelength of 490 nm. The technique for making bacterial preparations for light and scanning electron microscopy on dodged glasses immersed in Petri dishes with a liquid nutrient medium is proposed. A suspension of bacteria at a concentration of 105 m.k/ml in a volume of 5 ml was shaken on Vortex apparatus and introduced into Petri dishes with 20 ml of meat-peptone broth. Sterile non-greased cover glasses were placed on sterile object glasses and immersed in a liquid nutrient medium in Petri dishes. The material was incubated for 18...24 hours at 37 °C. Then the cover slips were removed with tweezers and some of them were stained with 1% aqueous solution of methylene blue (for light microscopy), and some were placed in Petri dishes with bottomed filters (for electron microscopy). The latter, in order to preserve natural architectonics, were fixed in vivo by pairs of 25% glutaraldehyde for 3...5 hours. Vapors of 2...4% osmic acid solution were used for 2...3-minutes to contrast the preparations. After treatment with vapors of osmic acid, biofilms with included bacteria acquired yellowish or brown color. The obtained preparations after dehydration with propylene oxide vapors and spraying with gold ions were examined in a scanning electron microscope (SEM). The technique allows us to study the phases of development of biofilms and obtain objective data on the morphology of populations of pathogenic and conditionally pathogenic bacteria without disturbing natural architectonics. It is shown that the intensity of biofilm formation by pathogenic microorganisms, such as salmonella, Yersinia, Staphylococcus aureus was slightly higher than that of non-pathogenic: Escherichia, Proteus, Citrobacter, Enterobacter.

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MONITORING OF FORMATION OF BIOFILMS BY OPPORTUNISTIC AND PATHOGENIC BACTERIA

Problems of Veterinary Sanitation, Hygiene and Ecology ◽

10.36871/vet.san.hyg.ecol.201902011 ◽

2019 ◽

Vol 1 (2) ◽

pp. 174-182

Author(s):

A. B. Kononenko ◽

◽

D. A. Bannikova ◽

S. V. Britova ◽

I. B. Pavlova ◽

...

Keyword(s):

Crystal Violet ◽

Filter Paper ◽

Biofilm Formation ◽

Pathogenic Bacteria ◽

Room Temperature ◽

Distilled Water ◽

Pathogenic Microorganisms ◽

Crystal Violet Solution ◽

Taxonomic Groups ◽

Peptone Broth

The aim of the work is monitoring the formation of biofilms by opportunistic and pathogenic microorganisms. Materials and methods. The cultures of the genera Salmonella, Escherichia, Yersinia, Proteus, Citrobacter, Enterobacter, Prtovidenzia, Morganella, Klebsiella, Cronobacter, Pseudomonas, Bacillus, Staphylococcus were used in the work. The studied microorganisms were cultured in polystyrene 96-well plates. For this purpose, a daily culture of microorganisms was introduced into the wells with meat-peptone broth, having previously established a concentration of 104 mc / ml, and incubated for 24...96 hours at temperature of 37 °C. Then the medium with plankton cells was removed from the wells. 200 μl of filtered 0,1% crystal violet solution was poured into the wells of the plate and the plates were kept for 10...15 min at room temperature. Then dye was removed from the wells. Unbound dye was thoroughly washed with saline or distilled water. The plates were turned over on filter paper and dried. The presence and density of biomatrix (biofilm) was determined visually by the intensity of staining the surfaces of plates. Then, for the extraction of paint from the film, 200 μl of 96% ethanol was added to the wells and the optical density was measured on KFK-3KM spectrophotometer at a wavelength of 590 nm. Results of research. The results of the experiments allowed us to assert that within 48 hours of cultivation microorganisms form a mature biofilm, which can serve as a model for studying the process of biofilm formation. Biofilm of microorganisms of different taxonomic groups differs in density. In addition, even bacteria belonging to the same genus, under the same conditions, can form a biofilm, the density of which differs by 30...60%.

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REGULARITIES OF DEVELOPMENT OF BIOFILM OF BACTERIA AT THE NATIVE PHASES OF THEIR FORMATION IN VITRO

Problems of Veterinary Sanitation, Hygiene and Ecology ◽

10.36871/vet.san.hyg.ecol.201804009 ◽

2018 ◽

Vol 1 (4) ◽

pp. 56-61

Author(s):

I. B. Pavlova ◽

◽

A. B. Kononenko ◽

D. A. Bannikova ◽

G. S. Tolmachyova ◽

...

Keyword(s):

Electron Microscopy ◽

Biofilm Formation ◽

Multilayer Structure ◽

Pathogenic Bacteria ◽

Antimicrobial Agents ◽

Single Cells ◽

Osmic Acid ◽

Nutrient Media ◽

Bacterial Cultures

The objects of research were the bacterial cultures of the genera Salmonella, Escherichia, Pseudomonas, Staphylococcus. The morphology of biofilms and the phases of its development were studied by the method of light and scanning electron microscopy. To study the formation of biofilms in liquid nutrient media, 24-hour microorganism cultures in S-form grown on dense or liquid nutrient media were used. The material was incubated for 24 hours at 37 °C. Then the cover glasses with biofilms formed on them were extracted with tweezers and placed in Petri dishes with filters laid on the bottom (for electron microscopy). In order to preserve the natural architectonics, were fixed by vapor of 25% glutaraldehyde during 3...5 hours. For contrasting preparations, vapor of 2...4% solution of osmic acid were used for 2...3 minutes. The laws of biofilm formation in conditionally pathogenic and pathogenic bacteria were experimentally confirmed: adhesion of single cells, association of exopolysaccharide matrix into clusters, formation of mature biofilm. SEM method shows the possibility of forming a multilayer structure of biofilm, which determines their increased resistance to antimicrobial agents (antibiotics, disinfectants).

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Antibiotics Application Strategies to Control Biofilm Formation in Pathogenic Bacteria

Current Pharmaceutical Biotechnology ◽

10.2174/1389201020666191112155905 ◽

2020 ◽

Vol 21 (4) ◽

pp. 270-286 ◽

Cited By ~ 2

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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Extract from phyllosphere bacteria with antibiofilm and quorum quenching activity to control several fish pathogenic bacteria

BMC Research Notes ◽

10.1186/s13104-021-05612-w ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Olivia Nathalia ◽

Diana Elizabeth Waturangi

Keyword(s):

Streptococcus Agalactiae ◽

Aeromonas Hydrophila ◽

Biofilm Formation ◽

Pathogenic Bacteria ◽

Vibrio Harveyi ◽

Quorum Quenching ◽

Indicator Bacteria ◽

Antibiofilm Activity ◽

Fish Pathogen ◽

Phyllosphere Bacteria

Abstract Objective The objective of this research were to screen quorum quenching activity compound from phyllosphere bacteria as well as antibiofilm activity against several fish pathogen bacteria such as Aeromonas hydrophila, Streptococcus agalactiae, and Vibrio harveyi. Results We found eight phyllosphere bacteria isolates with potential quorum quenching activity to inhibit Chromobacterium violaceum as indicator bacteria. Crude extracts (20 mg/mL) showed various antibiofilm activity against fish pathogenic bacteria used in this study. Isolate JB 17B showed the highest activity to inhibit biofilm formation of A. hydrophila and V. harveyi, meanwhile isolate JB 3B showed the highest activity to inhibit biofilm of S. agalactiae. From destruction assay, isolate JB 8F showed the highest activity to disrupt biofilm of A. hydrophila isolate JB 20B showed the highest activity to disrupt biofilm of V. harveyi, isolate JB 17B also showed the highest activity to disrupt biofilm of S. agalactiae.

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Evaluation of antibacterial, teratogenicity and antibiofilm effect of sulfated chitosans extracted from marine waste against microorganism

Journal of Bioactive and Compatible Polymers ◽

10.1177/08839115211014225 ◽

2021 ◽

pp. 088391152110142

Author(s):

Velu Gomathy ◽

Venkatesan Manigandan ◽

Narasimman Vignesh ◽

Aavula Thabitha ◽

Ramachandran Saravanan

Keyword(s):

Biofilm Formation ◽

Pathogenic Bacteria ◽

Antimicrobial Agents ◽

Inhibitory Effect ◽

Diffusion Method ◽

Marine Litter ◽

Ionization Time ◽

Gram Positive Bacteria ◽

Mineral Components ◽

Ft Ir

Biofilms play a key role in infectious diseases, as they may form on the surface and persist after treatment with various antimicrobial agents. The Staphylococcus aureus, Klebsiella pneumoniae, S. typhimurium, P. aeruginosa, and Escherichia coli most frequently associated with medical devices. Chitosan sulphate from marine litter (SCH-MW) was extracted and the mineral components were determined using atomic absorption spectroscopy (AAS). The degree of deacetylation (DA) of SCH was predicted 50% and 33.3% in crab and shrimp waste respectively. The elucidation of the structure of the SCH-MW was portrayed using FT-IR and 1H-NMR spectroscopy. The molecular mass of SCH-MW was determined with Matrix-Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF). The teratogenicity of SCH-MW was characterized by the zebrafish embryo (ZFE) model. Antimicrobial activity of SCH-MW was tested with the agar well diffusion method; the inhibitory effect of SCH-MW on biofilm formation was assessed in 96 flat well polystyrene plates. The result revealed that a low concentration of crab-sulfated chitosan inhibited bacterial growth and significantly reduced the anti-biofilm activity of gram-negative and gram-positive bacteria relatively to shrimp. It is potentially against the biofilm formation of pathogenic bacteria.

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Superhydrophobic Nanocoatings as Intervention against Biofilm-Associated Bacterial Infections

Nanomaterials ◽

10.3390/nano11041046 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1046

Author(s):

Yinghan Chan ◽

Xun Hui Wu ◽

Buong Woei Chieng ◽

Nor Azowa Ibrahim ◽

Yoon Yee Then

Keyword(s):

Biofilm Formation ◽

Bacterial Infections ◽

Therapeutic Strategies ◽

Public Healthcare ◽

Persistent Infections ◽

Promising Strategy ◽

Antimicrobial Interventions ◽

Novel Therapeutic Strategies ◽

Insight Into ◽

Microbial Attachment

Biofilm formation represents a significant cause of concern as it has been associated with increased morbidity and mortality, thereby imposing a huge burden on public healthcare system throughout the world. As biofilms are usually resistant to various conventional antimicrobial interventions, they may result in severe and persistent infections, which necessitates the development of novel therapeutic strategies to combat biofilm-based infections. Physicochemical modification of the biomaterials utilized in medical devices to mitigate initial microbial attachment has been proposed as a promising strategy in combating polymicrobial infections, as the adhesion of microorganisms is typically the first step for the formation of biofilms. For instance, superhydrophobic surfaces have been shown to possess substantial anti-biofilm properties attributed to the presence of nanostructures. In this article, we provide an insight into the mechanisms underlying biofilm formation and their composition, as well as the applications of nanomaterials as superhydrophobic nanocoatings for the development of novel anti-biofilm therapies.

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Trk2 Potassium Transport System in Streptococcus mutans and Its Role in Potassium Homeostasis, Biofilm Formation, and Stress Tolerance

Journal of Bacteriology ◽

10.1128/jb.00813-15 ◽

2016 ◽

Vol 198 (7) ◽

pp. 1087-1100 ◽

Cited By ~ 14

Author(s):

Gursonika Binepal ◽

Kamal Gill ◽

Paula Crowley ◽

Martha Cordova ◽

L. Jeannine Brady ◽

...

Keyword(s):

Stress Tolerance ◽

Streptococcus Mutans ◽

Transport System ◽

Biofilm Formation ◽

Cellular Response ◽

Pathogenic Bacteria ◽

Transport Systems ◽

Content Type ◽

Growth And Survival ◽

Dental Biofilm

ABSTRACTPotassium (K+) is the most abundant cation in the fluids of dental biofilm. The biochemical and biophysical functions of K+and a variety of K+transport systems have been studied for most pathogenic bacteria but not for oral pathogens. In this study, we establish the modes of K+acquisition inStreptococcus mutansand the importance of K+homeostasis for its virulence attributes. TheS. mutansgenome harbors four putative K+transport systems that included two Trk-like transporters (designated Trk1 and Trk2), one glutamate/K+cotransporter (GlnQHMP), and a channel-like K+transport system (Kch). Mutants lacking Trk2 had significantly impaired growth, acidogenicity, aciduricity, and biofilm formation. [K+] less than 5 mM eliminated biofilm formation inS. mutans. The functionality of the Trk2 system was confirmed by complementing anEscherichia coliTK2420 mutant strain, which resulted in significant K+accumulation, improved growth, and survival under stress. Taken together, these results suggest that Trk2 is the main facet of the K+-dependent cellular response ofS. mutansto environment stresses.IMPORTANCEBiofilm formation and stress tolerance are important virulence properties of caries-causingStreptococcus mutans. To limit these properties of this bacterium, it is imperative to understand its survival mechanisms. Potassium is the most abundant cation in dental plaque, the natural environment ofS. mutans. K+is known to function in stress tolerance, and bacteria have specialized mechanisms for its uptake. However, there are no reports to identify or characterize specific K+transporters inS. mutans. We identified the most important system for K+homeostasis and its role in the biofilm formation, stress tolerance, and growth. We also show the requirement of environmental K+for the activity of biofilm-forming enzymes, which explains why such high levels of K+would favor biofilm formation.

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A Real-Time Thermal Sensor System for Quantifying the Inhibitory Effect of Antimicrobial Peptides on Bacterial Adhesion and Biofilm Formation

Sensors ◽

10.3390/s21082771 ◽

2021 ◽

Vol 21 (8) ◽

pp. 2771

Author(s):

Tobias Wieland ◽

Julia Assmann ◽

Astrid Bethe ◽

Christian Fidelak ◽

Helena Gmoser ◽

...

Keyword(s):

Antimicrobial Peptides ◽

Real Time ◽

Bacterial Adhesion ◽

Biofilm Formation ◽

Pathogenic Bacteria ◽

Bovine Mastitis ◽

Inhibitory Effect ◽

Thermal Sensor ◽

Bacterial Cells ◽

Static Conditions

The increasing rate of antimicrobial resistance (AMR) in pathogenic bacteria is a global threat to human and veterinary medicine. Beyond antibiotics, antimicrobial peptides (AMPs) might be an alternative to inhibit the growth of bacteria, including AMR pathogens, on different surfaces. Biofilm formation, which starts out as bacterial adhesion, poses additional challenges for antibiotics targeting bacterial cells. The objective of this study was to establish a real-time method for the monitoring of the inhibition of (a) bacterial adhesion to a defined substrate and (b) biofilm formation by AMPs using an innovative thermal sensor. We provide evidence that the thermal sensor enables continuous monitoring of the effect of two potent AMPs, protamine and OH-CATH-30, on surface colonization of bovine mastitis-associated Escherichia (E.) coli and Staphylococcus (S.) aureus. The bacteria were grown under static conditions on the surface of the sensor membrane, on which temperature oscillations generated by a heater structure were detected by an amorphous germanium thermistor. Bacterial adhesion, which was confirmed by white light interferometry, caused a detectable amplitude change and phase shift. To our knowledge, the thermal measurement system has never been used to assess the effect of AMPs on bacterial adhesion in real time before. The system could be used to screen and evaluate bacterial adhesion inhibition of both known and novel AMPs.

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Eugenol-Functionalized Magnetite Nanoparticles Modulate Virulence and Persistence in Pseudomonas aeruginosa Clinical Strains

Molecules ◽

10.3390/molecules26082189 ◽

2021 ◽

Vol 26 (8) ◽

pp. 2189

Author(s):

Hamzah Basil Mohammed ◽

Sajjad Mohsin I. Rayyif ◽

Carmen Curutiu ◽

Alexandra Catalina Birca ◽

Ovidiu-Cristian Oprea ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Biofilm Formation ◽

Spherical Shape ◽

Infectious Process ◽

Phenotypic Resistance ◽

Persistent Infections ◽

Resistant Mutants ◽

Subinhibitory Concentrations ◽

Pathogenic Agents ◽

Soluble Enzymes

Efficient antibiotics to cure Pseudomonas aeruginosa persistent infections are currently insufficient and alternative options are needed. A promising lead is to design therapeutics able to modulate key phenotypes in microbial virulence and thus control the progression of the infectious process without selecting resistant mutants. In this study, we developed a nanostructured system based on Fe3O4 nanoparticles (NPs) and eugenol, a natural plant-compound which has been previously shown to interfere with microbial virulence when utilized in subinhibitory concentrations. The obtained functional NPs are crystalline, with a spherical shape and 10–15 nm in size. The subinhibitory concentrations (MIC 1/2) of the eugenol embedded magnetite NPs (Fe3O4@EUG) modulate key virulence phenotypes, such as attachment, biofilm formation, persister selection by ciprofloxacin, and the production of soluble enzymes. To our knowledge, this is the first report on the ability of functional magnetite NPs to modulate P. aeruginosa virulence and phenotypic resistance; our data highlights the potential of these bioactive nanostructures to be used as anti-pathogenic agents.

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