In this review, we present a comprehensive summary of the formation of honeycomb microstructures and their applications, which include tissue engineering, antibacterial materials, replication processes or sensors. The history of the honeycomb pattern, the first experiments, which mostly involved the breath figure procedure and the improved phase separation, the most recent approach to honeycomb pattern formation, are described in detail. Subsequent surface modifications of the pattern, which involve physical and chemical modifications and further enhancement of the surface properties, are also introduced. Different aspects influencing the polymer formation, such as the substrate influence, a particular polymer or solvent, which may significantly contribute to pattern formation, and thus influence the target structural properties, are also discussed.

• Klíčová slova
• antibacterial properties, biopolymer, breath figure, honeycomb, improved phase separation, morphology, polymer, replication, surface modification, tissue engineering,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

The use of halotolerant beneficial plant-growth-promoting (PGP) bacteria is considered as a promising eco-friendly approach to improve the salt tolerance of cash crops. One strategy to enhance the possibility of obtaining stress-alleviating bacteria is to screen salt impacted soils. In this study, amongst the 40 endophytic bacteria isolated from the roots of Sahara-inhabiting halophytes Atriplex halimus L. and Lygeum spartum L., 8 showed interesting NaCl tolerance in vitro. Their evaluation, through different tomato plant trials, permitted the isolate IS26 to be distinguished as the most effective seed inoculum for both plant growth promotion and mitigation of salt stress. On the basis of 16S rRNA gene sequence, the isolate was closely related to Stenotrophomonas rhizophila. It was then screened in vitro for multiple PGP traits and the strain-complete genome was sequenced and analysed to further decipher the genomic basis of the putative mechanisms underlying its osmoprotective and plant growth abilities. A remarkable number of genes putatively involved in mechanisms responsible for rhizosphere colonization, plant association, strong competition for nutrients, and the production of important plant growth regulator compounds, such as AIA and spermidine, were highlighted, as were substances protecting against stress, including different osmolytes like trehalose, glucosylglycerol, proline, and glycine betaine. By having genes related to complementary mechanisms of osmosensing, osmoregulation and osmoprotection, the strain confirmed its great capacity to adapt to highly saline environments. Moreover, the presence of various genes potentially related to multiple enzymatic antioxidant processes, able to reduce salt-induced overproduction of ROS, was also detected.

• Klíčová slova
• Comparative genomics, Plant growth-promotion, Plant-associated bacteria, Salt stress, Salt-tolerant bacteria, Solanum lycopersicum L,
• MeSH
• aminokyseliny cyklické metabolismus   MeSH
• endofyty klasifikace   fyziologie   MeSH
• halotolerantní rostliny mikrobiologie   MeSH
• interakce mikroorganismu a hostitele MeSH
• kořeny rostlin mikrobiologie   MeSH
• lipnicovité mikrobiologie   MeSH
• půdní mikrobiologie MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• rhizosféra MeSH
• RNA ribozomální 16S MeSH
• salinita MeSH
• sekvenční analýza DNA MeSH
• Solanum lycopersicum růst a vývoj   mikrobiologie   MeSH
• solný stres MeSH
• tolerance k soli * MeSH
• vývoj rostlin * MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• severní Afrika MeSH
• Názvy látek
• 1-aminocyclopropane-1-carboxylic acid MeSH Prohlížeč
• aminokyseliny cyklické MeSH
• reaktivní formy kyslíku MeSH
• RNA ribozomální 16S MeSH

Microscale self-propelled robots show great promise in the biomedical field and are the focus of many researchers. These tiny devices, which move and navigate by themselves, are typically based on inorganic microstructures that are not biodegradable and potentially toxic, often using toxic fuels or elaborate external energy sources, which limits their real-world applications. One potential solution to these issues is to go back to nature. Here, the authors use high-speed Aqua Sperm micromotors obtained from North African catfish (Clarias gariepinus, B. 1822) to destroy bacterial biofilm. These Aqua Sperm micromotors use water-induced dynein ATPase catalyzed adenosine triphosphate (ATP) degradation as biocompatible fuel to trigger their fast speed and snake-like undulatory locomotion that facilitate biofilm destruction in less than one minute. This efficient biofilm destruction is due to the ultra-fast velocity as well as the head size of Aqua Sperm micromotors being similar to bacteria, which facilitates their entry to and navigation within the biofilm matrix. In addition, the authors demonstrate the real-world application of Aqua Sperm micromotors by destroying biofilms that had colonized medical and laboratory tubing. The implemented system extends the biomedical application of Aqua Sperm micromotors to include hybrid robots for fertilization or cargo tasks.

• Klíčová slova
• Aqua Sperm micromotors, active bacterial biofilms, biobots, nanorobots, spermatozoa, spermbots,
• MeSH
• biofilmy * MeSH
• biomimetika přístrojové vybavení   MeSH
• design vybavení MeSH
• kontaminace zdravotnického vybavení prevence a kontrola   MeSH
• mikrotechnologie přístrojové vybavení   MeSH
• robotika přístrojové vybavení   MeSH
• spermatocyty chemie   MeSH
• sumci MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The microaerophilic pathogen Campylobacter jejuni is a leading bacterial cause of human gastroenteritis in developed countries. Even though it has a reputation as a fastidious organism, C. jejuni is widespread and can be easily isolated from various animals, food, and environmental sources. It is suggested that an ability to form biofilms is probably necessary for the survival of C. jejuni under harsh environmental conditions. The first step required for successful biofilm formation is adhesion to a suitable surface. Therefore, in this work, the degree of adhesion was evaluated, followed by characterization and quantification of biofilms using confocal laser scanning microscopy (CLSM). A total of 15 isolates of C. jejuni were used in the experiments (12 isolates from surface and waste waters, 1 human clinical, 1 food and 1 ACTT BAA-2151 collection strain, all samples originated from the Czech Republic). Regardless of the sample origin, all C. jejuni isolates were able to adhere to the polystyrene surface within 30 min, with the number of attached cells increasing with the time of incubation. The resulting data showed that all isolates were able to form complex voluminous biofilms after 24 h of cultivation. The average amount of biovolume ranged from 3.59 × 106 µm3 to 17.50 × 106 µm3 in isolates obtained from different sources of water, 16.79 × 106 µm3 in the food isolate and 10.92 × 106 µm3 in the collection strain. However, the highest amount of biomass was produced by the human clinical isolate (25.48 × 106 µm3). Similar to the quantity, the architecture of the biofilms also differed, from a rugged flat monolayer of cells to large clustered structures. Further, all isolates were tested for the presence of the luxS gene, as the luxS/AI-2 (autoinducer-2) quorum sensing pathway has been previously connected with enhanced biofilm formation. Two isolates originated from surface waters did not possess the luxS gene. These isolates formed thinner and sparser biofilms lacking the presence of significant clusters. However, the ability to adhere to the surface was preserved. The sequencing of the luxS-containing fragments shown a high similarity of the luxS gene among the isolates.

• Klíčová slova
• Campylobacter jejuni, adhesion, biofilm, confocal laser scanning microscopy, foodborne pathogen, luxS, water,
• MeSH
• bakteriální proteiny MeSH
• biofilmy MeSH
• Campylobacter jejuni * genetika   MeSH
• lidé MeSH
• lyasy štěpící vazby C-S MeSH
• quorum sensing MeSH
• voda MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• bakteriální proteiny MeSH
• lyasy štěpící vazby C-S MeSH
• voda MeSH

Biodegradable polymers are promising materials for use in medical applications such as stents. Their properties are comparable to commercially available resistant metal and polymeric stents, which have several major problems, such as stent migration and stent clogging due to microbial biofilm. Consequently, conventional stents have to be removed operatively from the patient's body, which presents a number of complications and can also endanger the patient's life. Biodegradable stents disintegrate into basic substances that decompose in the human body, and no surgery is required. This review focuses on the specific use of stents in the human body, the problems of microbial biofilm, and possibilities of preventing microbial growth by modifying polymers with antimicrobial agents.

• Klíčová slova
• antimicrobial agents, antimicrobial effects, biodegradable polymer, medicine, polylactide, stent,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Pseudomonas aeruginosa, a Gram-negative, rod-shaped bacterium causes widespread diseases in humans. This bacterium is frequently related to nosocomial infections such as pneumonia, urinary tract infections (UTIs) and bacteriaemia especially in immunocompromised patients. The current review focuses on the recent perspectives on biofilms formation by these bacteria. Biofilms are communities of microorganisms in which cells stick to each other and often adhere to a surface. These adherent cells are usually embedded within a self-produced matrix of extracellular polymeric substance (EPS). Pel, psl and alg operons present in P. aeruginosa are responsible for the biosynthesis of extracellular polysaccharide which plays an important role in cell surface interactions during biofilm formation. Recent studies suggested that cAMP signalling pathway, quorum-sensing pathway, Gac/Rsm pathway and c-di-GMP signalling pathway are the main mechanism that leads to the biofilm formation. Understanding the bacterial virulence depends on a number of cell-associated and extracellular factors and is very essential for the development of potential drug targets. Thus, the review focuses on the major genes involved in the biofilm formation, the state of art update on the biofilm treatment and the dispersal approaches such as targeting adhesion and maturation, targeting virulence factors and other strategies such as small molecule-based inhibitors, phytochemicals, bacteriophage therapy, photodynamic therapy, antimicrobial peptides and natural therapies and vaccines to curtail the biofilm formation by P. aeruginosa.

• Klíčová slova
• Alginate, Biofilm dispersal, Biofilms, EPS, Gac/Rsm pathway, Pel, Pseudomonas aeruginosa, Psl, Quorum-sensing pathway, Treatment advancement, c-di-GMP signalling pathway,
• MeSH
• antibakteriální látky farmakologie   MeSH
• bakteriální léková rezistence MeSH
• bakteriální polysacharidy chemie   MeSH
• biofilmy účinky léků   MeSH
• biologické modely MeSH
• lidé MeSH
• Pseudomonas aeruginosa účinky léků   genetika   růst a vývoj   fyziologie   MeSH
• quorum sensing MeSH
• regulace genové exprese u bakterií MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• antibakteriální látky MeSH
• bakteriální polysacharidy MeSH

Microorganisms are not commonly found in the planktonic state but predominantly form dual- and multispecies biofilms in almost all natural environments. Bacteria in multispecies biofilms cooperate, compete or have neutral interactions according to the involved species. Here, the development of mono- and dual-species biofilms formed by Staphylococcus aureus and other foodborne pathogens such as Salmonella enterica subsp. enterica serovar Enteritidis, potentially pathogenic Raoultella planticola and non-pathogenic Escherichia coli over the course of 24, 48 and 72 h was studied. Biofilm formation was evaluated by the crystal violet assay (CV), enumeration of colony-forming units (CFU cm-2 ) and visualization using confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). In general, Gram-negative bacterial species and S. aureus interacted in a competitive manner. The tested Gram-negative bacteria grew better in mixed dual-species biofilms than in their mono-species biofilms as determined using the CV assay, CFU ml-2 enumeration, and CLSM and SEM visualization. In contrast, the growth of S. aureus biofilms was reduced when cultured in dual-species biofilms. CLSM images revealed grape-like clusters of S. aureus and monolayers of Gram-negative bacteria in both mono- and dual-species biofilms. S. aureus clusters in dual-species biofilms were significantly smaller than clusters in S. aureus mono-species biofilms.

• MeSH
• barvení a značení MeSH
• biofilmy růst a vývoj   MeSH
• Enterobacteriaceae růst a vývoj   fyziologie   MeSH
• genciánová violeť analýza   MeSH
• konfokální mikroskopie MeSH
• mikrobiální interakce * MeSH
• mikroskopie elektronová rastrovací MeSH
• počet mikrobiálních kolonií MeSH
• Staphylococcus aureus růst a vývoj   fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• genciánová violeť MeSH

It is demonstrated that numerous bacteria are able to attach to surfaces of equipment used for food handling or processing. In this study, a strain of Enterococcus durans, originally isolated from a milking machine surface, was firstly studied for its biofilm formation potential on plastic and stainless steel supports. The strain was found to be a biofilm producer either at 25, 30 or 37 °C on polystyrene microtitre plates, with a best adherence level observed at 25 °C. En. durans showed a strong adhesion to stainless steel AISI-304. Antibacterial and anti-adherence activities of En. durans were tested against four foodborne pathogens (Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853 and Listeria innocua CLIP 74915) which were shown as biofilm producers on both plastic and stainless steel. En. durans cells and cell-free culture supernatant showed a significant (P < 0.05) inhibition potential of the pathogens either on solid media or in broth co-cultures. Characterization of the antibacterial substances indicated their proteinaceous nature which assigned them most probably to bacteriocins group.

• MeSH
• bakteriální adheze účinky léků   MeSH
• bakteriální proteiny metabolismus   MeSH
• biofilmy účinky léků   MeSH
• biologické přípravky metabolismus   MeSH
• Enterococcus metabolismus   fyziologie   MeSH
• gramnegativní bakterie účinky léků   fyziologie   MeSH
• grampozitivní bakterie účinky léků   fyziologie   MeSH
• mikrobiologie životního prostředí * MeSH
• nerezavějící ocel MeSH
• plastické hmoty MeSH
• potravinářská mikrobiologie MeSH
• teplota MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• bakteriální proteiny MeSH
• biologické přípravky MeSH
• nerezavějící ocel MeSH
• plastické hmoty MeSH

One of the universal traits of microorganisms is their ability to form multicellular structures, the cells of which differentiate and communicate via various signaling molecules. Reactive oxygen species (ROS), and hydrogen peroxide in particular, have recently become well-established signaling molecules in higher eukaryotes, but still little is known about the regulatory functions of ROS in microbial structures. Here we summarize current knowledge on the possible roles of ROS during the development of colonies and biofilms, representatives of microbial multicellularity. In Saccharomyces cerevisiae colonies, ROS are predicted to participate in regulatory events involved in the induction of ammonia signaling and later on in programmed cell death in the colony center. While the latter process seems to be induced by the total ROS, the former event is likely to be regulated by ROS-homeostasis, possibly H(2)O(2)-homeostasis between the cytosol and mitochondria. In Candida albicans biofilms, the predicted signaling role of ROS is linked with quorum sensing molecule farnesol that significantly affects biofilm formation. In bacterial biofilms, ROS induce genetic variability, promote cell death in specific biofilm regions, and possibly regulate biofilm development. Thus, the number of examples suggesting ROS as signaling molecules and effectors in the development of microbial multicellularity is rapidly increasing.

• MeSH
• Bacteria cytologie   metabolismus   MeSH
• fyziologická adaptace * MeSH
• houby cytologie   metabolismus   MeSH
• mikrobiální společenstva fyziologie   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• signální transdukce * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• reaktivní formy kyslíku MeSH

The activity of antagonistic substances produced by Pseudomonas aeruginosa and Lactobacillus acidophilus against the planktonic and sessile populations of Staphylococcus aureus strains was demonstrated. The strongest effects were caused by probiotic L. acidophilus strain - bacteriocin-like inhibitory substances (BLIS) positive. However, the S. aureus A3 growth, adhesion and biofilm formation was also limited by cell-free supernatant of L. acidophilus H-1 (BLIS negative). Moreover, competitive direct interactions were observed between staphylococci and the above bacteria, which influenced the formation of dualspecies aggregates on the surface.

• MeSH
• antibakteriální látky metabolismus   farmakologie   MeSH
• antibióza MeSH
• bakteriální adheze účinky léků   MeSH
• bakteriociny metabolismus   farmakologie   MeSH
• biofilmy účinky léků   MeSH
• kultivační média speciální farmakologie   MeSH
• Lactobacillus acidophilus růst a vývoj   metabolismus   fyziologie   MeSH
• lidé MeSH
• plankton růst a vývoj   MeSH
• probiotika MeSH
• Pseudomonas aeruginosa růst a vývoj   metabolismus   fyziologie   MeSH
• Staphylococcus aureus účinky léků   růst a vývoj   fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antibakteriální látky MeSH
• bakteriociny MeSH
• kultivační média speciální MeSH