scholarly journals Testing Laser-Structured Antimicrobial Surfaces Under Space Conditions: The Design of the ISS Experiment BIOFILMS

2022 ◽  
Vol 2 ◽  
Author(s):  
Katharina Siems ◽  
Daniel W. Müller ◽  
Laurens Maertens ◽  
Aisha Ahmed ◽  
Rob Van Houdt ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Space Station ◽  
Health And Safety ◽  
Model Organisms ◽  
Antimicrobial Surfaces ◽  
Microbial Biofilms ◽  
Staphylococcus Capitis ◽  
Antimicrobial Materials ◽  
Direct Laser ◽  
Inert Surfaces

Maintaining crew health and safety are essential goals for long-term human missions to space. Attaining these goals requires the development of methods and materials for sustaining the crew’s health and safety. Paramount is microbiological monitoring and contamination reduction. Microbial biofilms are of special concern, because they can cause damage to spaceflight equipment and are difficult to eliminate due to their increased resistance to antibiotics and disinfectants. The introduction of antimicrobial surfaces for medical, pharmaceutical and industrial purposes has shown a unique potential for reducing and preventing biofilm formation. This article describes the development process of ESA’s BIOFILMS experiment, that will evaluate biofilm formation on various antimicrobial surfaces under spaceflight conditions. These surfaces will be composed of different metals with and without specified surface texture modifications. Staphylococcus capitis subsp. capitis, Cupriavidus metallidurans and Acinetobacter radioresistens are biofilm forming organisms that have been chosen as model organisms. The BIOFILMS experiment will study the biofilm formation potential of these organisms in microgravity on the International Space Station on inert surfaces (stainless steel AISI 304) as well as antimicrobial active copper (Cu) based metals that have undergone specific surface modification by Ultrashort Pulsed Direct Laser Interference Patterning (USP-DLIP). Data collected in 1 x g has shown that these surface modifications enhance the antimicrobial activity of Cu based metals. In the scope of this, the interaction between the surfaces and bacteria, which is highly determined by topography and surface chemistry, will be investigated. The data generated will be indispensable for the future selection of antimicrobial materials in support of human- and robotic-associated activities in space exploration.

scholarly journals Silver-Derived Antimicrobial Coatings for the Prevention of Microbial Biofilms in Metal Pipes

2021 ◽  
Vol 232 (8) ◽  
Author(s):  
M. Vela-Cano ◽  
C. Garcia-Fontana ◽  
F. Osorio ◽  
A. González-Martinez ◽  
J. González-López
Keyword(s):  
Biofilm Formation ◽  
Antimicrobial Properties ◽  
Pilot Scale ◽  
Biological Factors ◽  
Antimicrobial Coatings ◽  
Microbial Biofilms ◽  
Physical Chemical ◽  
Silver Zeolite ◽  
Metal Pipes ◽  
Pipeline Corrosion

AbstractBiodeterioration is one of the most important processes in metal pipeline corrosion, and it can be due to physical, chemical, and biological factors. Coatings rich in silver have been used to inhibit this undesirable phenomenon. In this study, the antimicrobial properties of several silver-containing products used as a coating in pipelines were determined on a pilot scale in order to evaluate the ability of silver to inhibit biofilm formation. The results showed that the coating with silver zeolite at a concentration of 2000 mg L–1 inhibited the formation of a microbial biofilm and prevented the biodeterioration process. Therefore, from our study, it can be concluded that silver zeolite shows greater protection capacity than other silver preparations and presents advantages in relation to other silver coatings that are currently available

scholarly journals Blocking of Bacterial Biofilm Formation by a Fish Protein Coating

2008 ◽  
Vol 74 (11) ◽  
pp. 3551-3558 ◽  
Author(s):  
Rebecca Munk Vejborg ◽  
Per Klemm
Keyword(s):  
Biofilm Formation ◽  
Fish Muscle ◽  
Physicochemical Characteristics ◽  
Economic Problem ◽  
Bacterial Attachment ◽  
Bacterial Biofilm ◽  
Adhesive Properties ◽  
Muscle Extract ◽  
Wide Range ◽  
Inert Surfaces

ABSTRACT Bacterial biofilm formation on inert surfaces is a significant health and economic problem in a wide range of environmental, industrial, and medical areas. Bacterial adhesion is generally a prerequisite for this colonization process and, thus, represents an attractive target for the development of biofilm-preventive measures. We have previously found that the preconditioning of several different inert materials with an aqueous fish muscle extract, composed primarily of fish muscle α-tropomyosin, significantly discourages bacterial attachment and adhesion to these surfaces. Here, this proteinaceous coating is characterized with regards to its biofilm-reducing properties by using a range of urinary tract infectious isolates with various pathogenic and adhesive properties. The antiadhesive coating significantly reduced or delayed biofilm formation by all these isolates under every condition examined. The biofilm-reducing activity did, however, vary depending on the substratum physicochemical characteristics and the environmental conditions studied. These data illustrate the importance of protein conditioning layers with respect to bacterial biofilm formation and suggest that antiadhesive proteins may offer an attractive measure for reducing or delaying biofilm-associated infections.

Differential surface competition and biofilm invasion strategies of Pseudomonas aeruginosa PA14 and PAO1

2021 ◽  
Author(s):  
Swetha Kassety ◽  
Stefan Katharios-Lanwermeyer ◽  
George A. O’Toole ◽  
Carey D. Nadell
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Matrix Composition ◽  
Model Organisms ◽  
Culture Methods ◽  
Biofilm Growth ◽  
Biofilm Production ◽  
Direct Competition ◽  
Planktonic Phase ◽  
Do So

Pseudomonas aeruginosa strains PA14 and PAO1 are among the two best characterized model organisms used to study the mechanisms of biofilm formation, while also representing two distinct lineages of P. aeruginosa . Previous work has shown that PA14 and PAO1 use different strategies for surface colonization; they also have different extracellular matrix composition and different propensities to disperse from biofilms back into the planktonic phase surrounding them. We expand on this work here by exploring the consequences of these different biofilm production strategies during direct competition. Using differentially labeled strains and microfluidic culture methods, we show that PAO1 can outcompete PA14 in direct competition during early colonization and subsequent biofilm growth, that they can do so in constant and perturbed environments, and that this advantage is specific to biofilm growth and requires production of the Psl polysaccharide. In contrast, the P. aeruginosa PA14 is better able to invade pre-formed biofilms and is more inclined to remain surface-associated under starvation conditions. These data together suggest that while P. aeruginosa PAO1 and PA14 are both able to effectively colonize surfaces, they do so in different ways that are advantageous under different environmental settings. Importance Recent studies indicate that P. aeruginosa PAO1 and PA14 use distinct strategies to initiate biofilm formation. We investigated whether their respective colonization and matrix secretion strategies impact their ability to compete under different biofilm-forming regimes. Our work shows that these different strategies do indeed impact how these strains fair in direct competition: PAO1 dominates during colonization of a naïve surface, while PA14 is more effective in colonizing a pre-formed biofilm. These data suggest that even for very similar microbes there can be distinct strategies to successfully colonize and persist on surfaces during the biofilm life cycle.

scholarly journals Bacillus velezensisWall Teichoic Acids Are Required for Biofilm Formation and Root Colonization

2018 ◽  
Vol 85 (5) ◽  
Author(s):  
Zhihui Xu ◽  
Huihui Zhang ◽  
Xinli Sun ◽  
Yan Liu ◽  
Wuxia Yan ◽  
...  
Keyword(s):  
Plant Growth ◽  
Biofilm Formation ◽  
Root Colonization ◽  
Molecular Networks ◽  
Model Organisms ◽  
Bacillus Velezensis ◽  
Content Type ◽  
Plant Growth Promoting ◽  
Colonization Process ◽  
Growth Promoting

ABSTRACTRhizosphere colonization by plant growth-promoting rhizobacteria (PGPR) along plant roots facilitates the ability of PGPR to promote plant growth and health. Thus, an understanding of the molecular mechanisms of the root colonization process by plant-beneficialBacillusstrains is essential for the use of these strains in agriculture. Here, we observed that ansfpgene mutant of the plant growth-promoting rhizobacteriumBacillus velezensisSQR9 was unable to form normal biofilm architecture, and differential protein expression was observed by proteomic analysis. A minor wall teichoic acid (WTA) biosynthetic protein, GgaA, was decreased over 4-fold in the Δsfpmutant, and impairment of theggaAgene postponed biofilm formation and decreased cucumber root colonization capabilities. In addition, we provide evidence that the major WTA biosynthetic enzyme GtaB is involved in both biofilm formation and root colonization. The deficiency in biofilm formation of the ΔgtaBmutant may be due to an absence of UDP-glucose, which is necessary for the synthesis of biofilm matrix exopolysaccharides (EPS). These observations provide insights into the root colonization process by a plant-beneficialBacillusstrain, which will help improve its application as a biofertilizer.IMPORTANCEBacillus velezensisis a Gram-positive plant-beneficial bacterium which is widely used in agriculture. Additionally,Bacillusspp. are some of the model organisms used in the study of biofilms, and as such, the molecular networks and regulation systems of biofilm formation are well characterized. However, the molecular processes involved in root colonization by plant-beneficialBacillusstrains remain largely unknown. Here, we showed that WTAs play important roles in the plant root colonization process. The loss of thegtaBgene affects the ability ofB. velezensisSQR9 to sense plant polysaccharides, which are important environmental cues that trigger biofilm formation and colonization in the rhizosphere. This knowledge provides new insights into theBacillusroot colonization process and can help improve our understanding of plant-rhizobacterium interactions.

scholarly journals The Neurotransmitters Involved in Drosophila Alcohol-Induced Behaviors

2020 ◽  
Vol 14 ◽  
Author(s):  
Maggie M. Chvilicek ◽  
Iris Titos ◽  
Adrian Rothenfluh
Keyword(s):  
Drosophila Melanogaster ◽  
Behavioral Response ◽  
Recent Progress ◽  
Mammalian Species ◽  
Health And Safety ◽  
Model Organisms ◽  
Negative Consequences ◽  
Behavioral Repertoire ◽  
Significant Research ◽  
Alcohol Response

Alcohol is a widely used and abused substance with numerous negative consequences for human health and safety. Historically, alcohol's widespread, non-specific neurobiological effects have made it a challenge to study in humans. Therefore, model organisms are a critical tool for unraveling the mechanisms of alcohol action and subsequent effects on behavior. Drosophila melanogaster is genetically tractable and displays a vast behavioral repertoire, making it a particularly good candidate for examining the neurobiology of alcohol responses. In addition to being experimentally amenable, Drosophila have high face and mechanistic validity: their alcohol-related behaviors are remarkably consistent with humans and other mammalian species, and they share numerous conserved neurotransmitters and signaling pathways. Flies have a long history in alcohol research, which has been enhanced in recent years by the development of tools that allow for manipulating individual Drosophila neurotransmitters. Through advancements such as the GAL4/UAS system and CRISPR/Cas9 mutagenesis, investigation of specific neurotransmitters in small subsets of neurons has become ever more achievable. In this review, we describe recent progress in understanding the contribution of seven neurotransmitters to fly behavior, focusing on their roles in alcohol response: dopamine, octopamine, tyramine, serotonin, glutamate, GABA, and acetylcholine. We chose these small-molecule neurotransmitters due to their conservation in mammals and their importance for behavior. While neurotransmitters like dopamine and octopamine have received significant research emphasis regarding their contributions to behavior, others, like glutamate, GABA, and acetylcholine, remain relatively unexplored. Here, we summarize recent genetic and behavioral findings concerning these seven neurotransmitters and their roles in the behavioral response to alcohol, highlighting the fitness of the fly as a model for human alcohol use.

scholarly journals Disruption of de novo purine biosynthesis in Pseudomonas fluorescens Pf0-1 leads to reduced biofilm formation and a reduction in cell size of surface-attached but not planktonic cells

2015 ◽  
Author(s):  
Shiro Yoshioka ◽  
Peter D Newell
Keyword(s):  
Pseudomonas Fluorescens ◽  
Cell Size ◽  
Biofilm Formation ◽  
De Novo ◽  
Purine Biosynthesis ◽  
Model Organisms ◽  
Purine Nucleotides ◽  
Surface Attachment ◽  
Nucleotide Biosynthesis ◽  
Mutant Cells

Pseudomonas fluorescens Pf0-1 is one of the model organisms for biofilm research. Our previous transposon mutagenesis study suggested a requirement for the de novo purine nucleotide biosynthesis pathway for biofilm formation by this organism. This study was performed to verify that observation and investigate the basis for the defects in biofilm formation shown by purine biosynthesis mutants. Constructing deletion mutations in 8 genes in this pathway, we found that they all showed reductions in biofilm formation that could be partly or completely restored by nucleotide supplementation or genetic complementation. We demonstrated that, despite a reduction in biofilm formation, more viable mutant cells were recovered from the surface-attached population than from the planktonic phase under conditions of purine deprivation. Analyses using scanning electron microscopy revealed that the surface-attached mutant cells were 25~30% shorter in length than WT, which partly explains the reduced biomass in the mutant biofilms. The laser diffraction particle analyses confirmed this finding, and further indicated that the WT biofilm cells were smaller than their planktonic counterparts. The defects in biofilm formation and reductions in cell size shown by the mutants were fully recovered upon adenine or hypoxanthine supplementation, indicating that the purine shortages caused reductions in cell size. Our results are consistent with surface attachment serving as a survival strategy during nutrient deprivation, and indicate that changes in the cell size may be a natural response of P. fluorescens to growth on a surface. Finally, cell sizes in WT biofilms became slightly smaller in the presence of exogenous adenine than in its absence. Our findings suggest that purine nucleotides or related metabolites may influence the regulation of cell size in this bacterium.

scholarly journals The Effect of Gold and Iron-Oxide Nanoparticles on Biofilm-Forming Pathogens

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Madhu Bala Sathyanarayanan ◽  
Reneta Balachandranath ◽  
Yuvasri Genji Srinivasulu ◽  
Sathish Kumar Kannaiyan ◽  
Guruprakash Subbiahdoss
Keyword(s):  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Immune Cells ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Medical Applications ◽  
Oxide Nanoparticles ◽  
Biofilm Growth ◽  
Microbial Biofilms ◽  
Exopolymeric Substances

Microbial biofilms on biomaterial implants or devices are hard to eliminate by antibiotics due to their protection by exopolymeric substances that embed the organisms in a matrix, impenetrable for most antibiotics and immune-cells. Application of metals in their nanoparticulated form is currently considered to resolve bacterial infections. Gold and iron-oxide nanoparticles are widely used in different medical applications, but their utilisation to eradicate biofilms on biomaterials implants is novel. Here, we studied the effect of gold and iron oxide nanoparticles on Staphylococcus aureus and Pseudomonas aeruginosa biofilms. We report that biofilm growth was reduced at higher concentrations of gold and iron-oxide nanoparticles compared to absence of nanoparticles. Thus nanoparticles with appropriate concentration could show significant reduction in biofilm formation.

Characterization of biofilm producing methicillin resistant coagulase negative Staphylococci from India

2021 ◽  
Keyword(s):  
Biofilm Formation ◽  
Resistance Rate ◽  
Coagulase Negative Staphylococci ◽  
Methicillin Resistant ◽  
Antimicrobial Susceptibility Pattern ◽  
Healthcare Settings ◽  
Staphylococcus Capitis ◽  
Staphylococcus Epidermis ◽  
Staphylococcus Hominis

Abstract Methicillin-resistant coagulase-negative staphylococci (MR-CoNS) cause infectious diseases due to their potential to form biofilm and further colonization in hospital materials. This study evaluated the antibiotic susceptible phenotypes, biofilm-producing ability, and biofilm-associated genes (mecA, icaAD, bap, cna, and fnbA). Biofilm formation was detected through Congo red agar (CRA) method and MTP method. The presence of biofilm and associated genes in MR-CoNS were detected by PCR. A total of 310 (55.95%) isolates produced the biofilm. Among these isolates, Staphylococcus haemolyticus (34.83%), Staphylococcus epidermis (31.93%), Staphylococcus capitis (16.77%), Staphylococcus cohnii (10.96%), and Staphylococcus hominis (5.48%) were identified. The antimicrobial susceptibility pattern of CoNS isolates indicated resistance to cefoxitin (100%), erythromycin (94.8%), ciprofloxacin (66.7%), sulfamethoxazole/trimethoprim (66.7%), gentamicin (66.12%), and clindamycin (62.9%). Resistance rate to mupirocin was 48.5% in S. epidermidis and 38.9% in S. haemolyticus isolates. All isolates were sensitive to vancomycin and linezolid. The prevalence rates of icaAD, bap, fnbA, and cna were 18.06%, 12.5%, 47.4%, and 27.4%, respectively. icaAD and bap genes were detected in 18.06% and 12.5% of MR-CoNS isolates. fnbA and cna genes were detected in 47.41% and 27.41% of MRCoNS isolates. icaAD positive strains exhibited a significant increase in the biofilm formation compared with those that lacked icaAD (0.86 (0.42, 1.39) versus 0.36 (0.14, 0.75), respectively; P < 0.001). In conclusion, the majority of MR-CoNS isolates were biofilm producers, and S. capitis, which possessed icaAD genes, ranked as the great biofilm producer than other Staphylococcus. The study’s findings are important to form a strategy to control biofilm formation as an alternative strategy to counter the spread of MR-CoNS in healthcare settings.

Visualization of microbial biofilms in case of digestive disorders in lambs

2021 ◽  
Vol 1 (1) ◽  
pp. 59-67
Author(s):  
E. M. Lenchenko ◽  
N. P. Sachivkina ◽  
D. A. Blumenkrants ◽  
A. Yu. Arsenyuk
Keyword(s):  
Biofilm Formation ◽  
Three Dimensional ◽  
Density Measurement ◽  
Yeast Cells ◽  
Active Growth ◽  
Microbial Structures ◽  
Microbial Biofilms ◽  
Dense Grid ◽  
Digestive Disorders ◽  
Biofilm Structure

The paper demonstrates morphometric and densitometric parameters of microbial biofilms recovered from lambs with digestive disorders. Changes of quantitative and species composition of the intestinal microbiocenoses in the lambs with digestive disorders were compared with the ones of the clinically healthy lambs. Light microscopy results demonstrated formation of three-dimensional biofilm structure in the form of dense grid consisting of gram-negative and gram-positive bacteria, yeast cells, hyphas and pseudohyphas surrounded with intracellular polymer matrix. Presence of blastospores aided to the increased number of cells attached to the substrate, and biofilm was formed, which consisted of rod and round cells attached to the microfungi cells. In the process of dispersion that occurred during the destruction of the intercellular matrix and bacterial and yeast cell detachment, branched structures separated from the microcolonies and colonized microorganism- free regions of the substrate. The intensity of biofilm formation by the microorganisms under study was evaluated by optic density measurement in 48 hours of cultivation. Fluorescence microscopy results demonstrated that the dynamics of changes of the viable microbial structures was specified by intermittent periods of increased or decreased biofilm formation intensity. Cells characterized by active growth and replication and forming alternating subpopulations were detected in the examined microbial cultures. When determining the viability of the microorganisms in the biofilms, the viable (green fluorescence) and non-viable (red fluorescence) cells were differentiated.

scholarly journals Off Earth Identification of Bacterial Populations Using 16S rDNA Nanopore Sequencing

Genes ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 76 ◽  
Author(s):  
Aaron S. Burton ◽  
Sarah E. Stahl ◽  
Kristen K. John ◽  
Miten Jain ◽  
Sissel Juul ◽  
...  
Keyword(s):  
High Performance ◽  
Space Station ◽  
Bacterial Cells ◽  
Sequencing Data ◽  
Mock Community ◽  
Bacterial Populations ◽  
Microbial Identification ◽  
Staphylococcus Capitis ◽  
Staphylococcus Hominis ◽  
Community Standard

The MinION sequencer has made in situ sequencing feasible in remote locations. Following our initial demonstration of its high performance off planet with Earth-prepared samples, we developed and tested an end-to-end, sample-to-sequencer process that could be conducted entirely aboard the International Space Station (ISS). Initial experiments demonstrated the process with a microbial mock community standard. The DNA was successfully amplified, primers were degraded, and libraries prepared and sequenced. The median percent identities for both datasets were 84%, as assessed from alignment of the mock community. The ability to correctly identify the organisms in the mock community standard was comparable for the sequencing data obtained in flight and on the ground. To validate the process on microbes collected from and cultured aboard the ISS, bacterial cells were selected from a NASA Environmental Health Systems Surface Sample Kit contact slide. The locations of bacterial colonies chosen for identification were labeled, and a small number of cells were directly added as input into the sequencing workflow. Prepared DNA was sequenced, and the data were downlinked to Earth. Return of the contact slide to the ground allowed for standard laboratory processing for bacterial identification. The identifications obtained aboard the ISS, Staphylococcus hominis and Staphylococcus capitis, matched those determined on the ground down to the species level. This marks the first ever identification of microbes entirely off Earth, and this validated process could be used for in-flight microbial identification, diagnosis of infectious disease in a crewmember, and as a research platform for investigators around the world.

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