Bacteria use quorum sensing to coordinate group behaviors by producing and detecting signaling molecules called autoinducers. When the concentration of autoinducers surpasses a threshold level, it triggers gene expression in the entire population. This process allows bacteria to act as a group at high cell densities. Quorum sensing regulates behaviors like virulence, biofilm formation, and bioluminescence. It is mediated by acyl-homoserine lactones in gram-negative bacteria and modified peptides in gram-positive bacteria. Inhibiting quorum sensing is a potential approach to attenuating bacterial virulence without killing the bacteria.
This presentation elaborates on the process through which bacteria communicate with each other using signalling molecules which they can produce and receive.
Xanthomonas-Different types of Quorum sensing in Bacteria, QS in Xanthomonas,and mechanisms of pathogenesis, Chemotaxis mechanisms, Tests to find out QS.
This presentation elaborates on the process through which bacteria communicate with each other using signalling molecules which they can produce and receive.
Xanthomonas-Different types of Quorum sensing in Bacteria, QS in Xanthomonas,and mechanisms of pathogenesis, Chemotaxis mechanisms, Tests to find out QS.
Bacterial processes such as biofilm formation, virulence factor secretion, bioluminescence, antibiotic production, sporulation, and competence for DNA uptake are often critical for survival
However, these behaviors are seemingly futile if performed by a single bacterium acting alone. Yet, we know that bacteria perform these tasks effectively. How do bacteria manage?
We now understand that, through a process called quorum sensing, bacteria synchronously control gene expression in response to changes in cell density and species complexity.
The Quorum sensing is a communication system in microorganisms, allows them to behave like multicellular organisms.
The most important physiological activities of microorganisms that are affected by the Quorum sensing are symbiosis, conjugation, sporulation, biofilm formation, pathogenesis, and production of secondary metabolites.
It explains the relation of quantum mechanics in bacterial communication and various techniques to interrogate quorum sensing pathways. It also contain information on electrical signaling in bacterial communication.
This presentation talks about the molecular basis of Quorum sensing in the virulence of bacterial pathogens and the potential of quorum sensing to serve as drug target.
Bacterial processes such as biofilm formation, virulence factor secretion, bioluminescence, antibiotic production, sporulation, and competence for DNA uptake are often critical for survival
However, these behaviors are seemingly futile if performed by a single bacterium acting alone. Yet, we know that bacteria perform these tasks effectively. How do bacteria manage?
We now understand that, through a process called quorum sensing, bacteria synchronously control gene expression in response to changes in cell density and species complexity.
The Quorum sensing is a communication system in microorganisms, allows them to behave like multicellular organisms.
The most important physiological activities of microorganisms that are affected by the Quorum sensing are symbiosis, conjugation, sporulation, biofilm formation, pathogenesis, and production of secondary metabolites.
It explains the relation of quantum mechanics in bacterial communication and various techniques to interrogate quorum sensing pathways. It also contain information on electrical signaling in bacterial communication.
This presentation talks about the molecular basis of Quorum sensing in the virulence of bacterial pathogens and the potential of quorum sensing to serve as drug target.
Bacteriophages & Its classification, cycles, therapy, and applicationsZoqiaTariq
These slides are covering multiple aspects of Bacteriophages including History
Classification
Replication
Plaque Assay
Transduction
Phage Therapy and pahge types.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
The increased availability of biomedical data, particularly in the public domain, offers the opportunity to better understand human health and to develop effective therapeutics for a wide range of unmet medical needs. However, data scientists remain stymied by the fact that data remain hard to find and to productively reuse because data and their metadata i) are wholly inaccessible, ii) are in non-standard or incompatible representations, iii) do not conform to community standards, and iv) have unclear or highly restricted terms and conditions that preclude legitimate reuse. These limitations require a rethink on data can be made machine and AI-ready - the key motivation behind the FAIR Guiding Principles. Concurrently, while recent efforts have explored the use of deep learning to fuse disparate data into predictive models for a wide range of biomedical applications, these models often fail even when the correct answer is already known, and fail to explain individual predictions in terms that data scientists can appreciate. These limitations suggest that new methods to produce practical artificial intelligence are still needed.
In this talk, I will discuss our work in (1) building an integrative knowledge infrastructure to prepare FAIR and "AI-ready" data and services along with (2) neurosymbolic AI methods to improve the quality of predictions and to generate plausible explanations. Attention is given to standards, platforms, and methods to wrangle knowledge into simple, but effective semantic and latent representations, and to make these available into standards-compliant and discoverable interfaces that can be used in model building, validation, and explanation. Our work, and those of others in the field, creates a baseline for building trustworthy and easy to deploy AI models in biomedicine.
Bio
Dr. Michel Dumontier is the Distinguished Professor of Data Science at Maastricht University, founder and executive director of the Institute of Data Science, and co-founder of the FAIR (Findable, Accessible, Interoperable and Reusable) data principles. His research explores socio-technological approaches for responsible discovery science, which includes collaborative multi-modal knowledge graphs, privacy-preserving distributed data mining, and AI methods for drug discovery and personalized medicine. His work is supported through the Dutch National Research Agenda, the Netherlands Organisation for Scientific Research, Horizon Europe, the European Open Science Cloud, the US National Institutes of Health, and a Marie-Curie Innovative Training Network. He is the editor-in-chief for the journal Data Science and is internationally recognized for his contributions in bioinformatics, biomedical informatics, and semantic technologies including ontologies and linked data.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
2. Bacteria exhibit complex cooperative behaviours, such as conjugal
plasmid transfer, biofilm maturation and virulence.
Many of these behaviours are regulated by a process known as
quorum sensing.
Each individual bacterium is capable of producing a signaling
molecule (inducer) and each bacterium also has a receptor for the
inducer.
When the inducer binds to the receptor, it activates the
transcription of certain genes, including those responsible for the
synthesis of the inducer itself.
Imagine that only a few bacteria of the same kind are nearby…..
Diffusion reduces the concentration of the inducer in the
surrounding medium to a negligible amount, so each bacterium
produces a very small amount of the inducer.
2
4. CELL DENSITY AND QUORUM SENSING
R gene I gene
R protein I protein
AHL diffuse out
R gene I gene
R protein I protein
AHL diffuse
out
+
AHL diffuse in
Cell
density
Time
4
5. When concentration of these signaling molecules exceed a
particular threshold value, these molecules are internalized in the
cell and activate particular set of genes in all bacterial population,
such as genes responsible for virulence, competence, stationary
phase etc .
Quorum sensing thus enables bacteria to co-ordinate and respond
quickly to environmental changes, such as the availability of
nutrients, other microbes or toxins in their environment.
5
10. AUTOINDUCER PEPTIDES
These are small peptides, regulate gene expression in Gram-
positive bacteria such as Bacillus subtilis, Staphylococcus aureus etc.
Recognized by membrane bound histidine kinase as receptor.
Regulates competence and sporulating gene expressions.
10
11. AUTOINDUCER-2 (AI-2)
Involve in interspecies communication among bacteria.
Present in both Gram (+) and Gram (-) bacteria.
Chemically these are furanosylborate diester.
S-ribosyl-homocysteine (SRH)
4,5-dihydroxyl-2,3 pentanedione (DPD)
Autoinducer-2 (AI-2)
LuxS
Cyclization
11
12. Gram negative bacteria
Quorum sensing was originally discovered in the luminescent
bacterium Vibrio fischeri.
These bacteria exist as free-living cells or as symbionts in the
light-producing organ of an animal host, such as the Hawaiian
bobtail squid.
The host provides a nutrient-rich environment for the
bacterium and the bacterium provides light for the host.
It was observed that liquid cultures of V. fischeri produced
light only when large numbers of Bacteria were present.
The initial explanation for this was that the culture medium
contained an inhibitor of luminescence, which was removed
when large numbers of bacteria were present.
12
13. When a V. fischeri cell is alone, the autoinducer (3-oxo-
C6-HSL, an AHL) is at a low concentration.
At high cell concentrations, the level of the autoinducer
becomes sufficient to induce transcription of the genes that
produce the enzyme luciferase, leading to bioluminescence.
On reflection, this system is clearly a sensible one. Asingle cell
is not capable of producing enough luciferase to cause visible
luminescence.
Using quorum sensing, the cell can save its effort for the time
when sufficient similar cells are around, so that their combined
action produces a visible glow.
The bacteria thus behave differently in the free-living and
symbiotic states.
13
14. The pathogen Pseudomonas aeruginosa uses quorum sensing
to coordinate behaviours such as biofilm formation, swarming
motility, and aggregation.
These bacteria grow inside a host organism without harming
it, until they reach a threshold concentration.
Then, having detected that their number is sufficient to
overcome the host’s immune system, they become aggressive
and form a biofilm, causing disease.
This pathogen uses AHL-mediated quorum sensing to regulate
the production of many factors needed for virulence.
14
17. Gram-positive bacteria
They communicate using modified oligopeptides as signals and
“two component”- type membrane-bound sensor histidine kinases
as receptors.
Signaling is mediated by a phosphorylation cascade that
influences the activity of a DNA-binding transcriptional regulatory
protein termed a response regulator.
Each Gram-positive bacterium uses a signal different
from that used by other bacteria and the cognate receptors
are exquisitely sensitive to the signals’ structures.
Peptide signals are not diffusible across the membrane,
hence signal release is mediated by dedicated
oligopeptide exporters.
it is known that most peptide quorum-sensing signals are
cleaved from larger precursor peptides, which then are
modified to contain lactone and thiolactone rings,
lanthionines, and isoprenyl groups 17
18. S. aureus uses a biphasic strategy to cause disease:
At low cell density, the bacteria express protein factors that
promote attachment and colonization,
whereas at high cell density, the bacteria repress these traits
and initiate secretion of toxins and proteases that are presumably
required for dissemination
The system consists of an autoinducing peptide of
Staphylococcus aureus (AIP) encoded by agrD and a
two-component sensor kinase-response regulator pair,
AgrC and AgrA, respectively.
Activated AgrA induces expression of the agrBDCA.
results in increased AIP levels, which ensures that the
entire population switches from the low-cell-density to the
high-cell-density
18
22. INHIBITION OF QUORUM SENSING
Inhibition of quorum sensing has been proved to be very potent method
for bacterial virulence inhibition.
Several QS inhibitors molecules has been discovered.
QS inhibitors have been synthesized and have been isolated from several
natural extracts such as garlic extract.
QS inhibitors have shown to be potent virulence inhibitor both in in-vitro
and in-vivo, using infection animal models.
22
23. QUORUM QUENCHING
The ability to disrupt quorum sensing may give one
bacterial species an advantage over another that
relies on quorum sensing.
Likewise, a host’s ability to interfere with bacterial
cell-cell communication may be crucial in
preventing colonization by pathogenic bacteria that
use quorum sensing to coordinate virulence.
Thus, mechanisms that have evolved to interfere
with bacterial cell-cell communication in processes
termed quorum quenching.
23
24. Biotechnological Applications of
Quorum Quenching
Naturally occurring quorum-quenching processes are being tested as
novel antimicrobial therapies. Over expression of aiiA in tobacco and
potato plants confers resistance to E. carotovora, which requires AHL-
controlled virulence factor expression to cause disease.
Likewise, co culture of Bacillus thuringiensis decreased
E. carotovora–mediated plant disease in an aii A-dependent manner.
Mice treated with synthetic antagonists of S. aureus AIP show
resistance to infection.
Similarly, purified halogenated furanones appear to attenuate
virulence of bacteria in mouse models.
These and other examples predict that inhibition of quorum sensing
which offers an attractive alternative to traditional antibiotics because
these strategies are not bactericidal and the occurrence of bacterial
resistance therefore could be reduced.
Likewise, approaches aimed at promoting beneficial quorum sensing
associations may enhance industrial scale production of natural or
engineered bacterial products.
24
26. STRATEGIES FOR QUORUM SENSING INHIBITION
3 strategies can be applied
Targeting AHL signal
dissemination
Targeting the signal
receptor
Targeting signal
generation
Signal precursor
Signal
Signal receptor
Signal precursor Signal precursor
Signal Signal
Signal receptor Signal receptor
X
X
X
26