Bacteriophages are the most abundant entities on earth. These bacterial viruses have genetic material in the form of either DNA or RNA, encapsidated by a protein coat.The capsid is attached to a tail which has fibers, used for attachments to receptors on bacterial cell surface.
This presentation is made for the students of B.Sc. Microbiology and Biotechnology. The presentation includes the details about archaea and the characteristics of archaea bacteria
A bacteriophage (informally, phage) is a virus that infects and replicates within a bacterium. The term is derived from "bacteria" and the Greek (phagein), "to devour". Bacteriophages are composed of proteins that encapsulate a DNA or RNA genome, and may have relatively simple or elaborate structures. Their genomes may encode as few as four genes, and as many as hundreds of genes. Phages replicate within the bacterium following the injection of their genome into its cytoplasm. Bacteriophages are among the most common and diverse entities in the biosphere.
Phages are widely distributed in locations populated by bacterial hosts, such as soil or the intestines of animals. One of the densest natural sources for phages and other viruses is sea water, where up to 9×108 virions per milliliter have been found in microbial mats at the surface,] and up to 70% of marine bacteria may be infected by phages. They have been used for over 90 years as an alternative to antibiotics in the former Soviet Union and Central Europe, as well as in France. They are seen as a possible therapy against multi-drug-resistant strains of many bacteria (see phage therapy). Nevertheless, phages of Inoviridae have been shown to complicate biofilms involved in pneumonia and cystic fibrosis, shelter the bacteria from drugs meant to eradicate disease and promote persistent infection
This presentation is made for the students of B.Sc. Microbiology and Biotechnology. The presentation includes the details about archaea and the characteristics of archaea bacteria
A bacteriophage (informally, phage) is a virus that infects and replicates within a bacterium. The term is derived from "bacteria" and the Greek (phagein), "to devour". Bacteriophages are composed of proteins that encapsulate a DNA or RNA genome, and may have relatively simple or elaborate structures. Their genomes may encode as few as four genes, and as many as hundreds of genes. Phages replicate within the bacterium following the injection of their genome into its cytoplasm. Bacteriophages are among the most common and diverse entities in the biosphere.
Phages are widely distributed in locations populated by bacterial hosts, such as soil or the intestines of animals. One of the densest natural sources for phages and other viruses is sea water, where up to 9×108 virions per milliliter have been found in microbial mats at the surface,] and up to 70% of marine bacteria may be infected by phages. They have been used for over 90 years as an alternative to antibiotics in the former Soviet Union and Central Europe, as well as in France. They are seen as a possible therapy against multi-drug-resistant strains of many bacteria (see phage therapy). Nevertheless, phages of Inoviridae have been shown to complicate biofilms involved in pneumonia and cystic fibrosis, shelter the bacteria from drugs meant to eradicate disease and promote persistent infection
There is the fifth video by Miss Aymen Arif Sindh Biotechnologist Association has taken initiative for all young scientists, researchers, and students to have the platform to show their talent and interest in different activities.
Topic: Plasmids and its types
Presentation by: Aymen Arif
Research Officer at Halal Food and testing Laboratory,
Industrial Analytical Center, H.E.J (ICCBS).
Youtube: https://www.youtube.com/watch?v=-spdnc-2z6Q
Viruses are small, acellular particles that can replicate only in a host cell. They are obligatory intracellular parasites.They
consist of a nucleic acid genome enclosed in a protective protein shell or capsidBacteriophage is the virus that infect bacteria.Bacteriophages were discovered by Frederick Twort(1915)and Felix d'Herelle(1917).
This presentation gives you the detailed description of various cells & organs of immune systems that participates (particularly, in combination), make communication between themselves to regulate the whole immune system very precisely.
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.
There is the fifth video by Miss Aymen Arif Sindh Biotechnologist Association has taken initiative for all young scientists, researchers, and students to have the platform to show their talent and interest in different activities.
Topic: Plasmids and its types
Presentation by: Aymen Arif
Research Officer at Halal Food and testing Laboratory,
Industrial Analytical Center, H.E.J (ICCBS).
Youtube: https://www.youtube.com/watch?v=-spdnc-2z6Q
Viruses are small, acellular particles that can replicate only in a host cell. They are obligatory intracellular parasites.They
consist of a nucleic acid genome enclosed in a protective protein shell or capsidBacteriophage is the virus that infect bacteria.Bacteriophages were discovered by Frederick Twort(1915)and Felix d'Herelle(1917).
This presentation gives you the detailed description of various cells & organs of immune systems that participates (particularly, in combination), make communication between themselves to regulate the whole immune system very precisely.
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.
Viruses that infect and parsitized bacteria is known as bacteriophage.
It was discovered by Frederick.W.Twort in Great Britian (1915) and Felix d’ Herelle in France(1917).
D’ Herelle coined the term bacteriophage meaning ‘bacterial eater’ to describe the agent’s bacteriocidal activity. He observed lysis of a broth culture of a dysentry bacillus.
introduction of bacteriophage , discovery, morphology, structure and life cycle of bacteriophage,
imp. of bacteriophage and other briefly define lytic and lysogenic cycle.
A bacteriophage is a type of virus that infects bacteria. In fact, the word "bacteriophage" literally means "bacteria eater," because bacteriophages destroy their host cells. All bacteriophages are composed of a nucleic acid molecule that is surrounded by a protein structure
Bacteriophage is the most common and extensively studied virus. The life cycle of bacteriophages. The transfer of their genetic system via the process of transduction (Generalised and Specialised) and studying the gene mapping in phages. This theoretical explanation about viruses and their genetic system will help the learner in the fields of biotechnology, microbiology, basic science, life science, and various other fields of biology.
Good pipetting technique helps scientists achieve more reliable results from their experiments. Nothing is more frustrating than having to repeat an experiment because poor pipetting technique offset the accuracy of aspirated volumes by 10-50%. Good pipetting technique may also help avoid embarrassing retractions of manuscripts from journals after peers fail to replicate an experiment. Proper pipette technique not only improves experimental outcomes, but it also helps protect the scientist from injury resulting from poor micropipette technique. As proper pipetting technique encompasses the use of ergonomic pipettes, this can also translate to a long-lasting investment for your laboratory. By choosing CAPP’s range of ergonomic pipettes labs have the benefit of long-lasting and robust tools that can be used for a very long time. When coupled with the use of CAPP’s premium filter tips and pipette cone filters that protect pipette shafts from potentially harmful splashes, good pipette technique will save on the cost of equipment replacement.
KF Titrandos' modularity provides it significant flexibility and customization. For example, this KF titrator series contains a variety of coulometric, volumetric, and combination titrators, allowing you to analyse any water content ranging from 0.001 to 100%.
KF Titrandos can be used as standalone titrators or as part of a larger network. The operation has been optimised for both scenarios: you can tap the full power of your Titrando system by using a handy Touch Control unit, the sophisticated tiamo software, or the current OMNIS software.
You also don't have to worry about assembling your titrator, electrode, sample changer, and accessories. We provide all-inclusive packages that include everything you need for a particular application.
Animals secrete pheromones to trigger many types of behaviors, including:
raising an alarm
signaling a food trail
triggering sexual arousal
tell other female insects to lay their eggs elsewhere
delineating a territory
bond between mother and offspring
warning another animal to back off
Nitric oxide supplements are a category of supplements that includes L-citrulline and L-arginine. Researchers have performed multiple clinical trials related to nitric oxide supplements and their effectiveness, often with mixed results.
Mitochondrial biogenesis is the process by which cells increase mitochondrial numbers. It was first described by John Holloszy in the 1960s, when it was discovered that physical endurance training induced higher mitochondrial content levels, leading to greater glucose uptake by muscles. Mitochondrial biogenesis is activated by numerous different signals during times of cellular stress or in response to environmental stimuli, such as aerobic exercise.
Melatonin is a hormone made in the body. It regulates night and day cycles or sleep-wake cycles. Melatonin in supplements is usually made in a lab.
Darkness triggers the body to make more melatonin, which signals the body to sleep. Light decreases melatonin production and signals the body to be awake. Some people who have trouble sleeping have low levels of melatonin. It's thought that adding melatonin from supplements might help them sleep.
Ion channels have many features of typical membrane proteins. They are synthesized and inserted into the membrane of the endoplasmic reticulum, glycosylated in the Golgi, and transported and inserted into target membranes by membrane fusion. They are regulated by trafficking, phosphorylation, ubiquitination, reversible interactions with other signaling proteins and second messengers, proteolytic cleavage, and other modifications. Like other signaling proteins, ion channels are flexible molecules that undergo conformational changes between open (active) and closed (inactive) states. They evolve and increase in number through phylogeny and can be placed in gene families and super families according to their sequence similarities.
Glucose transporters are a wide group of membrane proteins that facilitate the transport of glucose across the plasma membrane, a process known as facilitated diffusion. Because glucose is a vital source of energy for all life, these transporters are present in all phyla.
"A biological database is a large, organized body of persistent data, usually associated with computerized software designed to update, query, and retrieve components of the data stored within the system. A simple database might be a single file containing many records, each of which includes the same set of information."
The attractive force which holds various constituents (atom, ions, etc.) together and stabilizes them by the overall loss of energy is known as chemical bonding. Therefore, it can be understood that chemical compounds are reliant on the strength of the chemical bonds between its constituents; The stronger the bonding between the constituents, the more stable the resulting compound would be.
The attractive force which holds various constituents (atom, ions, etc.) together and stabilizes them by the overall loss of energy is known as chemical bonding. Therefore, it can be understood that chemical compounds are reliant on the strength of the chemical bonds between its constituents; The stronger the bonding between the constituents, the more stable the resulting compound would be.
organic compound, any of a large class of chemical compounds in which one or more atoms of carbon are covalently linked to atoms of other elements, most commonly hydrogen, oxygen, or nitrogen. The few carbon-containing compounds not classified as organic include carbides, carbonates, and cyanides. See chemical compound.
The health effects of hazardous chemicals are often less clear than the physical hazards. Data on the health effects of chemical exposure, especially from chronic exposure, are often incomplete. When discussing the health effects of chemicals, two terms are often used interchangeably - toxicity and hazard.
Biogas is produced after organic materials (plant and animal products) are broken down by bacteria in an oxygen-free environment, a process called anaerobic digestion. Biogas systems use anaerobic digestion to recycle these organic materials, turning them into biogas, which contains both energy (gas), and valuable soil products (liquids and solids).
mass spectrometry, also called mass spectroscopy, analytic technique by which chemical substances are identified by the sorting of gaseous ions in electric and magnetic fields according to their mass-to-charge ratios.
Risk assessment for computer system validationBangaluru
A risk assessment is a process to identify potential hazards and analyze what could happen if a hazard occurs.
Computer system validation (sometimes called computer validation or CSV) is the process of documenting that a computer system meets a set of defined system requirements.
Recovery and purification of intracellular and extra cellular productsBangaluru
Product recovery and purification, such as centrifugal, chromatography, crystallization, dialysis, drying, electrophoresis, filtration, precipitation, etc., are essential finishing steps to any commercial fermentation process.
Iron is a mineral that the body needs for growth and development. Your body uses iron to make hemoglobin, a protein in red blood cells that carries oxygen from the lungs to all parts of the body, and myoglobin, a protein that provides oxygen to muscles. Your body also needs iron to make some hormones.
Good Documentation Practice (GDocP — or GRK for Good Recordkeeping) is an essential component of your overall pharmaceutical quality system (PQS) and quality risk management strategies (QRM).
new guidance on good data management was discussed and its development
recommended. The participants included national inspectors and specialists
in the various agenda topics, as well as staff of the Prequalification Team
(PQT)–Inspections
Zymography is an electrophoretic technique for the detection of hydrolytic enzymes, based on the substrate repertoire of the enzyme. ... Zymography also refers to a collection of related, fermented products, considered as a body of work.
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Ve...kevinkariuki227
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
MANAGEMENT OF ATRIOVENTRICULAR CONDUCTION BLOCK.pdfJim Jacob Roy
Cardiac conduction defects can occur due to various causes.
Atrioventricular conduction blocks ( AV blocks ) are classified into 3 types.
This document describes the acute management of AV block.
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
3. Bacteriophages have been viewed not only as important
genetic but also as potential antibacterial therapeutic
Over evolutionary time bacteriophages have developed
unique proteins that arrest critical cellular processes to
commit bacterial host metabolism to phage reproduction.
Introduction
4. One can exploit this concept of phage- mediated
bacterial growth inhibition to antibiotic discovery
So far many phages have been sequenced and
identified several novel polypeptide families that
inhibited growth upon expression in bacteria.
5. There is an urgent need to develop new classes of
antibiotics to tackle the increase in resistance in
many common bacterial pathogens.
Pathogens such as Staphylococcus aureus,
Streptococcus pneumoniae and Enterococcus
faecalis, which are each capable of causing severe
and even fatal infections , have become
increasingly resistant to multiple antibiotics.
6. The cellular targets for some of these polypeptides were
identified and several were shown to be essential
components of the host DNA replication and transcription
machineries
Mimicking the growth–inhibitory effect of phage
polypeptides by a chemical compound , coupled
with the plethora of phages on earth, will yield new
antibiotic to combat infectious diseases.
7. Phages are recently resurfaced as the saviors of
humankind in the best selling novel-Prey by
Michael Crichton(2002) –in which phages are
used to destroy laboratory–escaped “bacterial
nanoparticles” threatening life on earth.This
reflects the potential of bacteriophages to be
used as a powerful tool in dealing with infectious
diseases of bacterial etiology.
10. Structure of Bacteriophage
•Phage head: composed of coat
protein and genome in the core
•Genome: DNA codes for enzymes
and proteins necessary to replicate
more viruses
•Tail Sheath: DNA travels from
head to bacteria through sheath
•Tail fiber: helps anchor the phage
on the cell membrane
11. Phage life cycle: Lytic vs Lysogenic
Phage replicates by lytic life cycle
Non-integration of phage genetic material
Phage lyse host bacterium
lytic or virulent phage
Phage replicates by lysogenic life cycle
Integration of phage genetic material
temperate phages (prophages) generally larger than lytic
phages (carry ~40kb genetic material)
12. Adsorption by Lytic Bacteriophage
The bacteriophage binds to specific
receptors on the bacterial cell wall.
Tail conformation changes/contracts
central core penetrates cell wall
14. Early Replication
•
-Phage-coded enzymes shut down host’s DNA,RNA,protein
synthesis
-Early function inovolve the takeover of the host cell and the
synthesis of early viral mRNA
-Late functions include the subsequent synthesis of other proteins
and assembly of the nucleocapsid.
-Replication phage DNA protected from host restriction
endonucleaes
17. Conventional Bacteriophage Therapy in
humans
Biomedical technology today is very different
from what it was in the early days of phage
therapy research
In early days bacteriophage therapy was used by
making bacteriophage preparation and are
effective against P. aeruginosa, E.coli, S.aureus,
Streptococcus and proteus
18. The first reviwed report of the therapeutic efficacy
of PhagoBioDerm (Cock tail of lytic bacteriophages)
was recently published (Markoishvili et al., 2002)
107 patients with ulcers – failed to response to
conventional therapy
With PhagoBioDerm - Ulcers healed completely in
67(70%)
20. “Pio bacteriophagum fluidum”- one of the polyvalent phage
preparartions produced by the EIBMV.The preparation targets
a variety of bacterial pathogens, including P.aeruginosa, E.
coli, S.aureus, Streptococcus and proteus
21. Limitations of phage therapy
1.Emergence of bacterial strains resistant to
particular phages. The emergence of phage –
resistant bacterial mutants was observed and
the phenomenon was suggested to be a
potential problem of phage therapy
(Summers, 1999; d’Herelle,1930)
22. Limitations of phage therapy
2.The development of phage–neutralizing
antibodies-The production of neutralizing
antibodies should not be a significant obstacle
during initial or relatively short-term
therapeutic treatments at least.
23. Combating the limitations
Modernization of phage therapy
1. Sequencing of whole genome
2.Rapid and high –throughput, sequence –based
Screening methodologies(e.g., microarrays)
24. Contd……
High–throughput bacteriophage genomics
strategy is the improvised form of conventional
phage therapy.
Exploitation of the Concept of phage –mediated
inhibition of bacterial growth to systematically
identify antimicrobial phage –encoded
polypeptides.
25. To tackle the increase in resistance in many common
bacterial pathogens.
Methicillin resistance s.aureus
Vancomycin resistant enterococci.
Genomic is providing a new strategy by revealing new
molecular targets and peptides that are giving rise to
novel antimicrobialdrug.
26. Key steps in the genomics driven antibiotic drug
discovery process
27. Key criteria to be considered in target
selection
• The target should be present in a required
spectrum of organism.
• It should be absent in humans.
• It should be essential for bacterial growth.
• It should be expressed and relevant to be
infection process.
• Some thing about the function of target
should be known.
28. Peptides and their targets
• Product of bacteriophage T7 gene2(gp2) binds E.coli RNA
polymerase.
• The AsiA protein of phage T4 the bacterial RNA polymerase
σ70 transcription factors.
• Protein P of phage λ and B of phage P2 each bind to and
redirect the host DnaB helicase to there respective phage
origin of replication.
30. • Bacteriophages are even more elaborate than the poxviruses.
The T2, T4, and T6 phages that infect E. coli have been
intensely studied.
• Their head resembles an icosahedrons elongated by one or
two rows of hexamers in the middle and contains the DNA
genome.
• The tail is composed of a collar joining it to the head, a central
hollow tube, a sheath surrounding the tube, and a complex
baseplate.
31. TMV
• The tobacco mosaic virus (TMV) capsid contains a
single type of small subunit possessing 158 amino
acids.
• Only about 474 nucleotides out of 6,000 in the virus
RNA are required to code for coat protein amino
acids.
32.
33. A virus consists of a nucleic acid
surrounded by a protein coat
• Viruses were detected indirectly long before they were
actually seen
34. The Discovery of Viruses: Scientific Inquiry
• Tobacco mosaic disease stunts growth of tobacco
plants and gives their leaves a mosaic coloration
• In the late 1800s, researchers hypothesized that a
particle smaller than bacteria caused the disease
• In 1935, Wendell Stanley confirmed this hypothesis by
crystallizing the infectious particle, now known as
tobacco mosaic virus (TMV)
35. Extracted sap
from tobacco
plant with
tobacco mosaic
disease
Passed sap
through a
porcelain filter
known to trap
bacteria
Healthy plants
became infected
Rubbed filtered
sap on healthy
tobacco plants
1 2 3
4
36. Tobacco mosaic virus
Tobacco mosaic virus (TMV) of plants provides a good model to
learn about the relationship between a virus and its host.
Purpose: to learn about (1) properties of TMV and (2) symptoms
induced by the virus in susceptible and resistant plant hosts
Background information:
Viruses cause a variety of diseases in plants and animals. Virus
diseases that affect humans include measles, mumps, and polio. At
one time, these diseases posed major health concerns, but with
the widespread use of vaccinations in children, these diseases
occur rarely.
37. 1. View healthy and infected tobacco and tomato plats
1. Observe crushing of healthy and mosaic diseased tomato leaves in buffer using
mortar and pestle to produce virus infected plant sap.
2. Mark tobacco leaves with your initials using Sharpie.
3. Use sponge to rub TMV sap from crushed leaves onto your marked healthy
tobacco leaf.
Tobacco Mosaic Virus Infection Lesson:
Transmission of Virus and Mosaic Disease
44. Application of phages
Model system of
molecular biology
Cloning and
expression
Phage display system
Phage typing
Phage therapy:
phage as natural, self-
replicating, self-
limiting antibiotics.
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