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.
The document discusses the normal microbial flora that inhabit healthy humans. It is divided into resident and transient flora. The resident flora consists of microorganisms regularly found in a given area, while the transient flora inhabits areas temporarily. The four major phyla that make up most of the human microbiota are Actinobacteria, Firmicutes, Proteobacteria, and Bacteroidetes. The normal flora varies across body sites like skin, mouth, respiratory and GI tracts. Maintaining the balance of the normal flora is important for health.
This document discusses virus classification systems. It provides an overview of the Baltimore classification system, which categorizes viruses based on their method of mRNA production. Group I viruses contain double-stranded DNA and produce mRNA through transcription. Group II viruses have single-stranded DNA and produce a double-stranded DNA intermediate before transcription. Group III viruses use double-stranded RNA, with one strand serving as the mRNA template. Group IV viruses contain single-stranded RNA with positive polarity that directly serves as mRNA.
Virology is the study of viruses and their relationship with hosts. Viruses are acellular organisms that can only replicate inside host cells. They have nucleic acid genomes and use host cell machinery to assemble new viral particles. Viruses come in a variety of shapes and sizes, and some have envelopes derived from host cell membranes. They enter host cells, express their genes, replicate their genomes, assemble new viral particles, and exit host cells to infect new targets. Viruses are cultivated using various methods including cell cultures, embryonated eggs, and animal models to study viral replication and pathogenesis.
This document discusses the mechanisms of bacterial pathogenesis. It defines key terms like commensal, opportunistic pathogen, pathogen, virulence, infection, and portal of entry. It describes bacterial virulence factors such as capsules, adhesins, invasiveness, exoenzymes, and toxins. It also discusses concepts like infecting dose, clinical manifestations, and the evolution of infection.
The document discusses bacterial pathogenesis and virulence. It describes three main ways bacteria cause disease: 1) invasiveness through mechanisms like adhesion and toxin production, 2) toxigenesis through exotoxins and endotoxins, and 3) evading host immune responses. Specific virulence factors and pathogenesis mechanisms are discussed for different bacteria like Pseudomonas aeruginosa and Mycobacterium tuberculosis. The host barriers bacteria must overcome include phagocytosis, complement activation, and adaptive immune responses; bacteria have evolved strategies to inhibit or subvert these defenses.
Mechanism of bacterial pathogenesis and virulenceMeher Rizvi
This document discusses bacterial virulence factors and mechanisms of pathogenesis. It defines key terms like pathogens, opportunistic pathogens, virulence, and colonization. It then describes several virulence factors like adhesins, pili, capsules, toxins, enzymes, and plasmids that allow bacteria to adhere to and invade host cells, evade the immune system, and cause damage. Methods of acquiring new virulence genes like plasmids, bacteriophages, and horizontal gene transfer are also summarized.
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.
The document discusses the normal microbial flora that inhabit healthy humans. It is divided into resident and transient flora. The resident flora consists of microorganisms regularly found in a given area, while the transient flora inhabits areas temporarily. The four major phyla that make up most of the human microbiota are Actinobacteria, Firmicutes, Proteobacteria, and Bacteroidetes. The normal flora varies across body sites like skin, mouth, respiratory and GI tracts. Maintaining the balance of the normal flora is important for health.
This document discusses virus classification systems. It provides an overview of the Baltimore classification system, which categorizes viruses based on their method of mRNA production. Group I viruses contain double-stranded DNA and produce mRNA through transcription. Group II viruses have single-stranded DNA and produce a double-stranded DNA intermediate before transcription. Group III viruses use double-stranded RNA, with one strand serving as the mRNA template. Group IV viruses contain single-stranded RNA with positive polarity that directly serves as mRNA.
Virology is the study of viruses and their relationship with hosts. Viruses are acellular organisms that can only replicate inside host cells. They have nucleic acid genomes and use host cell machinery to assemble new viral particles. Viruses come in a variety of shapes and sizes, and some have envelopes derived from host cell membranes. They enter host cells, express their genes, replicate their genomes, assemble new viral particles, and exit host cells to infect new targets. Viruses are cultivated using various methods including cell cultures, embryonated eggs, and animal models to study viral replication and pathogenesis.
This document discusses the mechanisms of bacterial pathogenesis. It defines key terms like commensal, opportunistic pathogen, pathogen, virulence, infection, and portal of entry. It describes bacterial virulence factors such as capsules, adhesins, invasiveness, exoenzymes, and toxins. It also discusses concepts like infecting dose, clinical manifestations, and the evolution of infection.
The document discusses bacterial pathogenesis and virulence. It describes three main ways bacteria cause disease: 1) invasiveness through mechanisms like adhesion and toxin production, 2) toxigenesis through exotoxins and endotoxins, and 3) evading host immune responses. Specific virulence factors and pathogenesis mechanisms are discussed for different bacteria like Pseudomonas aeruginosa and Mycobacterium tuberculosis. The host barriers bacteria must overcome include phagocytosis, complement activation, and adaptive immune responses; bacteria have evolved strategies to inhibit or subvert these defenses.
Mechanism of bacterial pathogenesis and virulenceMeher Rizvi
This document discusses bacterial virulence factors and mechanisms of pathogenesis. It defines key terms like pathogens, opportunistic pathogens, virulence, and colonization. It then describes several virulence factors like adhesins, pili, capsules, toxins, enzymes, and plasmids that allow bacteria to adhere to and invade host cells, evade the immune system, and cause damage. Methods of acquiring new virulence genes like plasmids, bacteriophages, and horizontal gene transfer are also summarized.
This document provides an overview of bacterial pathogenesis. It discusses Koch's postulates, virulence factors, types of infections, mechanisms of pathogenesis including transmission, adherence, invasion, inflammation and toxin production. Key points covered include the definition of a pathogen and virulence, examples of virulence factors for common bacteria, how bacteria adhere and invade host tissues, and the role of exotoxins and endotoxins in disease.
This document discusses virus isolation and cultivation. It explains that viruses require living cells to replicate and the primary purposes of cultivation are to isolate viruses from clinical samples, conduct research, and produce vaccines. Viruses can be cultivated in experimental animals, embryonated eggs, or tissue culture. Tissue culture is now most commonly used and involves growing viruses in primary cells, diploid cell strains, or continuous cell lines. The document describes different tissue culture methods and how viral growth can be detected using cytopathic effects, hemadsorption, interference, transformation, and microscopy.
VIRUSES CLASSIFICATION , LIFE CYCLE OF VIRUSES. CHARACTERISTICS OF VIRUSES Shylesh M
VIRUSES
LIFE CYCLE OF BACTERIOPHAGES
The word virus is derived from Latin word venom which means poisonous fluid that causes infection.
The branch of science that deals with the study of viruses is called Virology. It is the branch of Microbiology.
They show living characters inside the host and non living characters outside the host.
They contain either DNA or RNA as genetic material.
They have different size and shape. They cause diseases in plants, animals and micro-organisms .
Not cellular
Cannot carry on metabolic activities independently.
Contain either DNA or RNA, not both ( true cells contain both ).
Lack ribosomes and enzymes necessary for protein synthesis.
Reproduce only within cells they infect.
CLASSIFICATION OF VIRUSES
Holmes, in 1948, proposed a simple system of classifying viruses based on the type of cell (host) they infect:
Phytophagineae: They infect plants and they RNA as their genetic material. Eg: TMV,CaMV.
Zoophagineae: They infect animals and they have mostly DNA as their genetic material. Eg: Polio virus.
Pagineae: They infect bacterial cells, called bacteriophages they usually have DNA as genetic material.
Based on the viral envelope
Named after David Baltimore, a noble prize winning biologist n 1971.
1. dsDNA viruses Eg: Adenoviruses, Herpiviruses.
2. ssDNA viruses Eg: Paravoviruses.
3. dsRNA viruses Eg: Reoviruses.
4. (+)ssRNA viruses Eg: Picornaviruses.
5. (-)ssRNA viruses Eg: Orthomyxoviruses.
6. ssRNA-RT viruses Eg: Retroviruses.
7. dsDNA-RT viruses Eg: Hepadnaviruses.
Tobacco mosaic:
Causative agent: Tobacco mosaic virus (TMV)
Symptoms: The leaves of infected plants develop mosaic patches ,it is due to destruction of chlorophyll or due to production of abnormal chlorophyll .blisters appear in the region of dark green spots these may be regular or irregular in advanced stages leaves curl and get distorted.
Adsorption of the virion to the bacterial cell.
Penetration and decoating of the nucleic acid .
Protein synthesis.
Breakdown of bacterial DNA.
Arrest of host cell development.
Replication of phage DNA.
Maturation of infective progeny.
Lysis and release of newly formed phages.
Holmes, in 1948, proposed a simple system of classifying viruses based on the type of cell (host) they infect:
Phytophagineae: They infect plants and they RNA as their genetic material. Eg: TMV,CaMV.
Zoophagineae: They infect animals and they have mostly DNA as their genetic material. Eg: Polio virus.
Pagineae: They infect bacterial cells, called bacteriophages they usually have DNA as genetic material.
This document provides an overview of bacterial physiology, including:
1. Bacteria can be classified based on their nutritional requirements as autotrophs, which can synthesize their own organic compounds, or heterotrophs, which depend on external organic compounds.
2. Bacterial growth involves an increase in cell size and number through binary fission, with a typical generation time of 20 minutes. Growth is affected by temperature, oxygen levels, pH, moisture, and other environmental factors.
3. When bacteria are inoculated into a liquid medium, their growth follows distinct lag, exponential, stationary, and decline phases as seen on a growth curve showing changes in bacterial numbers over time.
This document discusses various aspects of infectious diseases including definitions, classification, transmission, and pathogenic mechanisms. It defines infection as the lodgement and multiplication of an infectious agent in the body. Infections are classified as endogenous or exogenous depending on the source, and as acute, chronic, latent, or atypical depending on clinical manifestations. Microbes can be transmitted via contact, airborne droplets, ingestion, inoculation, transplacentally, or through iatrogenic means. Pathogenicity is determined by microbial adhesion, invasiveness, antiphagocytic factors, and toxins. Exotoxins are often heat-labile proteins that can be converted to toxoids.
The document defines key terms related to bacterial pathogenicity and mechanisms by which bacteria cause disease. It discusses how bacteria penetrate host defenses through adherence, capsules, and enzymes. It also describes the role of toxins, including exotoxins and endotoxins, in bacterial pathogenesis. The summary provides an overview of the main points covered in the document.
E. coli is a rod-shaped, Gram-negative bacterium commonly found in the large intestine. It has several protective outer layers including a capsule, cell wall, and outer plasma membrane. The capsule and slime layer help protect the bacterium from drying out and prevent phagocytosis. The cell wall provides shape and rigidity while the plasma membranes serve as selective barriers. Inside, the cytoplasm contains ribosomes and other structures for carrying out metabolic functions. E. coli can also contain extra-chromosomal DNA elements like plasmids that allow for antibiotic resistance or virulence factor encoding. It uses flagella and pili for motility and adhesion.
This document provides an overview of viruses, including their history of discovery, characteristics, components, shapes, classification, bacteriophages, replication cycles, enveloped viruses, and other related infectious agents like viroids and prions. It discusses key scientists and experiments that contributed to the understanding of viruses. The replication cycles of lytic and lysogenic bacteriophages as well as enveloped DNA and RNA viruses are described.
Immunity is the body's defense mechanism against foreign bodies like bacteria, viruses, and toxins. Innate immunity provides immediate protection through physical and chemical barriers like the skin and mucous membranes, as well as white blood cells that phagocytose pathogens. The complement system and interferons are also part of innate immunity. When barriers are breached, inflammation occurs, attracting more immune cells to the site of infection to destroy pathogens and repair tissue damage.
This document outlines the objectives, introduction, and conclusion of a student paper on virulence factors of bacteria. It discusses how virulence factors help bacteria colonize hosts, evade the immune system, and cause damage. The objectives are to understand how virulence factors promote colonization and damage, differentiate between endotoxins and exotoxins, and identify factors that induce autoimmune disease. Key virulence factors and their mechanisms are briefly mentioned.
Virology is the study of viruses, which were not well understood until the late 1800s. Early discoveries included Lady Montagu observing inoculation against smallpox in Turkey in the 18th century and Edward Jenner developing the smallpox vaccine using cowpox virus in 1798. In the late 19th century, the development of bacterial filters allowed viruses to be isolated and shown to be smaller than bacteria, causing diseases even when bacteria were removed. By the early 20th century, it was established that viruses could cause diseases in plants, animals, and humans and were distinct from bacteria.
Bacteriophages reproduce through two cycles: lytic and lysogenic. In the lytic cycle, the phage infects the bacterium and takes over its machinery to produce new viruses, ultimately causing the bacterial cell to lyse. In the lysogenic cycle, the phage inserts its DNA into the bacterial chromosome where it remains as prophage, copying itself along with the bacterial DNA during cell division without killing the cell until certain conditions trigger the lytic cycle. The key differences are that the lytic cycle damages the host cell while the lysogenic cycle does not, and lysogenic phages integrate their DNA into the host genome to establish prophage whereas lytic phages do not.
Viral vaccines use either live attenuated or killed viruses to stimulate the immune system and prevent infectious viral diseases. There are two main types - live attenuated vaccines contain weakened live viruses that can replicate in the body to induce an immune response, often with just one dose, while inactivated vaccines use killed viruses or viral components that do not replicate but typically require multiple doses to be effective. Common examples of each type include measles, mumps, and rubella vaccines for live attenuated, and hepatitis A, influenza and polio vaccines for inactivated.
This document discusses bacterial adhesion, invasion, and colonization. It describes how bacteria initially adhere to host surfaces through transient association with mucus, weak association with carbohydrates, or strong association with proteins. This adhesion allows bacteria to colonize sites like the nasal cavity or intestines. The document then examines two mechanisms of bacterial invasion - the zipper mechanism where engagement of bacterial and host proteins triggers strengthening of cell contacts, and the trigger mechanism where bacteria activate host signaling to induce membrane ruffling and bacterial uptake. Specific examples of Listeria and Salmonella invasion are provided. The document concludes with details on Salmonella colonization in the intestines facilitated by its ability to use tetrathionate as an electron acceptor.
This document discusses protoplast isolation and cell culture. It begins by defining a protoplast as a plant cell without a cell wall that contains normal cell organelles. Protoplasts can be isolated from actively growing tissues using mechanical and enzymatic methods. The mechanical method involves plasmolysis and cutting of tissues, while the enzymatic method uses lytic enzymes to remove the cell wall. Cell culture methods are also discussed, including primary cell cultures derived directly from tissues that have a finite lifespan, and continuous cell lines derived from tumors that can divide indefinitely. Different cell types, culture media, and tissue culture techniques are described.
This document discusses different types of vaccines and how they work. It describes passive immunization which transfers preformed antibodies, and active immunization which induces the immune system to produce its own antibodies. The main types of vaccines are listed as live-attenuated, inactivated, recombinant subunit, toxoid, conjugate polysaccharide-protein, and DNA vaccines. Each works in a different way, such as using live but weakened pathogens, killed pathogens, isolated proteins or toxins, or plasmid DNA, to elicit protective immunity against diseases.
This document discusses bacteriophages (phages), viruses that infect bacteria. It covers the composition and structure of phages, how they infect host cells through adsorption and nucleic acid injection, and their multiplication cycles of either the lytic or lysogenic pathways. The document also discusses phage typing, which uses specific phages to identify and differentiate bacterial pathogens, and applications of phages in areas like diagnostics, therapeutics, biocontrol, and more.
introduction of bacteriophage , discovery, morphology, structure and life cycle of bacteriophage,
imp. of bacteriophage and other briefly define lytic and lysogenic cycle.
Bacteriophages, or phages, are viruses that infect bacteria. There are two main life cycles for phages: lytic and lysogenic. In the lytic cycle, the phage hijacks the bacterial cell to produce new phages then causes the cell to burst. In the lysogenic cycle, the phage inserts its DNA into the bacterial chromosome where it remains inactive until conditions trigger the lytic cycle. Phages have many applications including phage therapy to treat bacterial infections, using phage lysins as antimicrobials, and phage display to identify molecules that bind to targets of interest.
This document provides an overview of bacterial pathogenesis. It discusses Koch's postulates, virulence factors, types of infections, mechanisms of pathogenesis including transmission, adherence, invasion, inflammation and toxin production. Key points covered include the definition of a pathogen and virulence, examples of virulence factors for common bacteria, how bacteria adhere and invade host tissues, and the role of exotoxins and endotoxins in disease.
This document discusses virus isolation and cultivation. It explains that viruses require living cells to replicate and the primary purposes of cultivation are to isolate viruses from clinical samples, conduct research, and produce vaccines. Viruses can be cultivated in experimental animals, embryonated eggs, or tissue culture. Tissue culture is now most commonly used and involves growing viruses in primary cells, diploid cell strains, or continuous cell lines. The document describes different tissue culture methods and how viral growth can be detected using cytopathic effects, hemadsorption, interference, transformation, and microscopy.
VIRUSES CLASSIFICATION , LIFE CYCLE OF VIRUSES. CHARACTERISTICS OF VIRUSES Shylesh M
VIRUSES
LIFE CYCLE OF BACTERIOPHAGES
The word virus is derived from Latin word venom which means poisonous fluid that causes infection.
The branch of science that deals with the study of viruses is called Virology. It is the branch of Microbiology.
They show living characters inside the host and non living characters outside the host.
They contain either DNA or RNA as genetic material.
They have different size and shape. They cause diseases in plants, animals and micro-organisms .
Not cellular
Cannot carry on metabolic activities independently.
Contain either DNA or RNA, not both ( true cells contain both ).
Lack ribosomes and enzymes necessary for protein synthesis.
Reproduce only within cells they infect.
CLASSIFICATION OF VIRUSES
Holmes, in 1948, proposed a simple system of classifying viruses based on the type of cell (host) they infect:
Phytophagineae: They infect plants and they RNA as their genetic material. Eg: TMV,CaMV.
Zoophagineae: They infect animals and they have mostly DNA as their genetic material. Eg: Polio virus.
Pagineae: They infect bacterial cells, called bacteriophages they usually have DNA as genetic material.
Based on the viral envelope
Named after David Baltimore, a noble prize winning biologist n 1971.
1. dsDNA viruses Eg: Adenoviruses, Herpiviruses.
2. ssDNA viruses Eg: Paravoviruses.
3. dsRNA viruses Eg: Reoviruses.
4. (+)ssRNA viruses Eg: Picornaviruses.
5. (-)ssRNA viruses Eg: Orthomyxoviruses.
6. ssRNA-RT viruses Eg: Retroviruses.
7. dsDNA-RT viruses Eg: Hepadnaviruses.
Tobacco mosaic:
Causative agent: Tobacco mosaic virus (TMV)
Symptoms: The leaves of infected plants develop mosaic patches ,it is due to destruction of chlorophyll or due to production of abnormal chlorophyll .blisters appear in the region of dark green spots these may be regular or irregular in advanced stages leaves curl and get distorted.
Adsorption of the virion to the bacterial cell.
Penetration and decoating of the nucleic acid .
Protein synthesis.
Breakdown of bacterial DNA.
Arrest of host cell development.
Replication of phage DNA.
Maturation of infective progeny.
Lysis and release of newly formed phages.
Holmes, in 1948, proposed a simple system of classifying viruses based on the type of cell (host) they infect:
Phytophagineae: They infect plants and they RNA as their genetic material. Eg: TMV,CaMV.
Zoophagineae: They infect animals and they have mostly DNA as their genetic material. Eg: Polio virus.
Pagineae: They infect bacterial cells, called bacteriophages they usually have DNA as genetic material.
This document provides an overview of bacterial physiology, including:
1. Bacteria can be classified based on their nutritional requirements as autotrophs, which can synthesize their own organic compounds, or heterotrophs, which depend on external organic compounds.
2. Bacterial growth involves an increase in cell size and number through binary fission, with a typical generation time of 20 minutes. Growth is affected by temperature, oxygen levels, pH, moisture, and other environmental factors.
3. When bacteria are inoculated into a liquid medium, their growth follows distinct lag, exponential, stationary, and decline phases as seen on a growth curve showing changes in bacterial numbers over time.
This document discusses various aspects of infectious diseases including definitions, classification, transmission, and pathogenic mechanisms. It defines infection as the lodgement and multiplication of an infectious agent in the body. Infections are classified as endogenous or exogenous depending on the source, and as acute, chronic, latent, or atypical depending on clinical manifestations. Microbes can be transmitted via contact, airborne droplets, ingestion, inoculation, transplacentally, or through iatrogenic means. Pathogenicity is determined by microbial adhesion, invasiveness, antiphagocytic factors, and toxins. Exotoxins are often heat-labile proteins that can be converted to toxoids.
The document defines key terms related to bacterial pathogenicity and mechanisms by which bacteria cause disease. It discusses how bacteria penetrate host defenses through adherence, capsules, and enzymes. It also describes the role of toxins, including exotoxins and endotoxins, in bacterial pathogenesis. The summary provides an overview of the main points covered in the document.
E. coli is a rod-shaped, Gram-negative bacterium commonly found in the large intestine. It has several protective outer layers including a capsule, cell wall, and outer plasma membrane. The capsule and slime layer help protect the bacterium from drying out and prevent phagocytosis. The cell wall provides shape and rigidity while the plasma membranes serve as selective barriers. Inside, the cytoplasm contains ribosomes and other structures for carrying out metabolic functions. E. coli can also contain extra-chromosomal DNA elements like plasmids that allow for antibiotic resistance or virulence factor encoding. It uses flagella and pili for motility and adhesion.
This document provides an overview of viruses, including their history of discovery, characteristics, components, shapes, classification, bacteriophages, replication cycles, enveloped viruses, and other related infectious agents like viroids and prions. It discusses key scientists and experiments that contributed to the understanding of viruses. The replication cycles of lytic and lysogenic bacteriophages as well as enveloped DNA and RNA viruses are described.
Immunity is the body's defense mechanism against foreign bodies like bacteria, viruses, and toxins. Innate immunity provides immediate protection through physical and chemical barriers like the skin and mucous membranes, as well as white blood cells that phagocytose pathogens. The complement system and interferons are also part of innate immunity. When barriers are breached, inflammation occurs, attracting more immune cells to the site of infection to destroy pathogens and repair tissue damage.
This document outlines the objectives, introduction, and conclusion of a student paper on virulence factors of bacteria. It discusses how virulence factors help bacteria colonize hosts, evade the immune system, and cause damage. The objectives are to understand how virulence factors promote colonization and damage, differentiate between endotoxins and exotoxins, and identify factors that induce autoimmune disease. Key virulence factors and their mechanisms are briefly mentioned.
Virology is the study of viruses, which were not well understood until the late 1800s. Early discoveries included Lady Montagu observing inoculation against smallpox in Turkey in the 18th century and Edward Jenner developing the smallpox vaccine using cowpox virus in 1798. In the late 19th century, the development of bacterial filters allowed viruses to be isolated and shown to be smaller than bacteria, causing diseases even when bacteria were removed. By the early 20th century, it was established that viruses could cause diseases in plants, animals, and humans and were distinct from bacteria.
Bacteriophages reproduce through two cycles: lytic and lysogenic. In the lytic cycle, the phage infects the bacterium and takes over its machinery to produce new viruses, ultimately causing the bacterial cell to lyse. In the lysogenic cycle, the phage inserts its DNA into the bacterial chromosome where it remains as prophage, copying itself along with the bacterial DNA during cell division without killing the cell until certain conditions trigger the lytic cycle. The key differences are that the lytic cycle damages the host cell while the lysogenic cycle does not, and lysogenic phages integrate their DNA into the host genome to establish prophage whereas lytic phages do not.
Viral vaccines use either live attenuated or killed viruses to stimulate the immune system and prevent infectious viral diseases. There are two main types - live attenuated vaccines contain weakened live viruses that can replicate in the body to induce an immune response, often with just one dose, while inactivated vaccines use killed viruses or viral components that do not replicate but typically require multiple doses to be effective. Common examples of each type include measles, mumps, and rubella vaccines for live attenuated, and hepatitis A, influenza and polio vaccines for inactivated.
This document discusses bacterial adhesion, invasion, and colonization. It describes how bacteria initially adhere to host surfaces through transient association with mucus, weak association with carbohydrates, or strong association with proteins. This adhesion allows bacteria to colonize sites like the nasal cavity or intestines. The document then examines two mechanisms of bacterial invasion - the zipper mechanism where engagement of bacterial and host proteins triggers strengthening of cell contacts, and the trigger mechanism where bacteria activate host signaling to induce membrane ruffling and bacterial uptake. Specific examples of Listeria and Salmonella invasion are provided. The document concludes with details on Salmonella colonization in the intestines facilitated by its ability to use tetrathionate as an electron acceptor.
This document discusses protoplast isolation and cell culture. It begins by defining a protoplast as a plant cell without a cell wall that contains normal cell organelles. Protoplasts can be isolated from actively growing tissues using mechanical and enzymatic methods. The mechanical method involves plasmolysis and cutting of tissues, while the enzymatic method uses lytic enzymes to remove the cell wall. Cell culture methods are also discussed, including primary cell cultures derived directly from tissues that have a finite lifespan, and continuous cell lines derived from tumors that can divide indefinitely. Different cell types, culture media, and tissue culture techniques are described.
This document discusses different types of vaccines and how they work. It describes passive immunization which transfers preformed antibodies, and active immunization which induces the immune system to produce its own antibodies. The main types of vaccines are listed as live-attenuated, inactivated, recombinant subunit, toxoid, conjugate polysaccharide-protein, and DNA vaccines. Each works in a different way, such as using live but weakened pathogens, killed pathogens, isolated proteins or toxins, or plasmid DNA, to elicit protective immunity against diseases.
This document discusses bacteriophages (phages), viruses that infect bacteria. It covers the composition and structure of phages, how they infect host cells through adsorption and nucleic acid injection, and their multiplication cycles of either the lytic or lysogenic pathways. The document also discusses phage typing, which uses specific phages to identify and differentiate bacterial pathogens, and applications of phages in areas like diagnostics, therapeutics, biocontrol, and more.
introduction of bacteriophage , discovery, morphology, structure and life cycle of bacteriophage,
imp. of bacteriophage and other briefly define lytic and lysogenic cycle.
Bacteriophages, or phages, are viruses that infect bacteria. There are two main life cycles for phages: lytic and lysogenic. In the lytic cycle, the phage hijacks the bacterial cell to produce new phages then causes the cell to burst. In the lysogenic cycle, the phage inserts its DNA into the bacterial chromosome where it remains inactive until conditions trigger the lytic cycle. Phages have many applications including phage therapy to treat bacterial infections, using phage lysins as antimicrobials, and phage display to identify molecules that bind to targets of interest.
Bacteriophages, or phages, are viruses that infect bacteria. They have either a lytic or lysogenic lifecycle. The lytic cycle involves the phage hijacking the host cell to replicate its DNA and proteins before lysing the cell. The lysogenic cycle incorporates the phage DNA into the host genome where it remains dormant until stress induces the lytic cycle. Phages have either DNA or RNA genomes encapsulated in protein capsids and may have complex or simple structures like tails. They are ubiquitous wherever bacteria exist and are the most abundant biological entity on Earth.
bacteriophage microbiology short notes.pptxitsmesuveksha
Bacteriophage, or phages, are viruses that infect and replicate within bacteria. They were discovered in the early 1900s and are classified based on their nucleic acid and structure. Phages have either a lytic or lysogenic lifecycle - the lytic cycle kills the host bacteria to release new phages, while the lysogenic cycle integrates the phage DNA into the host genome. Phages have potential applications in medicine, biotechnology, and agriculture due to their ability to target specific bacteria.
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.
Bacteriophages are viruses that infect and replicate inside bacteria. They were first observed in 1917 by Twort and d'Herelle who noticed that bacterial cultures could be dissolved by adding filtrate from sewage. Bacteriophages have complex structures when viewed under electron microscopes and there are over 5000 types classified into 13 families. They carry only the genetic information needed for replication and use the host cell's machinery. Bacteriophages can induce lysogenic conversion by integrating their DNA into the host chromosome, which may enhance the host's virulence by allowing it to produce toxins. They have potential medical applications as alternatives to antibiotics.
The document summarizes the lytic and lysogenic cycles of viruses. In the lytic cycle, a virus infects a host cell and uses its machinery to replicate itself before destroying the host cell. In the lysogenic cycle, the virus inserts its genome into the host's genome and remains dormant, replicating with the host cell before entering the lytic cycle. Some key terms are defined, including latency, bacteriophage, and pseudolysogeny. Examples are provided of viruses that undergo lytic replication like T4 bacteriophage and lysogenic replication like lambda bacteriophage.
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.
Bacteriophages are viruses that infect bacteria. They were discovered in the early 20th century and come in diverse structural forms. Bacteriophages have a nucleic acid core surrounded by a protein coat. They undergo either a lytic cycle that results in host cell lysis or a lysogenic cycle where the phage DNA integrates into the host chromosome. The lysogenic cycle can confer new properties on the host bacteria through lysogenic conversion. Bacteriophages play important roles in bacterial evolution, epidemiology, and have applications in genetic engineering and controlling bacterial growth.
Studying Viruses can be important because they are often disease .pdfsuhshbhosale
Studying Viruses can be important because they are often disease causing pathogens. Howeve,
because of how easy they are to control and mainpulate in the laboratory, viruses can be good
tools to study basic, fundamental principles of cell and molecular biology. Concisely explain one
example of how viruses were used to make a critical molecular genetics discovery (briefly, how
was the experiment done, and what was concluded?)
Studying Viruses can be important because they are often disease causing pathogens. Howeve,
because of how easy they are to control and mainpulate in the laboratory, viruses can be good
tools to study basic, fundamental principles of cell and molecular biology. Concisely explain one
example of how viruses were used to make a critical molecular genetics discovery (briefly, how
was the experiment done, and what was concluded?)
Solution
Viruses are intracellular parasites that are effective after infecting particular host cells. Viral
infection starts offevolved when proteins on the surface of a virion bind to particular receptor
proteins at the host cells. The specificity of this interaction determines the host range of an
endemic.
Aside from being the causative agents of many sicknesses, viruses are vital gear in cellular
biology research, mainly in research on macromolecular synthesis.
Individual viral particles (virions) usually incorporate both an RNA or a DNA genome,
surrounded via multiple copies of 1 or a small variety of coat proteins, forming the nucleocapsid.
The nucleocapsid of many animal viruses is surrounded with the aid of a phospholipid bilayer, or
envelope.
During lytic replication, host-cell ribosomes and enzymes are used to explicit viral proteins,
which then viral genome and package it into viral coats. The multiple progeny virions produced
within a single infected cellular eventually are launched, following cellular lysis or gradual
disintegration of the cell . Progeny nucleocapsids of enveloped viruses are launched by using
budding of the host-cell membrane in which viral membrane proteins have been deposited.
Some bacterial viruses (bacteriophages) might also go through lysogeny following infection of
host cells. In this situation, the viral genome is incorporated into host-cell chromosomes, forming
a prophage this is replicated along with the host genome. When suitably activated, a prophage
enters the lytic cycle.
All retroviruses and some different animal viruses can combine their genomes into host-cell
chromosomes . In a few instances, this leads to abnormal cell replication and the eventual
improvement of cancers.
Recombinant viruses can be used as vectors to transduce genes into cells. In this method, viral
genes required for the lytic cycle are changed with the aid of other genes. The use of viral
vectors for gene remedy continues to be in its infancy, but has super ability for treatment of
diverse diseases..
The document discusses various types of viruses that can be used as biopesticides, including baculoviruses like nucleopolyhedrosis viruses and granulosis viruses which infect insect hosts and form crystalline protein structures allowing them to survive outside the host, as well as less classified group C baculoviruses and entomopox viruses. Baculoviruses like NPVs and GVs produce occlusion bodies within infected cells that protect the virus and allow it to be transmitted between hosts, making them useful for biocontrol.
Bacteriophage are viruses that infect bacteria by injecting their DNA or RNA genome into the bacterial cell. The viral genome is then used by the host cell to produce more virus particles. T4 bacteriophage contains DNA bounded by a protein coat and looks like a small spaceship under a microscope.
HIV targets the immune system of humans by infecting T-helper cells. It contains an RNA genome bounded by a protein coat. HIV uses the enzyme reverse transcriptase to convert its RNA into DNA, which is then incorporated into the host cell's genome to produce new viral particles and ultimately cause AIDS.
Viruses are obligatory intracellular parasites that contain either DNA or RNA surrounded by a protein coat. They multiply by using the host cell's machinery to produce more virus particles. Viruses range greatly in size and structure, and are classified based on their nucleic acid, replication method, and morphology. Viruses must infect living host cells to replicate, and the process involves attachment, entry, hijacking the cell to produce new viral components, and eventual cell lysis or budding of new viral particles.
Viruses exist in two forms - living and non-living. They can infect virtually any organism and replicate only in certain cell types, known as their host range. Bacteriophages are viruses that infect and parasitize only bacteria. They were discovered in 1915 and 1917 and are referred to as "phages". Phages exist widely in nature and can be isolated from sewage. They have diverse structures and genetics. Phages attack bacteria through either a lytic cycle where they kill the host, or a lysogenic cycle where they integrate into the host genome. During lysogeny, phage genes can be expressed and alter the host cell, sometimes changing it from harmless to pathogenic like certain cholera-causing
Bacterial virus (Bacteriophage).
Structure of bacteriophage.
Where we can find phage?
Families of bacteriophage.
Life cycle of bacteriophage.
Potential uses of bacteriophage.
Bacteriophage vs. antibiotics.
Factors affecting phage therapy.
The document discusses the lytic cycle of bacteriophages. It begins by explaining that larger numbers of co-infecting phages make the lysogenic cycle more likely, to prevent wiping out the bacterial host. It then describes the steps of the lytic cycle: adsorption where the phage attaches to receptors on the host, penetration where the viral nucleic acid enters the host cell, and the eclipse phase where the host's machinery is used to produce viral proteins and new phage particles. The lytic cycle results in lysis of the host cell and release of new phage particles to infect other bacteria.
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
The document summarizes key aspects of virology. It describes that viruses are small infectious agents that contain either DNA or RNA and use the machinery of host cells to replicate. Viruses infect cells and program them to produce new viral components for assembly of new virus particles. The document then discusses viral structure, morphology, replication cycles involving attachment, entry, uncoating, production of components, assembly and release. It also covers pathogenesis, diagnosis, cultivation, and methods for prevention and treatment of viral infections including vaccines, interferons and antiviral drugs.
Microbiology - Noncellular Microbes - Louis Carlo LimLouis Lim
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Exploiting Artificial Intelligence for Empowering Researchers and Faculty, In...Dr. Vinod Kumar Kanvaria
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at Integral University, Lucknow, 06.06.2024
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Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
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Thinking of getting a dog? Be aware that breeds like Pit Bulls, Rottweilers, and German Shepherds can be loyal and dangerous. Proper training and socialization are crucial to preventing aggressive behaviors. Ensure safety by understanding their needs and always supervising interactions. Stay safe, and enjoy your furry friends!
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June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
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This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
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A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
South African Journal of Science: Writing with integrity workshop (2024)
Bacteriophage
1.
2. What is Bacteriophage?
The virus which attack, infect and reproduce inside the
bacteria is known as Bacteriophage.
Phage:- utilizes bacteria’s biological machinery to
complete its own reproduction.
They are also known as bacteria eaters.
3. DEFINITION
Obligate intracellular parasites that multiply inside
bacteria by making use of some or all of the host
biosynthetic machinery.
DETAIL:
like most of the virus, bacteriophages typically carry
only the genetic information needed for replication of
their nucleic acid and synthesis of their protein coat.
They require precursors, energy generation and
ribosomes supplied by their bacterial host cells.
4. FACTS:
A virus that infects.
Replicates within a bacterium.
Single or double-stranded.
Surrounded by protein capsid.
It also infect archaea.
It as two life cycle are lytic and lysogenic.
At present over, 5000 bacteriophages have been
studied under electronic microscope.
It can be divided into 13 virus families.
Bacteriophage need bacteria to activate.
5. DISCOVERY:
Bacteriophage were discovered independently by two
scientists, Frederick Twort and Felix d’Herelle in 1915 and
1917.
They observed that broth culture of certain intestinal
bacteria could be dissolved by addition of bacterial-free
filters obtained from sewage.
6. MORPHOLOGY:
Phages have a complex structure.
They have tadpole shaped, with hexagonal head and a
cylinderical tail.
The head consists of a tightly packed core of nucleic acid
[DNA].
It surrounded by a protein coat or capsid.
size of the head vary in different phages; from 28nm to 100nm.
Tail is composed of a tightly packed core and the tail fiber is
attached.
9. Lytic Cycle:
With lytic cycle, bacterial cells are broken open (lysed)
and destroyed after immediate replication of the
virion.
As soon as the cell is destroyed,the phage progeny can
find new host to infect.
EXAMPLE:
a lytic bacteriophage is T4, which infects E.coli
found in the human intestinal track.
10. STEPS OF LYTIC CYCLE
Attachment
Penetration
SynthesisAssembly
Release
11. ATTACHMENT
Virus lands on cell membrane.
Virus attaches to a cell receptor.
No attachment=no infection.
Virus acts as a “key” to the receptor.
13. SYNTHSIS
Virus DNA/RNA uses ribosome to make virus proteins.
Protein created by transcription/translation.
Virus protein makes new virus parts and they
replicates.
15. RELEASE & LYSIS
Virus enzyme cause cell membrane to ‘lyse’
New virus are released to find new host.
Cycle repeats.
16.
17. Lysogenic cycle
The lysogenic cycle allows the host cell to continue to
survive and reproduce , the virus is reproduced in all of
the cell’s offsprings.
EXAMPLE:
an example of a bacteriophage known to follow the
lysogenic cycle and lytic cycle is the phage lambda of
E.coli.
19. Summary of lysogenic
1. adsorption
2. entry
3. integration: formation of provirus or prophage by
inserting viral DNA into host genome.
4. spontaneous induction : release of viral DNA from
host genome.
5. replication
6. assembly
7. lysis & release
20. LYTIC CYCLE LYSOGENIC
CYCLE
The DNA of virus
doesn’t integrate
into the DNA.
The DNA of the
virus integrates
into the host
DNA.
Host DNA
hydrolyzed
Host DNA do not
hydrolyzed
Absence of
prophage stages.
Presence of
prophage stage.
Occurs within a
short period of
time.
It takes time.
DNA replication
of virus takes
place
independently
from the host
DNA replication.
DNA replication
of the virus takes
place along with
the host DNA
replication.
21.
22. TRANSMISSION OF GENETIC
INFORMATION:
Phages may act as the carriers of gene from one
bacterium to another. This is known as transduction.
TYPES:
Restricted transduction- only bacterial gene
contiguous to the prophage are transmitted.
Generalised transduction- any bacterial gene may be
transferred.
23. PHAGE ASSAY
Lysis of the bacteriophage is indicated by theformation of a
zone of clearing or plaque within the lawnof bacteria.
The number of plaques that develop and the appropriate
dilution factors can be used to calculate the number of
bacteriophages.
i.e. Plaque forming units[PFU] in a sample.
PURPOSE;
This can be used to purify a clonal population of virus or
determine viral titer as pfu/ml. So that known amount of
virus can be used to infect cells during subsequent work.
24.
25.
26. PHAGE TYPING
It is a method used for detecting single stains of
bacteria
These are used to identify different strains of bacteria
with in a single species.
Specific bacteriophage isolated is mixed with known
bacterial pathogen.
27.
28. ADVANTAGE
Individual components of phage can also be used as
antibiotic substence.
Its is not harmful to animals or human beings.
Phages are also active against bacteria that have
become resistance to antibiotics.
Some resistance bacteria that have been selected
during the treatment with phages are less virulent and
can be fought by the immune system.
Phages are intelligent drug. They multiply at site of the
infection until there is no more bacteria..
29. DISADVANTAGE
There are few international recognized studies that
prove the efficacy of phages in humans.
The great specificity of phage is disadvantage when the
exact species of infecting bacteria is unknown or if
there is a multiple infection.
Sometimes 100 in 2 case , the bacteria resistance to
phage.
Phages can not activate without bacteria as a host.