Name: how bacteria stick, share genes, and move
Uploaded: 2025-06-12T09:31:02.000Z
Duration: 1 min 28 s
Channel: JoVE

K12 Standards

Virginia  Standards of Learning

HIgh School

Biology

BIO.4

BIO.4.c

Fimbriae, Pili, and Axial Filaments

Fimbrien und Pili sind dünne, haarähnliche Anhängsel mit einem Durchmesser von meist 2-10 Nanometern, die aus Pilin-Protein bestehen und sich von der bakteriellen Zelloberfläche erstrecken. Fimbrien ermöglichen es Bakterienzellen, sich an die verfügbaren Oberflächen zu heften, wodurch Biofilme gebildet werden können. Sie helfen auch Bakterien, sich an ihre Wirtszellen zu heften, erleichtern die Besiedlung und etablieren Infektionen, wie sie bei Krankheitserregern wie Neisseria gonorrhoeae beobachtet werden. Pili sind im Allgemeinen länger und weniger zahlreich als Fimbrien. Pili tragen auch zur Adhäsion bei, so dass sich pathogene Bakterien wie Pseudomonas aeruginosa an ihre Wirtszellen anheften können. Pili helfen auch bei der bakteriellen Konjugation, bei der spezialisierte Pili, die als Sex-Pili oder konjugative Pili bekannt sind, die Übertragung von genetischem Material zwischen Bakterienzellen erleichtern. Pili vom Typ IV, ein weiterer spezialisierter Pilus, sind an der zuckenden Motilität beteiligt, die es Bakterien ermöglicht, sich entlang von Oberflächen zu bewegen. Axiale Filamente oder Endoflagellen, die in Spirochäten vorkommen, wie z. B. Treponema pallidum, befinden sich im periplasmatischen Raum. Diese axialen Filamente ermöglichen es Spirochäten, sich mit einer korkenzieherartigen Bewegung zu bewegen, die es ihnen ermöglicht, sich effizient durch viskose Umgebungen wie Körperflüssigkeiten zu bewegen.

fimbrien, pili und axialfilamente

Fimbrien und Pili sind spezialisierte Strukturen auf der Zelloberfl&#228;che von Bakterien, die eine zentrale Rolle bei der Adh&#228;sion, dem genetischen Austausch und der Motilit&#228;t spielen. Diese haar&#228;hnlichen Anh&#228;nge bestehen haupts&#228;chlich aus Pilin-Proteinen und sind f&#252;r das &#220;berleben sowie die Pathogenit&#228;t von Bakterien in unterschiedlichen Umgebungen entscheidend.
Fimbrien: Adh&#228;sion und Pathogenit&#228;t
Fimbrien sind feine, filament&#246;se Strukturen mit einem Durchmesser von 2 bis10 Nanometern und dicht auf der bakteriellen Zelloberfl&#228;che verteilt. Sie erm&#246;glichen die Adh&#228;sion von Bakterien an abiotische Oberfl&#228;chen und Wirtsgewebe, was einen essenziellen Schritt f&#252;r die Kolonisation und den Beginn von Infektionen darstellt. Neisseria gonorrhoeae und Escherichia coli nutzen Fimbrien, um sich an Epithelzellen zu heften und k&#246;nnen in infolgedessen Erkrankungen wie Gonorrh&#246; und Harnwegsinfektionen ausl&#246;sen. In dieser F&#228;higkeit liegt die Bedeutung der Fimbrien in Wirt-Pathogen-Interaktionen und der bakteriellen Virulenz.
Pili: Genetischer Austausch und Motilit&#228;t
Pili sind im Allgemeinen weniger zahlreich und l&#228;nger als Fimbrien und erf&#252;llen spezialisierte Funktionen, die &#252;ber die Adh&#228;sion hinausgehen. F-Pili, auch Sexpili genannt, erm&#246;glichen durch einen Prozess, der als Konjugation bezeichnet wird, den horizontalen Gentransfer zwischen Bakterienzellen. Dieser Mechanismus ist entscheidend f&#252;r die Verbreitung genetischen Materials, einschlie&#223;lich antibiotikaresistenter Gene, innerhalb bakterieller Populationen.
Typ-IV-Pili sind besonders vielseitig und beteiligen sich an der Twitching-Motilit&#228;t &#8211; einer ruckartigen, kriechenden Bewegung, durch die Bakterien sich auf festen Oberfl&#228;chen fortbewegen k&#246;nnen. Bei Pathogenen wie Pseudomonas aeruginosa und Vibrio cholerae erleichtern diese Art von Pili zudem die Kolonisation des Wirts, wobei ihre doppelte Funktion in Motilit&#228;t und Adh&#228;sion die Infektion und Biofilmbildung f&#246;rdert.
Axialfilamente: Motilit&#228;t bei Spiroch&#228;ten
Bei Spiroch&#228;ten befinden sich Axialfilamente, auch Endoflagellen genannt, im periplasmatischen Raum und erm&#246;glichen eine charakteristische, korkenzieherartige Bewegung. Diese durch die Rotation der Filamente angetriebene Fortbewegung erlaubt Pathogenen wie Treponema pallidum und Borrelia burgdorferi, sich durch viskose Umgebungen wie K&#246;rperfl&#252;ssigkeiten zu bewegen. Diese einzigartige Motilit&#228;t ist ein wesentlicher Faktor f&#252;r die invasive F&#228;higkeit dieser Organismen und erleichtert ihr &#220;berleben und ihre Verbreitung im Wirtsgewebe. Zusammen veranschaulichen Fimbrien, Pili und Axialfilamente die Anpassungsf&#228;higkeit bakterieller Zelloberfl&#228;chen, die Adh&#228;sion, Mobilit&#228;t und den genetischen Austausch unterst&#252;tzen und somit grundlegend f&#252;r ihre erfolgreiche Verbreitung und ihr pathogenes Potenzial sind.

Fimbrien, Pili und Axialfilamente

Fimbrien und Pili sind spezialisierte Strukturen auf der Zelloberfl&#228;che von Bakterien, die eine zentrale Rolle bei der Adh&#228;sion, dem genetischen ...

Education

Lehre

JoVE Core

Microbiology

Mikrobiologie

Unit

Einheit

Microbial Cell Structure and Function        

Mikrobielle Zellstruktur und Funktion

KEY TERMS AND CONCEPTS

KERNBEGRIFFE UND KONZEPTE

how bacteria stick, share genes, and move

Fimbriae, pili, and axial filaments are bacterial surface structures that help cells attach, exchange genes, and move. These hairlike appendages are made mainly of pilin protein. They support bacterial survival in different environments and can also increase pathogenicity.

Fimbriae are fine, filament-like structures that are densely packed on the bacterial surface. They are about 2 to 10 nanometers wide and help bacteria attach to nonliving surfaces and to host tissues. This adhesion is an important first step in colonization and infection. Neisseria gonorrhoeae and Escherichia coli use fimbriae to bind to epithelial cells, which is linked to gonorrhea and urinary tract infections.

Pili are usually longer and less numerous than fimbriae. Some pili, called conjugative pili or sex pili, help bacteria carry out conjugation, a process in which genetic material moves from one cell to another. This horizontal gene transfer can spread antibiotic-resistant genes through bacterial populations. Type IV pili have another role as well. They help bacteria move by twitching motility, a jerky crawling motion on solid surfaces.

Type IV pili also help some pathogens attach to host cells. In Pseudomonas aeruginosa and Vibrio cholerae, this support for both movement and adhesion can aid colonization and biofilm formation. Biofilms are groups of bacteria that stick together on a surface. These traits make pili important for infection and survival.

Axial filaments, also called endoflagella, are found in spirochetes. They sit inside the periplasmic space, which is the area between the cell membrane layers. Their rotation creates a corkscrew-like motion that helps the cells move through thick fluids. Treponema pallidum and Borrelia burgdorferi use this kind of movement to travel through bodily fluids and spread within host tissues.

Together, fimbriae, pili, and axial filaments show how bacteria use surface structures for attachment, motion, and gene exchange. These features help microbes adapt to their surroundings and strengthen their ability to cause disease.

How Bacteria Stick, Share Genes, and Move

prokaryotic vs. eukaryotic cells

Cell Organization in Prokaryotes and Eukaryotes

Prokaryotic and eukaryotic cells show two major patterns of cell organization. These differences shape the structure, size, and function of living things across the domains of life. Prokaryotic cells, such as bacteria and archaea, are simple in structure. They do not have a nucleus or other membrane-bound organelles. Their DNA is usually a single circular molecule found in the nucleoid region, which is not surrounded by a nuclear membrane. Prokaryotes are usually very small, about 0.1 to 5.0...

microbial morphologies 

Microbial Shapes and Cell Forms

Microbial shapes and cell forms help bacteria, archaea, and eukaryotic microbes survive in many environments. Cell shape affects how these organisms grow, take up nutrients, and handle waste. It also reflects the link between structure and function. Among bacteria, cocci and bacilli are the most common shapes. Cocci are spherical cells, and they may appear alone or in pairs called diplococci, chains called streptococci, clusters called staphylococci, or groups of four called tetrads. Bacilli...

bacterial cell wall 

Gram-Positive and Gram-Negative Walls

Bacterial cell walls give bacteria their shape and help protect them from osmotic stress. This rigid but flexible layer surrounds the plasma membrane and supports cellular integrity. Its main building block is peptidoglycan, a mesh-like polymer that adds strength while still allowing some flexibility. Peptidoglycan is made of alternating N-acetylglucosamine, or NAG, and N-acetylmuramic acid, or NAM. Short amino acid chains connect these sugar units and help form the strong network. The...

archaeal cell wall

Archaeal Cell Wall Types and Functions

Archaeal cell walls protect archaea and help them survive in extreme environments. Unlike bacterial cell walls, they do not have the peptidoglycan layer found in most bacteria. Instead, archaea use a range of materials, including proteins, polysaccharides, and pseudomurein, to build their outer layer. The most common archaeal cell wall is the S-layer, or surface layer. It is made of tightly packed protein or glycoprotein units that form a crystalline lattice. These repeating patterns can make...

peptidoglycan synthesis

Building the Bacterial Cell Wall

Peptidoglycan builds the bacterial cell wall and gives the cell its shape and strength. It is a mesh-like polymer around the bacterial plasma membrane. The polymer is made of repeating sugar units, N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM), linked by β-1,4 glycosidic bonds. Short peptide chains cross-link the sugar chains and make the wall more rigid. Peptidoglycan biosynthesis starts in the cytoplasm with soluble precursors. Uridine diphosphate, or UDP, binds to NAG and NAM to...

plasma membrane in bacteria and archaea

Bacterial vs Archaeal Membrane Lipids

Bacterial and archaeal plasma membranes control what enters and leaves the cell. They also help maintain cell integrity. Although both membranes do the same basic job, their structures are different because bacteria and archaea face different environmental demands. Bacterial plasma membranes are mainly made of phospholipids. These lipids have fatty acid chains linked to a glycerol backbone by ester bonds. They form a bilayer, with hydrophilic glycerol-phosphate heads facing outward and...

outer layers of the cell envelope

Capsules, Slime Layers, and S-Layers

Capsules, slime layers, and S-layers are outer coverings on prokaryotic cells. These layers help bacteria and archaea survive, attach to surfaces, and interact with their environment. They are often made of polysaccharides, polypeptides, proteins, or glycoproteins. Capsules are tightly bound and highly organized layers that stick firmly to the bacterial cell wall. They are usually made of polysaccharides, although some are made of polypeptides. A capsule protects cells from dehydration and can...

flagella and motility in bacteria

Bacterial Flagella as Tiny Rotary Motors

Bacterial flagella are thread-like structures that help cells move and respond to their surroundings. They extend from the cell envelope and support both motility and chemotaxis, which is the ability to move in response to chemical signals. Their design shows how bacteria use specialized structures to survive in different environments. A flagellum has three main parts: the filament, the hook, and the basal body. The filament is the long, helical part made of repeating flagellin protein...

fimbriae, pili, and axial filaments

Fimbriae, pili, and axial filaments are bacterial surface structures that help cells attach, exchange genes, and move. These hairlike appendages are made mainly of pilin protein. They support bacterial survival in different environments and can also increase pathogenicity. Fimbriae are fine, filament-like structures that are densely packed on the bacterial surface. They are about 2 to 10 nanometers wide and help bacteria attach to nonliving surfaces and to host tissues. This adhesion is an...

cell inclusions

Prokaryotic Cell Storage Inclusions

Prokaryotic cell storage inclusions help bacteria store nutrients, manage energy, and adapt to changing environments. These inclusions let cells survive when food, phosphate, sulfur, light, or oxygen levels change. They are important examples of how simple cells can still have highly specialized structures. Some inclusions store carbon. Poly-β-hydroxybutyric acid, or PHB, forms granules that act as a long-term carbon and energy reserve. Glycogen granules also store carbon, but they provide a...

endospores and sporulation

How Bacteria Survive with Endospores

Endospores help some bacteria survive harsh conditions. These dormant cells are made mainly by Gram-positive bacteria such as Bacillus and Clostridium. They are highly resistant to heat, ultraviolet and ionizing radiation, drying, and toxic chemicals. In rare cases, endospore-like structures have also been seen in some Gram-negative bacteria, including Coxiella burnetii and Sporosarcina ureae, as well as in other species exposed to extreme conditions. Sporulation begins when bacteria face...

nucleoid

How Prokaryotes Organize DNA

Prokaryotes organize their DNA in the nucleoid, a distinct region where genetic material and associated proteins are packed. Because prokaryotic cells do not have a membrane-bound nucleus, the nucleoid helps keep DNA organized and available for cell activities. In most bacteria and archaea, the DNA is a single, circular, double-stranded molecule that is tightly compacted by supercoiling and protein interactions. Nucleoid-associated proteins, or NAPs, help shape and maintain this DNA region.

surface appendages of archaea

Archaeal Pili and Archaella in Action

Archaeal pili and archaella help archaea survive, attach, and move in challenging environments. These surface appendages support adhesion, biofilm formation, and motility. They give archaeal cells key advantages in habitats that can be extreme. Pili are filament-like structures made from pilin protein subunits. Their main role is adhesion, which means helping cells stick to surfaces. They also support biofilm formation, where cells live in a shared, surface-attached community. Some pili are...

key terms and concepts

Explore how fimbriae, pili, and axial filaments help bacteria attach, exchange genes, and move, with examples from disease-causing microbes.

How Bacteria Stick, Share Genes, and Move | JoVE K12

JoVE Core Microbiology provides an engaging introduction to the microbial world and its influence on health, industry, and the environment. This comprehensive collection covers key concepts such as microbial structure, metabolism, genetics, and ecology. It introduces essential laboratory techniques and microscopy methods through visually engaging animations. Corresponding scientist-in-action videos bridge classroom concepts with real-world research and applications.

microbiology

Tennessee Academic Standards

Earth and Space Sciences

Earth's Systems

b-plate-tectonics-and-large-scale-systems-interactions

B. Plate Tectonics and Large-Scale Systems Interactions

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Viral Replication: Lysogenic Cycle

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DNA Bacteriophages

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Viruses of Archaea

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Viruses with RNA Genomes

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Subviral Agents

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BIO.4.a

Binary Fission

Binary fission is the primary mode of asexual reproduction in prokaryotes, such as bacteria. It results in the production of two genetically identical ...

Generation Time

Bacterial generation time, the period required for a bacterial population to double during its exponential growth phase, serves as a critical measure of ...

Bacterial Growth Curve

The bacterial growth curve is a fundamental concept in microbiology that describes the dynamics of bacterial population growth in a closed system with ...

microbial-growth-measurement-direct-methods

Microbial Growth Measurement: Direct Methods

Direct methods for measuring microbial populations in a culture are essential tools in microbiology, providing quantitative data for various applications. ...

microbial-growth-measurement-indirect-methods

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factors-influencing-microbial-growth-temperature

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Biofilms

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BIO.4.b

Prokaryotic vs. Eukaryotic Cells

Prokaryotic and eukaryotic cells represent two fundamental types of cellular organization, differing significantly in structure, complexity, and function. ...

Microbial Morphologies 

Bacterial and archaeal cells exhibit remarkable diversity in shape and structure, critical in their adaptability and functionality. Among bacteria, the ...

Bacterial Cell Wall 

The bacterial cell wall is an essential structural component that encases the plasma membrane, preserving cellular integrity, determining shape, and ...

Archaeal Cell Wall

Archaeal cell walls are structurally and compositionally distinct from their bacterial counterparts, lacking the characteristic peptidoglycan layer found ...

Peptidoglycan Synthesis

Structure of PeptidoglycanPeptidoglycan is a vital structural component of the bacterial cell wall, providing mechanical strength and shape to the cell. ...

Plasma Membrane in Bacteria and Archaea

The plasma membrane is an essential cellular structure responsible for maintaining cellular integrity and regulating the selective transport of molecules. ...

Outer Layers of the Cell Envelope

The outermost layers of prokaryotic cells play a critical role in their survival, virulence, and interaction with the environment. These layers, often ...

Flagella and Motility in Bacteria

Flagella are specialized, thread-like structures that extend from a bacteria's cell envelope. They play a crucial role in motility and chemotaxis. Their ...

Fimbriae and pili are specialized bacterial surface structures that play pivotal roles in adhesion, genetic exchange, and motility. Composed primarily of ...

Cell Inclusions

Prokaryotic cells possess a variety of inclusions that play crucial roles in nutrient storage, metabolic processes, and environmental adaptation. These ...

Endospores and Sporulation

Endospores are specialized, dormant cells primarily formed by Gram-positive bacteria, including Bacillus and Clostridium, enabling survival under extreme ...

Nucleoid

The nucleoid represents a structurally and functionally distinct region within prokaryotic cells, where the cell's DNA and associated proteins are housed. ...

Surface Appendages of Archaea

Archaeal surface appendages are highly specialized structures essential for environmental adaptation, encompassing roles in adhesion, biofilm formation, ...

The student will investigate and understand that bacteria and viruses have an effect on living systems. Key ideas include  the structures and functions can be compared

Types of Microorganisms

Microorganisms are a diverse group of microscopic entities broadly categorized into cellular and acellular types based on their structural organization. ...

environmental-applications-of-microorganisms

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RNA Analysis of Environmental Samples Using RT-PCR

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Quantifying Environmental Microorganisms and Viruses Using qPCR

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BIO.4.d

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Infection

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Defense Mechanism Against Infection

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The student will investigate and understand that bacteria and viruses have an effect on living systems. Key ideas include  the germ theory of infectious disease is supported by evidence.

BIO.4.e

How Bacteria Stick, Share Genes, and Move

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