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

Le fimbrie e i pili sono appendici sottili, simili a peli, di solito di 2-10 nanometri di diametro, fatte di proteina pilina e si estendono dalla superficie della cellula batterica.Le fimbrie consentono alle cellule batteriche di aderire alle superfici disponibili, consentendo la formazione di biofilm.Aiutano anche i batteri ad aderire alle loro cellule ospiti, facilitando la colonizzazione e stabilendo infezioni, come osservato in agenti patogeni come la Neisseria gonorrhoeae.I pili sono generalmente più lunghi e meno numerosi delle fimbrie.I pili contribuiscono anche all'adesione, consentendo a batteri patogeni come Pseudomonas aeruginosa di attaccarsi alle loro cellule ospiti.I pili aiutano anche nella coniugazione batterica, dove i pili specializzati, noti come pili sessuali o pili coniugativi, facilitano il trasferimento di materiale genetico tra le cellule batteriche.I pili di tipo IV, un altro pilo specializzato, sono coinvolti nella motilità delle contrazioni, che consente ai batteri di muoversi lungo le superfici.I filamenti assiali, o endoflagelli, che si trovano nelle spirochete, come il Treponema pallidum, si trovano all'interno dello spazio periplasmatico.Questi filamenti assiali consentono alle spirochete di muoversi con un movimento simile a un cavatappi, che consente loro di muoversi in modo efficiente attraverso ambienti viscosi come i fluidi corporei.

fimbrie, pili e filamenti assiali

Le fimbrie e i pili sono strutture specializzate della superficie batterica che svolgono ruoli fondamentali nell'adesione, nello scambio genetico e nella motilit&#224;. Composte principalmente dalla proteina pilina, queste appendici simili a peli sono cruciali per la sopravvivenza batterica e la patogenicit&#224; in vari ambienti.
Fimbrie: Adesione e Patogenicit&#224;
Le fimbrie sono strutture sottili e filamentose di 2-10 nanometri di diametro e sono densamente distribuite sulla superficie cellulare batterica. Facilitano l'adesione batterica a superfici abiotiche e tessuti dell'ospite, un passaggio essenziale nella colonizzazione e nell'instaurarsi di infezioni. Ad esempio, Neisseria gonorrhoeae ed Escherichia coli utilizzano le fimbrie per ancorarsi alle cellule epiteliali, contribuendo a malattie come la gonorrea e le infezioni del tratto urinario. Questa capacit&#224; adesiva sottolinea l'importanza delle fimbrie nelle interazioni ospite-patogeno e nella virulenza batterica.
Pili: Scambio Genetico e Motilit&#224;
I pili sono generalmente pi&#249; lunghi e meno numerosi delle fimbrie, svolgendo funzioni specializzate oltre all'adesione. I pili coniugativi, o pili sessuali, consentono il trasferimento orizzontale di geni tra le cellule batteriche tramite un processo noto come coniugazione. Questo meccanismo &#232; cruciale per la diffusione del materiale genetico, inclusi i geni di resistenza agli antibiotici, nelle popolazioni batteriche.
I pili di tipo IV sono particolarmente versatili, partecipando alla motilit&#224; a "contrazione" - un moto a scatti che aiuta i batteri a muoversi su superfici solide. Questi pili migliorano anche la colonizzazione dell'ospite in patogeni come Pseudomonas aeruginosa e Vibrio cholerae, dove il loro doppio ruolo nella motilit&#224; e nell'adesione promuove l'infezione e la formazione di biofilm.
Filamenti Assiali: Motilit&#224; negli Spirocheti
Negli spirocheti, i filamenti assiali, o endoflagelli, sono situati nello spazio periplasmico, consentendo un movimento elicoidale distintivo. Questo movimento, alimentato dalla rotazione dei filamenti, permette a patogeni come Treponema pallidum e Borrelia burgdorferi di attraversare ambienti viscosi come i fluidi corporei. Questa motilit&#224; unica &#232; un fattore chiave nelle propriet&#224; invasive di questi organismi, facilitando la loro sopravvivenza e diffusione nei tessuti dell'ospite. Insieme, fimbrie, pili e filamenti assiali illustrano l'adattabilit&#224; delle strutture superficiali batteriche nel supportare l'adesione, la mobilit&#224; e lo scambio genetico, che sono fondamentali per il loro successo ecologico e potenziale patogeno.

Fimbrie, Pili e Filamenti Assiali

Le fimbrie e i pili sono strutture specializzate della superficie batterica che svolgono ruoli fondamentali nell'adesione, nello scambio genetico e nella ...

Education

Didattica

JoVE Core

Microbiology

Microbiologia

Unit

Unità

Microbial Cell Structure and Function        

Struttura e funzione della cellula microbica

KEY TERMS AND CONCEPTS

TERMINI E CONCETTI CHIAVE

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

Introduction to Virus

Viruses are unique biological entities that blur the boundary between living and non-living systems. Although they lack cellular structure and metabolic ...

Size and Structure of Viral Genomes

Viral genomes exhibit remarkable diversity in size, structure, and composition, influencing their replication strategies and interactions with host cells. ...

Viral Replication: Lytic Cycle

Bacteriophages, or phages, are viruses that specifically infect bacteria. Among them, T-even bacteriophages, such as T4, exhibit a well-characterized ...

Viral Replication: Lysogenic Cycle

The lysogenic cycle is a crucial viral replication strategy that allows bacteriophages to persist within host cells without immediately destroying them. ...

DNA Bacteriophages

Bacteriophages, or phages, are viruses that specifically infect bacteria, utilizing their genetic material to hijack host cellular machinery for ...

Viruses of Archaea

Archaeal viruses play a crucial role in the ecosystems of extremophilic archaea, particularly those belonging to the phyla Euryarchaeota and ...

Viruses with RNA Genomes

RNA viruses are categorized into positive-strand, negative-strand, or double-stranded groups based on their genomic structure and replication mechanisms. ...

the-antiviral-system-of-bacteria-and-archaea-crispr

The Antiviral System of Bacteria and Archaea: CRISPR

CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats is a adaptive immune system found in bacteria and archaea that protects ...

CRISPR/Cas9 Genome Editing

The CRISPR-Cas system serves as a bacterial defense mechanism against invading genetic elements such as viruses and plasmids, forming the foundation for ...

Subviral Agents

Subviral agents are infectious entities that resemble viruses but lack one or more viral components, such as a capsid or essential replication machinery. ...

The student will investigate and understand that bacteria and viruses have an effect on living systems. Key ideas include  viruses depend on a host for metabolic processes;

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

Microbial Growth Measurement: Indirect Methods

Estimating microbial growth is essential for understanding population dynamics and environmental adaptations. Indirect methods provide valuable insights ...

Microbial Growth Media

Microbial growth media are essential tools in microbiology, providing the nutrients and conditions necessary to cultivate and study microorganisms. These ...

Need for Obtaining Pure Cultures

Pure cultures, defined as the growth of a single microorganism species isolated from mixed populations, are fundamental tools in microbiological research ...

techniques-for-isolation-of-pure-cultures

Techniques for Isolation of Pure Cultures

Microorganisms are routinely cultured in the laboratory using various techniques to isolate, grow, and quantify them for further study. These methods rely ...

Factors Influencing Microbial Growth: pH

Microorganisms are classified as acidophiles, neutrophiles, or alkaliphiles based on their pH growth preferences, reflecting their adaptations to specific ...

factors-influencing-microbial-growth-temperature

Factors Influencing Microbial Growth: Temperature

Microorganisms display remarkable adaptations, enabling them to thrive in diverse ecological niches across a wide range of temperatures. Temperature ...

factors-influencing-microbial-growth-osmolarity

Factors Influencing Microbial Growth: Osmolarity

Osmolarity is the measure of solute concentration in a solution. It plays a critical role in determining water availability for organisms. Water moves ...

Oxygen Requirements and Growth Patterns

Microorganisms exhibit diverse oxygen requirements and growth patterns driven by their metabolic strategies and environmental adaptations. Oxygen, while ...

Biofilms

Biofilms are complex communities of microorganisms encased in a self-produced extracellular polysaccharide matrix attached to surfaces. These microbial ...

The student will investigate and understand that bacteria and viruses have an effect on living systems. Key ideas include the modes of reproduction/replication can be compared

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

Environmental Applications of Microorganisms

Microorganisms play a pivotal role in maintaining ecosystem balance by recycling essential elements such as carbon, nitrogen, and phosphorus, as well as ...

community-dna-extraction-from-bacterial-colonies

Community DNA Extraction from Bacterial Colonies

Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba - The University of Arizona
Demonstrating Author: Luisa Ikner
Traditional methods of analysis ...

detecting-environmental-microorganisms-with-polymerase-chain-reaction

Detecting Environmental Microorganisms with the Polymerase Chain Reaction and Gel Electrophoresis

Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba - Arizona University
Demonstrating Author: Bradley Schmitz
Polymerase chain reaction (PCR) is ...

rna-analysis-of-environmental-samples-using-rt-pcr

RNA Analysis of Environmental Samples Using RT-PCR

Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba - The University of Arizona
Demonstrating Author: Bradley Schmitz
Reverse ...

quantifying-environmental-microorganisms-and-viruses-using-qpcr

Quantifying Environmental Microorganisms and Viruses Using qPCR

Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba - The University of Arizona
Demonstrating Author: Bradley Schmitz
Quantitative polymerase ...

water-quality-analysis-via-indicator-organisms

Water Quality Analysis via Indicator Organisms

Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba -The University of Arizona
Demonstrating Author: Luisa Ikner
Water quality analysis monitors ...

isolation-of-fecal-bacteria-from-water-samples-by-filtration

Isolation of Fecal Bacteria from Water Samples by Filtration

Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba - The University of Arizona
Demonstrating Author: Luisa Ikner
The quality of water destined ...

detection-of-bacteriophages-in-environmental-samples

Detection of Bacteriophages in Environmental Samples

Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba - The University of Arizona
Demonstrating Author: Alex Wassimi
Viruses are a unique group of ...

culturing-and-enumerating-bacteria-from-soil-samples

Culturing and Enumerating Bacteria from Soil Samples

Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba - The University of Arizona
Demonstrating Authors: Bradley Schmitz and Luisa Ikner
Surface ...

bacterial-growth-curve-analysis-and-its-environmental-applications

Bacterial Growth Curve Analysis and its Environmental Applications

Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba - The University of Arizona
Demonstrating Author: Luisa Ikner
Bacteria are among the most ...

The student will investigate and understand that bacteria and viruses have an effect on living systems. Key ideas include  bacteria and viruses have a role in other organisms and the environment; and

BIO.4.d

History of Microbiology

Microbiology, a scientific field dedicated to the study of microorganisms, has undergone profound development since its inception in the 17th century. Its ...

Infection

When a pathogen enters the body and reproduces, it can cause an infection, damage body cells, and cause illness symptoms that eventually lead to disease. ...

Defense Mechanism Against Infection

Natural flora, body system defenses, and inflammation are natural barriers of the body against infectious agents regardless of previous exposure. Normal ...

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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