4.2 THE OUTER STRUCTURES OF BACTERIA

Give an examples of motile species.

Bacteria exhibit diverse mechanisms of motility, with flagellar movement being the most common. Here are some motile bacterial species:

Listeria Monocytogenes+ Helicobacter Jejuni+ Enterobacter + Serratia+ Salmonella+ Bacillus Cereus+ Vibrio Choleare + Pseudomonas + Campylobacter + Clostridium Tetani + Treponema Pallidum+ Leptospira+ Borrelia 

  • Listeria Monocytogenes:Intracellularly motile due to its ability to induce actin polymerization in the host cell, allowing it to move within and between cells. It also possesses flagella for extracellular movement, although the flagella are primarily functional at temperatures below 37°C.

  • Helicobacter Jejuni: Uses multiple flagella for its high motility. This movement aids in its colonization of the mucus layer in the stomach.

  • Enterobacter: A genus of bacteria that is known to be motile, primarily due to the presence of peritrichous flagella (flagella that cover the entire surface of the bacterium).

  • Serratia: Particularly Serratia marcescens, is known for its motility and the red pigment it produces.

  • Salmonella: These bacteria have flagella that allow them to move towards favorable environments and away from harmful ones, a behavior called chemotaxis.

  • Bacillus Cereus: A rod-shaped bacterium that uses flagella for movement.

  • Vibrio Cholerae: The causative agent of cholera. It's curved (shape? ) and has a single polar flagellum that propels it forward.

  • Pseudomonas: Pseudomonas aeruginosa, for instance, is motile due to its polar flagella.

  • Campylobacter: Like C. jejuni, is highly motile with flagella.

  • Clostridium Tetani (C. tetani):Though many Clostridium species are non-motile, C. tetani possesses peritrichous flagella.

  • Treponema Pallidum (T. pallidum): The causative agent of syphilis, is a spirochete and moves in a corkscrew manner due to its axial filaments.

  • Leptospira: Another spirochete, it's known for its corkscrew movement facilitated by axial filaments.

  • Borrelia: Borrelia burgdorferi, the causative agent of Lyme disease, is a spirochete that also uses axial filaments for movement.


The above-mentioned species utilize their motility to navigate through their environments, find nutrients, avoid harmful conditions, and in some cases, to establish infections within hosts.

Mind Map: Examples of Motile Species

Listeria Monocytogenes

  • Intracellularly motile

  • Induces actin polymerization in host cells

  • Possesses flagella for extracellular movement

Helicobacter Jejuni

  • Uses multiple flagella for high motility

  • Colonizes the mucus layer in the stomach

Enterobacter

  • Motile due to peritrichous flagella

Serratia

  • Serratia marcescens is motile and produces a red pigment

Salmonella

  • Moves using flagella

  • Exhibits chemotaxis

Bacillus Cereus

  • Uses flagella for movement

  • Rod shaped

Vibrio Cholerae

  • Curved shape with a single polar flagellum

Pseudomonas

  • Pseudomonas aeruginosa is motile due to polar flagella

Campylobacter

  • Highly motile with flagella

Clostridium Tetani

  • Possesses peritrichous flagella

Treponema Pallidum

  • Moves in a corkscrew manner

  • Axial filaments enable movement

Leptospira

  • Moves in a corkscrew manner

  • Axial filaments facilitate movement

Borrelia

  • Uses axial filaments for movement

Motility allows these species to navigate their environment, find nutrients, avoid harmful conditions, and establish infections within hosts.