Plate 11

Bacterial Shapes

Bacillus

• Bacillus = rod • 0.5-20 µm in

length

Rectangle-Shaped Bacilli

• Bacillus anthracis (anthrax) bacteria is rectangular in shape

Club-shaped Bacilli

• Cornybacterim diphtheria (diptheria) bacteria is club-shaped

Swollen-Shaped Bacilli

• Clostridium tetani (tetnus) bacteria is club shape w/ spore at end

Strepto Bacilli

• Strepto means that the bacteria are linked end-to-end in a chain

• Rat bite fever is an example

Spores in bacilli

Photomicrograph Drawing

Cocci Bacteria

• Cocci = sphere

• Small in diameter (usually 0.5µm)

Forms of Coccus Bacteria

• Diplo – 2 cells fused on one side

• Strepto – long chain• Packet (sarcina) –

group of 4• Staphylo – irregular

group “grape like”

Diplococcus

• Diplo means “double”

• Neisseria gonorrhoeae (gonorrhea) is an example

Streptococcus

• Strepto = long chain

• “Strep Throat” is an example

Sarcina Coccus

• Sarcina = packet

• Micrococcus luteus is an example

• Found on human skin

Staphylococcus

• Staphylo = irregular shape

• Staphylococcus aureus is an example

• “Staph” infection

Spiral Bacteria

•Wave-like shape

•Average 15 µm long

Single Spiral Bacteria

• Vibrio – “comma like”

• Vibrio cholerae (cholera) is an example

Corkscrew and Flagellum Bacteria

• Spirillum = wave like w/ flagella

• Rat bite fever is an example

Corkscrew and No Flagellum

• Spirochete – flexible wall no flagella

• Treponema pallidum (syphilis) is an example

Leptospirilum

What is the practical value of knowing the bacteria’s form?