Let's check out Bacteria's
Shape
Back in the 19th century, scientists didn’t really have many tools to identify bacteria. So, the easiest way to classify them at that time was to look at the bacteria under the microscope and observe its shape. Bacteria come in many different shapes and arrangements.
01
Cocci
These types of bacteria are spherical or elliptical shape. They remain as a single cell or may aggregate together in various arrangements.
Streptococcus
Appears as a chain of round-shaped cells.
Example: Streptococcus pneumoniae, causes symptoms of pneumonia in immunocompromised people.
Sarcina
in this case the cells divide in three planes but they form a cube like configuration consisting of eight or sixteen cells but they have a regular shape. Example: Sarcina ventriculi, causes implications in gastric diseases.
Diplococcus
Appears as two cells that remain attached to each other.
Example: Neisseria meningitidis, causes meningitis.
Staphylococcus
Appears like a bunch of grapes sticking together in an irregular formation.
Example: Staphylococcus aureus, causes pimples, abscesses and possibly pneumonia.
Monococcus
a.k.a micrococcus and appears single, discrete, and round-shaped. Example: Micrococcus flavus.
Tetrad
Appears as four round cells in a square-like formation. Example: Tetragenococcus halophilus, used to ferment Japanese miso-paste.
02
Bacilli
Appears as rod shaped or cylindrical bacteria which either remain singly, in pairs (diplo), or in long chains (strepto).
Example:
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Bacillus cereus, causes food poisoning and sepsis.
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Escherichia coli, some strains causes diarrhoea and urinary tract infection.
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Lactobacillus casei, a probiotic found in Yakult (Shirota strain).
03
Vibrio
Appears as curved and comma shaped bacteria.
Example: Vibrio cholerae, causes cholera.
04
Spirilla
Appears like a spiral or spring with curved surfaces
Example: Helicobacter pylori, causes gastric ulcer.
