Bacillus and Bacilli

[rainbow]

What is the difference between bacillus and bacilli?

[Mr Skeptic]

Bacillus is singular, bacilli is plural.

[Guest Candydoll]

ya i agree with Mr Skeptic

[Blahah]

Bacilli, with a capital letter but not italicised, is a class of bacteria.

Bacillus, with a captial and italicised, is a genus of bacteria

bacillus (bacilli plural), not capitalised or italicised, refers to any rod-shaped bacterium.

 

all are from the same root, the diminutive form of the latin 'baculum' which means stick, so bacillus means (literally) 'little stick'.