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bacillus

Syllabification: ba·cil·lus
Pronunciation: /bəˈsiləs
 
/

Definition of bacillus in English:

noun (plural bacilli /-ˈsilī/)

1A disease-causing bacterium.
Example sentences
  • The isolation of the tuberculosis bacillus in 1882 by Robert Koch, who later became professor of hygiene and director of the Institute for Infectious Diseases in Berlin, was a scientific breakthrough.
  • When infectious people cough, sneeze, talk or spit, they propel TB germs, known as bacilli, into the air.
  • The man, who is unidentified as yet, does not have anthrax - the bacillus is on his person, but he's not infected, and with proper treatment, he should be fine.
1.1A rod-shaped bacterium.
Example sentences
  • One is a microscopic rod-shaped bacterium called bacillus anthracis, easy to grow in the lab but fragile and easily killed in the open.
  • At far right, Methanobacterium thermoautotrophicum, an elongate bacillus form.
  • The victim carried an enormous number of bacilli shaped with the typical ‘short rounded ends.’

Origin

late 19th century: from late Latin, diminutive of Latin baculus 'stick'.

More
  • bacterium from (mid 19th century):

    This modern Latin term is formed from Greek baktērion ‘little staff’; the first bacteria to be discovered were rod-shaped. The word bacillus (late 19th century), a pathogenic bacterium, also meant ‘little rod’ in late Latin. Bacillus is also behind the French word debacle, adopted into English in the early 19th century. It literally means an unbarring and was first used of the breaking of ice or other blockage in a river and its effects, and then transferred to human behaviour.

Usage

All bacteria belonging to the genus Bacillus are called bacilli, but not all bacteria called bacilli belong to the genus Bacillus.

Derivatives

bacillary

1
Pronunciation: /ˈbasəˌlerē/
adjective
Example sentences
  • Shigellosis, also known as acute bacillary dysentery, is characterized by the passage of loose stools mixed with blood and mucus and accompanied by fever, abdominal cramps and tenesmus.
  • During 1967-70, bacillary dysentery was first reported in Central American countries.
  • Approximately a third of cases of dysentery were classified amoebic, a third as bacillary and the rest remained undifferentiated.

Words that rhyme with bacillus

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