GC: n

S: (last access: 1 November 2019); (last access: 1 November 2019).

N: 1. 1877, medical Latin, from Late Latin bacillus “wand,” literally “little staff,” diminutive of baculum “a stick, staff, walking stick,” from PIE *bak- “staff” (also source of Greek bakterion; see bacteria) + instrumentive suffix -culo. Introduced as a term in bacteriology 1853 by German botanist Ferdinand Cohn (1828-1898).

  • bacilli (plural).

2. Any member of the genus Bacillus; broadly: any straight rod-shaped bacterium – distinguished from coccus and spirillum.
3. Bacillus is a very diverse genus with more than 200 species, and the identification and diagnosis of potential disease-causing Bacillus species from patient material by the clinical lab can be challenging.
4. Bacillus, (genus Bacillus), any of a group of rod-shaped, gram-positive, aerobic or (under some conditions) anaerobic bacteria widely found in soil and water. The term bacillus has been applied in a general sense to all cylindrical or rodlike bacteria. The largest known Bacillus species, B. megaterium, is about 1.5 μm (micrometres; 1 μm = 10−6 m) across by 4 μm long. Bacillus frequently occur in chains.
5. In 1877 German botanist Ferdinand Cohn provided an authoritative description of two different forms of hay bacillus (now known as Bacillus subtilis): one that could be killed upon exposure to heat and one that was resistant to heat. He called the heat-resistant forms “spores” (endospores) and discovered that these dormant forms could be converted to a vegetative, or actively growing, state. Today it is known that all Bacillus species can form dormant spores under adverse environmental conditions. These endospores may remain viable for long periods of time. Endospores are resistant to heat, chemicals, and sunlight and are widely distributed in nature, primarily in soil, from which they invade dust particles.

S: 1. OED – (last access: 1 November 2019); TERMIUM PLUS – (last access: 1 November 2019). 2. TERMIUM PLUS – (last access: 1 November 2019). 3. SDir – (last access: 1 November 2019). 4 & 5. EncBrit – (last access: 1 November 2019).


CR: bacterium, coccus, Gram-negative bacterium, Gram-positive bacterium, Gram stain, tuberculosis.