bacterial

bacterial — adjective

1. caused by bacteria, made by bacteria, or directly involving bacteria — for examp

1.adjectiveB2
Definition

caused by bacteria, made by bacteria, or directly involving bacteria — for example, a throat infection, the souring of milk, or a sample grown in a lab dish.

Example

Dr. Anaya explained that Mia's sore throat was a bacterial infection, not a virus.

common collocation: bacterial infection

The factory threw out a whole batch of milk after tests showed bacterial contamination from a dirty pipe.

collocation: bacterial contamination

Common collocations
  • bacterial infection
  • bacterial growth
  • bacterial culture
  • bacterial contamination
  • bacterial cell
Synonyms
  • microbial

    broader; covers bacteria, viruses, and fungi together

  • germ-related

    informal; everyday speech rather than medical writing

Antonyms
  • viral

    caused by a virus rather than bacteria

  • fungal

    caused by fungi such as mould or yeast

Grammar Patterns

bacterial + noun

be bacterial

Usage Note

Almost always used before a noun (bacterial infection, bacterial growth, bacterial culture). Distinguish from 'viral': bacterial illnesses can usually be treated with antibiotics, viral ones cannot.

Common Mistakes

I took antibiotics for a viral bacterial flu.
I took antibiotics for a bacterial chest infection.
an illness is either bacterial or viral, not both.
The yoghurt has bacteria culture inside.
The yoghurt has bacterial cultures inside.
use the adjective 'bacterial', not the noun 'bacteria', before another noun.

Word family

  • bacterium
    nounB2
  • bacteria
    nounB1
  • bacterially
    adverbC1
  • antibacterial
    adjectiveB2
  • bacteriology
    nounC2

Synonym discussion

Sense: adjective/1

These four adjectives all describe tiny living things, but each points to a different group. 'Bacterial' is the narrowest of the four — it refers only to bacteria, the single-celled organisms behind illnesses like strep throat and processes like yoghurt fermentation. 'Microbial' is an umbrella term that covers bacteria, viruses, fungi, and other microbes together, so scientists prefer it when the exact organism is unknown or mixed. 'Viral' is the natural opposite in everyday speech: a viral cold will not respond to antibiotics, while a bacterial chest infection often will. 'Fungal' points to moulds and yeasts and is common when talking about skin or plant disease. Compare: 'a bacterial throat infection' (treat with antibiotics), 'a viral cough' (rest and fluids), 'a fungal nail problem' (antifungal cream).

bacterial ↗microbialviral ↗fungal

Common collocations

Nouns

Adverbs

  • highly bacterial
  • primarily bacterial

Phrases

  • bacterial infection
  • bacterial growth
  • bacterial culture
  • bacterial contamination
  • bacterial resistance

Etymology

GreekLatinEnglish

Built in English in the late 1800s by adding the adjective ending '-al' to 'bacterium', the scientific name for a single bacteria cell. 'Bacterium' was borrowed into modern Latin from Greek 'baktērion', meaning 'little stick or rod', because the first bacteria scientists looked at under microscopes had a rod-like shape. The word spread quickly once Louis Pasteur and Robert Koch showed that these tiny organisms could cause disease.