Definition

1. Noun:
   • A taxonomic order of bacteria: "order Rickettsiales" is the scientific name for a specific order of small, pleomorphic, Gram-negative bacteria. These microorganisms are often obligate intracellular parasites, meaning they typically must live inside the cells of a host organism.

Usage Examples

• Noun:
  • Rickettsia and Ehrlichia are genera within the order Rickettsiales.
  • The study focused on the evolutionary history of the order Rickettsiales.
  • Many bacteria in the order Rickettsiales are transmitted by arthropods like ticks and lice.

Advanced Usage

• Taxonomic context: The term is used almost exclusively in scientific, microbiological, or medical literature when discussing classification, characteristics, or diseases caused by these organisms.
  • Phylogenetic analysis confirmed its placement within the order Rickettsiales.

Variants and Related Words

• Rickettsial (adj): Of or pertaining to the order Rickettsiales.
  • Rickettsial diseases include typhus and Rocky Mountain spotted fever.
• Rickettsia (n): A genus within the order Rickettsiales, containing many disease-causing species.
• Anaplasmataceae (n): A family within the order Rickettsiales.

Synonyms

• Rickettsias (informal, plural noun): Often used informally to refer to members of this order.
  • The patient was infected with rickettsias.

Related Phrases

• "of the order Rickettsiales": A common phrasing to specify taxonomic classification.
  • The causative agent is a small bacterium of the order Rickettsiales.

Noun

1. pleomorphic Gram-negative microorganisms