Spirillum minus

Spirillum minus is an organism associated with rat-bite fever (specifically sodoku)^[2][3][4] that has never been fully identified and was assigned to the genus Spirillum in 1887 based on morphology, although it is not a validly published name. As Spirillum species are generally obligately microaerophiles and not found in mammals, this organism may be misclassified. Sequencing data should help to resolve this question.

Spirillum minus
Scientific classification
Domain:	Bacteria
Kingdom:	Pseudomonadati
Phylum:	Pseudomonadota
Class:	Betaproteobacteria
Order:	Nitrosomonadales
Family:	Spirillaceae
Genus:	Spirillum
Species:	S. minus
Binomial name
Spirillum minus Carter, 1887[1]

This organism is presumed to be a bacterium. It stains gram-negative and has a coiled rod shape. It does not grow in vitro, and requires inoculation in animals for growth. No attempts to sequence the organism are known as of 2015.^[5]