Aerococcus suis

Aerococcus suis is a species of Gram-positive coccoid bacterium in the family Aerococcaceae. It was first isolated from a pig in Spain with meningitis and formally described in 2007.^[1] A. suis is an alpha-hemolytic, catalase-negative bacterium and a potentially opportunistic pathogen of swine.

Aerococcus suis
Scientific classification
Domain:	Bacteria
Kingdom:	Bacillati
Phylum:	Bacillota
Class:	Bacilli
Order:	Lactobacillales
Family:	Aerococcaceae
Genus:	Aerococcus
Species:	A. suis
Binomial name
Aerococcus suis Vela et al., 2007

Taxonomy

Aerococcus suis was described by Vela et al. in 2007 based on isolates from pigs with clinical infections in Spain.^[1] The species name is derived from the Latin word suis, meaning "of a pig." The type strain is 1821/02^T (= CECT 7139^T = CCUG 52530^T = DSM 21500^T). It is phylogenetically related to Aerococcus viridans and Aerococcus urinaeequi, but differs from them based on 16S rRNA gene sequence (<96% similarity), phenotypic traits, and biochemical profiles.

An emended description of the species was published in 2014 to clarify phenotypic characteristics and differentiate it from other species within the genus.^[2]

Morphology

Aerococcus suis cells are Gram-positive, spherical cocci that typically form tetrads or clusters. Colonies on blood agar are small (<1 mm), non-pigmented, and display alpha-hemolysis after 24 hours at 37 °C. The species is non-motile, non-spore-forming, and catalase- and oxidase-negative. It is facultatively anaerobic and tolerates 6.5% NaCl and pH 9.6.