Streptococcus ferus

Streptococcus ferus is a facultatively anaerobic, gram-positive species of the genus Streptococcus.[1] The species is a member of the Viridans streptococci group [2] which are a large mixed-group of mostly alpha-hemolytic streptococci.[3] The alpha-hemolytic bacteria are ones that exhibit a partial hemolysis with green coloration when grown on sheep blood agar[4] (see image.)

S. ferus was originally isolated from the oral cavity wild rats who were living in sugar cane fields and eating a high sucrose diet [5] The species name ferus, meaning wild, refers to their association with these animals.[5] More recently the strain has also been isolated from the nasal and oral cavities of pigs.[1] The species has not been identified in any other host organisms.

S. ferus are gram positive lanceolate coccobacillus[1] Non-motile and approximately 0.5 micrometers in diameter.[6] They are non-sporulating and catalase-negative[1] The majority of specimens test positive for the production of acetoin (Vogues-Proskauer reaction).[5] They occur singly, in pairs or in short chains.[5]

S. ferus is commensal in wild rats and pigs and demonstrates a relatively weak cariogenic potential compared to other streptococcus species such as S. mutans[7] S. ferus has not had any reported pathogenic instances in humans.[6]

S. ferus was originally proposed as a species in 1977 [5]

• Type strain of Streptococcus ferus at BacDive - the Bacterial Diversity Metadatabase