Human infections caused by Streptococcus canis. A case series and description of a zoonotic infection in a northern Spain university hospital.

Streptococcus canis is a β-hemolytic streptococcus first described in 1986. It belongs to Lancefield's group G and is part of the commensal flora of the skin and mucosa of the urinary, gastrointestinal and reproductive tract, mainly in dogs and cats. The first human infection by this microorganism was described in 1997 in a patient with sepsis. We conducted a retrospective descriptive study by reviewing medical records of all patients presenting with a positive culture of S. canis between December 2017 and June 2022, both as a pure culture and accompanied by other microorganisms. Thirty-nine patients (18 males and 21 females) with a mean of 51.2 years and median of 51 years (range, 5 to 90 years) were included. This series demonstrates the ability of S. canis to produce serious infections in humans.