Staphylococcus schleiferi

Staphylococcus schleiferi is a Gram-positive, cocci-shaped bacterium of the family Staphylococcaceae. It is facultatively anaerobic, coagulase-variable, and can be readily cultured on blood agar where the bacterium tends to form opaque, non-pigmented colonies and beta (β) hemolysis. There exists two subspecies under the species S. schleiferi: Staphylococcus schleiferi subsp. schleiferi (coagulase negative) and Staphylococcus schleiferi subsp. coagulans (coagulase positive).

Staphylococcus schleiferi is commonly recognized as a veterinary pathogen affecting household pets, but has not been identified as a disease causing organism in large animals. S. schleiferi has been identified as a causative agent of conditions of Pyoderma, Otitis Externa, and Otitis media in both dogs and cats; although more commonly causing inflammatory conditions in dogs than in cats. Human infections have been described in some case reports, resulting in certain disease conditions including: surgical site infections, pediatric meningitis, endocarditis, and intravascular device-related bacteremia. Although both companion animals and humans can acquire disease from this organism, its zoonotic potential is not well understood. Antimicrobial therapy has been generally successful in treatment of infections, however, resistance to beta-lactam antibiotics have been reported, resulting in persistent infections for both humans and veterinary species.

Since its first description in 1988, little has been reported regarding the pathogenicity and virulence of Staphylococcus schleiferi. However, similarities with infections caused by Staphylococcus aureus suggest that the two species may also share similar determinants of virulence. Virulence factors associated with S. schleiferi have been identified to include the production of fatty acid modifying enzyme (FAME), biofilms, penicillin-binding protein 2a (PBP2a), as well as various enterotoxins and exoenzymes.

Staphylococcus schleiferi is differentiated from other Staphylococcal species based on their coagulation reaction, but because there is a coagulase positive and a coagulase negative subspecies of S. schleiferi, additional biochemical tests are required. These tests are often not done clinically as treatment is based on susceptibility testing and location of the infection.