Staphylococci: identification methods

Staphylococci, including Staphylococcus aureus and Coagulase Negative Staphylococci (CoNS) are Gram positive cocci that form irregular grape-like clusters. They arenormal commensals of the skin and mucus membranes and are increasingly being known as opportunistic pathogens causing hospital and community acquired infections. S. aureus is the most common cause ofwound infections, whereas CoNSis the most common in nosocomial blood streaminfections.Rapid and efficient identification of Staphylococci is important for correct management of patients with staphylococcal infections. The development of reliable, simple, and low-cost procedures is essen tial for identifying outbreaks and new strains of Staphylococci.In recent years, the research toolbox has significantly expanded, providing a large collection of different commercial sys tems for the identification of Staphylococci as an alternative to biochemical identification methods. Automated systems and phenotypic tests are widely used today both, in microbiology laboratories. However, these diagnostic systems have some disadvantages such as their high cost. In addition, they are unable to reliably distinguish between dif ferent staphylococcal species due to the variable expression of phenotypic characteristics.In the present discussion, the different identification methods of Staphylococci are reviewed.