Adjunctive Clindamycin Versus Linezolid for β-lactam Treated Patients With Invasive Group A Streptococcal Infections

Inclusion Criteria: * Adult inpatients patients (=\> 18 y of age) * Monomicrobial Group A streptococcus invasive infection * Primary therapy with a B-lactam agent (initiated before or on same day as adjunctive anti-toxin therapy) Exclusion Criteria: * Patients with a polymicrobial GAS culture (non-GAS organisms identified on eligibility GAS culture) * Patients who received linezolid but have a documented linezolid resistant isolate * Patients with GAS infections of non-sterile non-invasive sites (i.e sites which do not meet above mentioned inclusion criteria) which include but not limited to the lower urinary tract, upper respiratory tract * Patient with concomitant MSSA/MRSA invasive infection (+/- seven days of index GAS eligibility culture) * Patients who receive both anti-toxin agents (violation of protocol) * Patient who do not complete at least 3 days of B-lactam (violation of protocol)