Reappearance and treatment of penicillin-susceptible Staphylococcus aureus in a tertiary medical centre.

OBJECTIVES: The purpose of this study was to describe trends in the prevalence and treatment patterns of penicillin-susceptible Staphylococcus aureus (SA) infections. METHODS: This was a cross-sectional study of MSSA isolates from blood cultures at a tertiary-care centre between 1 January 2003 and 31 December 2012. All blood cultures positive for MSSA drawn during the study period were used to calculate the prevalence of penicillin-susceptible SA. Repeat cultures were excluded if they were isolated within 6 weeks of the index culture. The analysis was then restricted to inpatient blood cultures to assess treatment patterns. Antibiotics administered 48-96 h after the culture were analysed. RESULTS: A total of 446 blood cultures positive for MSSA were included in the analysis. There was a distinct trend showing an increase in the percentage of penicillin-susceptible SA over 10 years from 13.2% (95% CI 4.1%-22.3%) in 2003 to 32.4% (95% CI 17.3%-47.5%) in 2012 (P trend <0.001). During the study period, penicillin use for penicillin-susceptible SA bacteraemia increased from 0.0% in 2003-04 to 50.0% in 2011-12 (P trend = 0.007). CONCLUSIONS: Over a decade, there was an ∼3-fold increase in penicillin susceptibility among MSSA blood cultures at a large tertiary-care facility. Although treatment with penicillin increased over the study period, only 50% of penicillin-susceptible SA was treated with penicillin in the final study period. This study suggests that while susceptibility to penicillin appears to be returning in SA, the use of penicillin for penicillin-susceptible SA bacteraemia is low.

Clinical experience with daptomycin for outpatient parenteral antibiotic therapy.

The investigation reviewed the experience of a single institution using outpatient parenteral antibiotic therapy with daptomycin as monotherapy. After institutional review board approval, patients discharged from Baystate Medical Center on daptomycin as monotherapy were investigated for clinical outcome. The authors present their data descriptively comparing the success rates of daptomycin therapy according to clinical factors. Thirty-three persons were included, and all of them survived during the therapy. All patients received 6 to 8 mg/kg/day of daptomycin administered over 30 minutes, were treated between 2 to 8 weeks and received 74% to 90% of therapy after hospital discharge. Ninety-four percent of patients studied were clinically cured. Thirty-three percent of patients with osteomyelitis required surgery for cure, but all successfully completed treatment. Twelve percent had complications that did not alter treatment course. No elevations of creatine phosphokinase were noted; however, this was inconsistently checked. These results indicate that outpatient parenteral antibiotic therapy using daptomycin is a suitable agent for patients with selected Gram-positive bacterial infections. After a relatively brief hospitalization, the majority of patients can complete at least three fourths of total treatment duration outside of the hospital.

Management of infective endocarditis in outpatients: clinical experience with outpatient parenteral antibiotic therapy.

BACKGROUND: There is limited experience in treating infective endocarditis (IE) with outpatient parenteral antibiotic therapy (OPAT). METHODS: Following institutional review board (IRB) approval, patients discharged from Baystate Medical Center with IE documented by modified Duke criteria treated with OPAT were identified. Data obtained included organisms implicated, indications of clinical stability, percentage of total therapy rendered after hospitalization, and one year follow up. RESULTS: Forty-three patients met criteria. Thirty-five percent were infected with staphylococci; 38% harbored streptococci or enterococci. Native valves and left-sided valves each constituted approximately 75% of total. All patients received >4 weeks of therapy, with >66% rendered after hospital discharge A median of 7 days of hemodynamic stability and negative blood cultures occurred prior to discharge. After one year, no patients died from IE. Twenty-three percent were hospitalized during OPAT from intravenous catheter, antibiotic, or other complications, but none for direct complications of IE. CONCLUSIONS: OPAT for IE can be safely utilized, and at least 66% of care can be given in this manner. Our investigation provides enhanced data on employing OPAT for IE caused by staphylococci, left-sided infections, and also provides outcomes after one year after treatment.