Optimizing delivery of care for patients with MRSA infection: focus on transitions of care

Current and future trends in antibiotic therapy of acute bacterial skin and skin-structure infections

In 2013 the US Food and Drug Administration (FDA) issued recommendations and guidance on developing drugs for treatment of skin infection using a new definition of acute bacterial skin and skin-structure infection (ABSSSI). The new classification includes cellulitis, erysipelas, major skin abscesses and wound infection with a considerable extension of skin involvement, clearly referring to a severe subset of skin infections. The main goal of the FDA was to better identify specific infections where the advantages of a new antibiotic could be precisely estimated through quantifiable parameters, such as improvement of the lesion size and of systemic signs of infection. Before the spread and diffusion of methicillin-resistant Staphylococcus aureus (MRSA) in skin infections, antibiotic therapy was relatively straightforward. Using an empiric approach, a β-lactam was the preferred therapy and cultures from patients were rarely obtained. With the emergence of MRSA in the community setting, initial ABSSSI management has been changed and readdressed. Dalbavancin, oritavancin and tedizolid are new drugs, approved or in development for ABSSSI treatment, that also proved to be efficient against MRSA. Dalbavancin and oritavancin have a long half-life and can be dosed less frequently. This in turn makes it possible to treat patients with ABSSSI in an outpatient setting, avoiding hospitalization or potentially allowing earlier discharge, without compromising efficacy. In conclusion, characteristics of long-acting antibiotics could represent an opportunity for the management of ABSSSI and could profoundly modify the management of these infections by reducing or in some cases eliminating both costs and risks of hospitalization.

Hospitalist perspective on the treatment of skin and soft tissue infections

The prevalence of skin and soft tissue infections (SSTIs) has been increasing in the United States. These infections are associated with an increase in hospital admissions. Hospitalists play an increasingly important role in the management of these infections and need to use hospital resources efficiently and effectively. When available, observation units are useful for treating low-risk patients who do not require hospital admission. Imaging tools may help to exclude abscesses and necrotizing soft tissue infections; however, surgical exploration remains the principal means of diagnosing necrotizing soft tissue infections. The most common pathogens that cause SSTIs are streptococci and Staphylococcus aureus. Methicillin-resistant S aureus (MRSA) is a prevalent pathogen, and concerns are increasing regarding the unclear distinctions between community-acquired and hospital-acquired MRSA. Other less frequent pathogens that cause SSTIs include Enterococcus species, Escherichia coli, Klebsiella species, Enterobacter species, and Pseudomonas aeruginosa. Cephalexin and clindamycin are suitable options for infections caused by streptococcal species and methicillin-susceptible S aureus. The increasing resistance of S aureus and Streptococcus pyogenes to erythromycin limits its use in these infections, and better alternatives are available. Parenteral cefazolin, nafcillin, or oxacillin can be used in hospitalized patients with nonpurulent cellulitis caused by streptococci and methicillin-susceptible S aureus. When oral MRSA therapy is indicated, clindamycin, doxycycline, trimethoprim-sulfamethoxazole, or linezolid is appropriate. Vancomycin, linezolid, daptomycin, tigecycline, telavancin, and ceftaroline fosamil are intravenous options that should be used in MRSA infections that require patient hospitalization. In the treatment of patients with SSTIs, hospitalists are at the forefront of providing proper patient care that reduces hospital costs, duration of therapy, and therapeutic failures. This review updates guidelines on the management of SSTIs with a focus on infections caused by S aureus, particularly MRSA, and outlines the role of the hospitalist in the effective management of SSTIs.

Changes in Staphylococcus aureus susceptibility across Latin America between 2004 and 2010

The Tigecycline Evaluation and Surveillance Trial is a global surveillance study monitoring the efficacy of tigecycline and comparators against clinically important pathogens. Between 2004 and 2010, 3126 isolates of Staphylococcus aureus were collected from 66 centers in 13 countries in Latin America; of these, 1467 (46.9%) were resistant to methicillin. The main contributors of S. aureus isolates were Mexico (n = 846), Argentina (n = 740), and Colombia (n = 445). The methicillin-resistant S. aureus rate was greater than 50% in five countries, the highest reported in Puerto Rico (73.9%). Methicillin-resistant S. aureus rates across Latin America ranged from 40.1% to 50.6% over the study period. All S. aureus isolates were susceptible to linezolid and vancomycin, while 100% of methicillin-susceptible S. aureus isolates and 99.8% of methicillin-resistant S. aureus isolates were susceptible to tigecycline. Both methicillin-susceptible S. aureus and methicillin-resistant S. aureus were highly susceptible to minocycline (99.2% and 97.0%, respectively). Latin American methicillin-susceptible S. aureus were highly susceptible to levofloxacin (94.6%) while only 16.2% of methicillin-resistant S. aureus were levofloxacin-susceptible. This study shows that linezolid, vancomycin, and tigecycline are all highly active against S. aureus from Latin America, regardless of methicillin resistance.