NIH-Funded Researchers Find Off-Patent Antibiotics Effectively Combat MRSA Skin Infections

March 19, 2015
Researchers funded by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, have found that two common antibiotic treatments work equally well against bacterial skin infections caused by methicillin-resistant Staphylococcus aureus (MRSA) acquired outside of hospital settings. Known as community-associated MRSA, or CA-MRSA, these skin infections have been reported in athletes, daycare-age children, students, military personnel and prison inmates, among others, and can lead to hospitalization, surgical procedures, bacteria in the blood, and in severe cases, death.
Although MRSA is an increasingly common pathogen and the most common cause of skin infection in the United States, there is no standard treatment approach for CA-MRSA. As CA-MRSA emerged in community settings, there were concerns about how to identify the best treatment options and preserve the effectiveness of last-line drugs. Two older antibiotics that are no longer under patent, clindamycin and TMP-SMX, are recommended to treat CA-MRSA. It was unknown whether one antibiotic was associated with better outcomes in patients.
To answer this question, scientists tested clindamycin and TMP-SMX in adults and children with uncomplicated skin infections for 10 days. Of 466 study participants who received either antibiotic, the cure rate was 89.5 percent for clindamycin and 88.2 percent for TMP-SMX. The side effects of both drugs were comparable. The findings, which appear in The New England Journal of Medicine, suggest that uncomplicated skin infectious acquired outside of hospitals can be treated inexpensively and successfully with either drug, according to the researchers.
This project is one of multiple clinical trials NIAID began funding in 2007 aimed at identifying ways to reduce the risk of antimicrobial resistance by reducing and/or optimizing the use of licensed antibacterials. This study is being led by Dr. Henry F. Chambers of the University of California, San Francisco.
LG Miller et al. Clindamycin versus Co-trimoxazole for Uncomplicated Skin Infections. New England Journal of Medicine DOI: 10.1056/NEJMoa1403789 (2015).
NIAID Director Anthony S. Fauci, M.D., and Dennis Dixon, M.D., chief of the Bacteriology and Mycology Branch (BMB) in NIAID's Division of Microbiology and Infectious Diseases, are available to comment on this study.

Content last reviewed on March 19, 2015