MRSA prevalence rises at outpatient derm clinic

Relative proportions of methicillin-resistant Staphylococcus aureus (MRSA) in the S. aureus isolates rose by 17 percent in three years at an outpatient dermatology clinic, and methicillin-sensitive S. aureus (MSSA) increased its antibiotic resistance during that time, results of a recent study indicate.

Investigators from the University of Miami collected retrospective observational data from skin culture isolates each year from January 2005 to December 2010, and monthly from Jan. 1, 2011 to June 30, 2011, from an outpatient dermatology clinic at University of Miami Hospital, according to the study abstract.

Researchers analyzed 387 S. aureus isolates and then measured the relative proportions of MRSA and MSSA as well as antibiotic sensitivity profiles. From January 2008 through December 2010, the relative proportion of MRSA was significantly higher than the proportion from January 2005 through December 2007, researchers found (45.3 versus 28.3 percent, P=0.001).

“Despite this increase, MRSA became more sensitive to ciprofloxacin, while MSSA demonstrated increased antibiotic resistance to ciprofloxacin, clindamycin, gentamicin and trimethoprim-sulfamethoxazole,” study authors wrote.

The findings were published online Jan. 16 in JAMA Dermatology.