Introduction: Since 2007 the Galician Surveillance Program on Antimicrobial Resistance has been collected data of Staphylococcus aureus susceptibility patterns. The data from 2007 to 2012 have been analyzed and are reported.
Methods: A total of 4,577 different isolates of S. aureus from cerebrospinal fluid and blood cultures were included. The Institutions involved provided the information about the susceptibility patterns, the assay methods used and the interpretative guidelines followed, and demographic data of patients.
Results: The rate of methicillin-resistance S. aureus (MRSA) was 22% in 2007-2010 and 26% in 2011-2012, although in some areas the percentage reached 57% (2007- 2010) or 66% (2011-2012). The higher rates of resistance were found in patients older than 75 years. Gentamycin resistance was less than 9% and for quinolones were about 25%. A strong association between methicillin and quinolone-resistance were observed (91%). The resistance against linezolid and glycopeptides were exceptional.
Conclusions: The percentage of MRSA has evolved slightly along the period of this study reaching no significant differences between Galicia and the global data in Spain in 2012. Nevertheless, there are significant differences among the geographic areas studied. Most MRSA isolates were recovered from hospitalized patients, but an increase in the number of MRSA among outpatients was observed, while old patients from nursing homes are included in the outpatient group, so the MRSA rate in this group could be overestimated.