Abstract
Recent reports suggest that methicillin-resistant
Staphylococcus aureus
(MRSA) may be emerging as a community pathogen. In Portuguese hospitals, the incidence of MRSA among disease causing isolates
is extremely high (48-50%). To determine the prevalence of MRSA in the Portuguese community, nasal samples were obtained from 823 draftees, 484 nonmedical university students, and 107 high-school students.
In addition, throat samples were obtained from the 823 draftees and
S. aureus
isolates were also recovered from 283 (13%) nasopharyngeal samples obtained from 2,111 children attending day-care centers.
The rate of nasal colonization of
S. aureus
was 34%, 25%, and 46% for draftees, nonmedical university students, and high-school students, respectively. The rate of pharyngeal colonization of the
draftees was 33%. Of the 1,001
S. aureus
isolates obtained, seven were MRSA and eight were borderline oxacillin-resistant
S. aureus
(BORSA). By molecular typing techniques, five of the seven
MRSA were identified as belonging to one of three highly epidemic clones, the Brazilian, Iberian, and Pediatric clones of MRSA, which were identified as endemic in Portuguese hospitals. The eight BORSA
were all members of clones previously identified in international samples. In spite of the extremely high prevalence of MRSA in Portuguese hospitals, the carriage rate of MRSA in healthy and young individuals
remains low.