@article{TEXTUAL,
      recid = {8427},
      author = {David, Michael Z. and Boyle-Vavra, Susan and Zychowski,  Diana L. and Daum, Robert S.},
      title = {Methicillin-Susceptible &amp;lt;i&amp;gt;Staphylococcus  aureus&amp;lt;/i&amp;gt; as a Predominantly Healthcare-Associated  Pathogen: A Possible Reversal of Roles?},
      journal = {PLOS ONE},
      address = {2011-04-13},
      number = {TEXTUAL},
      abstract = {&lt;p&gt;Background: Methicillin-resistant &lt;em&gt;Staphylococcus  aureus&lt;/em&gt; (MRSA) strains have become common causes of  skin and soft tissue infections (SSTI) among previously  healthy people, a role of methicillin-susceptible (MSSA)  isolates before the mid-1990s. We hypothesized that, as  MRSA infections became more common among &lt;em&gt;S. aureus&lt;/em&gt;  infections in the community, perhaps MSSA infections had  become more important as a cause of healthcare-associated  infection.&lt;/p&gt;&lt;p&gt;Methods: We compared patients, including  children and adults, with MRSA and MSSA infections at the  University of Chicago Medical Center (UCMC) from all  clinical units from July 1, 2004-June 30, 2005; we also  compared the genotypes of the MRSA and MSSA infecting  bacterial strains.&lt;/p&gt;&lt;p&gt;Results: Compared with MRSA  patients, MSSA patients were more likely on bivariate  analysis to have bacteremia, endocarditis, or sepsis  (&lt;em&gt;p&lt;/em&gt; = 0.03), to be an adult (&lt;em&gt;p&lt;/em&gt; = 0.005),  to be in the intensive care unit (21.9% vs. 15.6%) or  another inpatient unit (45.6% vs. 40.7%) at the time of  culture. MRSA (346/545) and MSSA (76/114) patients did not  differ significantly in the proportion classified as  HA-&lt;em&gt;S. aureus&lt;/em&gt; by the CDC CA-MRSA definition  (&lt;em&gt;p&lt;/em&gt; = 0.5). The genetic backgrounds of MRSA and  MSSA multilocus sequence type (ST) 1, ST5, ST8, ST30, and  ST59 comprised in combination 94.5% of MRSA isolates and  50.9% of MSSA isolates. By logistic regression, being cared  for in the Emergency Department (OR 4.6, CI 1.5-14.0,  &lt;em&gt;p&lt;/em&gt; = 0.008) was associated with MRSA  infection.&lt;/p&gt;&lt;p&gt;Conclusion: Patients with MSSA at UCMC  have characteristics consistent with a  health-care-associated infection more often than do  patients with MRSA; a possible role reversal has occurred  for MSSA and MRSA strains. Clinical MSSA and MRSA strains  shared genotype backgrounds.&lt;/p&gt;},
      url = {http://knowledge.uchicago.edu/record/8427},
}