title: Comparison of community-acquired pneumonia due to methicillin-resistant and methicillin-susceptible Staphylococcus aureus producing the Panton-Valentine leukocidin.
abstract: OBJECTIVE
  To investigate the clinical features and prognosis of patients with methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) community-acquired pneumonia (CAP) producing the Panton-Valentine leukocidin (PVL).
  
  
  METHODS
  PubMed and Scopus were searched. Inclusion was stratified according to S. aureus susceptibility and clinical, microbiological and outcome data of patients with S. aureus CAP; both primary and secondary cases of CAP (hematogenous spread from other sites of infection) were included.
  
  
  RESULTS
  We identified 71 articles reporting data on patients with MRSA (n = 76) and MSSA (n = 31) PVL-positive CAP. There were no differences in demographics and history among patients with MRSA and MSSA CAP. Features associated with MRSA CAP were gastrointestinal tract symptoms (P = 0.016) and unilobar infiltrates (P = 0.043). Features associated with MSSA CAP were airway hemorrhage (P = 0.01), multilobar infiltrates (P = 0.043) and acute respiratory distress syndrome (ARDS, P = 0.023). Although MSSA patients were more likely to receive initial appropriate antimicrobial therapy (P < 0.001), there was no difference in mortality between the two groups (P = 0.919). Univariate analysis showed that influenza-like symptoms (P < 0.001), multi-organ failure (P < 0.001), admission to the intensive care unit (P < 0.001), mechanical ventilation (P < 0.001), leucopenia (P < 0.001), shock (P = 0.001), development of complications (P = 0.003), vein thrombosis (P < 0.001), disseminated intravascular coagulation (P = 0.03), acidosis (P = 0.012), rash (P = 0.024), ARDS (P = 0.021), necrotizing pneumonia (P = 0.026), and use of macrolides after culture results (P = 0.011) were factors associated with death.
  
  
  CONCLUSIONS
  Patients with MRSA PVL-positive CAP did not have higher rates of mortality than patients with MSSA PVL-positive CAP.
authors.affiliation: Alfa Institute of Biomedical Sciences, Athens, Greece.
authors.forename: K Z
authors.initials: KZ
authors.lastname: Vardakas
authors.forename: D K
authors.initials: DK
authors.lastname: Matthaiou
authors.forename: M E
authors.initials: ME
authors.lastname: Falagas
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001427:Bacterial Toxins / Q000378:metabolism*; D017714:Community-Acquired Infections / Q000188:drug therapy* / Q000382:microbiology / Q000401:mortality; D005098:Exotoxins / Q000378:metabolism*; D005260:Female; D006801:Humans; D007956:Leukocidins / Q000378:metabolism*; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D011023:Pneumonia, Staphylococcal / Q000188:drug therapy* / Q000382:microbiology / Q000401:mortality; D011379:Prognosis; D013211:Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D001427:Bacterial Toxins; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin