title: Severity of disease and clinical outcomes in patients with hospital-acquired pneumonia due to methicillin-resistant Staphylococcus aureus strains not influenced by the presence of the Panton-Valentine leukocidin gene.
abstract: BACKGROUND
  Patients with community-acquired pneumonia (CAP) infected with methicillin-resistant Staphylococcus aureus (MRSA) strains carrying the Panton-Valentine leukocidin (PVL) gene have severe clinical presentation and poor clinical outcomes. Antibiotics that suppress toxin production have been suggested for the management of these patients. The objective of this study was to compare the severity of disease and clinical outcomes of patients with hospital-acquired pneumonia/ventilator-associated pneumonia (HAP/VAP) infected with MRSA carrying the PVL gene with those patients infected with MRSA strains that do not carry the PVL gene.
  
  
  METHODS
  This was a multicenter observational study of patients with HAP and VAP. MRSA isolates were subjected to genetic analysis to define the presence of the PVL gene, the USA type and the staphylococcal cassette chromosome mec type. Severity of disease was evaluated with the Acute Physiology and Chronic Health Evaluation II (APACHE II) score. The primary clinical outcome was mortality at hospital discharge.
  
  
  RESULTS
  A total of 109 cases of MRSA HAP/VAP were evaluated. The incidence of PVL(+) MRSA was 27%. APACHE II score at diagnosis of HAP/VAP was 21 ± 8 for PVL(+) MRSA and 20 ± 6 for PVL(-) MRSA (P = .67). Mortality was 10% (3/29) for patients with PVL(+) MRSA versus 10% (8/80) for patients with PVL(-) MRSA (P > .99).
  
  
  CONCLUSIONS
  In patients with HAP or VAP due to MRSA, severity of disease and clinical outcomes are not influenced by the presence of the PVL gene. Therapeutic strategies directed to block PVL exotoxin may not impact outcomes in these patients.
authors: Division of Infectious Diseases, University of Louisville, Kentucky, USA.
authors: Paula
authors: P
authors: Peyrani
authors: Marty
authors: M
authors: Allen
authors: Timothy L
authors: TL
authors: Wiemken
authors: Nadia Z
authors: NZ
authors: Haque
authors: Marcus J
authors: MJ
authors: Zervos
authors: Kimbal D
authors: KD
authors: Ford
authors: Ernesto G
authors: EG
authors: Scerpella
authors: Julie E
authors: JE
authors: Mangino
authors: Daniel H
authors: DH
authors: Kett
authors: Julio A
authors: JA
authors: Ramirez
mesh_terms: D000368:Aged; D001427:Bacterial Toxins / Q000235:genetics*; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology* / Q000401:mortality; D005098:Exotoxins / Q000235:genetics*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D007956:Leukocidins / Q000235:genetics*; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics*; D008875:Middle Aged; D011023:Pneumonia, Staphylococcal / Q000453:epidemiology / Q000382:microbiology* / Q000401:mortality; D053717:Pneumonia, Ventilator-Associated / Q000453:epidemiology / Q000382:microbiology* / Q000401:mortality; D012720:Severity of Illness Index; D014481:United States / Q000453:epidemiology; D037521:Virulence Factors / Q000235:genetics
chemical_list: D001427:Bacterial Toxins; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin; D037521:Virulence Factors