Carlos M Luna1, Didier A Bruno2, Joaquín García-Morato3, Keli C Mann4, Juan Risso Patrón2, Judith Sagardía3, Rubén Absi5, Milagros García Bottino5, Diana Marchetti5, Angela Famiglietti5, Mónica Baleztena6, Cesar Biancolini3. 1. Department of Medicine, Universidad de Buenos Aires, Buenos Aires, Argentina. Electronic address: cymluna@advancedsl.com.ar. 2. Department of Medicine, Universidad de Buenos Aires, Buenos Aires, Argentina. 3. Experimental Surgery University Center, Universidad de Buenos Aires, Buenos Aires, Argentina. 4. Department of Pulmonary Medicine, Universidade Federal do Rio Grande Do Sul, Porto Alegre, Brazil. 5. Hospital de Clínicas, and the Facultad de Farmacia y Bioguímica, Universidad de Buenos Aires, Buenos Aires, Argentina. 6. Department of Pathology, Universidad de Buenos Aires, Buenos Aires, Argentina.
Abstract
OBJECTIVES: To investigate if compared with glycopeptides, antimicrobial therapy (AMT) with linezolid (LZD) improves the outcome in methicillin-resistant Staphylococcus aureus (MRSA) experimental pneumonia in mechanically ventilated piglets. METHODS: The MRSA minimal inhibitory concentration (MIC) was 0.5 for vancomycin (VAN), 0.25 for teicoplanin (TEI), and 2.0 microg/mL for LZD was inoculated in Largewhite-Landrace piglets divided into five groups. One group (n = 6) did not receive mechanical ventilation (MV) or AMT. Those in the remaining groups received MV and VAN (n = 9), TEI (n = 7), LZD (n = 9), or no AMT (n = 7). Plasma and BAL tumor necrosis factor-alpha, interleukin-6, and C-reactive protein (CRP) concentrations, postmortem lung pathology, cultures (lung, blood, and BAL) and plasma, epithelial lining fluid (ELF), and lung antibiotic concentrations were evaluated. MEASUREMENTS AND MAIN RESULTS: All piglets developed severe pneumonia; lung pathology score was lower in those receiving LZD vs those receiving glycopeptides (p = 0.049) or no AMT (p = 0.037). Serum CRP and serum and BAL cytokines increased; there were no differences between the groups. Fourteen died spontaneously at 44.4 +/- 16.8 h; the remaining 24 were killed after 72 to 96 h. The concentrations of the antimicrobial agents tested in 15 piglets were higher than the MIC for the three antimicrobial agents in peak and trough plasma, ELF, and lung specimens. Survival at 72 h was higher in the LZD comparing with the no-AMT group. CONCLUSIONS: Inoculation produced severe MRSA pneumonia. LZD AMT was associated with lower pathology score, better survival, and a trend to better clearance of MRSA, not attributable exclusively to pharmacokinetic or pharmacodynamic reasons.
OBJECTIVES: To investigate if compared with glycopeptides, antimicrobial therapy (AMT) with linezolid (LZD) improves the outcome in methicillin-resistant Staphylococcus aureus (MRSA) experimental pneumonia in mechanically ventilated piglets. METHODS: The MRSA minimal inhibitory concentration (MIC) was 0.5 for vancomycin (VAN), 0.25 for teicoplanin (TEI), and 2.0 microg/mL for LZD was inoculated in Largewhite-Landrace piglets divided into five groups. One group (n = 6) did not receive mechanical ventilation (MV) or AMT. Those in the remaining groups received MV and VAN (n = 9), TEI (n = 7), LZD (n = 9), or no AMT (n = 7). Plasma and BAL tumor necrosis factor-alpha, interleukin-6, and C-reactive protein (CRP) concentrations, postmortem lung pathology, cultures (lung, blood, and BAL) and plasma, epithelial lining fluid (ELF), and lung antibiotic concentrations were evaluated. MEASUREMENTS AND MAIN RESULTS: All piglets developed severe pneumonia; lung pathology score was lower in those receiving LZD vs those receiving glycopeptides (p = 0.049) or no AMT (p = 0.037). Serum CRP and serum and BAL cytokines increased; there were no differences between the groups. Fourteen died spontaneously at 44.4 +/- 16.8 h; the remaining 24 were killed after 72 to 96 h. The concentrations of the antimicrobial agents tested in 15 piglets were higher than the MIC for the three antimicrobial agents in peak and trough plasma, ELF, and lung specimens. Survival at 72 h was higher in the LZD comparing with the no-AMT group. CONCLUSIONS: Inoculation produced severe MRSA pneumonia. LZD AMT was associated with lower pathology score, better survival, and a trend to better clearance of MRSA, not attributable exclusively to pharmacokinetic or pharmacodynamic reasons.
Authors: Alexander J Lepak; Karen Marchillo; Solen Pichereau; William A Craig; David R Andes Journal: Antimicrob Agents Chemother Date: 2012-09-10 Impact factor: 5.191