Impact of Multidrug Resistance on Experimental Empyema by Pseudomonas aeruginosa

Background: Pseudomonas aeruginosa is a cause of infections of the lower respiratory tract among patients with chronic lung disorders. It is questionable whether virulence of this species may be influenced by multidrug resistance (MDR). Objectives: To define the impact of MDR in experimental lung infection. Methods: Experimental empyema was induced in rabbits by MDR (group A, n = 16) and by susceptible isolates (group B, n = 10). Pleural fluid was sampled for quantitative culture and estimation of cell apoptosis and of tumor necrosis factor-alpha (TNF ) and malondialdehyde (MDA). Survival was recorded. Cytokine production was stimulated in U937 monocytes by samples of pleural fluid. Whole blood of rabbits was incubated with the isolates; induction of apoptosis was assessed. Results: Survival of group A was prolonged compared to group B. This was accompanied by lower bacterial counts of the inoculated pathogens in pleural fluid and in the lungs of group A compared with group B. Early apoptosis of neutrophils of pleural fluid of group A was lower compared with group B. Pleural Received: September 4, 2010 Accepted after revision: February 14, 2011 Published online: April 28, 2011 E.J. Giamarellos-Bourboulis, MD, PhD 4th Department of Internal Medicine Attikon University Hospital 1 Rimini Str., GR–12462 Athens (Greece) Tel. +30 210 5831 994, E-Mail giamarel @ ath.forthnet.gr © 2011 S. Karger AG, Basel 0025–7931/11/0821–0046$38.00/0 Accessible online at: www.karger.com/res D ow nl oa de d by : 54 .7 0. 40 .1 1 11 /1 9/ 20 17 2 :3 1: 34 P M