[Risk factors of nosocomial infections caused by piperacillin-tazobactam resistant Pseudomonas aeruginosa].

Introduction. Pseudomonas aeruginosa is a common cause of serious infections in hospitalized patients and is associated with high rates of hospital morbidity and mortality. Objective. The aim of this study was to identify the risk factors of nosocomial infections caused by piperacillin­tazobactam­ resistant P. aeruginosa (PT­RPA). Methods. A case­control study was conducted in the Clinical Centre Kragujevac from January 2010 to December 2011. Results. In the observed period, 79 (38.16%) patients had PT­ RPA infections, while 128 (61.84%) patients had infections caused by piperacillin­tazobactam­sensitive P. aeruginosa (PT­SPA). Pneumonia was more frequently found in the PT­RPA group (55.70%) (p<0.05), whereas urinary tract infections were more frequent in the group of patients with PT­SPA infections (26.56%) (p<0.01). Multivariate analysis was used to identify an injury on admission (OR=3.089; 95%CI=1.438­6.635; p=0.004), administration of imipenem (OR=15.027; 95%CI=1.778­ 127.021; p=0.013), meropenem (OR=2.618; 95%CI=1.030­ 6.653; p=0.043), ciprofloxacin (OR=3.380; 95%CI=1.412­8.090; p=0.006), vancomycin (OR=4.294; 95%CI=1.477­12.479; p=0.007), piperacillin­tazobactam (OR=4.047; 95%CI=1.395­11.742; p=0. 010) as independent risk factors associated with PT­RPA infection. Conclusion. In hospitalized patients, the risk of PT­RPA infections is associated with previous administration of imipenem, meropenem, ciprofloxacin, vancomycin, piperacillin­tazobactam, and the presence of injury on admission.