Clinical and microbiological features of infections caused by Pseudomonas aeruginosa in patients hospitalized in intensive care units

Funda??o Amaz?nia Paraense de Amparo ? Pesquisa: 155/2012 Edital 61/2010. CAPES; Bolsa de demanda social. Programa de P?s-gradua??o em Biologia Parasit?ria na Amaz?nia da Universidade do Estado do Par? e Instituto Evandro Chagas/SVS/MS. Universidade Federal do Par?. N?cleo de Medicina Tropical. Programa de P?s-Gradua??o em Medicina Tropical. Bel?m, PA, Brasil. Minist?rio da Sa?de. Secretaria de Vigil?ncia em Sa?de. Instituto Evandro Chagas. Ananindeua, PA, Brasil. Universidade do Estado do Par?. Programa de P?s-Gradua??o em Biologia Parasit?ria na Amaz?nia. Bel?m, PA, Brasil. Universidade do Estado do Par?. Programa de P?s-Gradua??o em Biologia Parasit?ria na Amaz?nia. Bel?m, PA, Brasil. Universidade do Estado do Par?. Centro de Ci?ncias Biol?gicas e Sa?de. Bel?m, PA, Brasil. Minist?rio da Sa?de. Secretaria de Vigil?ncia em Sa?de. Instituto Evandro Chagas. Ananindeua, PA, Brasil / Universidade do Estado do Par?. Programa de P?s-Gradua??o em Biologia Parasit?ria na Amaz?nia. Bel?m, PA, Brasil. Introduction: The spread of multidrug-resistant Pseudomonas aeruginosa in Brazilian hospitals has greatly impacted upon the morbidity and mortality of individuals in intensive care units. Given the lack of information regarding the dynamics of multidrug resistance in northern Brazil, we analyzed the clinical and microbiological features of nosocomial infections caused by P. aeruginosa. Methods: Between January 2010 and March 2012, we conducted a retrospective cohort study of P. aeruginosa isolates from 54 patients who were hospitalized in intensive care units. The clinical and epidemiologic variables were analyzed, including the patients? demographic data and comorbidities, and the lengths of the intensive care unit stays, the classification of the infections as nosocomial, the use of invasive procedures, antimicrobial therapy, and the patients? outcomes. We undertook susceptibility tests, molecular detection of the metallo-?-lactamase genes, and genotypic analyses of the isolates using the repetitive element-polymerase chain reaction. Results: Multidrug resistance occurred most frequently among isolates from adults who had been hospitalized for an average of 87.1 days. The use of mechanical ventilation and urinary catheters were risk factors for infection. The four isolates that harbored the blaSPM-1-like gene showed >95% genetic similarity. Conclusions: This study?s findings show that P. aeruginosa has a high death rate, and that inadequate treatment and invasive procedures are risk factors for infection. This is the first report describing the detection of the blaSPM-1-like gene in northern Brazil. These results highlight the need for better monitoring and a greater understanding of nosocomial infections and their public health impacts.