Úlcera por pressão como reservatório e fonte de infecção de bacilos gram-negativo em pacientes internados em um hospital de nível terciário e em residentes de instituições de longa permanência para idosos

Abstract

Introduction: Pressure ulcers (PU) are common in hospitalized patients and residents of Long Term Care Facilities (LTCF) for elderly, are susceptible to colonization/infection by bacteria epidemiologically important and potential source of secondary bacteremia. Objectives: To evaluate the colonization of the PU as a reservoir and/or source of infection by gram-negative bacilli (GNB), and the risk of evolution to secondary infection of the bloodstream and colonization of the oropharyngeal mucosa by these bacteria in patients hospitalized in Hospital de Clinicas, Universidade Federal de Uberlandia and in residents of LTCF. Methods: The study was conducted at Clinical Hospital of Federal University of Uberlandia and three LTCF of city. The study desing was prospective cohort in different clinics of hospital and longitudinal, in the LTCF, both during the period August 2009 to July 2010. The PU were classified according to severity (stage I to IV) and the presence of local infection by evaluation of clinical signs and microscopic by positive evaluation of wound s smears, by ratio of inflammatory cells (polymorphonuclear leukocytes) to epithelial cells of 2:1 per field, after staining the smear from the ulcer Giemsa method. The surveillance was conducted via active monitoring with the volunteers until discharge or death. Individual records for demographic data, clinical and development was completed. The collections of PU stage II and mucosal oropharyngeal swabs were performed and we used the means of MacConkey Agar (for PU and oropharyngeal mucosa) and Mannitol Salt Agar (for PU) in primary culture identification of gender/species was performed by classical phenotypic tests and antimicrobial resistance profiles were determined by means of agar diffusion according to CLSI standards 2005/2009. Results: In total, the study included 60 in patients and 81 residents of LTCF. Volunteers from both groups were elderly, with prolonged hospitalization average of 103 days for patients 91 months and they are in the LTCF. The frequencies of participants with PU colonized by BGN were similar and high, 83.3% and 77.7% in the hospital and the LTCF, respectively, with a predominance of polymicrobial colonization in both institutions. Among the predominant microorganisms recovered from PU: Escherichia coli, Klebsiella pneumoniae, among microorganisms of the Enterobacteriaceae and Pseudomonas aeruginosa between BGN non-fermenting. The presence of multidrug resistance was observed at rates greater than 50.0% between samples isolated from the hospital as opposed to those derived from LTCF. The independent risk factor for patients with polymicrobial colonization with PU versus monomicrobial for GNB was the presence of clinical infection at another anatomic site (P = 0.03). Overall, among patients colonized with PU BGN, about one-third were infected and 62.5% of this group progressed to bacteremia by the same organism/resistance phenotype of those isolated from ulcers, with a significant mortality (100.0%) Unlike evidenced by the residents of LTCF. The frequencies of colonization of the oropharyngeal mucosa in both groups of volunteers were also similar, but lower than observed in the PU and detection of multiresistant GNB only in hospitalized patients. Conclusions: PU colonized/infected with multidrug-resistant GNB are an important reservoir of these bacteria in the hospital with minor risk of bacteremia and poor outcomes.