[The bacteriological profile of bacteriuria in residents of a long-term geriatric facility].

Background: Little is known on the bacteriological profile of consecutive urine samples in elderly patients institutionalized in nursing homes.

Aim: This retrospective study aims to characterize urinary pathogens, rates of isolation of the same pathogen in subsequent urine samples and predicting factors associated with such repeated isolations. Data were retrospectively retrieved from medical charts of nursing home patients during a four-year period. The authors looked for changes in rates of positive cultures, changes in urine flora, in rates of repeated isolation of the same pathogens and the possible interrelations with the use of antibiotics.

Methods: A total number of 3229 urine cultures were studied, 1311 of which (43%) were positive and 493 out of these positive cultures (37.6%) were treated with antibiotics. The rates of positive cultures increased consistently during the study period (p=0.003). E. coli (68.1%), Klebsiella pneumoniae and Proteus mirabilis accounted for more than 90% of positive cultures.

Results: There was no difference with regard to pathogen types isolated from symptomatic or asymptomatic cases. The rates of recurrent bacteriuria, by the same pathogen isolated at baseline urine culture, were similar in treated and untreated cases. A regression analysis aiming to predict factors associated with subsequent positive cultures had negative results, except for cases of untreated bacteriuria with pseudomonas (CI 1.36-7.09, O.R. 3.11, p=0.006).

Conclusion: Our data support earlier studies underscoring the need to carefully consider the role of antibiotics and for better clinical guidelines for the treatment of bacteriuria in this population.