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The Scientific World Journal
Volume 2012, Article ID 349597, 6 pages
Research Article

Gender and Age-Dependent Etiology of Community-Acquired Urinary Tract Infections

1Bacteriological Laboratory, Centro Diagnostico Italiano, Via Saint Bon 20, 20147 Milan, Italy
2Department of Public Health, Microbiology and Virology, University of Milan, Via Pascal 36, 20166 Milan, Italy
3Department of Clinical and Preventive Medicine, University of Milano-Bicocca, Via Cadore 48, 20052 Monza, Italy

Received 31 October 2011; Accepted 28 December 2011

Academic Editors: A. I. El Sakka and R. Gonzalez

Copyright © 2012 Enrico Magliano et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Urinary tract infections (UTIs) are among the most frequent community-acquired infections worldwide. Escherichia coli is the most common UTI pathogen although underlying host factors such as patients’ age and gender may influence prevalence of causative agents. In this study, 61 273 consecutive urine samples received over a 22-month period from outpatients clinics of an urban area of north Italy underwent microbiological culture with subsequent bacterial identification and antimicrobial susceptibility testing of positive samples. A total of 13 820 uropathogens were isolated and their prevalence analyzed according to patient’s gender and age group. Overall Escherichia coli accounted for 67.6% of all isolates, followed by Klebsiella pneumoniae (8.8%), Enterococcus faecalis (6.3%), Proteus mirabilis (5.2%), and Pseudomonas aeruginosa (2.5%). Data stratification according to both age and gender showed E. coli isolation rates to be lower in both males aged ≥60 years (52.2%), E. faecalis and P. aeruginosa being more prevalent in this group (11.6% and 7.8%, resp.), as well as in those aged ≤14 years (51.3%) in whom P. mirabilis prevalence was found to be as high as 21.2%. Streptococcus agalactiae overall prevalence was found to be 2.3% although it was shown to occur most frequently in women aged between 15 and 59 years (4.1%). Susceptibility of E. coli to oral antimicrobial agents was demonstrated to be as follows: fosfomycin (72.9%), trimethoprim/sulfamethoxazole (72.9%), ciprofloxacin (76.8%), ampicillin (48.0%), and amoxicillin/clavulanate (77.5%). In conclusion, both patients’ age and gender are significant factors in determining UTIs etiology; they can increase accuracy in defining the causative uropathogen as well as providing useful guidance to empiric treatment.