Can urinary nitrites or other urinalysis findings be a predictor of bacterial resistance of uncomplicated urinary tract infections?

Background and objectivesTo evaluate whether initial urinalysis (UA) and urinary nitrite results can be used as a proxy for choosing empiric antibiotic therapy.Materials and methodsA retrospective study was conducted in an urban inner city community hospital in New York City (NYU Woodhull Medical Center). We reviewed the charts of patients seen in the Emergency Department and Pediatric Clinic who had a diagnosis of urinary tract infection (UTI) during a 3 year time period (January 2010–December 2012). Statistical analysis was performed using SPSS 20.0 statistical software.ResultsBetween January 2010 and December 2012, a total of 378 patients had a diagnosis of UTI. Seventy-five (19.8%) were males and 203 (80.2%) were females. Of the 378 patients with a diagnosis of UTI, the most common isolated pathogen was Escherichia coli, which was detected in 283 (74.9%) isolates. Other bacteria included Klebsiella spp 30 (7.9%), Proteus 21 (5.6%), Enterococcus 14 (3.7%), and others 30 (7.9%). The resistance rate was higher in the nitrite positive group for the following antibiotics: TMP/SMX and ampicillin with or without sulbactam. No significant correlation was found with the remaining studied antibiotics. No significant correlation was found between leukoesterase and the resistance patterns in all of the studied antibiotics, except cefazolin.ConclusionUrinary nitrite results are not helpful in choosing an initial antibiotic to treat a UTI. Leukocytosis in the blood or urine or the presence of a fever cannot be used to predict bacterial resistance. The use of nitrofurantoin or cephalexin for the treatment of cystitis was optimum, and in the presence of negative leukoesterase, nitrofurantoin was preferable to cephalexin.