Increasing resistance in community-acquired urinary tract infections in Latin America, five years after the implementation of national therapeutic guidelines

Summary 

Background

The worldwide increasing resistance to antibiotics has complicated antimicrobial treatment of urinary tract infections (UTIs), especially in Latin America. This study aimed to report the present etiology and antimicrobial susceptibility of UTIs, and the effects of the national guidelines for UTIs introduced in 2003.

Methods

Urine samples were collected from 304 patients with a clinical suspicion of UTI at the university hospital and primary health centers of León, Nicaragua. When bacterial growth was reported, antimicrobial susceptibility tests for nine frequently used antibiotics were performed.

Results

Ninety-one (29.9%) patients had a positive urine culture. The most frequently isolated microorganisms were Escherichia coli (n=44), Serratia spp (n=11), and Escherichia fergusonii (n=10). High resistance rates were observed in E. coli to ampicillin (61.4%), cefalothin (45.5%), trimethoprim–sulfamethoxazole (38.6%), ciprofloxacin (31.8%), and ceftriaxone (20.5%). Amikacin and nitrofurantoin were the only drugs to which >90% of E. coli were susceptible. E. fergusonii and Serratia spp showed comparable high resistance patterns. Thirteen strains (29.5%) of E. coli were suspected to produce extended-spectrum beta-lactamase (ESBL).

Conclusions

Resistance rates in community-acquired UTIs in Nicaragua are increasing. The introduction of therapeutic guidelines with ceftriaxone recommended for upper UTIs and nitrofurantoin for lower UTIs, has led to increasing resistance against both antibiotics. The emergence of ESBL-producing E. coli is worrisome, along with the appearance of Serratia spp in the population.

Keywords: Urinary tract infections, Resistance, Antibiotics, Extended-spectrum beta-lactamase, Epidemiology