Antimicrobial susceptibility profiles of bacteria causing urinary tract infections in Mexico: Single-centre experience with 10 years of results.

OBJECTIVES: The aim of this retrospective study was to describe urinary tract infections (UTIs) diagnosed in a single centre in Mexico through 10 years of results, with a particular emphasis on the aetiology, patterns of antimicrobial susceptibility and incidence of extended-spectrum β-lactamase (ESBL)-producing strains.

METHODS: This study involved all urine samples analysed during the period March 2007 to September 2017 in a single centre in Mexico. Isolated uropathogens were identified to species level using routine laboratory methods, and antimicrobial susceptibility was determined by the disk diffusion method.

RESULTS: Overall, 859 urinary isolates were identified, including 582 (67.8%) Escherichia coli, 69 (8.0%) Enterococcus faecalis, 29 (3.4%) Klebsiella pneumoniae, 24 (2.8%) Proteus mirabilis, 24 (2.8%) Pseudomonas aeruginosa, 23 (2.7%) Candida albicans, 18 (2.1%) Streptococcus agalactiae and 10 (1.2%) Candida glabrata. Patient sex and age were the main risk factors associated with UTI in this population. Nitrofurantoin together with fosfomycin and amikacin had the highest percentages of susceptibility. Of the 859 isolates, 213 (24.8%) presented a positive double-disk synergy test indicating the presence of an ESBL phenotype, with E. coli showing a gradual increase in ESBL-producing isolates over time.

CONCLUSIONS: These results provide additional evidence in relation to the role of different bacterial species as aetiological agents of UTI as well as antimicrobial susceptibility information that will help to guide the selection of antimicrobial treatment for UTIs and the prevalence of ESBL-producing strains over a 10-year period in a Mexican centre.