Antimicrobial resistance and extended spectrum beta-lactamases in urinary tract infections: A serious problem in Northern Mexico

Abstract

Objective: To describe the causal agents, prevalence of antimicrobial resistance, and risk factors associated with extended spectrum beta-lactamase (ESBL)-producing agents in urinary tract infections (UTIs).
 Materials and methods: A retrospective study was conducted at a tertiary care hospital in Monterrey, Mexico. Inclusion criteria were patients that clinically presented with a UTI and had a positive urine culture, within the time frame of March to October 2017. The association with ESBL-producing agents was determined through the Χ2 test for categorical variables. Statistical significance was set at a p <0.05, utilizing SPSS version 20.0 software.
 Results: A total of 353 positive urine cultures were confirmed. ESBL production was found in 21.5% of the strains. There was a high level of resistance (>50%) to amoxicillin-clavulanate, ciprofloxacin, levofloxacin, fosfomycin, and trimethoprim-sulfamethoxazole and moderate resistance (10-50%) to gentamicin and ceftriaxone. Amikacin, ertapenem, nitrofurantoin, and colistin had the lowest resistance rates (<10%). The ESBL-producing agents were associated with complicated UTI (p≤0.0001). The comorbidities associated with ESBL-positive UTIs were diabetes mellitus (p=0.02) and immunodeficiency (p=0.008), as was having undergone radiotherapy (p=0.025) and previous antibiotic use (p≤0.001).
 Limitations: The clonal relationship of isolates, especially of E. coli, was not analyzed. We could not establish whether there was a high level of genetic diversity between the isolates or whether independent acquisition or cross-transmission occurred.
 Value: We evaluated the epidemiologic characteristics of the ESBL-producing agents in UTIs at a Mexican tertiary care hospital.
 Conclusions: One out of every five UTIs was caused by ESBLs in our study population. There was a high level of resistance to the antibiotics used as first-line empiric therapy in the patients studied.

What is the prognosis of emphysematous pyelonephritis associated with extended-spectrum beta-lactamases producing microorganisms?

“…Furthermore, they suggested that the use of gentamicin and fluoroquinolones should be avoided due to the high rates of resistance reported in this population [ 14 ]. The previous recommendations do not seem to be adequate for our population, since it was demonstrated in a previous study that the resistance rate to third generation cephalosporins was higher (48%) [ 9 ], and increased to 52.1% in patients with EPN. In our population, empirical use of carbapenems seems to be the treatment of choice, adjusting the treatment according to the resistance profile as soon as the sensitivity patterns are available.…”

“…In a previous study carried out in our center, it was determined that the rate of ESBL-producing microorganisms in non-gas-forming urinary tract infections was 21.5%, compared to 31.7% reported in EPN in the present study. Third generation cephalosporins, fluoroquinolones [ 8 ], and carbapenemics were reported with higher resistance rates between patients with EPN compared to non-gas-forming infections [ 9 ].…”

“…An increase has recently been observed in extended-spectrum beta-lactamase (ESBL) producing microorganisms in urinary tract infections. The production of ESBL confers to the bacteria a natural resistance to penicillins, cephalosporins, and aztreonam, limiting the therapeutic options for these infections [ 9 ]. Recent literature has focused on determining prognostic factors in EPN [ 6 , 10 ]; however, none of them considered the microbiological factors as predictors of clinical responses or outcomes.…”

Emergence of Fosfomycin Resistance by Plasmid-Mediated fos Genes in Uropathogenic ESBL-Producing E. coli Isolates in Mexico

“…Different studies in Mexico have assessed the fosfomycin resistance rates among uropathogenic E. coli strains [ 15 , 16 ]; however, none reported the molecular mechanism of resistance against this agent. Furthermore, information on the incidence of plasmid-mediated fosfomycin resistance in ESBL-producing E. coli strains isolated from urine is lacking in our country.…”