Emergence of Extended spectrum β-lactamase (ESBL) and carbapenemase producing Escherichia coli (E. coli) in mid-stream urine cultures of patients presenting in outpatient department of tertiary care hospital with uncomplicated cystitis (2016-2022): A retrospective analysis of Laboratory data

Abstract

Objective: To determine the prevalence of antimicrobial resistance (AMR) in E. coli isolated from urine cultures of patients with uncomplicated cystitis in Pakistan. Another objective was to analyze and compare the resistance rates of E. coli to specific antibiotics, conducting a year-by-year evaluation of these rates to identify trends and changes over the past seven years.

Methods: Retrospective analysis of susceptibility data of E. coli isolated from midstream urine culture samples of patients presenting in outpatient department with uncomplicated cystitis, from January 2016 to December 2022 in the section of Microbiology, Liaquat University of Medical and Health Sciences was done. All the demographic data, clinical information and susceptibility results were obtained from laboratory data base. All the cultures were performed on CLED agar and E. coli was identified using biochemical tests, susceptibility test was performed by disk diffusion method and clavulanate inhibition test for analysis of extended spectrum β-lactamase (ESBL) was performed.

Results: A total of 5169 patients with uncomplicated cystitis with no history of renal disease, pregnancy, hospitalization, catheterization and no elderly or pediatric population were included, 76% of which were of females. Mean age was 37 ±11 years Rising trends of resistance were observed in ampicillin (86.3%-95.3%), cotrimoxazole (12.8-48.6%), ciprofloxacin (57.3-81.6%) and low rates of resistance were seen in fosfomycin (0.57-2.96%), nitrofurantoin (0.72-2.96%) and amikacin (2.09-3.15%). Presence of ESBL and emerging resistance to ceftriaxone (15.7-48.7%), piperacillin/tazobactam (0-4.84%) and carbapenems (0-0.39%) was observed.

Conclusion: The national guidelines offer an empirical treatment regimen for patients with uncomplicated cystitis. However, regional variations in antimicrobial resistance (AMR) complicate adherence to these guidelines. Our study supports the use of fosfomycin and nitrofurantoin in management of uncomplicated cystitis, However, ongoing annual regional surveillance is essential to keep clinicians informed about the latest trends in AMR.

Keywords: Antimicrobial resistance; E. coli; Uncomplicated cystitis; Urinary tract Infection; empirical therapy.

Fig.1

Flowchart showing study design and selection of participants.

Fig.2

Increasing trend of ceftriaxone and carbapenem resistance over the period of 7 years.