Vol 15, Issue 6, 2022 Online - 2455-3891 Print - 0974-2441 STUDY OF MAGNITUDE OF UTI CAUSED BY ESBL-PRODUCING ESCHERICHIA COLI AND ASSOCIATED RISK FACTORS ADYA CHATURVEDI 1 , BHAVNA GUPTA 2 , ASHUTOSH CHATURVEDI 3 , RASHMI SISODIYA 1 , RAJNI SHARMA 4 * ABSTRACT Objective: Globally, urinary tract infections (UTIs) caused by Escherichia coli that produce extended-spectrum lactamase (ESBL) have become more common. Our study determined the magnitude of UTI occurring due to ESBL-producing E. coli and associated risk factors. Different methods for their phenotypic detection were also compared. Methods: Uropathogenic E. coli isolated in significant numbers were assayed microbiologically. E. coli isolates (n=247) that were found significant in number tested for ESBL production using three different phenotypic methods: Phenotypic combined disk diffusion test (PCDDT), double-disk approximation test (DDAT), and E-test for ESBL production. An antibiotic susceptibility test was performed for different antibiotics. Various risk factors associated with UTIs were correlated with ESBL- and non-ESBL-producing E. coli. Results: We found that diabetes mellitus type 2 was the most common risk factor for UTI caused due to ESBL-producing E. coli (25%). Pregnant females and patients having recurrent UTI showed less positivity for ESBL production. DDAT detected 32 ESBL-positive isolates and PCDDT detected 37 positive isolates. E-test was taken as the gold standard for ESBL detection which detected 49 isolates as ESBL producers. The highest sensitivity (71.2%) and specificity (75%) were shown by PCDDT. Conclusion: According to the study conducted, it was concluded that PCDDT was the most reliable and economic method for phenotypic detection of ESBL. Keywords: UTI, Risk factors, ESBL, PCDDT, DDAT, E-test, Sensitivity, Specificity. INTRODUCTION Urinary tract infections (UTIs) are the most common of all the community- and hospital-acquired infections around the globe. The clinical pictures of UTI can range from asymptomatic bacteriuria to sepsis-induced severe pyelonephritis [1,2]. The primary pathogen causing UTI is Escherichia coli. Multidrug resistance is growing in isolates from community-onset and hospital-acquired illnesses, exacerbating the problem. Extended-spectrum lactamase (ESBL)-producing organisms from Enterobacteriaceae are now common in outdoor patients without recognized risk factors [3]. Therefore, the identification of ESBL- producing microorganisms has become a concerning issue for patients. Different phenotypic methods have been carried out to detect ESBL production by Enterobacteriaceae [4,5]. Therefore, a better perception of UTIs caused due to ESBL-positive E. coli will help physicians to choose suitable empirical therapy. Furthermore, it will lead clinicians to take measures to bring down risk factors for these resistant infections. This study was made to compare the phenotypic methods applied in most microbiological laboratories to discriminate between ESBL-positive and non-ESBL strains of E. coli. METHODS This study was done between October 2016 and September 2017 in cases of UTI caused by E. coli. Urine samples from clinically suspected UTI patients have been analyzed for significant bacteriuria. The urine samples received were cultured by semi-quantitative method on MacConkey agar and blood agar media by calibrated loop technique [6,7] and were incubated aerobically for 24 h at 37°C. The most common symptoms of UTIs include fever >38°C, higher frequency, suprapubic tenderness, urgency, or dysuria. A sample showing E. coli ≥10 5 CFU/ml was considered for the study [8]. Growth with three or more types of colonies in a sample was considered to be contamination and a repeat sample has been advised. Characteristics of UTI due to ESBL- and non-ESBL-producing E. coli have been collated demographically, associated with underlying diseases and risk factors for ESBL-producing E. coli were identified. The processed samples have been incubated and studied according to the standard laboratory protocol. Detection of ESBL The phenotypic combined disk diffusion test • A broth culture of the test strain with 0.5 McFarland opacity standard suspension has been plated on an MHA plate. • Cefotaxime (30 g) and cefotaxime plus clavulanic acid (30/10 g) and ceftazidime (30 g) and ceftazidime plus clavulanic acid (30/10 g) disks have been added to Mueller-Hinton agar plates and were incubated. The bacterium was classified as an ESBL producer by phenotypic combined disk diffusion test (PCDDT) if the inhibitory zone width of the clavulanate disk exceeded that of the antibiotic disk alone by 5 mm [9]. Double-disk approximation test (DDAT) Similarly, a broth culture of the test strain with 0.5 McFarland opacity standard suspension has been inoculated on a Mueller-Hinton agar plate [10]. • Amoxicillin/clavulanic acid (20/10 μg) and cefotaxime (30 μg) were placed at a distance of 15 mm and incubated. © 2022 The Authors. Published by Innovare Academic Sciences Pvt Ltd. This is an open access article under the CC BY license (http://creativecommons.org/ licenses/by/4.0/) DOI: http://dx.doi.org/10.22159/ajpcr.2022v15i6.43478. Journal homepage: https://innovareacademics.in/journals/index.php/ajpcr Research Article 1 Department of Zoology, University of Rajasthan, Jaipur, Rajasthan, India. 2 Department of Microbiology, Government Medical College, Kota, Rajasthan, India. 3 Department of Mahatma Gandhi Medical College, Jaipur, Rajasthan, India. 4 Department of Microbiology SMS Medical College, Jaipur, Rajasthan, India. Email: drrajnisharma02@gmail.com Received: 19 October 2021, Revised and Accepted: 15 April 2022