Prevalence of Multi-Antibiotic Resistance marA and Quorum Sensing luxS Genes and Evaluation of Biofilm Formation in Uropathogenic Escherichia coli

Abstract

Uropathogenic Escherichia coli (UPEC) are one of the main organisms that cause 80–90% of community-acquired urinary tract infections (UTIs) and catheter-associated urinary tract infections (CAUTIs). It is essential that UPEC have the ability to colonize the bladder by producing phenotypic virulence factors such flagella, pili, curli, and non-pilus adhesion. Pathogens growing on indwelling medical devices can communicate with one another using quorum sensing (QS) signals. The direction of the formation of biofilms, which result in the encasing of bacterial cells in extracellular polymeric substances (EPS), is crucially influenced by QS. The aim of this study was to evaluate the pathogenicity of the main pathogenic E. coli isolated from UTI patients and determine antibiotic resistance pattern and biofilm production. From December 2022 to February 2023, Out of 150 urine samples taken from UTI patients in various hospitals in Baghdad/Iraq, 25 UPEC isolates with various clinical UTI symptoms were found. These isolates were recognized by conventional and rapid techniques, and their identification was later verified by a molecular strategy based on the 16S rRNA gene.  All 25 E. coli isolates were tested for antibiotic sensitivity using the Kirby-Bauer disk diffusion method on Muller-Hinton agar, and it was the highest resistance toward cefotaxime and amoxicillin-clavulanate, while the lowest toward meropenem, nitrofurantoin, and imipenem. Using traditional PCR techniques and specially designed primers, 25 UPEC isolates were screened for the presence of the multi-antibiotic resistance marA gene and the quorum sensing luxS gene. According to the results, both investigated genes were present in high percentages (92%). It concludes that this high percentage of marA is correlated with a high rate of antibiotic resistance and luxS, which indicate a high ability of biofilm formation; thus, the marA and luxS percent indicate the level of pathogenicity among multidrug-resistant UPEC.