Antibacterial Potential of Actinomycete Extracts and Characterization of β-Lactamase-Producing Multidrug-Resistant Uropathogenic Escherichia coli.

The increasing prevalence of multidrug-resistant (MDR) uropathogenic Escherichia coli (UPEC) strains, particularly those producing β-lactamase enzymes, complicates urinary tract infection (UTI) treatment and poses a significant public health threat. This study investigates the antibacterial potential of actinomycete extracts against MDR UPEC isolates while characterizing their phylogenetic diversity and β-lactamase profiles. From 300 clinical UTI samples collected in Babil Province, Iraq, 50 UPEC isolates were confirmed via standard microbiological and biochemical assays. Phylogenetic analysis, utilizing PCR-based detection of chuA, yjaA, and TspE4.C2 loci, revealed that most isolates belonged to the virulent B2 group. Antibiotic susceptibility testing showed 64% of isolates were MDR, with high resistance to cephalosporins and fluoroquinolones. Screening for β-lactamase genes identified blaCTX-M-I, blaTEM, and blaOXA as prevalent resistance determinants. Actinomycete isolates from soil samples produced ethyl acetate extracts that exhibited potent antibacterial effects against MDR UPEC, with inhibition zones exceeding 15 mm. These findings highlight actinomycetes as a promising source of novel antimicrobials to combat β-lactamase-producing UPEC, emphasizing the need for further compound characterization.