CTX-M-Producing <i>Escherichia Coli</i> Strains: Resistance To Temocillin, Fosfomycin, Nitrofurantoin And Biofilm Formation

Abstract

<b>Aim:</b> ESBL-producing and bacterial biofilms-forming <i>Escherichia coli</i> are associated with antimicrobial treatment failure. This study aimed to investigate the phenotypic resistance mechanisms of CTX-M <i>E. coli</i> against old antibiotics - cell wall synthesis inhibitors temocillin, nitrofurantoin and fosfomycin. <b>Materials & Methods:</b> Susceptibility to old antibiotics testing was performed using disk diffusion method, biofilm formation was evaluated spectrophotometrically, and PCR was used for the determination of CTX-M type. <b>Results & conclusion:</b> Temocillin was active against nearly 93%, nitrofurantoin and fosfomycin, respectively, 91.7% and 98.6% of tested <i>E. coli.</i> Thus, it demonstrated to be a good alternative therapeutic option against ESBL infections. Bacteria resistant to old antibiotics had CTX-M-15 or CTX-M-15, TEM-1 and OXA-1 combinations. No significant association was found between CTX-M <i>E. coli</i> resistance to temocillin, nitrofurantoin and fosfomycin; however, the level of biofilm formation was found as not affected by the type of CTX-M β-lactamases.