Are we winning the battle but losing the war?- Antibiotic resistance in multidrug resistant E. coli.

The problem of antibiotic resistance is an increasing concern in the present world, recognised and highlighted by many professional bodies, including the World Health Organization (WHO). When used properly, antibiotics can save lives, however their overuse in both animals and humans has led to the development of antimicrobial resistance, consequently reducing or overcoming the effectiveness of many important drugs.
E. coli belongs to Gram-negative bacteria and is a causal agent of bacterial infections in both humans and animals. Most E.coli are commensal bacteria, however some can be pathogenic and cause unpleasant gastro-intestinal or invasive infections. Antibiotic resistance is widespread in E.coli, including multidrug resistance (MDR) to several antibiotic classes.
Cephalosporins belong to β-lactam antibiotics and are one of the WHO essential medicines for treating bacterial infections. In our lab, we have been looking into the physiological response of multidrug resistant E .coli mostly to cephalosporin treatment. Can we observe any differences and if yes, what is the likely cause of them?