Enterobacterieaceae (and specially Escherichia coli) showing resistance due to multidrug-resistant Escherichia coli, plasmid mediated AmpC or quinolone resistance caused by chromosomal mechanisms have spread worldwide during the last decades. This is important because many of these isolates are also resistant to other first-line agents such as fluoroquinolones or aminoglycosides, leaving few available options for therapy, and this condition is associated with increased morbidity- mortality and length of hospital stay. While carbapenems are considered the drugs of choice for multidrug-resistant Escherichia coli and AmpC producers, recent data suggests that certain alternatives may be suitable for some types of infections.