Furthermore, we analyzed the role of fluoroquinolones in treating pneumonia caused by ESBL producers. Empirical fluoroquinolone monotherapy is not inferior to carbapenem in terms of the crude 30-day mortality rate. However, high resistance to fluoroquinolones (79.3%) was found in our cohort, and therefore, choosing it as empirical therapy for covering possible ESBL-producer pneumonia may not be suitable. However, in areas with low resistance to fluoroquinolones, it can be a suitable choice for empirical therapy to treat bacteremic pneumonia caused by ESBL producers