Clinical samples — blood, sputum, throat swab, midstream urine, hydrothorax, and ascites — were collected by conventional methods recommended in the clinic. Samples were processed according to the standard operating procedure of our institution. All isolates were identified by the VITEK 2 compact system and VITEK 2 Gram-negative identification card (BioMérieux, Marcy-l’Étoile, France). The microbiology laboratory performed antimicrobial-susceptibility testing of the Gram-negative bacterial isolates based on minimum inhibitory concentration. More detailed methods have been described in our previous studies.13 (link),14 (link)