Atb new

Twelve isolates of XDRAB were derived from the bacterial specimens of patients from the critical care units, internal medicine, and emergency departments at the First Affiliated Hospital of Chengdu Medical College from 2018 to 2020 (Chengdu, China). Standard laboratory methods and ATB New (BioMérieux, France) were used to identify these isolates, which were also confirmed by PCR of the genes 16S rRNA and blaOXA-51 (Chang et al., 2015 (link)); Chromobacterium violaceum 026 (CV026) was purchased from Biobw (Beijing, China); A. baumannii ATCC 17978 and Escherichia coli DH5a were preserved in our laboratory.

Nine isolates of XDRAB were derived from clinical specimen (septum, endotracheal aspirate or respiratory lavage fluid) of patients from the critical care units, geriatrics, internal medicine and emergency department at the First Affiliated Hospital of Chengdu Medical College in 2018 to 2019 (Chengdu, Sichuan, China). These isolates were identified by standard laboratory methods and ATB New (bioMérieux, France) and also were further verified by PCR of two genes, 16S rRNA (with primers 5′-CATTATCACGGTAATTAGTG-3′ and 5′-AGAGCACTGTGCACTTAAG-3′) and bla_OXA-51 (with primers 5′-TAATGCTTTGATCGGCCTTG-3′ and 5′-TGGATTGCACTTCATCTTGG-3′)^{42 (link),43 (link)}. Staphylococcus aureus ATCC29213 and Escherichia coli ATCC25922 used as quality control strains in antimicrobial susceptibility testing were obtained from the American Type Culture Collection (USA).

A total of 47 A. baumannii clinical isolates were derived from the blood, sputum or swab samples of patients from different departments at the First Affiliated Hospital of Chengdu Medical College, China from 2014 to 2015. Bacteria were aerobically grown at 37°C in Mueller-Hinton (MH) broth or agar (Oxoid, England) or in Luria-Bertani (LB) broth (Lin et al., 2009 (link)). These isolates were identified by ATB New (bioMérieux, France) (Chang et al., 2015 (link)) and further verified by PCR products of rpoB (Wang et al., 2014 (link)) and 16S rRNA gene (Chiang et al., 2011 (link)) with the primers included in Table S1. The PCR products were sequenced by Tsingke Biological Technology (Tsingke, Chengdu, China), followed by sequence alignment using BLAST (http://blast.ncbi.nlm.nih.gov/Blast.cgi).