Antimicrobial susceptibility of Gram-negative ESKAPE pathogens isolated from hospitalized patients with intra-abdominal and urinary tract infections in Asia-Pacific countries: SMART 2013-2015

Gram-negative ESKAPE pathogens (Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp.) are responsible for increases in antimicrobial-resistant infections worldwide. We determined in vitro susceptibilities to eight parenteral antimicrobial agents using Clinical and Laboratory Standards Institute broth microdilution methodology for Gram-negative ESKAPE pathogens isolated from hospitalized patients with intra-abdominal infections (IAIs) (n = 3052) and urinary tract infections (UTIs) (n = 1088) in 11 Asia-Pacific countries/regions from 2013 to 2015. Amikacin (98.3, 96.4 %), imipenem (97.1, 95.5 %) and ertapenem (95.3, 93.2 %) demonstrated the highest rates of susceptibility for isolates of K. pneumoniae from IAI and UTI, respectively, whereas susceptibility to advanced-generation cephalosporins was < 4 and <71 %, respectively. K. pneumoniae with an extended-spectrum beta-lactamase-positive phenotype were more common in UTI (27.1 %) than IAI (16.2 %). Imipenem and amikacin were the most active agents against extended-spectrum beta-lactamase-positive K. pneumoniae from IAI (95.1, 91.8 %) and UTI (94.9, 92.3 %), respectively, whereas < 54% were susceptible to piperacillin-tazobactam. Against Enterobacter spp. and P. aeruginosa, amikacin demonstrated the highest rates of susceptibility for isolates from IAI (99.7, 95.5 %) and UTI (90.9, 91.5 %), respectively. K. pneumoniae, Enterobacter spp. and P. aeruginosa from urine demonstrated lower susceptibility to levofloxacin (74.1, 81.8 and 73.8 %) than from IAI (87.6, 91.8 and 85.4 %). For A. baumannii, rates of susceptibility to all agents tested were <43 %. We conclude that the studied Gram-negative ESKAPE pathogens demonstrated reduced susceptibility to commonly prescribed advanced-generation cephalosporins, piperacillin-tazobactam and levofloxacin, while amikacin and carbapenems were the most active. Ongoing surveillance to monitor evolving resistance trends and the development of novel antimicrobial agents with potent activity against Gram-negative ESKAPE pathogens are mandatory.