Infection and Drug Resistance (Oct 2018)
In vitro activity of ceftazidime–avibactam, ceftolozane–tazobactam, and other comparable agents against clinically important Gram-negative bacilli: results from the 2017 Surveillance of Multicenter Antimicrobial Resistance in Taiwan (SMART)
Abstract
Shio-Shin Jean,1,2 Min-Chi Lu,3 Zhi-Yuan Shi,4 Shu-Hui Tseng,5 Ting-Shu Wu,6 Po-Liang Lu,7 Pei-Lan Shao,8 Wen-Chien Ko,9 Fu-Der Wang,10,11 Po-Ren Hsueh12,13 1Department of Emergency Medicine and Emergency and Critical Care Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan; 2Department of Emergency, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; 3Department of Microbiology and Immunology, School of Medicine, China Medical University, Taichung, Taiwan; 4Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan; 5Center for Disease Control and Prevention, Ministry of Health and Welfare, Taiwan; 6Division of Infectious Diseases, Department of Internal Medicine, Chang Gung Memorial Hospital at Linkou, Chang Gung University College of Medicine, Taoyuan, Taiwan; 7Department of Internal Medicine, Kaohsiung Medical University Hospital, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; 8Department of Pediatrics, Hsin-Chu Branch, National Taiwan University Hospital, Hsin-Chu, Taiwan; 9Department of Internal Medicine, National Cheng Kung University Medical College and Hospital, Tainan, Taiwan; 10Division of Infectious Diseases, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; 11School of Medicine, National Yang-Ming University, Taipei, Taiwan; 12Department of Laboratory Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan; 13Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan Objectives: We investigated the in vitro antimicrobial susceptibilities of clinically important Gram-negative bacteria (GNB) from 16 major teaching hospitals in Taiwan in 2017. Materials and methods: Escherichia coli (n=686) and Klebsiella pneumoniae bloodstream isolates (n=673), non-typhoid Salmonella (NTS; n=221) from various sources, Shigella species (n=21) from fecal samples, and Neisseria gonorrhoeae (n=129) from the genitourinary tract were collected. Antibiotic minimum inhibitory concentrations (MICs) were determined using the broth microdilution method. Alleles encoding K. pneumoniae carbapenemases (KPCs), New Delhi metallo-β-lactamases (NDMs), Verona integron-encoded metallo-β-lactamase, imipenemase, OXA-48-like, and mcr-1-5 genes were detected by molecular methods in Enterobacteriaceae isolates. Results: Five (0.7%) E. coli isolates harbored mcr-1 alleles. Twenty-four (3.6%), seven (1.0%), four (0.6%), and one (0.15%) K. pneumoniae isolates contained bla KPC, bla OXA-48-like, mcr-1, and bla NDM, respectively. Three (1.4%) NTS and no Shigella isolates harbored mcr-1 genes. Seventy-one (10.5%) K. pneumoniae isolates displayed non-susceptibility (NS) to carbapenem agent(s). Phenotypically extended-spectrum β-lactamase (ESBL)-producing K. pneumoniae isolates showed significantly higher rates of ertapenem, tigecycline, and ceftolozane–tazobactam (CLZ–TAZ) NS (40.2%, 16.3%, and 71%–80%, respectively) than E. coli isolates exhibiting ESBL phenotypes (5.4%, 0.7%, and 18%–28%, respectively). All phenotypically ESBL-producing E. coli isolates were ceftazidime–avibactam (CAZ–AVB) susceptible. Two (8.3%) KPC-producing K. pneumoniae isolates showed CAZ–AVB NS. Hospital-acquired K. pneumoniae isolates were significantly less susceptible to ertapenem and CLZ–TAZ than hospital-acquired E. coli isolates. Conclusion: Third-generation cephalosporins remain the optimal choice for treating NTS, Shigella, and gonococcal infections in Taiwan. Hospital-acquired and phenotypically ESBL-producing K. pneumoniae are a heavy resistance burden in Taiwan. Keywords: Enterobacteriaceae, Neisseria gonorrhoeae, extended-spectrum β-lactamases, carbapenemase, ceftolozane–tazobactam, ceftazidime–avibactam