{"doi":"10.2147/idr.s387097","title":"Ceftolozane/Tazobactam Activity Against Drug-Resistant Pseudomonas aeruginosa and Enterobacterales Causing Healthcare-Associated Infections in Eight Asian Countries: Report from an Antimicrobial Surveillance Program (2016–2018)","abstract":"Purpose: To evaluate the in vitro activity of ceftolozane/tazobactam and comparator agents tested against Pseudomonas aeruginosa and Enterobacterales isolates from hospitalised patients in Asia. Ceftolozane/tazobactam is an antipseudomonal cephalosporin combined with a well-established β-lactamase inhibitor. Methods: A total of 2038 Gram-negative organisms (376 P. aeruginosa and 1662 Enterobacterales) were collected consecutively using a prevalence-based approach from 11 medical centres. Organisms were susceptibility tested by broth microdilution according to CLSI guidelines. CLSI and EUCAST breakpoint criteria were used. Results: Ceftolozane/tazobactam was the most potent (MIC 50/90 , 0.5/4 mg/L) β-lactam agent tested against P. aeruginosa isolates, inhibiting 91.0% of the isolates at an MIC of ≤ 4 mg/L. P. aeruginosa exhibited high rates of susceptibility to amikacin (92.0/92.0% [CLSI/EUCAST]) and colistin by EUCAST criteria only (99.2% intermediate [CLSI]/99.2% susceptible [EUCAST]). Ceftolozane/tazobactam (MIC 50/90 , 0.25/16 mg/L; 86.8/86.8% susceptible [CLSI/EUCAST]) and meropenem (MIC 50/90 , 0.03/0.12 mg/L; 93.0/93.3% susceptible [CLSI/EUCAST]) were the most active compounds tested against Enterobacterales. Isolates displayed susceptibility rates to other β-lactam agents, ranging from 81.5/77.7% for piperacillin/tazobactam, 66.0/64.5% for cefepime, and 65.3/60.9% for ceftazidime using CLSI/EUCAST breakpoints. Among the Enterobacterales isolates, 6.8% were carbapenem-resistant Enterobacterales (CRE) and 29.6% exhibited an extended-spectrum β-lactamase (ESBL) non-CRE phenotype. Ceftolozane/tazobactam showed good activity against ESBL non-CRE phenotype strains of Enterobacterales (MIC 50/90 , 0.5/8 mg/L; 84.8/84.8% susceptible), but not against isolates with a CRE phenotype (MIC 50/90 , > 32/> 32 mg/L). Conclusion: Ceftolozane/tazobactam was the most active β-lactam agent tested against P. aeruginosa and demonstrated higher in vitro activity than the available cephalosporins when tested against Enterobacterales from Asian countries. Keywords: Asia, ceftolozane/tazobactam, drug resistance, Enterobacterales, P. aeruginosa , surveillance","journal":"Infection and Drug Resistance","year":2022,"id":266862,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":9,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.955,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2022-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":927003,"name":"Dee Shortridge","orcid":"0000-0002-1215-5216","position":1,"is_corresponding":false},{"id":927004,"name":"Wei‐Ting Chen","orcid":"0009-0008-0547-9459","position":2,"is_corresponding":false},{"id":832381,"name":"Hélio S. Sader","orcid":"0000-0001-7022-6644","position":3,"is_corresponding":false},{"id":546673,"name":"Mariana Castanheira","orcid":"0000-0003-0126-1782","position":4,"is_corresponding":false},{"id":716654,"name":"Michael A. Pfaller","orcid":"0000-0003-4501-6068","position":0,"is_corresponding":true}],"reference_count":31,"raw_metadata":null,"created_at":"2026-07-19T00:26:58.102271Z","pmid":"36444213","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}