TY - JOUR T1 - Activity of ceftolozane/tazobactam against a collection of Pseudomonas aeruginosa isolates from bloodstream infections in Australia. AU - Henderson,A, AU - Tan,E, AU - McCarthy,K L, AU - Paterson,D L, Y1 - 2018/11/02/ PY - 2018/05/27/received PY - 2018/07/31/revised PY - 2018/08/07/accepted PY - 2018/11/6/pubmed PY - 2019/1/16/medline PY - 2018/11/6/entrez KW - Ceftolozane/tazobactam KW - Pseudomonas aeruginosa KW - antimicrobial susceptibility testing SP - 748 EP - 752 JF - Pathology JO - Pathology VL - 50 IS - 7 N2 - Pseudomonas aeruginosa is a common pathogen causing nosocomial infection. In particular, bloodstream infection (BSI) is associated with a high rate of morbidity and mortality. Ceftolozane/tazobactam is a new β-lactam/β-lactamase antimicrobial with activity against P. aeruginosa as well as multidrug resistant (MDR) Gram negative Enterobacteriaceae. Ceftolozane/tazobactam has frequently been used in salvage therapy for MDR P. aeruginosa infections. The aim of this study was to determine the activity of ceftolozane/tazobactam against P. aeruginosa isolates from BSIs collected from three clinical microbiology laboratories in Queensland, Australia, with a high proportion of isolates demonstrating β-lactam resistance. Antimicrobial susceptibility testing was performed by broth microdilution using custom made sensititre plates sourced from ThermoFisher Scientific. In addition to ceftolozane/tazobactam, we also tested piperacillin/tazobactam, ceftazidime, cefepime, meropenem, doripenem, imipenem, aztreonam, ciprofloxacin, levofloxacin, gentamicin, amikacin, tobramycin and colistin. Overall, ceftolozane/tazobactam was the most active agent tested [(MIC50/90 = 1/2 μg/mL, 96% susceptible (S)]. Against 44 isolates with resistance to at least one other β-lactam agent, 40 were susceptible to ceftolozane/tazobactam. Three ceftolozane/tazobactam resistant isolates were susceptible to colistin, with one of those isolates also susceptible to levofloxacin but not to any other antimicrobials tested. One ceftolozane/tazobactam resistant isolate was susceptible only to meropenem and doripenem but was non-susceptible to imipenem. An association was found between fluoroquinolone resistance and aminoglycoside resistance but not with β-lactam resistance. In summary, ceftolozane/tazobactam was active against most strains tested, including those resistant to other β-lactams. Laboratories should consider testing P. aeruginosa against ceftolozane/tazobactam in suspected MDR or extensively drug resistant (XDR) infections. SN - 1465-3931 UR - https://www.unboundmedicine.com/medline/citation/30392710/Activity_of_ceftolozane/tazobactam_against_a_collection_of_Pseudomonas_aeruginosa_isolates_from_bloodstream_infections_in_Australia_ DB - PRIME DP - Unbound Medicine ER -