Safa S Almarzoky Abuhussain1,2, Christina A Sutherland1, David P Nicolau1,3. 1. Center for Anti-Infective Research and Development, Hartford Hospital, Hartford, CT, USA. 2. Umm Al-Qura University, Makkah, Saudi Arabia. 3. Division of Infectious Diseases, Hartford Hospital, Hartford, CT, USA.
Abstract
BACKGROUND: Challenges due to multidrug resistant (MDR) Gram-negative bacterial pathogens such as P. aeruginosa (PSA) are increasing globally. Suboptimal antimicrobial therapy of infections caused by PSA is associated with increased morbidity and mortality. As a result, antimicrobial susceptibility (%S) studies are pivotal to identifying trends in antimicrobial resistance that inform decisions regarding choice of antimicrobial therapy. This study assessed the in vitro potency of 7 antipseudomonal agents including ceftolozane/tazobactam (C/T) against PSA collected from numerous sites across the US. METHODS: Multiple US hospitals provided non-duplicate respiratory and blood isolates of PSA for potency testing. MICs against PSA were determined using broth microdilution methods according to CLSI for 7 antimicrobials with antipseudomonal activity: aztreonam (ATM), cefepime (FEP), ceftazidime (CAZ), C/T, imipenem (IPM), meropenem (MEM) and piperacillin/tazobactam (TZP). %S was defined per CLSI or FDA breakpoint criteria. RESULTS: Thirty-five hospitals geographically spread across the US provided a total of 1,209 PSA isolates. Of the antibiotics assessed, %S to C/T was the highest at 95% with an MIC50 of 0.5 mg/L and MIC90 of 2 mg/L. In comparison, other %S (MIC50/MIC90) was as follows: ATM 66% (8/32); FEP 76% (4/32); CAZ 78% (4/64); IPM 68% (2/16); MEM 74% (0.5/16); and TZP 73% (8/128). CONCLUSIONS: For this geographically diverse PSA population, C/T demonstrated the highest overall susceptibility (95%). Other antipseudomonal agents inclusive of the carbapenems displayed susceptibilities of 66-78%. In the era of escalating PSA resistance to the β-lactams, the potency of C/T may represent an important clinical option.
BACKGROUND: Challenges due to multidrug resistant (MDR) Gram-negative bacterial pathogens such as P. aeruginosa (PSA) are increasing globally. Suboptimal antimicrobial therapy of infections caused by PSA is associated with increased morbidity and mortality. As a result, antimicrobial susceptibility (%S) studies are pivotal to identifying trends in antimicrobial resistance that inform decisions regarding choice of antimicrobial therapy. This study assessed the in vitro potency of 7 antipseudomonal agents including ceftolozane/tazobactam (C/T) against PSA collected from numerous sites across the US. METHODS: Multiple US hospitals provided non-duplicate respiratory and blood isolates of PSA for potency testing. MICs against PSA were determined using broth microdilution methods according to CLSI for 7 antimicrobials with antipseudomonal activity: aztreonam (ATM), cefepime (FEP), ceftazidime (CAZ), C/T, imipenem (IPM), meropenem (MEM) and piperacillin/tazobactam (TZP). %S was defined per CLSI or FDA breakpoint criteria. RESULTS: Thirty-five hospitals geographically spread across the US provided a total of 1,209 PSA isolates. Of the antibiotics assessed, %S to C/T was the highest at 95% with an MIC50 of 0.5 mg/L and MIC90 of 2 mg/L. In comparison, other %S (MIC50/MIC90) was as follows: ATM 66% (8/32); FEP 76% (4/32); CAZ 78% (4/64); IPM 68% (2/16); MEM 74% (0.5/16); and TZP 73% (8/128). CONCLUSIONS: For this geographically diverse PSA population, C/T demonstrated the highest overall susceptibility (95%). Other antipseudomonal agents inclusive of the carbapenems displayed susceptibilities of 66-78%. In the era of escalating PSA resistance to the β-lactams, the potency of C/T may represent an important clinical option.
Authors: Andrew J Denisuik; Lauren A Garbutt; Alyssa R Golden; Heather J Adam; Melanie Baxter; Kimberly A Nichol; Philippe Lagacé-Wiens; Andrew J Walkty; James A Karlowsky; Daryl J Hoban; Michael R Mulvey; George G Zhanel Journal: J Antimicrob Chemother Date: 2019-03-01 Impact factor: 5.790
Authors: Dee Shortridge; Mariana Castanheira; Michael A Pfaller; Robert K Flamm Journal: Antimicrob Agents Chemother Date: 2017-06-27 Impact factor: 5.191
Authors: Michael A Pfaller; Matteo Bassetti; Leonard R Duncan; Mariana Castanheira Journal: J Antimicrob Chemother Date: 2017-05-01 Impact factor: 5.790
Authors: Dawn M Sievert; Philip Ricks; Jonathan R Edwards; Amy Schneider; Jean Patel; Arjun Srinivasan; Alex Kallen; Brandi Limbago; Scott Fridkin Journal: Infect Control Hosp Epidemiol Date: 2012-11-27 Impact factor: 3.254
Authors: Bryan D Lizza; Kevin D Betthauser; David J Ritchie; Scott T Micek; Marin H Kollef Journal: Antimicrob Agents Chemother Date: 2021-06-17 Impact factor: 5.191
Authors: András Fodor; Birhan Addisie Abate; Péter Deák; László Fodor; Ervin Gyenge; Michael G Klein; Zsuzsanna Koncz; Josephat Muvevi; László Ötvös; Gyöngyi Székely; Dávid Vozik; László Makrai Journal: Pathogens Date: 2020-06-29