Ceftolozane/Tazobactam In-Vitro Activity against Clinical Isolates from Complicated Intra-Abdominal Infection...

Area of Science:

• Infectious Diseases
• Clinical Microbiology
• Antimicrobial Stewardship

Background:

• Complicated intra-abdominal infections (cIAIs) present significant morbidity and mortality risks, particularly with limited local antimicrobial susceptibility data in Indonesia.
• Ceftolozane/tazobactam (C/T) is a novel antibiotic with reported efficacy against a range of pathogens, necessitating local validation.

Purpose of the Study:

• To evaluate the in vitro activity of ceftolozane/tazobactam (C/T) against clinical isolates obtained from patients with complicated intra-abdominal infections (cIAIs) in Indonesia.
• To assess the potential of C/T as a carbapenem-sparing agent in managing cIAIs within the Indonesian context.

Main Methods:

• A prospective cross-sectional study involving 284 patients diagnosed with cIAIs across three major Indonesian hospitals from 2019-2021.
• Collection of blood and intraoperative tissue/aspirate specimens for microbial culture and subsequent antimicrobial susceptibility testing.
• Determination of minimum inhibitory concentrations (MICs) following CLSI M100 guidelines.

Main Results:

• Gram-negative bacteria (GNB) predominated in abdominal tissue isolates (79.5%), with *E. coli*, *K. pneumoniae*, and *P. aeruginosa* being the most frequent.
• Ceftolozane/tazobactam (C/T) demonstrated high susceptibility rates: 96.7% for *E. coli*, 70.2% for *K. pneumoniae*, and 94.1% for *P. aeruginosa*.
• C/T exhibited activity against challenging isolates, including ESBL-producing *Enterobacterales* and carbapenem-non-susceptible *P. aeruginosa*.

Conclusions:

• Ceftolozane/tazobactam (C/T) displays significant in vitro potency against Gram-negative bacteria commonly isolated from cIAI patients in Indonesia.
• The proven susceptibility profile supports considering C/T as a valuable component of a carbapenem-sparing strategy for managing cIAIs in this region.