Efficacy of Fosfomycin-Containing Regimens for Treatment of Bacteremia Due to Pan-Drug Resistant Acinetobacter baumannii in Critically Ill Patients: A Case Series Study

Abstract

Acinetobacter baumannii (AB) has evolved over the last decades as a major problem in carbapenem-resistant gram-negative nosocomial infections, associated with high mortality rates especially in the intensive care unit (ICU). Recent reports highlight the increasing prevalence of resistance to colistin, a last resort therapeutic option for carbapenem-resistant AB. We retrospectively evaluated the characteristics, treatment regimens and outcomes of twenty patients with pan-drug resistant (PDR) AB primary bacteremia hospitalized in the ICU of the University General Hospital of Patras, during a two-year period (October 2020–September 2022). The 28-day mortality reached 50%. Between survivors and non-survivors, no differences were found regarding age, gender, and Charlson comorbidity index (CCI). However, non-survivors had higher APACHE II scores and higher prevalence of septic shock and COVID-19 infection. A significantly higher percentage in the survivor group received Fosfomycin as part of the combination regimen. Inclusion of fosfomycin in the combination therapeutic regimen was associated with significantly better survival as compared to non-fosfomycin-containing regimens. In view of the increasing prevalence of PDR-AB infections in ICUs, its associated high rates of mortality and the lack of effective treatment options, the observed survival benefit with fosfomycin inclusion in the therapeutic regimen merits further validation in larger prospective studies.

A retrospective analysis of carbapenem-resistant Acinetobacter baumannii infections in critically ill patients: Experience at a tertiary-care teaching hospital ICU

“…Larger studies are needed to reveal the impact of fosfomycin on clinical outcomes when used in combination with the treatment of such highly resistant Gram-negative infections. [ 24 , 25 ]…”

NDM-1- and OXA-23-producing Acinetobacter baumannii in wastewater of a Nigerian hospital

“…Minimum inhibitory concentration (MIC) values were interpreted using the AMR R package version 1.8.1 ( https://msberends.github.io/AMR/ ) according to the clinical breakpoints of the Clinical Laboratory Standards Institute (CLSI) ( 39 ), except for the tigecycline MIC values as the current guidelines by CLSI and the European Committee on Antimicrobial Susceptibility Testing ( 40 ) do not contain breakpoints for interpreting tigecycline MIC values for A. baumannii . Tigecycline MICs of 2 µg/mL were reported as resistant ( 41 ). All non-susceptible isolates are reported as resistant in the analyses.…”

How to treat severe Acinetobacter baumannii infections

“…The available data do not allow the combination with Fosfomycin to become a standard of care in treating severe ABI [158,159 ▪ ]. We believe Fosfomycin should be considered an experimental agent in treating ABI, and further randomised clinical trials are needed.…”