Do bacteria isolated from ICU patients 'ESKAPE' antibiotic treatment? In vitro susceptibility of the Enterobacteriaceae family to tigecycline

Background: Enterobacteriaceae are currently causing the majority of healthcare-associated infections (HAI) and simultaneously expressing increasing levels of antibiotic resistance. The purpose of this study is to assess the in vitro sensitivity of MDR strains from the family Enterobacteriaceae to tigecycline in relation to their origin from patients hospitalized in intensive care units (ICUs) and non-ICUs. Methods: The study involved 156 clinically significant strains of the Enterobacteriaceae family isolated from patients with complicated intraabdominal infections (cIAIs) and/or complicated skin and skin structure infections (cSSSIs) hospitalized in ICUs and other surgical departments. Tigecycline MICs were determined by Etest. Results: The highest percentage of tigecycline non-susceptible (intermediate + resistant strains) in vitro strains among the Enterobacteriaceae species were observed for Serratia spp. 77.3%, followed by Citrobacter spp. (76.9%) and Enterobacter spp. (70%); whereas K. pneumoniae and E. coli showed 73–73.8% tigecycline susceptibility rates. Conclusion: Tigecycline demonstrates a high level of antimicrobial in vitro activity when tested against E. coli and K. pneumoniae , even those with the ESBL-phenotype. Tigecycline retained activity against merely 22–30% of Enterobacter , Citrobacter and Serratia genera .