Investigation of Isepamicin In-Vitro Efficiency in Gram Negative Bacteria

Abstract

Context: Isepamicin is a new semisynthetic aminoglycoside derived from gentamicin B and it is effective against Gram negative bacteria. Antibiotic resistance is an emerging problem and new options need for the treatment of infections caused by Gram negative bacteria. Aims: In this study we aimed to investigate the in vitro efficiency in carbapenem susceptible and nonsusceptible Enterobacterales and Pseudomonas aeruginosa. Methods and material: A total of 214 isolates of Gram-negative bacteria (Enterobacterales n = 129 and P. aeruginosa n = 85). Identification of the bacteria was tested in Vitek MS (Biomeriux, France). Susceptibility of isepamicin, amikacin, gentamicin, tobramycin and netilmicin was determined by Kirby Bauer disc diffusion method. The breakpoints for susceptibility to isepamicin, amikacin, gentamicin, streptomycin, tobramycin and netilmicin were evaluated according to the Comite de l'Antibiogramme dela Societe Francaise de Microbiologie (CA-SFM) and EUCAST, respectively. Aminoglycoside modifying enzyme (AME) genes were investigated by multiplex PCR method. Results: Isepamicin susceptibility was determined as 92.3% for Enterobacterales and 67% for P. aeruginosa and 94.4% for carbapenem resistant Enterobacterales. The most common AME gene was aac (60)-Ib in both Enterobacterales (76%) and P. aeruginosa (14.1%). Seven of the isepamicin intermediate or resistant isolates were positive aac (6')-Ib in Enterobacterales and P. aeruginosa. Conclusions: In this study, isepamicin showed good efficiency against both susceptible and carbapenem nonsusceptible Enterobacterales. But amikacin was prior to isepamicin P. aeruginosa isolates. Isepamicin could be a therapeutic option for the infections caused by Enterobacterales.