title: Antimicrobial susceptibility of non-fermenting Gram-negative isolates to isepamicin in a region with high antibiotic resistance.
abstract: The alarmingly increasing resistance rates among non-fermenting Gram-negative species, particularly Pseudomonas aeruginosa and Acinetobacter baumannii, intensified the interest in alternative antibiotic treatment options. Isepamicin, an old aminoglycoside, may play a role in the treatment of patients with infections caused by those multi-drug resistant pathogens. We evaluated the antimicrobial activity of isepamicin against non-fermenting Gram-negative isolates collected of the microbiological laboratory at the University Hospital of Heraklion, Crete, Greece from 2004 to the first trimester of 2011. We tested a total of 4,219 isolates (66.2 % Pseudomonas spp., 30 % Acinetobacter spp., 3.8 % other non-fermenters). The lower respiratory tract, pus, and urine were the most frequent sites of isolation (29.7 %, 19.9 %, and 12.9 %, respectively). Overall, 2768 (65.6 %) of the evaluated isolates were susceptible to isepamicin (including 79.9 % of Pseudomonas spp, 37.2 % of Acinetobacter spp, 43.1 % of other non-fermenters). Isepamicin exhibited higher antimicrobial activity compared to broad spectrum penicillins, cephalosporins, other aminoglycosides, carbapenems, and fluoroquinolones. Only colistin was more active than isepamicin. Additionally, 41.7 % of carbapenem-resistant and 53.2 % of colistin-resistant P. aeruginosa isolates were susceptible to isepamicin. The susceptibility rates for the respective types of A. baumannii isolates were 12 % and 6.2 %. Yet, isepamicin was active against 29.2 % of A. baumannii that were resistant to all other tested aminoglycosides. Isepamicin exhibits considerable antimicrobial activity against Gram-negative non-fermenters in a region with high antimicrobial resistance. Particularly, isepamicin may provide a therapeutic option for infections from carbapenem- and colistin-resistant P. aeruginosa and other aminoglycoside-resistant A. baumannii. Further modifications in the aminoglycoside molecule may provide formulations with enhanced antimicrobial activity.
authors: Department of Internal Medicine, University Hospital of Heraklion, Heraklion, Crete, Greece.
authors: G
authors: G
authors: Samonis
authors: S
authors: S
authors: Maraki
authors: E K
authors: EK
authors: Vouloumanou
authors: G G
authors: GG
authors: Georgantzi
authors: D P
authors: DP
authors: Kofteridis
authors: M E
authors: ME
authors: Falagas
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D005839:Gentamicins / Q000494:pharmacology; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D016905:Gram-Negative Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology; D006115:Greece / Q000453:epidemiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D015995:Prevalence
chemical_list: D000900:Anti-Bacterial Agents; D005839:Gentamicins; C016927:isepamicin