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: G Samonis, S Maraki, E K Vouloumanou, G G Georgantzi, D P Kofteridis, M E Falagas
• Journal: European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology (Eur J Clin Microbiol Infect Dis) Vol. 31 Issue 11 Pg. 3191-8 (Nov 2012) ISSN: 1435-4373 [Electronic] Germany
• PMID: 22752194 (Publication Type: Journal Article)

Chemical References

• Anti-Bacterial Agents
• Gentamicins
• isepamicin

Topics

• Anti-Bacterial Agents (pharmacology)
• Drug Resistance, Bacterial
• Gentamicins (pharmacology)
• Gram-Negative Bacteria (drug effects, isolation & purification)
• Gram-Negative Bacterial Infections (epidemiology, microbiology)
• Greece (epidemiology)
• Humans
• Microbial Sensitivity Tests
• Prevalence