Antimicrobial resistance of nosocomial Pseudomonas aeruginosa isolates in Russia: results of multicenter epidemiological study «MARATHON» 2013-2014

Abstract

Pseudomonas aeruginosa is the most abundant bacterial species causing nosocomial infections in Russia. In this paper, we report the data on antimicrobial susceptibility of 743 isolates of P. aeruginosa collected in 63 hospitals of 22 cities of Russia in 2013-2014 as part of the national multicenter surveillance study on antimicrobial resistance of nosocomial pathogens, «MARATHON». P. aeruginosa isolates comprised 19.6% of all bacterial nosocomial isolates. Among them, the non-susceptibility rates to main antipseudomonal β-lactams were: 51.9% to cefepime, 55.9% to ceftazidime, 57.9% to piperacillin-tazobactam, 65.7% to imipenem, and 59.7% to meropenem. Production metallo-β-lactamases was detected in 21.3% of the isolates: VIM-type – 20.7, IMP-type – 0.5%. Most of the isolates were insusceptible to fluoroquinolones: ciprofloxacin (61.1%) and levofloxacin (62.8%), and to aminoglycosides: gentamicin (57.7%), amikacin (50.5%), and tobramycin (46.4%). Polymyxins had the highest in vitro activity with non-susceptibility rates being as low as 2.6% to colistin and strains not sensitivity to polymyxin B were not detected. Twenty nine percent of the isolates had the MIC of fosfomycin exceeding the epidemiological cut-off value of 128 mg/l. Notably, 51.4% of the isolates were categorised as extensively drug-resistant (XDR) and pan-resistance (PDR) strain was detected in 1 case.

Keywords

• pseudomonas aeruginosa
• antimicrobial resistance
• carbapenemases
• nosocomial infections