Clinical Microbiology and Antimicrobial Chemotherapy. 2015; 17(3):241-249
Aim. To evaluate current susceptibility patterns of the potential ocular bacterial pathogens to netilmicin in comparison with other antimicrobials in Russia.
Overall in the study were included 200 S. aureus strains (100 — MRSA), 50 — coagulase-negative staphylococci, 50 — P. aeruginosa, 50 — Acinetobacter spp., and 50 — Enterobacteriaceae strains, isolated from outpatients and inpatients located in 17 cities of different regions of Russia during 2010–2014. All strains were identified to the species level using MALDI-TOF mass-spectrometry. Minimal inhibitory concentrations (MICs) of netilmicin and other antimicrobials were determined by serial dilution method and interpreted according EUCAST criteria (v.4.1).
Activity of netilmicin against methicillin-susceptible S. aureus strains (98% of isolates were susceptible to netilmicin) according to MIC50/90 values was superior compare to other aminoglycosides (gentamicin, tobramycin) and lower only if compared with respiratory quinolones and fusidic acid. In spite the fact that all MRSA isolates were formally resistant to netilmicin (as well as to gentamicin and tobramycin), according to MIC50/90 values and MIC distributions netilmicin was superior to majority of antimicrobials tested with exception of tigecycline, fusidic acid and co-trimoxazole. Against coagulase-negative staphylococci netilmicin (96% isolates susceptible) was the most in vitro active among all antimicrobials tested. According to MIC50/90 values, in vitro activity of netilmicin (46% isolates susceptible) against Enterobacteriaceae was comparable with the activity of other aminoglycosides, quinolones, cephalosporins, co-trimoxazole, and inhibitor-protected aminopenicillins. In vitro activity of netilmicin against P. aeruginosa and Acinetobacter spp. (50% and 76% susceptible isolates, respectively) was higher compare with other aminoglycosides (amikacin, gentamicin, tobramycin), and with other antimicrobials tested except colistin.
Netilmicin might be considered as an option for the topical treatment of bacterial eye infections, especially nosocomial, as well as for topical prophylaxis in eye surgery.