[Estimation of level of aminoglycosides susceptibility of bacterial strains isolated from patients with systemic and general infections].

Susceptibility tests to aminoglycosides of 200 bacterial strains isolated in period 1.01.2007-30.04.2008 from hospitalized patients in different Wroclaw clinics were performed. Among tested strains were 96 Gram-negative rods belonging to the Enterobacteriaceae family, 74 non-fermentative rods and 30 strains of Staphylococcus aureus. The results of antibiotic susceptibility determined by serial antibiotic dilution in solid medium indicated that among Enterobacteriaceae the most susceptible to aminoglycosides were E. coli (90-95%) and least susceptible Enterobacter spp., Citrobacter spp. and Serratia spp (62-76%). Among non-fermentative rods, Pseudomonas aeruginosa was more susceptible than Acinetobacter spp. 97% strains of Staphylococcus aureus were susceptible to all aminoglycosides. Enterobacteriaceae strains isolated from adults were more resistant to aminoglycosides than isolated from children and non-fermentative rods isolated from adults more susceptible to netilmicin. Among S. aureus only one strains was MRSA and aminoglycoside resistant. Twenty two of 96 examined strains belonging to Enterobacteriaceae and 46 of 74 examined non-fermentative rods were resistant at least to one aminoglycoside. Predominant resistance patterns were as follow: simultaneous resistance to all aminoglycosides and resistance to gentamicin and netilmicin with susceptible to amikacin. High level resistance (MIC > or = 256 microg/ml) was found in 23 gentamicin resistant strains (12 rods of Enterobacteriaceae and 11 non-fermentative rods), in 33 netilmicin resistant strains (respectively 10 and 21 strains) and in 14 amikacin resistant Gram-negative rods (respectively 9 and 5 strains). Among 96 rods of Enterobacteriaceae family 19 ESBL (+) strains were found. High level of resistance (MIC > or = 256 microg/ml) was found in 10 ESBL (+) strains.