Objective: To determine gentamicin resistance among Pseudomonas spp., Acinetobacter spp. and enteric gram negative bacilli isolated from various clinical materials of patients from intensive care unit (ICU) and other clinics.

Materials and Methods: A total of 121 bacteria included in this study were identified by conventional methods and API ID 32E (BioMerieux, France). Gentamicin resistance was tested by E test (AB Biodisk, Sweden) method according to the recommendations of Clinical Laboratory Standards Institute (CLSI).

Results: The distribution of the bacteria were as follows: 59 enteric gram-negative bacilli (7 Klebsiella spp., 7 Enterobacter spp. and 45 E. coli); 43 Acinetobacter spp. and 19 Pseudomonas spp. Sixty-three of the isolates were from ICU and 58 from other clinics. Gentamicin susceptibility rate was 75% among the Enterobacteriaceae family. Among Pseudomonas strains, susceptibility rate was higher in isolates from clinics (88%) than from ICU (27%). The susceptibility rates were similarly low among the Acinetobacter strains isolated from ICU and clinics (16% and 17%, respectively).

Conclusion: Since 1994 the use of antimicrobial agents is under the control of Clinical Microbiology and Infectious Diseases specialists in our hospital, however, gentamicin has been administered freely. Nevertheless, aminoglycoside resistance declined considerably since the last 10 years due to the widespread use of quinolones.