In the present study, ciprofloxacin resistance in Gram-negative bacteria isolated from different clinical samples during 2 year period, between January 1, 2000 and December 31, 2001, were retrospectively assessed. Bacterial isolation from clinical samples was made using standard microbiological methods. Antimicrobial sensitivity was assessed using disk-diffusion method according to NCCLS recommendations.

We observed ciprofloxacin resistance in 116 strains (28%) out of 411 strains that was assessed during study. The resistance was found to be 19% in strains; which were isolated in 2000, and 35% which were isolated in 2001. In addition, ciprofloxacin resistance was observed as 19% and 35% in community-acquired and nosocomial strains, respectively. The resistance rate increased from 15% to 23% in community-acquired strains and from 22% to 42% in nosocomial strains during 2000 to 2001 years, respectively. According to the isolated bacteria, the resistance was found to be 27% in Enterobacteriaceae family (Klebsiella spp 42%, Escherichia coli 28%, Enterobacter spp. 27%, Proteus spp. %14 and others 7%), 14% in Pseudomonas aeruginosa and 55% in Acinetobacter spp.

In conclusion, there is a marked increase in ciprofloxacin resistance in Gram-negative bacteria isolated as an infection agent from different samples between 2000 and 2001 years. This increase was higher in the nosocomial strains than community-acquired strains, and the highest increase was observed in Acinetobacter spp.