Abstract
Background: Gram-negative bacteria are associated with an increase in rates of antibacterial
resistance. In most low- and middle-income countries such as Iran, there is no continuous
surveillance system for antibiotic resistance.
Objective: The purpose of this survey was to determine the pattern of antimicrobial
sensitivity of gram-negative bacteria within 3 consecutive years at a nephrology ward of
Nemazee hospital in Shiraz.
Materials and Methods: During a 3-year period from 2013 to 2015 at the adult nephrology
ward, bacteriological data of all biological samples of hospitalized patients in favor of
gram-negative microorganisms were analyzed retrospectively. Antimicrobial susceptibility
was performed by the Kirby-Bauer disc diffusion method.
Results: The most common gram negative bacterium isolated from biological samples was
Escherichia coli (43.9%). The highest (86.3%-94.1%) antibacterial resistance rate was associated
with Acinetobacter spp. The most frequent resistance was seen with cephalosporins. In
contrast to ceftriaxone, ciprofloxacin, and trimethoprim/sulfamethoxazole, nitrofurantoin
and aminoglycosides remained their acceptable activity against E. coli. At least three-fourths
(75%) of Acinetobacter spp. isolates was resistant to either aminoglycosides or imipenem.
All (100%) isolated Acinetobacter spp. and Pseudomonas aeruginosa species were susceptible to
colistin. The rate of Acinetobacter spp. and P. aeruginosa resistant to three or more drugs was
81.7% and 74.6%, respectively.
Conclusions: The resistant rate of gram negative pathogens to different tested antibacterial
agents was considerably high and has increased during the recent three years in our center.