Background: According to the studies, Iran’s per capita antibiotic consumption is remarkable. Since the emergence of Antibiotic Resistant Organisms (AROs) is considered a global problem in the community and hospitals, this study aimed to investigate the pattern of antibiotic resistance in Gram-negative bacteria isolated from patients in an academic and a non-academic hospital in Arak, Iran.

Materials and Methods: This descriptive cross-sectional study included all specimens referred to the microbiology laboratory at Amir Al-Momenin Hospital (academic hospital) and Imam Khomeini Hospital (non-academic hospital) in a one-year period from June 2012 to June 2013. The susceptibility of the isolated Gram-negative bacteria against the important antibiotics used in clinical practice was determined using the disk diffusion method.

Results: A total of 846 specimens were collected from patients in the two hospitals where 520 (61.5%) were Gram-negative bacteria, of which 63.3% were E. coli. The prevalence of Gram-negative organisms in the academic and the non-academic hospital was measured 79.8% and 20.2%, respectively (p=0.097). It was also determined that there is a significant difference between the two hospitals in the prevalence of ESBL (Extended-Spectrum Beta-Lactamase) Gram-negative bacteria (p=0.003).

Conclusion: There was a significant difference between the two hospitals in the prevalence of ESBL Gram-negative bacteria. Therefore, conducting regional surveillance programs to examine the patterns of antibiotic resistance is recommended.