Reza Khashei - Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
Zahra Navabi - Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
Samaneh Mohebi - Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
Naser Samadi - Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran

Background and Aim:The monitoring of the causative agents of nosocomial infections (Nis), particularly in the Intensive Care Unit (ICU) ward to detect any change in pattern of infection and their resistance profile are crucial. The aim of this study was to investigate the antibiotic resistance pattern among Gram-negative rods isolated from inpatients in ICU different wards in Shiraz, Iran.Methods:In this cross-sectional study from Jaunary to June 2017, 91 different clinical samples were collected from Nemazi teaching hospital ICU wards. After confirmation of all the isolates by the conventional microbiologic methods, antimicrobial susceptibility pattern of them against 11 antibiotics using the disk diffusion test were investigated. Extended-spectrum β-lactamase (ESBL) production was also examined.Results:The isolated bacteria were Acinetobacter baumannii (n=72, 79.1%), Pseudomonas aeruginosa (n=14, 15.4%), and Escherichia coli (n=5, 5.5%). The majority of bacteria were isolated from the respiratory infections. The highest and the lowest resistance rates were observed against ampicillin (100% and 95.8%) among P. aeruginosa and A. baumannii and imipenem and amikacin (0%) among P. aeruginosa and E. coli isolates, respectively. The frequency of multidrug-resistant (MDR) and ESBL-producing isolates was found 84.6% and 19.8%, respectively. Of the MDR isolates, 23.4% were ESBL producers. A significant difference was determined between ESBL production and MDR isolates.Conclusion:Regarding the high rate of antimicrobial resistace among clinical isolates in our region, the antibiotic susceptibility results may be a useful guide for empirical therapy used by physicians.

Nosocomial infections, ICU, Antimicrobial resistace, Iran