This study was conducted to determine the antimicrobial susceptibility patterns among common pathogens in the intensive care units (ICUs) of a university hospital in northwestern Iran. A retrospective study was done on laboratory records of patients with nosocomial infection who were admitted to five ICUs of Imam Reza Hospital during a 21-month period from March 2010 to January, 2012. A total number of 556 isolates from 328 patients were evaluated. The most common sites of infections included respiratory (51.7%), urinary (24.8%), and blood (10.4%). The most frequently isolated microorganisms were Enterobacter aerogenes (50.6%) followed by Escherichia coli (16.7%) and Pseudomonas aeruginosa (7.5%). Staphylococcus aureus was the most frequent pathogen among gram-positives (39.7%). The rate of methicillin-resistant Staphylococcus aureus (MRSA) was 87.5%. Multidrug-resistant (MDR) gram-negative bacteria were documented in 25.8% of Acinetobacter, 20% of Klebsiella, and 16.6% of Pseudomonas. The most active antimicrobials were vancomycin (93.5%) followed by amikacin (71.5%) and gentamicin (46%). The overall antibiotic susceptibility was as follows: 36% ciprofloxacin, 19% imipenem, 20% trimethoprim-sulfamethoxazole, 20.5% ceftazidime, and 12% ceftriaxone. Due to the high rate of antimicrobial resistance in the ICU setting, more surveillance and control of the use of antimicrobials is needed to combat infections.
Uniterms:Intensive care units/anti-infective agents/cross infection. Hospital University/Iran.
INTRODUCTION
Patients a d m i t t e d t o intensive care units (ICUs)are more vulnerable to various nosocomial infections because of their underlying illnesses and exposure to various invasive medical devices (Jatin, Mary, 2012;Archibald et al., 1997;Fridkin, 2001;Kollef, Fraser, 2001;Rhomberg et al., 2006).Hospital infections affect approximately two million patients annually and lead to 90,000 deaths and a cost of $4.5 to $5.7 billion according to reports from the United States (Weinstein, 1998;Jarvis, 2001). They involve 5-10% of ICU patients (CDC, 1992;Stone, Larson, Kawar, 2002).Antibiotics are the mainstay tools in the management of infections. Disappointingly, a number of studies have reported inappropriate uses of antimicrobials as well as the emergence of antibiotic resistance in most parts of the world (Tunger et al., 2009; Bergman et al., 2006). Today, the emergence of multidrug-resistant (MDR) gramnegative and methicillin-resistant Staphylococcus aureus (MRSA) pathogens has become a major public health concern. Moreover, they negatively influence patients' outcomes and increase the length of hospital stays and healthcare costs (Giske et al., 2008;De Kraker et al., 2011;Resch, Wilke, Fink, 2009;Mulvey, Simor, 2009).Many studies have also showed that controlled use of antibiotics leads to improved microorganism sensitivity H. Hamishehkar, P. Shadmehr, A. Mahmoodpoor, S. O. Mashayekhi, T. Entezari-Maleki 404 to antimicrobial agents (Lee et al., 2010;Takesue et al., 2010). The emergence of resistant pathogens ...
