Fax +41 61 306 12 34 E-Mail karger@karger.ch www.karger.com Microbiology Chemotherapy 2009;55:287–292 DOI: 10.1159/000224656 Prevalence and Antimicrobial Susceptibility of Extended-Spectrum Beta-Lactamase-Producing Bacteria in Intensive Care Units of Sanandaj General Hospitals (Kurdistan, Iran) Rashid Ramazanzadeh a Mohsen Chitsaz b Nasrin Bahmani a a Microbiology Department, Faculty of Medicine, Kurdistan University of Medical Sciences, Sanandaj, and b Microbiology Department, Faculty of Medicine, Shahed University, Tehran, Iran the ICU setting of Sanandaj’s hospitals. There is a need to institute a strict hospital infection control policy and regular surveillance of bacterial resistance to antimicrobial agents. Copyright © 2009 S. Karger AG, Basel Introduction The risk of a nosocomial infection in patients hospital- ized in intensive care units (ICUs) is 5–7 times higher than those bedded on non-ICU wards, and 20–25% of all nosocomial infections develop in ICUs [1]. Therefore, factors such as underlying disease, severity of illness, type of ICU, extended length of hospital stay and the number, type and duration of invasive devices and pro- cedures are among a range of factors that increase the risk of acquiring nosocomial infections [2]. On the other hand, exposure to various antimicrobial agents may create conditions conducive to resistance se- lection among host bacterial flora or nosocomially trans- mitted pathogens. Thus, the ICU patient frequently expe- riences colonization and infections by resistant patho- gens which pose major clinical problems despite the introduction of new and potent antibiotics [3, 4] . Infec- tions due to Gram-negative organisms continue to be one Key Words Extended-spectrum -lactamase  Intensive care units  Gram-negative bacteria Abstract This study focused on analyzing the spread of extended- spectrum -lactamase (ESBL) enzymes among Gram-nega- tive bacteria at intensive care units (ICUs). Between January 2007 and January 2008, 301 consecutive clinical isolates of Gram-negative type were isolated. Of these, 66 strains were collected from patients in ICUs in two major hospitals in Sanandaj (Kurdistan, Iran). The isolates were identified, tested for antimicrobial susceptibility, and analyzed for the presence of ESBL using the double-disk synergy test. Isolates with a positive ESBL phenotype were subjected to PCR for SHV, TEM, OXA and CTX-M -lactamase gene families. Sixty-six Gram-negative bacteria were isolated from clinical samples of 66 ICU patients. These isolates included 16 Escherichia coli, 28 Enterobacter spp., 5 Pseudomonas spp., 10 Klebsiella pneumoniae, 3 Serratia marcescens and 1 Stenotro- phomonas maltophilia. Twenty-three (34.85%) of these iso- lates were ESBL producing. The ESBL genes detected were SHV, TEM, OXA-1, OXA-2 and CTX-M. The results show the presence of ESBL genes among Gram-negative bacteria in Received: August 5, 2008 Accepted after revision: March 6, 2009 Published online: June 10, 2009 Rashid Ramazanzadeh Microbiology Department, Faculty of Medicine Kurdistan University of Medical Science Pasdaran Street, 66177-13446 Sanandaj (Iran) Tel. +98 914 310 4424, Fax +98 871 666 674, E-Mail atrrop_t@yahoo.com © 2009 S. Karger AG, Basel 0009–3157/09/0554–0287$26.00/0 Accessible online at: www.karger.com/che