* Corresponding author. Dr. Mohamad Reza Razavi Tel.: +98 21 66 96 88 55 E-mail address: mrrazavi@yahoo.com International Journal of Molecular and Clinical Microbiology 2 (2012) 194-198 International Journal of Molecular and Clinical Microbiology Evaluation of Antibiotic Resistance to Fluoroquinolones and Third Generation Cephalosporines in Iranian Clinical Isolates of Salmonella spp. Nahid Sepehri Rad 1 (MSc), Mohamad Reza Razavi *1,2 (Ph.D), Seyed Davar Siadat 3 (Ph.D), Mohammad Reza Aghasadeghi 3 (Ph.D), Bahareh Rajaei 3 (MSc), Somieh Khanjani Jafroodi 2 (MSc), Mariam Amin Eshghabadi 2 (MSc), Alireza Azizi Saraji 3 (MSc), Mohammad Doroudian 4 (MSc), Roqiah Gholizadeh Doran Mahaleh 5 (MSc), AmadReza Salehi chaleshtori 6 (MSc) 1 Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran. 2 Department of Parasitology, Pasteur Institute of Iran, Tehran, Iran. 3 Department of Hepatitis and AIDS, Pasteur Institute of Iran, Tehran, Iran. 4 Young Researchers and Elite club, Central Tehran Branch, Islamic Azad University, Tehran, Iran 5 Department of Medical Sciences, Islamic Azad University, Zahedan, Iran. 6 Young Researchers Club, Shahrekord Branch, Islamic Azad University, PO BOX 166 ARTICLE INFO ABSTRACT Article history: Received 15 June 2012 Accepted 26 september 2012 Available online 1 November 2012 Salmonella enterica serotypes are one of the most important food borne pathogens and significant public health concerns around the world in humans and other animal species. A total of eighty three epidemiologically unrelated clinical isolates of Salmonella enterica serovars were subjected to antimicrobial susceptibility testing. Eleven isolates (13.1%) which were resistant to at least 4 groups of antimicrobial agents considered as multidrug resistant (MDR) Salmonella serovars. Emergence of MDR Salmonella serovars demonstrates that antimicrobial selection pressure is widespread in our clinical settings. According to the results of antimicrobial susceptibility testing, Salmonella clinical isolates are more susceptible to fluoroquinolones and third generation cephalosporins and these drugs may be used as drugs of choice to treat Salmonella infections. Keywords: Salmonella spp., Antimicrobial Susceptibility Testing, Multidrug Resistance (MDR) 1. Introduction Salmonella enterica serotypes are one of the most important food borne pathogens and significant public health concerns around the world in humans and other animal species (Hopkins et al., 2005; Yildirim et al., 2011). Invasive Salmonella spp. infections can be fatal and antimicrobial treatment is essential in this situation (Yan et al., 2005). In the past the antibiotics used for the treatment of salmonellosis were chloramphenicol,