ORIGINAL ARTICLE Distribution of virulence genes and multiple drug-resistant patterns amongst different phylogenetic groups of uropathogenic Escherichia coli isolated from patients with urinary tract infection A. Derakhshandeh 1 , R. Firouzi 1 , M. Motamedifar 2 , A. Motamedi Boroojeni 1 , M. Bahadori 1 , S. Arabshahi 1 , A. Novinrooz 1 and S. Heidari 1 1 Department of Pathobiology, School of Veterinary Medicine, Shiraz University, Shiraz, Iran 2 Department of Bacteriology & Virology, Shiraz Medical School, Shiraz University of Medical Sciences, Shiraz, Iran Significance and Impact of the Study: Due to differences in antimicrobial resistance pattern of UPEC iso- lates reported from different geographical regions, the obtained results regarding to antimicrobial sus- ceptibility testing will help physicians, especially those who work in regional healthcare system, to utilize effective targeted antibiotic therapy for UTIs. In addition, the data collected from study of viru- lence genes can be useful for determining frequency of these genes to draw new targets for UPEC anti- biotic independent therapies. Keywords gimA, Iss, ibeA, malX, multiple drug resistance, ompT, traT, uropathogenic Escherichia coli, virulence factors. Correspondence Abdollah Derakhshandeh, Department of Pathobiology, School of Veterinary Medicine, Shiraz University, Shiraz 71345-1731, Iran. E-mail: drkhshnd77@gmail.com 2014/1490: received 22 July 2014, revised 12 October 2014 and accepted 22 October 2014 doi:10.1111/lam.12349 Abstract A total of 85 Uropathogenic Escherichia coli (UPEC) isolates were screened against ceftiofur, oxacillin, nitrofurantoin and lincospectin using Kirby-Bauer disc diffusion method, following CLSI guidelines. Prevalence of virulent factor genes amongst the isolates was determined by PCR, using gene-specific primers against the different virulent factors. Statistical analysis of the data was performed using SPSS software. The prevalence of traT, ompT, Iss, malX and ibeA genes was 471%, 388%, 20%, 165% and 94%, respectively. The most prevalent gene in group A and D was traT, whilst in group B2 was Iss. The highest resistance has been shown against oxacillin (988%), followed by ceftiofur (776%), whilst resistance to lincospectin (24%) and nitrofurantoin (129%) had the lowest frequencies. Multidrug resistance was shown in 8235% of the isolates, whilst this study recommend lincospectin and nitrofurantoin as choice drugs for treatment, but more investigation of the bacterial pathogenicity associated with urinary tract infection (UTI) may contribute to a better medical intervention. Introduction Urinary tract infections (UTIs) are one of the most fre- quent infectious diseases around the world (Kulkarni et al. 2009). Uropathogenic Escherichia coli (UPEC) is the most common pathotype of extra-intestinal pathogenic E. coli is found amongst patients with UTI (Nicolle 2008). UPEC strains possess specialized virulence factors, enabling them to survive and grow in urine and other extra-intestinal environments and invade the host tissues (Russo and Johnson 2000). UPEC virulence factors are located on large plasmids and/or in particular regions, called ‘pathogenicity islands’ (PAIs), on the chromosome. Increased serum survival (Iss) gene and conjugal transfer surface exclusion protein TraT (traT) are tow of plasmid- associated genes encoding outer membrane proteins which is believed to play a role in serum resistance (Mon- tenegro et al. 1985; Johnson et al. 2008). The invasion protein IbeA (ibeA) gene is located on a genomic island, GimA, encoded a protein which plays an important role Letters in Applied Microbiology 60, 148--154 © 2014 The Society for Applied Microbiology 148 Letters in Applied Microbiology ISSN 0266-8254