REGULAR ARTICLE The population structure of Salmonella enterica Enteritidis in Iran analyzed by multiple-locus variable-number tandem repeat analysis Rainak Ghaderi & Keyvan Tadayon & Sargis Avagyan & Pejvak Khaki & Soheila Moradi Bidhendi & Ken James Forbes & Nader Mosavari & Mohammad Reza Toroghi & Farhad Moosakhani & Reza Banihashemi & Mohamad Sekhavati & Nasim Karimnasab Accepted: 12 October 2012 / Published online: 25 October 2012 # Springer Science+Business Media Dordrecht 2012 Abstract Salmonella enterica Enteritidis is the most fre- quent etiological agent of salmonellosis in humans and poul- try. To understand the genetic diversity of S. Enteritidis in Iran, we examined 69 chicken isolates from 18 broiler farms and six non-epidemic human isolates from six geographically distant provinces by multi-locus variable-number tandem repeat anal- ysis (MLVA). Among SE2, SE3, SE5, SE7, SE8, SENTR4, and SENTR7, only SE5 with four and SENTR7 with two alleles, respectively, proved variable giving estimates of locus genetic diversity of 0.58 and 0. In all, six closely related MLVA profiles were identified among which three were com- monly represented by human and chicken isolates. This pop- ulation homogeneity contrasts with the high diversity at these loci reported elsewhere and is likely a consequence of a single clone of S. Enteritidis distributed across Iran. Keywords Salmonella enterica Enteritidis . MLVA . VNTR . Genetic diversity Introduction Salmonella enterica consisting of six subgroups (Ι, ΙΙ, ΙΙΙa, ΙΙΙb, ΙV, and VΙ) together with Salmonella bongori compose the Salmonella genus (Popoff et al. 2004; Kruy et al. 2011). Subgroup Ι, generally known as S. enterica subsp. enterica R. Ghaderi : K. Tadayon (*) : R. Banihashemi : M. Sekhavati Veterinary Aerobic Bacterial Research and Vaccine Production Department, Razi Vaccine and Serum Research Institute, Karaj 3197619751, Iran e-mail: k.tadayon@rvsri.ac.ir K. Tadayon e-mail: k.tadayon@rvsri.ac.ir P. Khaki : S. M. Bidhendi Microbiology Department, Razi Vaccine and Serum Research Institute, Karaj, Iran R. Ghaderi : S. Avagyan Microbiology and Virology Department, Faculty of Veterinary Medicine and Animal Husbandry, Armenian State Agrarian University, Yerevan, Armenia K. J. Forbes School of Medicine and Dentistry, University of Aberdeen, Aberdeen, UK N. Mosavari PPD Tuberculin Department, Razi Vaccine and Serum Research Institute, Karaj, Iran M. R. Toroghi Mashad Branch, Razi Vaccine and Serum Research Institute, Mashad, Iran F. Moosakhani Microbiology Sciences Department, Faculty of Veterinary Medicine, Islamic Azad University, Branch of Karaj, Karaj, Iran N. Karimnasab Islamic Azad University, Branch of Karaj, Karaj, Iran Trop Anim Health Prod (2013) 45:889–894 DOI 10.1007/s11250-012-0301-3