Infection and Drug Resistance (Jan 2020)
Distribution of Genes Encoding Virulence Factors and the Genetic Diversity of Enteroinvasive Escherichia coli (EIEC) Isolates from Patients with Diarrhea in Ahvaz, Iran
Abstract
Ahmad Farajzadeh-Sheikh, 1, 2 Mohammad Savari, 1, 2 Khadijeh Ahmadi, 2, 3 Hossein Hosseini Nave, 4 Mojtaba Shahin, 5 Maryam Afzali 2 1Department of Microbiology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; 2Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; 3Abadan Faculty of Medical Sciences, Abadan, Iran; 4Department of Microbiology and Virology, School of Medicine, Kerman University of Medical Sciences, Kerman, Iran; 5Department of Medical Laboratory Sciences, Faculty of Medical Sciences, Islamic Azad University, Arak, IranCorrespondence: Maryam AfzaliDepartment of Microbiology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Golestan Blvd 39345-61355, Ahvaz, IranTel +09156127753Fax +98-61-3333 2036Email [email protected]: Entero-invasive E. coli (EIEC) is one of the causes of bacillary dysentery in adults and children. The ability of EIEC to invade and colonize the surface of epithelial cells is influenced by many virulence factors. This study aimed to investigate the distribution of virulence factor genes in EIEC strains isolated from patients with diarrhea in Ahvaz, Iran, as well as the genetic diversity between these isolates by Multilocus variable-number tandem repeat analysis (MLVA).Materials and Methods: A total of 581 diarrheic stool samples were collected from patients with diarrhea attending two hospitals, in Ahvaz, Iran. The E. coli strains were identified by biochemical methods. Subsequently, all E. coli isolates were identified as EIEC by polymerase chain reaction (PCR) for the ipaH gene. The EIEC isolates evaluated by PCR for the presence of 8 virulence genes (ial, sen, virF, invE, sat, sigA, pic, and sepA). All EIEC strains were genotyped by the MLVA typing method.Results: A total of 13 EIEC isolates were identified. The presence of ial, virF, invE, sen, sigA, pic, and sat genes was confirmed among 92.3%, 84.6%, 84.6%, 76.9%, 69.2%, and 15.3% of EIEC isolates, respectively. On the other hand, none of the isolates were positive for the sepA gene. The EIEC isolates were divided into 11 MLVA types.Conclusion: Our results showed a high distribution of virulence genes among EIEC isolates in our region. This study showed that MLVA is a promising typing technique for epidemiological studies. MLVA can supply data in the form of codes that can be saved in the database and easily shared among laboratories, research institutes, and even hospitals.Keywords: entero-invasive Escherichia coli, diarrhea, virulence factor, MLVA
