Aida Hajihosein-Tabrizi, Mehri Habibi, Mohsen Tabasi, Mohammad Reza Asadi Karam,
Volume 6, Issue 1 (1-2018)
Abstract
Introduction: Diarrheagenic Escherichia coli (DEC) including enteropathogenic (EPEC), enteroaggregative (EAEC), enterotoxigenic (ETEC), and shiga toxin producing E. coli are among the most common agents of diarrhea. There are various classes of iron uptake receptors, but there is not much data on the presence of these iron receptors in DEC isolates. The present study aimed to evaluate the presence of iron receptor genes and also hemolysis activity in these isolates. Methods: Totally, 88 DEC isolates (EAEC, ETEC, STEC, and EPEC) from a previous microbial collection were included in this study. The isolates were tested for the production of hemolysin on blood agar plates. Then, Polymerase Chain Reaction (PCR) was used for detection of iron acquisition genes, including chuA, hma, iroN, fyuA, iutA and ireA. Results: Our results showed that 8 (66.7%), 25 (89.3%), 17 (44.4%) and 10 (83.4%) of EPEC, STEC, ETEC and EAEC isolates, respectively had hemolytic activity. All the EPEC isolates were negative for hma gene, and iroN and ireA genes were absent in the EAEC isolates. The frequency of chuA, hma and fyuA genes in the STEC and EAEC isolates was higher, whereas EPEC and ETEC isolates revealed a higher frequency of iroN gene than the STEC and EAEC isolates. Conclusion: This study reports the presence of various iron receptor genes with a significant hemolysin activity in DEC isolates from Iran. The presence of these genes may contribute to the increased pathogenesis of these isolates in the intestinal tract.
Fateme Sefid, Roghayyeh Baghban, Zahra Payandeh, Bahman Khalesi, Mohammad Mahmoudi Gomari,
Volume 7, Issue 4 (10-2019)
Abstract
Introduction: Some strains of Escherichia Coli, including intestinal pathogenic strains, commensal strains, and extra intestinal pathogenic E. coli (ExPEC) have a significant impact on human health status. A standard vaccine designed based on conserved epitopes can stimulate a protective immune response against these pathogens. Additionally, enhanced expression at the infection site as a pathogenesis factor in disease is crucial for an ideal vaccine candidate. The IroN protein plays a role in severe infections of E. coli. Hence, this protein will assist in developing the novel and more efficient treatments for E. coli related infections. A better understanding of protein tertiary structure can help to percept their functions and also their interactions with other molecules. There is a growing interest in using bioinformatics tool to make accurate predictions about the functional, immunological, and biochemical features of target antigens. Method: Herein, we aimed to predict the structure of the IroN protein upon its folding and determine their immunological properties. Results: In the present study, using bioinformatics analyses, we identified the highly antigenic regions of IroN protein. Our designed vaccine candidate had the highest immunological properties and folded into a typical beta-barrel structure. Conclusion: The approach of assigning structural and immunological properties of the target antigen to design the vaccine candidate could be deployed as an efficient strategy to circumvent the challenges ahead of empirical methods without dealing with ethical concerns of animal usage and human participants. Although the obtained results are promising, further experimental studies could bring about more insights on the efficiency of the designed vaccine.
