Search

Mycobacterium tuberculosis has infected more than two billion individuals worldwide, of whom 5%–10% have clinically active disease and 90%–95% remain in the latent stage with a reservoir of viable bacteria in the macrophages for extended periods of time. The tubercle bacilli at this stage are usually called dormant, non-viable, and/or non-culturable microorganisms. The patients with latent bacilli will not have clinical pictures and are not infectious. The infections in about 2%–23% of the patients with latent status become reactivated for various reasons such as cancer, human immunodeficiency virus infection, diabetes, and/or aging. Many studies have examined the mechanisms involved in the latent state of Mycobacterium and showed that latency modified the expression of many genes. Therefore, several mechanisms will change in this bacterium. Hence, this study aimed to briefly examine the genes involved in the latent state as well as the changes that are caused by Mycobacterium tuberculosis. The study also evaluated the relationship between the functions of these genes.

Background: Escherichia coli uropathogen is the most prevalent pathogen separated from urinary tract that often is originated from intestinal flora of the own person. Urinary tract infection is one of the most prevalent infectious diseases in Human. Whereas binding stage has an important role in bacteria colonization and then the infection is created, one of the most important strategies for inhibiting the infection is inhibiting the bacterial binding. As fimH protein is acting as adhesion it could be an appropriate candidate for producingvaccine. Material and Methods: First, genomic DNA of Escherichia coli bacteria extracted from strain 35218 ATCC. Upon designing primer for fimH gene, the PCR reaction has been applied with Taq DNA Polymerase and then pfu DNA polymerase enzymes. pBluescript (SK-) plasmid has been applied for cloning the product of PCR. Using ClustalW and MEGA4 software, the subsequence was alignmented with the gene subsequence existing in gene bank and its gene diversity was examined. Results: After sequencing the cloned fimH gene using ClustalW and MEGA4 software, the result of this subsequence were alignmented with the subsequence of Escherichia coli containing fimH gene existing in gene bank and based on this alignment, N terminal on the protein surface and DNA are protected. Conclusion: N terminal domain of fimH gene is a conserved sequence among clinical isolates and it could be used for designing a vaccine against urinary tract infection.