en تشخیص کمی سالمونلا تیفی با تکنیک Real-Time Loop-Mediated Isothermal Amplification براساس ژن ViaB ميكروبیولوژی Microbiology پژوهشي Research <div style="text-align: justify;"><strong>Background & Objective:</strong>&nbsp;The <em>Salmonella</em> origin diseases is wide which could be from gastroenteritis, enteric fever, bacteraemia and focal infection. The infection of salmonella usually comes from the consumption of the contaminated food or water with animal or human excrement. This study aimed to design a Quantitative-LAMP method to real-time detection of <em>Salmonella enterica</em> serovar Typhi (<em>S. </em>Typhi), the causative agent of Typhoid fever.<br> <strong>Materials & Methods:</strong> A new LAMP primer set specifically was designed based on <em>ViaB</em> gene and used for detection of <em>S. Typhi.</em> To evaluate the analytical specificity, the genome of some Salmonella-related and non-related bacteria were subjected to the <em>S. </em>Typhi LAMP assay. Also, the analytical sensitivity or limit of detection of the assay was evaluated. Furthermore, in the experiment, turbidity in tubes was assessed by a turbidimeter and then a standard curve was depicted by plotting time threshold values against the log of <em>ViaB</em> gene copy number. With this standard curve, we could use the method to make a quantitative method</div> <strong>Results:</strong> The <em>Salmonella</em> <em>Typhi</em> LAMP assay specifically assessed the <em>ViaB</em> gene. The analytical sensitivity of the assay when using agarose gel electrophoresis or amplification plot obtained from Loop amp real-time turbidimeter system was 0.28 fg whereas with direct observation of fluorescent color change to evaluate amplification was 2.8 fg. So, the lower limit of detection of the assay when applying the revealing methods was ~1 and 8 copies of the <em>ViaB</em> gene respectively.&nbsp;<br> <strong>Conclusions:</strong> The <em>Salmonella</em> <em>Typhi</em> LAMP assay is a simple and accurate tool to detect the causative agent of Typhoid fever that may designate to apply in clinical laboratories LAMP, Salmonella Typhi, Typhoid fever, Specificity and Sensitivity 3831 3838 http://jabs.fums.ac.ir/browse.php?a_code=A-10-2134-4&slc_lang=en&sid=1 Mahdi Sohrab مهدی سهراب 100319475328460026350 100319475328460026350 No Department of Microbiology, Islamic Azad University, Qom Branch, Qom, Iran گروه میکروبیولوژی، دانشگاه آزاد اسلامی واحد قم، قم، ایران Keivan Majidzadeh کیوان مجیدزاده 100319475328460026351 100319475328460026351 No Breast Cancer Research Center (BCRC), Academic Center for Education, Culture & Research (ACECR), Tehran, Iran مرکز تحقیقات سرطان سینه، جهاد دانشگاهی تهران، تهران، ایران Abbas Morovvati عباس مروتی Abbasmorovvati@gmail.com 100319475328460026352 100319475328460026352 No Department of Microbiology, Islamic Azad University, Qom Branch, Qom, Iran گروه میکروبیولوژی، دانشگاه آزاد اسلامی واحد قم، قم، ایران Mohammad Soleimani محمد سلیمانی Soleimanidor@yahoo.com 100319475328460026353 100319475328460026353 Yes Department of Microbiology, Faculty of Medicine, AJA University of Medical Sciences, Tehran, Iran گروه میکروبیولوژی، دانشگاه علوم پزشکی ارتش، تهران، ایران