Determination of genetics variability of Salmonella typhi using molecular RAPD techniques in Ramadi population, Iraq

The main goal of our study is to use the Random Amplification of Polymorphic DNA (RAPD) PCR technique to detect the genetic dimension of isolates of typhoid bacteria to determine which genetic mutation occurred or to presence of the S. typhi and determination of possible usage of PCR technique of S. typhi. Culture results of blood samples taken from a total of 50 individuals were found to be positive in 30 individuals in terms of S. typhi. The number of positive culture cases in the disease period ranging from five to ten days was determined as 20% (10 samples). Likewise, positive blood results had the highest percentage, which was 50% (25 samples). Following this, the rate of positivity in urine analyzes performed in the second period of the disease ranks second with 40% (20 samples). 14 bands with sizes ranging from 200-3000 base pairs in OP-E20, 12 bands with sizes between 250-3000 base pairs in OP-L20, and finally 16 bands with sizes between 350-2500 base pairs in OP-M14 were determined. In this context, the efficiency ratios of OP-E20, OP-L20, and OP-M14 were determined as 33.33, 28.57, and 38.10, respectively. The discrimination abilities of OP-E20, OP-L20, and OP-M14 were determined as 30.76, 28.21, and 41.03, respectively. Number of S. typhi in rural areas is more than in urban areas. Isolation of these bacteria in the early stages of infection is more frequent, and it is isolated from the blood in the later stages of infection. Molecular diagnosis is found more suitable compared to the rest of the types of diagnosis. Results of using primers in RAPD reactions showed a difference in the number of the resulting bands and their molecular weights according to the different primers used. Current study proved that the OP-M14 primer is the most efficient because it contains 16 bands, all of which are different. The efficiency and discrimination ability of OP-M14 were found to be 38.10 and 41.03, respectively, and these ratios were determined as the highest among the primers studied.