Isoӏation molecular identification of Salmoneӏla typhemurium from Iraqi patients/Babylon

A Total of 190 clinical blood specimens were collected during this study which obtained from patients suffering from typhoid fever, who attended to Imam Al-Sadiq Teaching Hospital, and private medical clinics in Babylon province during the period from November 2021 to February 2022. The clinical diagnosis depended on the presence of some symptoms such as fever, headache, anorexia, nausea and vomiting, abdominal discomfort with diarrhea or constipation for (6-18) days. From190 samples were collected and taken out 120 blood samples 70 exit samples. Out of a total of 190 samples, 44 samples showed positive results for salmonella bacteria and 146 negative samples. Out of a total of 120 blood samples, 26 blood samples were positive divided as follows15 samples of Salmonella Typhi,16 Paratyphi B, 1 Samples S. paratyphi A and Sample S. paratyphi B and 12 Samples was S. typhimurium. Enteric fever is a serious public health concern in low-income and middle-income countries, including Iraq. There were 190 samples obtained from a patient suspected of having typhoid fever, with 44 isolates (23 %) testing positive for Salmonella in the culture. Out of 190 specimens 44 (23%) were positive for Salmonella typhi using biochemical tests, VITEK2 compact system, and PCR assay using specific primer. It is probable that the low prevalence of Salmonella isolation from blood and pre-hospital antibiotic treatment was attributable to a shortage of resources at the hospital as a result of the delay in hospital admission. A blood culture is performed on patients in the first week of illness to confirm the diagnosis. Although this method is highly specific, it has a low sensitivity due to a number of factors, one of which is the small number of bacteria required to cause severe infection, which can be less than 10/mL, resulting in a very low positive culture yield and thus the inability to make a definitive diagnosis. Except for the antibacterial effect of antibiotics other potential limitations include the type of culture medium used, the time of blood collection (which may be too late for some patients), the host's immune response system, and the intracellular characteristics of Salmonella. At a molecular level, genotyping of Salmonella typhi isolates was carried out to characterize the genotypic traits by using PCR method targeting the main virulence factors genes. Of the overall 34 Salmonella typhi positive samples were screened for virulence genes included (tyv F, tyv R). PCR technique also used for screening the ( prt F par R gene) which observed in S. paratyphi, while the (tym F, tym R) used for detection of S.typhimurium. Multiplex PCR is a widespread molecular biology technique for simultaneously amplification of multiple targets in a single PCR experiment. In a multiplexing assay, more than one target sequence is amplified by using multiple primer pairs in the same reaction mixture. Multiplex PCR is a cost effective solution for detection of several targets from the same sample.