Standardisation of polymerase chain reaction for the detection of Salmonella typhi in typhoid fever

摘要

To improve the diagnosis of Salmonella typhi infection, a polymerase chain reac- tion (PCR) assay was developed for the amplification of the dH flagellin gene of S typhi. Primers were designed from dH flagellin gene sequence which will give an amplification product of 486 base pairs. In tests to study the specificity of the assay, no amplification was seen in non- salmonella strains or salmonella strains with flagellar gene other than "d". Sensi- tivity tests determined that 28 pg of S typhi target DNA or 3×10~2 target bacteria could be detected by the PCR assay.