爲了解以聚合酶鏈反應之快速方法，代替傳統生化型及血清型鑑定分離自臨床檢體之 傷寒桿菌之可行性，本研究以妳M之鞭毛抗原基因（m-d)所發展出之PCR引子ST1及 ST2對衛生署預防醫學研究所提供，由臨床檢體分離之50株S.妳扮菌株進行PCR檢測，其 結果皆爲正反應，而其他血清型沙門氏菌及非沙門氏菌之腸内菌科細菌，則皆無PCR產物 之產生。若直接進行一次聚合酶鏈反應，則其檢測之靈敏度達104 CFU，然若進行二次聚合 酶鏈反應，則其檢測靈敏度可提高至10G CFU。上述實結果顯示PCR技術爲一快速、可靠 之方法，並可用於臨床分離之傷寒桿菌之快速鑑定。

In order to evaluate the applicability for using the polymerase chain reaction (PCR) method to replace the conventional biotyping and serotyping method for identification of Salmonella typhi isolated from suspected typhoid patients, PCR primers derived from the H 1-d gene coding for S. typhi flagellin were used for the identification of S. typhi strains obtained from the Institute of Preventive Medicine, Taipei, Taiwan. All 50 S. typhi isolates were capable of generating positive reactions. In addition , Salmonella isolates other than S. tvphi and non-Salmonella isolates includ-ing strains of Enterobacteriaceae did not yield positive reaction. Study on the detection sensitivity for this PCR system shows that when single PCR running was performed, the minimal cell number required to give a positive reaction was 104 . However , when double PCR running was performed, the detection sensitivity increased to I 0° CFU. Therefore, these preliminary data indicates that PCR is a rapid and reliable method that can be used for the identification of S. typhi responsible for sporadic typhoid cases.