Proteomic analysis on the expression of outer membrane proteins of Salmonella enterica serovar Typhimurium putative transporter gene yjeH associated with ceftriaxone-resistance

• Main Authors: Yin-Hung Lin, 林胤宏
• Other Authors: Wensi S. Hu
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/89704054239011748857

碩士 === 國立陽明大學 === 醫學生物技術研究所 === 94 === Insertion mutant 6B7 was derived from the ceftriaxone-resistant strain of Salmonella enterica serovar Typhimurium and has a transposon inserted in the putative transporter gene yjeH. This mutant showed a more-than-four-fold reduction in resistance to ceftriaxone and also significantly changed the levels of expression of four outer membrane proteins. Complementation of the 6B7 mutant by the introduction of a plasmid pBAD-yjeH-DsRed that expressed the wild-type yjeH gene resulted in a return to the normal levels of expression of four outer membrane proteins found in the resistant strain R200. It also completely restored resistance to ceftriaxone. To understand more detail of which outer membrane protein can be influenced by YjeH, the outer membrane protein profile between highly resistant strain R200 and yjeH mutant strain was compared using two-dimensional gel electrophoresis. We observed several protein spots showed either increased or decreased in comparative 2-DE gel. A total of 19 proteins including the protein excised from the SDS-PAGE analyzed by using mass spectrometry (LC-ESI-Q-Tof).We identified the protein in 12 of 19 protein spots. Among these, there are five protein spots with reduced expression. STM3031 protein was found overexpressed in highly resistant strain and merely expressed in the low resistant strain. The E. coli and S. Typhimurium LT2 overexpressed STM3031 protein were susceptible to CRO. The MIC of CRO were raised 4~5 folds in E.coli and 125 folds in S. Typhimurium LT2, respectively. The result suggested the STM3031 is likely associated with CRO-resistance directly.