Characterization of imp/ostA and msbA functions and the mechanism in hydrophobic drugs resistance of Helicobacter pylori

• Main Authors: Hung-Chuan Chiu, 邱泓銓
• Other Authors: Jin-Town Wang
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/17332560438765771970

博士 === 國立臺灣大學 === 微生物學研究所 === 97 === Pre-cleaning and soaking in glutaraldehyde is the necessary procedure to disinfect endoscopes. However, some chemical solvent tolerance bacteria may survive after incomplete endoscopic disinfection. Basing on this, we selected the expression library of H. pylori strain NTUH-C1 with 0.1 % glutaraldehyde obtained seven colonies. After DNA sequencing, DNA fragments of five colonies were identical (homologous to 2.2 kb DNA fragment containing HP0929 and HP0930 of H. pylori strain 26695) and DNA fragments of the other two of the seven colonies were identical (homologous to HP1216 of H. pylori strain 26695). OstA recombinant protein was expressed and used to generate anti-OstA polyclonal antibody. Using OstA polyclonal antibody against cell lysate of wild-type and imp/ostA mutant showed that it is not essential in H. pylori. Organic solvent tolerance assay demonstrated the role of imp/ostA in organic solvent tolerance. Antibiotic susceptibility test showed that the mutation of imp/ostA was susceptible to hydrophobic and β-lactam antibiotics. NPN assay demonstrated that the level of outer membrane permeability was increased 50 % in mutant strain comparing to wild-type strain (P< 0.001). We sought to further clarify the mechanism of glutaraldehyde resistance. The minimal inhibitory concentrations of glutaraldehyde and imp/ostA RNA expression in 49 clinical isolates from National Taiwan University Hospital were determined. After glutaraldehyde induction, RNA expression was higher for strains with minimal inhibitory concentrations of 4~10 μg/ml than for strains with minimal inhibitory concentrations of 1~3 μg/ml. When a microarray was used to study full-genome expression of a strain NTUH-S1 with minimal inhibitory concentration of 6