Research On Host-parasite Interaction And Virulence Factors In Microorganisms

Microorganisms are a large group of organisms that is unicellular or lives in a colony of cellular organism in our world. Though these organisms are small, their activities are closely related with human lives. In the form of parasitism or symbiosis, microorganisms bring people beneficial as well as harm. The microorganisms in human gut play an important role in gaining of nutrients, immunology and metabolism of drugs. Meanwhile, nearly 50% of human diseases were caused by microorganisms.Our studies focused on the influence that microorganism may bring to their hosts. At the first part of this article, we study the parasitic influence on gene expression of host cells. Using the samples of a sort of diseases which are caused by Apicomplexa, we revealed the influence of parasites on the metabolic pathways of host cells. Using the gene expression data of host cells that were infected by plasmodium falcium or Cryptospridium parvum, we revealed the influence of parasites on the metabolic pathways of host cells. The results provided by our enrichments shows the significantly altered pathways after infection. Some of these pathways were reported that have directly interactions with the parasites. The changes of gene expression level in metabolic pathways of host cells showed, from one aspect, how parasites scavenge metabolites from host cells. After the clues provided by gene expression verification and the topological structure of host and parasite, we discussed the character of influences introduced by these two kind of Apicomplexa parasites, we also give a hypothesis of how parasites influences gene expression of metabolic pathways in host cells.In the second part, we integrated gene/protein sequences data of microbial pathogene and build database. As the emergence of Next Generation sequencing technology, the high throughput and low cost facilitates the use of sequencing in microorganism study, and genome sequencing might be the most widely used data in microorganism study. This database provided the sequence data of pathogens and workflow designed for Next Generation sequencing. It quickly checks the possible pathogens in microbial genome, giving clues in gene level. We emphasized the safety problem of probiotics which was overlook in previous study. We collected a sort of gene sequences which are related to the possible harmfulness of probiotics. In our study, we give a method the evaluate harmfulness of different virulence factors, and tried to classify them. Finally, we studied a set of sequence data provided by microorganism we got from clinic follow the work flow in our database. It showed how the database could be used in pathogen classification and harmfulness evaluation.