Endophytes, found ubiquitous in all plant species in the world, contribute to their host plants by producing plenty of substances that provide protection and ultimately survival value to the plant. Many researches have proven that endophyte is a new and potential source of novel natural products for exploitation in modern medicine, agriculture and industry. So far, a great number of novel natural products possessing antimicrobial activities have been isolated from endophytes. It is believed that screening for antimicrobial compounds from endophytes is a promising way to overcome the increasing threat of drug resistant strains of human and plant pathogen. Antimicrobial metabolites isolated from endophytes belong to diverse structural classes, including: alkaloids, peptides, steroids, terpenoids, phenols, quinones, and flavonoids. In this review, many well-studied areas are presented and examples will be given to discuss the structure of compounds isolated from endophytes extracts with antimicrobial activities and show the wide variety of approaches taken within the field. These achievements would provide the opportunity to utilize endophytes as a new source for production of antibiotics.

Background:No transcriptional factor has been characterized as a c-di-AMP-responsive regulator in bacteria. Results: A TetR-like regulator, DarR, could specifically bind c-di-AMP and repressed gene expression in M. smegmatis. Conclusion: DarR is the first cyclic di-AMP receptor regulator to be identified in bacteria. Significance: Our findings provided an opportunity to understand the physiological function and regulatory mechanism of c-di-AMP.

Analysis of the protein-protein interaction network of a pathogen is a powerful approach for dissecting gene function, potential signal transduction, and virulence pathways. This study looks at the construction of a global protein-protein interaction (PPI) network for the human pathogen Mycobacterium tuberculosis H37Rv, based on a high-throughput bacterial two-hybrid method. Almost the entire ORFeome was cloned, and more than 8000 novel interactions were identified. The overall quality of the PPI network was validated through two independent methods, and a high success rate of more than 60% was obtained. The parameters of PPI networks were calculated. The average shortest path length was 4.31. The topological coefficient of the M. tuberculosis B2H network perfectly followed a power law distribution (correlation = 0.999; R-squared = 0.999) and represented the best fit in all currently available PPI networks. A cross-species PPI network comparison revealed 94 conserved subnetworks between M. tuberculosis and several prokaryotic organism PPI networks. The global network was linked to the protein secretion pathway. Two WhiB-like regulators were found to be highly connected proteins in the global network. This is the first systematic noncomputational PPI data for the human pathogen, and it provides a useful resource for studies of infection mechanisms, new signaling pathways, and novel antituberculosis drug development.

No abstract

No abstract