Endophytic bacteria reside in most healthy plants;it can not be easily influenced by outer environment.Some endophytic bacteria are beneficial to host plants,such as growth promotion,disease prevention and nitrogen fixation etc.Therefore,endophytic bacteria ale the potential microbial fungicides,it may be widely applied.In this study,endophytic bacteria were isolated from soybcan cultivar Hefeng 25 that was a main soybean cultivar in Heilongjiang province,China.The results indicated that the density of endophytic bacteria varied in different tissues of the plant.It was 3.4×103CFU/g in roots,2.8×103CFU/g in leaves,2.9×102 CFU/g in stems and 1.4×102 CFU/g in seeds.The activity of 121strains against Fusarium oxysporum f.sp.soybean,caused soybean root rot,were assayed.25.6% of them showed antagonistic activity against F. oxysporum f. sp.soybean.One of them,strain TF28 isolated from soybean roots could inhibit the growth of many fungal pathogens.The inhibitory rates against F. oxysporum from different plant species were 80.2%-96.7%.Based on the morphological,physiological and biochemical characteristics as well as the sequence of 16S rRNA,strain TF28 was identified as Bacillus amyloliquefaciens.

In recent years,the global situation of tuberculosis disease has deteriorated sharply,and the susceptibility of host to mycobacterium tuberculosis is heterogeneous.Therefore,polymorphism of gene loci plays an important role in the susceptibility to tuberculosis.Vitamin D receptor (VDR) gene has been confirmed as one of the major candidate genes for genetic susceptibility to tuberculosis.The four well-studied major sites are Foki,Bsmi,Apai and Taqi.However,the specific mechanism by which polymorphism affects the occurrence and development of tuberculosis has not been fully elucidated.There is considerable controversy about the relationship between VDR gene polymorphism and tuberculosis susceptibility,mainly due to the interaction between environment and genes,racial differences,etc.This article reviews the polymorphism of VDR gene and its effect on host infected tuberculosis.

Sepsis is a clinical syndrome manifested by organ dysfunction due to disordered inflammatory response after severe infection.The occurrence, development and prognosis of sepsis are closely related to the immune regulation of the body.The essence of sepsis is that the state of excessive proinflammatory response in the early stage gradually progresses to the state of immunosuppression in the late stage, which leads to the body′s inability to resist inflammation and endangers life.As a highly conserved signaling pathway, Notch pathway has the ability to regulate cell growth and differentiation, and participates in the occurrence and development of various inflammatory diseases.In recent years, the important role of Notch signaling pathway in the occurrence and development of sepsis has attracted extensive attention.This article mainly reviews the role of Notch signaling pathway in immune regulation of sepsis.

Mycobacterium tuberculosis(Mtb)is an intracellular bacteria that lives in the phagocytosis of host macrophages.After it invades the human body, it can cause a series of immune responses.Part of Mtb can be eliminated by the body′s immune function; some of them can survive by the immune escape mechanism and cause latent tuberculosis infection(LTBI)or tuberculosis(TB). Exosomes are extracellular vesicles with a diameter of 30-100 nm that are secreted by living cells.They are rich in proteins, lipids and nucleic acids, and exist in many body fluids of the human body.During Mtb infection, the components of exosomes released by the body can change significantly, and they can play an important role in the body′s infection and immune response, providing new ideas and theoretical basis for the prevention, diagnosis and treatment of tuberculosis infection.This article reviews the role and application value of exosomes in Mtb infection.