Peste des petits ruminants(PPR)is an acute and highly contagious disease caused by peste des petits ruminants virus(PPRV),which mainly infects goats and sheep with high morbidity and mortality. Because of its serious pathological damage and wide spread,PPR has caused huge economic losses to the aquaculture industry and international trade in various countries,so it is particularly important to establish a rapid and accurate detection method for the prevention and control of the disease. This paper reviews the progress in research on biological detection techniques for PPRV detection,such as routine RT-PCR,routine multiplex PCR,real-time fluorence quantitative PCR(RT-qPCR),pyrosequencing,nested PCR(nPCR),loop-mediated isothermal amplification(LAMP)and recombinase polymerase amplification(RPA),so as to provide bases and ideas for scientific detection and identification of PPRV.

Escherichia coli biofilm is a complex membrane aggregation produced by the adhesion and secretion of extracellular polymeric substances by E. coli cells aggregated on specific media. Pathogenic E. coli will evade the immune system and the impact of various harmful factors in the environment after the formation of biofilm, causing sustained and even fatal damage to the host. Cyclic diguanosine monophosphate (c-di-GMP) is a second messenger ubiquitous in bacteria and plays a crucial role in regulating biofilm formation. This paper reviewed the recent studies about the role of c-di-GMP in the movement, adhesion, and EPS production mechanism of E. coli during biofilm formation, aiming to provide a basis for inhibiting E. coli biofilm from the perspective of c-di-GMP.
Bacterial Proteins/genetics* ; Biofilms ; Cyclic GMP/analogs & derivatives* ; Escherichia coli/metabolism* ; Escherichia coli Proteins/metabolism* ; Gene Expression Regulation, Bacterial

Bacillus cereus belongs to Gram-positive bacteria, which is widely distributed in nature and shows certain pathogenicity. Different B. cereus strains carry different subsets of virulence factors, which directly determine the difference in their pathogenicity. It is therefore important to study the distribution of virulence factors and the biological activity of specific toxins for precise prevention and control of B. cereus infection. In this study, the hemolysin BL triayl was expressed, purified, and characterized. The results showed that the bovine pathogenic B. cereus hemolysin BL could be expressed and purified in the prokaryotic expression system, and the bovine pathogenic B. cereus hemolysin BL showed hemolysis, cytotoxicity, good immunogenicity and certain immune protection in mice. In this study, the recombinant expression of hemolysin BL triayl was achieved, and the biological activity of hemolysin BL of bovine pathogenic ceroid spore was investigated. This study may facilitate further investigating the pathogenic mechanism of B. cereus hemolysin BL and developing a detection method for bovine pathogenic B. cereus disease.
Cattle ; Animals ; Mice ; Bacterial Proteins/metabolism* ; Bacillus cereus/metabolism* ; Hemolysin Proteins/metabolism* ; Virulence Factors/metabolism* ; Enterotoxins/metabolism*