Currently,emerging and re-emerging infectious diseases pose a serious threat to global health security,and have a huge impact on the economies and daily lives of countries around the world.Rapid detection and identification are crucial for monitoring,early warning,and prevention and control of infectious diseases.In recent years,with the rapid development of new materials and scientific technology,detection techniques have continued to innovate and be applied,progressively advancing towards automation,high throughput and real-time diagnosis.This article summarizes the research progress of new infectious disease diagnosis technologies,including CRISPR system,microfluidics technology,and nanoscale PCR,analyzes the advantages and limitations of various new detection technologies and their applications,and proposes prospects for the future develop-ment of detection technologies,in the hope of providing recommendations for monitoring human and animal diseases.

African swine fever(ASF)is a highly contagious and pathogenic disease affecting both domestic and wild pigs,which is caused by African swine fever virus(ASFV).In European epidem-ics,low-virulence strains of ASFV,which do not have hemadsorbing properties,have been identi-fied.Following the identification of highly virulent genotype Ⅱ ASFV strains in China in 2018,subsequently,low-virulence strains of genotype Ⅱ and genotype Ⅰ emerged.Recombination be-tween genotypes Ⅰ and Ⅱ has also led to the occurrence of high-virulence strains.This indicates a complex and diverse genetic evolution of ASFV during the epidemiological transmission,which po-ses significant challenges for vaccine development and disease surveillance.Here,we provide an o-verview of the novel epidemiological characteristics of ASFV,with a focus on genetic variations and pathogenic differences during the outbreaks of ASF.We also explore how ASFV genetic varia-tions impact immune escape and pathogenicity of the virus,and the challenges they pose for vac-cine development,disease diagnosis,and surveillance.The aim of this review is to enhance our un-derstanding of the genetic evolution and mutation mechanisms of ASFV,providing a theoretical basis for the development of vaccines and research on diagnostic technologies.

African swine fever(ASF)is a virulent,hemorrhagic disease of swine caused by African swine fever virus(ASFV),which seriously affects the healthy development of Chinese pig indus-try.The genome of ASFV is large and encodes more than 165 proteins.Among them,the p54 pro-tein is encoded by the E183L gene,which has various functions such as participating in viral as-sembly,inducing apoptosis and inducing immune response.The conventional Chinese vaccine(C-strain)is a safe and effective attenuated vaccine developed by Chinese scientists.It can efficiently protect against attacks from various genotypes of classical swine fever virus(CSFV).The aim of this study was to investigate whether C-strain can express ASFV p54 protein serve as a delivery vector for ASF genetically engineered vaccines.An infectious clone of pHCLV-p54 was constructed by homologous recombination,the recombinant virus rHCLV-p54 was rescued by transfecting it into SK6 cells by blind passaging.Its genetic stability and growth curve were determined in vitro,while rabbits were immunized to evaluate its immunity effect.The results showed that the E183L gene remained genetically stable in the recombinant virus,indicating that the E183L gene could be stably inherited in recombinant viruses,but the inserted exogenous gene affected the replication of the C-strain.The results of the rabbit immunization test showed that the recombinant virus rHCLV-p54 was able to induce ASFV-specific antibodies.The above results indicated that we have successfully constructed a recombinant C-strain that stably expresses the ASFV p54 protein.In summary,the recombinant virus rHCLV-p54 has a good immunogenicity and is warranted for fur-ther evaluation as a vaccine candidate.

Quantitative analysis of UL35 and gB genes at different time points after PRV infection showed that there were significant differences between the two at 2.5,5.0 and 20.0 h after infec-tion,and the expression of UL35 gene could be observed in the early stage of PRV infection.To de-termine whether the UL 35 gene can be used as a target for the diagnosis of PRV infection,a spe-cific primer pair was designed and synthesized according to the conserved sequence of the UL35 gene of different PRV strains,and used to amplify a fragment of 54 bp in length.After optimizing the reaction conditions and system,the standard curve for the established by SYBR Green Ⅰ real-time PCR detection method showed that it had good repeatability,specificity and a good linear rela-tionship to the template concentration.No amplifications for porcine reproductive and respiratory syndrome virus(PRRSV),classical swine fever virus(CSFV),and African swine fever virus(AS-FV)were detected.Compared with the existing similar methods,the established method showed no difference in sensitivity.The coefficient of variation of inter-and intra-group repeatability for the method was less than 2％.Detection of the samples in mice challenged with PRV revealed a certain amount of viral load in tissue.The results showed that UL35 gene can be used as a target for the diagnosis of PRV infection.

Viruses are powerful tools for the study of modern neurosciences. Most of the research on the connection and function of neurons were done by using recombinant viruses, among which neurotropic herpesvirus is one of the most important tools. With the continuous development of genetic engineering and molecular biology techniques, several recombinant neurophilic herpesviruses have been engineered into different viral tools for neuroscience research. This review describes and discusses several common and widely used neurophilic herpesviruses as nerve conduction tracers, viral vectors for neurological diseases, and lytic viruses for neuro-oncology applications, which provides a reference for further exploring the function of neurophilic herpesviruses.
Herpesviridae/genetics* ; Neurosciences ; Genetic Vectors/genetics* ; Genetic Engineering ; Neurons

Viral infection of cells is a highly intricate process that involves the complex virus-cell interactions. Recently, virologists can monitor the virus life cycle at the primary infection site in real-time using various virus tracking techniques. Herpesviruses, a class of large enveloped DNA viruses, are important pathogens threatening the health of humans and animals. This review discussed the applications of different virus tracking techniques in herpesvirus studies, to provide new insights into virus-cell interactions and replication mechanisms of herpesviruses. Though the techniques have widely been exploited, some issues need to be addressed, such as the selection of the optimal site to insert reporters and the inability to track the whole process of the virus life cycle. With the updated tracking techniques, hopefully, more complex replication mechanismsof herpesviruses will be revealed in detail.
Animals ; Herpesviridae ; pathogenicity ; physiology ; Humans ; Virus Diseases ; Virus Physiological Phenomena ; Virus Replication

Classical swine fever (CSF), one of OIE-listed diseases, is a highly contagious and economically important disease of pigs. Classical swine fever virus (CSFV) is the causative agent of CSF. The capsid (C) protein and the glycoproteins Erns, E1 and E2, are structural components of the virus. E2 is the most immunogenic protein of the CSFV glycoproteins, inducing neutralizing antibodies that provide protection against lethal CSFV challenge. In a previous study, we developed a murine MAb HQ06 against the E2 protein of CSFV. In this study, the variable region genes from HQ06 and constant regions gene of swine antibody are fused and cloned into the eukaryotic expression vectors to establish a cell line which can stably express a chimeric porcinized MAb (cHQ06) against E2 in CHO cell. The purified cHQ06 antibody protein was determined to be successfully generated, which exhibited high reactivity between cHQ06 and the E2 protein of CSFV by enzyme-linked immunosorbent assay (ELISA) and Western blotting. More importantly, we investigated the neutralizing activity of cHQ06 against CSFV. In conclusion, this study generated cHQ06 for efficient and stable production which can be used against to develop novel diagnostic assays, investigate the structure and function of the E2 protein and generate novel preparations of diagnosis and treatment.

Vaccination is an important strategy to prevent infectious diseases. However, low antigen yield of vaccine producing strains may lead to high cost of vaccines, low antigen production and vaccine failure. In recent years, many efforts have been made to improve the antigen yield of many vaccines. This mini-review summarizes various methods for increasing the antigen yield for vaccine production, including genetic modification of viruses, improvement of the adaptation of viruses to cells, and optimization of antigen expression systems and manufacturing procedures. Furthermore, we discuss the advantages and the problems of current strategies, as well as indicate the perspectives.

Veterinary biotechnologies that represent the applications of biotechnologies in veterinary science are advancing rapidly in the last decade in spite of relatively late kickoff. This special issue consists of four sections, reviews, new technologies, new methods and others, presenting the recent progress in diagnostic assays, vaccines and others of emerging and reemerging animal infectious diseases.

Classical swine fever (CSF), an acute and highly contagious disease of swine, is caused by classical swine fever virus. CSF is one of the most devastating diseases to the pig industry worldwide and results in serious economic losses. Currently prophylactic vaccination is still an important strategy for the control of CSF. Live attenuated vaccines (such as C-strain) are safe and effective. However, there are significant changes in the clinical features of CSF, displaying concurrent typical and atypical CSF, and simultaneous inapparent and persistent infections. Immunization failure has been reported frequently and it is difficult to distinguish between wild-type infected and vaccinated animals (DIVA). So there is an urgent need to develop more effective and safer DIVA or marker vaccines for the control of CSF. In this review, some of the most recent advances in new-type vaccines against CSF, including DNA vaccines, live virus-vectored vaccines, protein or peptide-based vaccines, gene-deleted vaccines and chimeric pestivirus-based vaccines, are reviewed and discussed.
Animals ; Classical Swine Fever ; prevention & control ; Classical swine fever virus ; Swine ; Vaccination ; veterinary ; Vaccines, Attenuated ; immunology ; Vaccines, DNA ; immunology ; Vaccines, Subunit ; immunology ; Viral Vaccines ; immunology