Research Advances in Infectious Mononucleosis Caused by Epstein-Barr Virus

Infectious mononucleosis (IM), primarily caused by the Epstein-Barr virus (EBV), manifests as the classic triad of fever, pharyngitis, and cervical lymphadenopathy. Severe cases may involve organ damage, most commonly affecting the liver. Diagnosis relies on a combination of clinical presentation and laboratory parameters, with commonly used indicators including EBV-specific antibodies, EBV-DNA load, and the ratio of atypical lymphocytes. Treatment primarily involves symptomatic supportive care, with a cautious approach to the routine use of antiviral medications. In recent years, significant research in traditional Chinese medicine has been conducted in China, showing promising advancements. This article provides a comprehensive review of EBV-induced infectious mononucleosis, offering insights for clinical diagnosis and treatment.

Genotyping and pathotyping of diversified strains of infectious bronchitis viruses circulating in Egypt

AIM: To characterize the circulating infectious bronchitis virus(IBV) strains in Egypt depending on the sequence of the spike-1(S1) gene [hypervariable region-3(HVR-3)] and to study the pathotypic features of these strains.METHODS: In this work, twenty flocks were sampled for IBV detection using RRT-PCR and isolation of IBV in specific pathogen free(SPF) chicks during the period from 2010 to 2015. Partial sequencing and phylogenetic analysis of 400 bp representing the HVR-3 of the S1 gene was conducted. Pathotypic characterization of one selected virus from each group(Egy/Var-Ⅰ, Egy/Var-Ⅱ and classic) was evaluated in one day old SPF chicks. The chicks were divided into 4 groups 10 birds each including the negative control group. Birds were inoculated at one day by intranasal instillation of 105EID50/100 μL of IBV viruses [IBV-EG/1212B-2012(Egy/Var-Ⅱ), IBV/EG/IBV1-2011(Egy/Var-Ⅰ) and IBV-EG/11539F-2011(classic)], while the remaining negative control group was kept uninfected. The birds were observed for clinical signs, gross lesions and virus pathogenicity. The real-time rR TPCR test was performed for virus detection in the tissues. Histopathological examinations were evaluated in both trachea and kidneys.RESULTS: The results revealed that these viruses were separated into two distinct groups; variant(GI-23) and classic(GI-1), where 16 viruses belonged to a variant group, including 2 subdivisions [Egy/Var-Ⅰ(6 isolates) and Egy/Var-Ⅱ(10 isolates)] and 4 viruses clustered to the classic group(Mass-like). IBV isolates in the variant group were grouped with other IBV strains from the Middle East. The variant subgroup(Egy/Var-Ⅰ) was likely resembling the original Egyptian variant strain(Egypt/Beni-Suif/01) and the Israeli strain(IS/1494/2006). The second subgroup(Egy/Var-Ⅱ) included the viruses circulating in the Middle East(Ck/EG/BSU-2 and Ck/EG/BSU-3/2011) and the Israeli strain(IS/885/00). The two variant subgroups(Egy/Var-Ⅰ and Egy/Var-Ⅱ) found to be highly pathogenic to SPF chicks with mortalities up to 50% than those of the classic group which was of low virulence(10% mortality). Pathogenicity indices were 25(Egy/Var-Ⅱ), 24(Egy/Var-Ⅰ) and 8(classic); with clinical scores 3, 2 and 1 respectively.CONCLUSION: These findings indicated that the recent circulating Egyptian IBVs have multiple heterogeneous origins in marked diversifying nature of their spread, with high pathotype in specific pathogen free chicks.

Protection against Infectious Bronchitis Virus, a Corona Virus Infection, Using Ostrich Antibodies

In chickens, infectious bronchitis (IB) is a major respiratory disease. The respiratory system is the primary multiplication site of IB virus (IBV), a coronavirus, after which the virus is distributed to other organs. Poultry farms sustain considerable economic damage due to IB outbreaks in flocks, since IB causes a severe reduction in weight gain in chicks. In the present study, we produced the ostrich IgY against IBV by immunizing female ostriches with the IB viral antigens. The resultant purified IgY showed a strong neutralizing activity against IBV infection of cultured primary chick kidney cells. The infectivity of IBV was markedly inhibited in the trachea of chicks when ostrich IgY was injected intra-muscularly into newly hatched chicks prior to viral inhalation challenge at two weeks of age. Furthermore, the infection was strongly blocked in the tracheae when IgY was injected into chicks at one day and one week of age, with viral inhalation performed at three weeks of age. These findings suggest that the injection of ostrich IgY can help protect young chicks from IBV infections. In south Asian and African countries, broiler chicks are sent to poultry market around 30 days of age, so it is important to prevent IB outbreaks in very young flocks. We strongly believe that ostrich IgY will be a powerful weapon against IB infection in poultry farms on a wide scale and also hope that these findings will aid in the development of antibody vaccines for new type corona viruses, SARS-CoV and MERS-CoV.

Cloning and Sequencing of S Gene of Novel Variant of Infectious Bronchitis Virus ZJ971 Isolates in China

A novel proventriculopathogic variant (isolate ZJ971) of infectious bronchitis virus (IBV) was identified from enlarged proeventriculus of the sick chickens in the study. The S gene cDNA segment with 3.6 kb in length was amplified by RT-PCR with special primers from the ZJ971 viral isolate of (IBV) and cloned into plasmid pBluescript SK( + ). The recombinants containing S gene of IBV-ZJ971 isolate were identified by digestion of restriction enzyme EcoRI, BamHI and PCR amplification. The cloned S gene from isolate IBV-7J971 was composed of 3492 bp in length encoding for a polypeptide of 1080 amino acids. Comparing the nucleotide of S gene of IBV isolate ZJ971 with that of reported IBV strains Beaudette, M41, Ark99 and CuT2, the homology was 97.3%, 97.5%, 88.6% and 85.6%, respectively; and the homology of the deduced amino acids of S protein of IBV isolate ZJ971 was 96%, 96.3%, 86.1% and 83.1% respectively; especially, the mutation of 3241st nucleotide of S gene of IBV isolate ZJ971 from G to T resulted in the translating termination of S protein at 3240th nucleotide site.

Effects of Traditional Chinese Herbal Medicine on Immune Organ Indexes and Macrophages Phagocytic Indexes in Chickens Infected by Infectious Bronchitis Virus

[ Objective] To study the therapeutic effects of traditional Chinese medicine prescriptions on infectious bronchitis （IB） and find a novel avenue for prevention and treatment of viral diseases in poultry. [Method] A total of 160 cockerels at the age of 15 d were divided into four groups randomly, including traditional Chinese medicine group, moroxydine control group, challenge control group and healthy control group. Except the healthy control group, other groups were challenged with infectious bronchitis virus （IBV） on Day 15. After 48 h post challenge, the traditional Chinese medicine groupand moroxydine control group were respectively administrated with Chinese herbal medicine prescription and moroxydine, continuously for 5 d. The immune organ indexes and macrephage phagocytic indexes were detected on Day 18, 24 and 30, respectively. [ Result] The immune organ indexes and macrophage phagocytic indexes were not significantly different between traditional Chinese medicine group and moroxydine control group on Day 18. But all the indexes of the traditional Chinese medicine groups were increased significantly （ P 〈 0.05） on Day 24 and 30, and showed extremely significant difference （ P 〈 0.01 ） with those of challenge control group on Day 30. [ Conclusion] The traditional Chinese herbal medicine can enhance macrophage phagocytic indexes and immune organs indexes of chickens infected by IBV.

A duplex RT-PCR assay for detection of H9 subtype avian influenza viruses and infectious bronchitis viruses

H9 s ubtype avian influenza virus（AIV） and infectious bronchitis virus（IBV） are major pathogens circulating in poultry and have resulted in great economic losses due to respiratory disease and reduced egg production. As similar symptoms are elicited by the two pathogens, it is difficult for their differential diagnosis. So far, no reverse transcription-polymerase chain reaction（RT-PCR） assay has been found to differentiate between H9 AIV and IBV in one reaction. Therefore, developing a sensitive and specific method is of importance to simultaneously detect and differentiate H9 AIV and IBV. In this study, a duplex RT-PCR（d RT-PCR） was established. Two primer sets target the hemagglutinin（HA） gene of H9 AIV and the nucleocapsid（N） gene of IBV, respectively. Spec ific PCR products were obtained from all tested H9 AIVs and IBVs belonging to the major clades circulating in China, but not from AIVs of other subtypes or other infectious avian viruses. The sensitivity of the d RT-PCR assay corresponding to H9 AIV, IBV and mixture of H9 AIV and IBV were at a concentration of 1×10^1, 1.5×10^1 and 1.5×10^1 50% egg infective doses（EID_（50）） m L^–1, respectively. The concordance rates between the d RT-PCR and virus isolation were 99.1 and 98.2%, respectively, for detection of samples from H9N2 AIV or IBV infected chickens, while the concordance rate was 99.1% for detection of samples from H9N2 AIV and IBV co-infected chickens. Thus, the d RT-PCR assay reported herein is specific and sensitive, and suitable for the differential diagnosis of clinical infections and survei llance of H9 AIVs and IBVs.

Evolutionary implications of Avian Infectious Bronchitis Virus(AIBV)analysis

为开发有效疫苗，识别变化对病毒的幸存哪个氨基酸很重要是必要的。我们在鸟的传染支气管炎病毒(AIBV ) 反调查氨基酸替换特征疫苗的 serotype (DE072 ) 和剧毒的病毒的紧张(GA98 ) 到的遗传因子的领域更好理解 AIBV 的适应进化。另外， SARS Coronavirus (SARS-CoV ) 也以一样的方法被分析。发现极端相似性在氨基酸替换模式在 AIBV 和 SARS 之间存在有趣。它建议总的来说导致的氨基酸变化残余充电变，极性应该被付特殊注意到在疫苗的发展期间。

Molecular Characteristics of S1 Gene of Infectious Bronchitis Virus Isolated from Chicken Proventriculus

Infectious bronchitis virus was isolated from swollen proventriculi of clinically ill chicken. The suspected virus samples (2/97, 3/97, 1/98) were adapted in SPF chicken embryos for virus isolation and identification. All the virus isolates were able to agglutinate chicken erythrocytes after treatment with trypsin, and interfer with the reproduction of Newcastle disease virus in chicken embryos, and have low antigenic relat-edness values with reference positive IBV. The isolates 2/97, 3/97, 1/98 RNAs extracted from the allantoic fluid of inoculated embryonated eggs were converted to cDNA by reverse transcription with 3'-primer of S1 gene of (IBV). Polymerase chain reaction (PCR) was performed with two primers which span the S1 gene. Amplified product of 1. 93 kb was subjected to EcoR I and BamH I digestion and the fragments obtained were the same as expected size. The PCR product was ligated to pBlueScript-SK ( + ) vector, and its nucleotide sequence was determined by the dideoxy-mediated chain termination method. Nucleotide sequence analysis showed 73. 6 - 99. 7% homology between the isolated IBV and the IBV strains in GenBank. The homology of amino acid was 71. 4 - 99.4%.

E Protein Prokaryotic Expression of Avian Infectious Bronchitis Virus

The small envelope protein （E） gene of avian infectious bronchitis virus （IBV） M41 strain was cloned, and then it was subcloned into prokaryotic expressing vector pGEX-6P-1. The recombinant plasmid was transformed into E.coli. BL21 and induced by IPTG. SDS-PAGE result showed that when objective protein fused with GST （about 20 ku）, the relative molecular mass of fusion protein was 38 ku. It indicated that objective protein was about 12.4 ku. The result showed that E protein was expressed successfully, it was useful to the subsequent E protein research.

Isolation and Identification of Avian Infectious Bronchitis Virus

[ Objective] The aim was to isolate and identify avian infectious bronchitis virus （IBV） from diseased chickens. [ Method] IBVs were iso- lated from the diseased chickens in a chicken farm in Anhui Province with blind passage method to observe virus pathogenicity. Then animal regres- sion test was made to replicate symptoms of bronchial congestion in SPF chickens and S1 gene segments were amplified and isolated, followed by comparison with IBV vaccine strains. [ Result] Detection of Hemagglutinating activity （HA） showed that allantoic fluid had no concerning effect on erythrocyte, suggesting that NDV and AIV were not included in the isolated viruses. However, the erythrocyte could be agglutinated with allantoic fluid treated with 1% of pancreatin, which is in consistent with biological characters of IBV. After SPF chickens were inoculated with the 6^th SPF al- lantoic fluid, bronchial congestion was replicated, proving that the isolated virus was avian IBV, named IBV XZ strain. [ Conclusion] This study pro- vides a theoretical basis for prevention of avian infectious bronchitis.

Prokaryotic Expression of Infectious Bronchitis Virus S1 Gene and Analysis of Biological Activity of Recombinant Protein

[Objective] To study the prokaryotic expression and antigenicity identification of S1 gene from avian infectious bronchitis virus （IBV）. [Method] The S1 gene was cloned into a pMD18-T vector to yield a recombinant plasmids pMD18-T-IBV-S1. Then S1 gene was inserted into the multiple cloning site of a prokaryotic expression vector pET-32a （ ＋ ）. The recombinant plasmid was transformed into E. coil BL21. The recombinant protein was induced by IPTG and measured by SDS-PAGE and western-blotting. [Result] The S1 gene was successfully expressed in E. coil BL21, the fusion proteins were about 66.0 kDa in a form of inclusion body. Western-blotting test showed that the recombinant proteins could be identified by IBV polyclonal antibody. [ Conclusion] The recombinant proteins of S1 gene have the antigenicity, which lays a good foundation for further research on new generation vaccine of IBV.

The Establishment of Fluorescent PCR Detection Method for Avian Infectious Bronchitis Virus

[ Objective] The aim was to to establish a kind of peculiar, sensitive and quick fluorescent PCR detection method. [Method] A peculiar, sensitive and quick method of fluorescent PCR detection for avian infectious bronchitis virus was established, the standard curve was built, specific primers, susceptibility and repeatability was detected. [ Result] This method diagnosed avian infectious bronchitis virus peculiarly, sensitively and quickly, simple and easy to use, time short, suitable for clinical testing. [ Conclusion] This research laid the foundation to diagnose avian infectious bronchitis virus.

Isolation and Identification of Avian Nephropathogenic Infectious Bronchitis Virus

In November 2009, a respiratory disease with rapid transmission, rapid onset and mortality of about 8% appeared many times in a large chicken farm in Jiangsu Province of China. Necropsy revealed tracheal bleeding, kidney enlargement and white-spotted kidney. An isolate from the farm was identified as an avian infectious bronchitis virus （IBV） by chicken embryo inoculation, hemagglutination assay, virus interference assay, animal regression and tracheal rings culture. The complete ,S1 gene was amplified by RT-PCR, and its homology to that of the vaccine strains com- monly used in China was analyzed with DNAStar software. Therefore, the IBV isolate was initially classified into nephropathogenic IBV and named IBV JS09 strain.

Development of a Microplate Lectin-Capture RT-PCR (MLC-RT-PCR) for the Detection of Avian Infectious Bronchitis Virus

Rapid, sensitive and specific methods are necessary to confirm the diagnosis of outbreaks of avian infectious bronchitis virus (IBV) infection. The amplification of IBV genome by reverse transcription followed by polymerase chain reaction (RT-PCR) has been one of the most used methods for the detection of this virus in clinical samples. To reduce the time and the number of steps in the molecular diagnosis of IBV, we developed a sensitive and rapid detection method based on viral capture by a lectin (Concanavalin A—Con A) in the microplate wells, followed by RT-PCR to amplify the S1 gene. The detection limit of IBV was 103 EID50/ml for the amplification of 5’part of the S1 gene, and 104 EID50/ml for the amplification of full S1 gene. This technique was specific for IBV detection, and no amplified products were detected for other avian viral pathogens (bursal infectious disease virus, avian metapneumovirus and Newcastle disease virus). The MLC-RT-PCR was as sensitive as conventional RT-PCR, and virus isolation method for the detection of IBV in tissue samples collected from experimentally infected birds. The MLC-RT-PCR technique demonstrated a great potential for the rapid and specific diagnosis of IBV.

Correlation between Hemagglutination Inhibition Titer and Protection against Infectious Bronchitis Virus Challenge in SPF Layers

[ Objective] To study the correlation between HI titer and protection against IBV challenge in SPF layers. [ Method ] SPF layers were randomly divided into four groups, namely group A1, A2, B1 and B2. The group A1 was immunized with H120 live vaccine. The group A2 was first immunized with H120 live vaccine and later boosted with ND-IB-EDS trivalent inactivated vaccine. The group B1 was used as unimmunized chal- lenge control. The group B2 was kept as unimmunized unchallenged control. The blood samples were taken prior and post-vaccination at intervals and HI tests were conducted. At the laying peak, the group A1, A2 and B1 were challenged with IBV M4t virulent strain. The clinical features and egg production of layers were monitored and recorded. [Result] After 30 d post vaccination with H120 live vaccine, the HI titer reached 4.45 log2; after 30 days boosting with ND-IB-EDS trivalent inactivated vaccine, the HI titer reached to 7.35 log2. Before challenge, HI antibody titer in group A1, A2, B1 and B2 were respectively 4.24 log2, 7.40 Iog2, 2.10 log2 and 2.10 log2. After challenge, chickens in unimmunized challenge control group B1 showed respiratory symptoms, egg production dropped by 30.9%, and they produced more soft-shelled, no-shelled or abnormal eggs. In the group A1, some chickens had light respiratory symptoms and egg production dropped by 11.7%. In the group A2, the egg production of all chickens was as normal as the group B2. [ Conclusion] When the HI titer was over 6 log2, challenge by virulent virus had no impact on egg produc- tion; when the HI titer was 5 log2, 4 log2 and less 3 log2, egg production dropped by 6.0%, 11.3% and 29.6%, respectively. Thus, the HI anti- body level in chickens has close correlation with protection against IBV challenge.

Characterisation and separation of infectious bursal disease virus-like particles using aqueous two-phase systems

Infectious bursal disease(IBD)causes considerable economic losses in the commercial poultry industry worldwide.The principal way to control IBD virus(IBDV),the causative agent of IBD,is still through vaccination programs.Virus-like particles(VLPs)are recognised as a safe and potent recombinant vaccine platform.This research work explores the characterisation and separation of infectious bursal disease virus-like particles(IBD-VLPs)from crude feedstock.Various characteristics were studied with highperformance size-exclusion chromatography(HP-SEC),sodium dodecyl sulphate–polyacrylamide gel electrophoresis(SDS-PAGE)and transmission electron microscopy(TEM)analyses.Subsequently,the separation of IBD-VLPs using polyethylene glycol(PEG)/sodium citrate-based aqueous two-phase systems(ATPSs)was conducted and optimised.Moreover,a scale-up study of the best ATPS constituted of 15%PEG 6000,11%sodium citrate and 10%crude feedstock was performed to compare the separation performance of IBD-VLPs with and without centrifugation-assisted.The results indicated that the optimised ATPS with centrifugation-assisted for both 5 g and 50 g systems showed good recovery of IBDVLPs of>97%in the interphase between the PEG-rich top and salt-rich bottom phases.These optimised systems also showed high removal efficiencies of impurities of>95%.The results demonstrated that aqueous two-phase extraction could be a promising technology for efficient VLPs separation.

Effect of Astragalus polysaccharides on Erythrocyte Immune Adherence of Chickens Inoculated with Infectious Bursal Disease Virus

Two hundred and forty specific pathogen free leghorn chickens were randomly divided into four groups and reared in isolated pens. The tested chickens were negative to infectious bursal disease virus （IBDV） at 25 d old. Group 1 was treated with saline, whereas Groups 2, 3, and 4 were inoculated with 0.3 mL IBDV suspension intranasally the next day. Groups 3 and 4 were also administered with Astragalus polysaccharides （APS） intramuscularly twice daily at 5 or 10 mg kg-1 BW, respectively, until 31 d old. The erythrocyte-C3b receptor rosette rate （E-C3bRR） and the erythrocyte-C3b immune complex rosette rate （E-ICRR） were measured at 25, 29, 32, 35, and 38 d old. The results showed that IBDV significantly reduced E-C3bRR and E-ICRR when compared with the control group （P 〈 0.05）, while simultaneous administration of APS with 1BDV maintained E-C3bRR at similar levels to the control group （P 〉 0.05） and increased E-ICRR when compared with the control group and the group non-treated with APS （P 〈 0.05）. APS treatment reduced the morbidity and mortality of chickens inoculated with IBDV （P 〈 0.05）. The results suggest that APS may enhance the immune adherence of chickens erythrocytes by affecting the activity and/or the number of complement receptors on the erythrocyte membrane. These findings can be beneficial in providing an understanding of the basic mechanisms required for the rational application of APS in modern medicine.

Infectious laryngotracheitis virus in chickens

Infectious laryngotracheitis(ILT) is an important respiratory disease of chickens and annually causes significant economic losses in the poultry industry worldwide. ILT virus(ILTV) belongs to alphaherpesvirinae and the Gallid herpesvirus 1 species. The transmission of ILTV is via respiratory and ocular routes. Clinical and post-mortem signs of ILT can be separated into two forms according to its virulence. The characteristic of the severe form is bloody mucus in the trachea with high mortality. The mild form causes nasal discharge, conjunctivitis, and reduced weight gain and egg production. Conventional polymerase chain reaction(PCR), nested PCR, real-time PCR, and loop-mediated isothermal amplification were developed to detect ILTV samples from natural or experimentally infected birds. The PCR combined with restriction fragment length polymorphism(RFLP) can separate ILTVs into several genetic groups. These groups can separate vaccine from wild type field viruses. Vaccination is a common method to prevent ILT. However, field isolates and vaccine viruses can establish latent infected carriers. According to PCR-RFLP results, virulent field ILTVs can be derived from modified-live vaccines. Therefore, modified-live vaccine reversion provides a source for ILT outbreaks on chicken farms. Two recently licensed commercial recombinant ILT vaccines are also in use. Other recombinant and gene-deficient vaccine candidates are in the developmental stages. They offer additional hope for the control of this disease. However, in ILT endemic regions, improved biosecurity and management practices are critical for improved ILT control.

An improved scheme for infectious bursal disease virus genotype classification based on both genome-segments A and B

Infectious bursal disease(IBD)is caused by infectious bursal disease virus(IBDV),which has a genome consisting of two segments of double-stranded linear RNA.IBDVs have been traditionally divided into four phenotypes based on their pathogenicity and antigenicity,including classic,variant,very virulent,and attenuated IBDV.With the emergences of divergent molecular characteristics of novel strains produced by continuous mutations and recombination,it is increasingly difficult to define new IBDV strains using the traditional descriptive classification method.The most common classification scheme for IBDV with segmented genome is based solely on segment A,while the significance of segment B has been largely neglected.In this study,an improved scheme for IBDV genotype classification based on the molecular characteristics of both VP2(a viral capsid protein encoded by segment A)and VP1(an RNA-dependent RNA polymerase protein encoded by segment B)was proposed for the first time.In this scheme,IBDV was classified into nine genogroups of A and five genogroups of B,respectively;the genogroup A2 was further divided into four lineages.The commonly used phenotypic classifications of classic,variant,very virulent,and attenuated IBDVs correspond to the A1 B1,A2 B1,A3 B2,and A8 B1 genotypes of the proposed classification scheme.The novel variant IBDVs including the strains identified in this study were classified as belonging to genotype A2 d B1.The flexibility and versatility of this improved classification scheme will allow the unambiguous identification of existing and emerging IBDV strains,which will greatly facilitate molecular epidemiology studies of IBDV.

Genome Analysis of the Bombyx mori Infectious Flacherie Virus Isolated in China

We reported here the complete genome of the Bombyx mori infectious flacherie virus （BmlFV）, BmlFV-CHN01, isolated in China and compared it with the Japanese strain IFV （BmIFV-JAN） sequence. BmIFV-JAN and BmIFV-CHN01 were 99% identical in nucleotide and amino acid sequences. The amino acid sequences of the three structural proteins （VP1, VP3 and VP4） and L protein were 100% identical between the two strains. Phylogenetic analyses based on conserved domains in RNA-dependent RNA polymerases （RdRps） by the neighbor-joining method showed that these two strains were from the same virus. The gain of the whole genome of the BmIFV isolated in China and its weak mutation character established a great foundation to the study of functional genome and the molecular epidemiology of BmIFV.