In this issue, we established rapid, cost-effective, and simple detection methods including recombines polymerase amplification with lateral flow dipstick (RPA-LFD) and real-time RPA for cyprinid herpesvirus 3(CyHV-3), and evaluated their sensitivity, specificity, and applicability, the real-time RPA method could achieve sensitive diagnosis of CyHV-3 within 1.3 copies per reaction, respectively. The real-time RPA method is 10-fold more sensitive than RPA-LFD method. The exact number of CyHV-3 can be calculated in each sample by real-time RPA. The sera from koi also can be tested in these methods. In addition, no cross-reaction was observed with other related pathogens, including carp oedema virus (CEV), spring viraemia of carp virus (SVCV), cyprinid herpesvirus 1(CyHV-1), cyprinid herpesvirus 2(CyHV-2), type I grass carp reovirus (GCRV-I), type II GCRV (GCRV-II), type III GCRV (GCRV-III), and Aeromonas hydrophila.

Sera obtained from convalescent individuals, and vaccinated individuals can induce low neutralizing efficacy against variants of concerns (VOCs) of SARS-CoV-2. In addition, the majority of COVID-19 vaccines are less efficacious against VOCs when compared to their efficacy against the original virus. Immune escape is one of the significant mechanisms observed during SARS-CoV-2 infection due to the substantial mutational capacity of VOCs such as B.1.1.7, P.1, B.1.351, B.1.617.2, C.37, and B.1.621. Omicron, a novel strain of SARS-CoV-2, also referred to as B.1.1.529, was identified in South Africa. This variant is a potential new VOC by the World Health Organization (WHO), and confirmed cases have been arising across several nations due to its rapid spreading ability. Omicron variant can acquire substantial immune escape following Delta, Beta/Gamma D614G VOCs and subsequently facilitating potential infectivity due to its enhanced ACE2 binding ability. The Omicron variant is a highly mutated variant accompanied by higher transmissibility and immune evasion. This mini review describes the ability of VOCs to acquire immune escape and also describes the comparative neutralization efficacy of several vaccines, including Booster doses against SARS-CoV-2.

African swine fever (ASF), caused by African swine fever virus (ASFV), is a fatal infectious disease of pigs and causes great socioeconomic losses globally. The reliable diagnostic method is critical for prevention and control of the disease. In this study, an improved Luciferase immunosorbent assay (LISA) for detecting ASF was developed using the cell lysates containing ASFV p35 protein fused with a reporter Nano-luciferase (p35-Luc protein). The improved method avoids the complicate procedures of immobilizing the serum samples with protein G in the normal LISA method, and replaced by directly coating the serum samples with carbonate buffer, therefore reduces the productive cost and simplifies the operation procedures. The p35-Luc LISA exhibited high specificity for anti-ASFV sera while no cross-reactions with the sera against other swine viruses. The detection limit of the p35-Luc LISA was shown to be at least four times higher than that of the p35 based indirect ELISA established in our lab. The receiver operating characteristic (ROC) analysis showed the 96.36% relative specificity and 96.97% relative sensitivity of the p35-Luc LISA with the cutoff values of 3.55 as compared to the commercial Ingezim p72-ELISA kit. Furthermore, a total of 248 serum samples were tested by both the p35-Luc LISA and commercial Ingezim p72-ELISA kit, and there was a high degree of agreement (97.6%, kappa = 0.9753) in the performance of the two assays. Collectively, the improved LISA based on the p35-Luc protein could be used as a rapid, ultrasensitive, cost-effective and reliable diagnostic tool for serological survey of ASF in pig farms.

We have witnessed the 2-year-long global rampage of COVID-19 caused by the wide spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, knowledge about biomarkers of the entire COVID-19 process is limited. Identification of the systemic features of COVID-19 will lead to critical biomarkers and therapeutic targets for early intervention and clinical disease course prediction. Here, we performed a comprehensive analysis of clinical measurements and serum metabolomics in 199 patients with different stages of COVID-19. In particular, our study is the first serum metabolomic analysis of critical rehabilitation patients and critical death patients. We found many differential metabolites in the comparison of metabolomic results between ordinary, severe, and critical patients and uninfected patients. Through the metabolomic results of COVID-19 patients in various stages, and critical rehabilitation patients and critical death patients, we identified a series of differential metabolites as biomarkers, a separate queue and precise distinction, and predicted COVID-19 verification. These differentially expressed metabolites, included 1,2-di-(9Z,12Z-octadecadienoyl)-sn-glycero-3-phosphate, propylparaben, 20-hydroxyeicosatetraenoic acid, triethanolamine, chavicol, disialosyl galactosyl globoside, 1-arachidonoylglycerophosphoinositol, and alpha-methylstyrene, all of which have been identified for the first time as biomarkers in COVID-19 progression. These biomarkers are involved in many pathological and physiological pathways of COVID-19, for example, immune responses, platelet degranulation, and metabolism which might result in pathogenesis. Our results showed valuable information about metabolites obviously altered in COVID-19 patients with different stages, which could shed light on the pathogenesis as well as serve as potential therapeutic agents of COVID-19.

Toxoplasma gondii is a worldwide zoonotic protozoan. Donkeys are often susceptible to many pathological agents, acting as carriers of pathogens for other animal species and humans. However, data on the prevalence of T. gondii in donkeys during lactation and on the status of antibodies against T. gondii in donkey milk are lacking. A cross-sectional study evaluated the variation of the anti-T. gondii antibodies in the blood and milk of domestic donkeys during lactation. A total of 418 domestic donkeys were randomly selected from the Shandong province, eastern China from January 2019 to March 2020. The anti-T. gondii antibodies were found in 11.72% (49/418) serum and 9.81% (41/418) milk samples using a commercial ELISA kit, respectively. There was a very high consistency between the serum and milk (Spearman\'s coefficient = 0.858, p-value < 0.0001 and Kendall\'s tau = 0.688, p-value < 0.0001), particularly at the 45th to 60th day of lactation. The present results of the statistical analysis showed that the history of abortion (p = 0.026; adjusted OR = 2.20; 95% CI: 1.15-4.20) and cat in the house (p = 0.008; adjusted OR = 2.36; 95% CI: 1.26-4.44) were significantly associated with T. gondii infection in the domestic donkeys. This is the first report to detect antibodies against T. gondii in donkey milk in China. These results indicate a potential risk of humans contracting the infection through the consumption of raw milk from the naturally infected donkeys.

Serine is important for nearly all microorganisms in protein and downstream amino acids synthesis, however, the effect of serine on growth and nitrogen fixation was not completely clear in many bacteria, besides, the regulatory mode of serine remains to be fully established. In this study, we demonstrated that L-serine is essential for growth and nitrogen fixation of Paenibacillus polymyxa WLY78, but high concentrations of L-serine inhibit growth, nitrogenase activity, and nifH expression. Then, we revealed that expression of the serA whose gene product catalyzes the first reaction in the serine biosynthetic pathway is regulated by the T-box riboswitch regulatory system. The 508 bp mRNA leader region upstream of the serA coding region contains a 280 bp T-box riboswitch. The secondary structure of the T-box riboswitch with several conserved features: three stem-loop structures, a 14-bp T-box sequence, and an intrinsic transcriptional terminator, is predicted. Mutation and the transcriptional leader-lacZ fusions experiments revealed that the specifier codon of serine is AGC (complementary to the anticodon sequence of tRNAser). qRT-PCR showed that transcription of serA is induced by serine starvation, whereas deletion of the specifier codon resulted in nearly no expression of serA. Deletion of the terminator sequence or mutation of the continuous seven T following the terminator led to constitutive expression of serA. The data indicated that the T-box riboswitch, a noncoding RNA segment in the leader region, regulates expression of serA by a transcription antitermination mechanism.

Campylobacter is a leading causative pathogen of acute bacterial gastroenteritis among humans. Contaminated chicken products are regarded as major sources of human infection. The flagellar capping protein (FliD), which plays important roles in colonization and adhesion to the mucosal surface of chicken ceca, is conserved among Campylobacter jejuni strains. In this study, the recombinant C. jejuni FliD protein was expressed, purified and used as a coated protein to examine the prevalence of C. jejuni antibodies in chickens. The anti-FliD antibody was prevalent among chicken serum samples taken from different farms in the diverse regions of Jiangsu province by using enzyme-linked immunosorbent assay. The Campylobacter antibody was present in culture-negative chickens. No strong dose-response relationships were observed between serum FliD antibody levels and Campylobacter cultural status. These results provide a basis for further evaluating FliD as a vaccine candidate for broiler chickens or for examining host-C. jejuni interactions, with implications for improving food safety.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is a common malignant disease worldwide, especially in China. We aimed to determine the level of autoantibodies against L1CAM in patients with ESCC.
METHODS: Levels of circulating autoantibodies against L1CAM antigens were determined by an enzyme-linked immunosorbent assay in cohort 1 (191 patients with ESCC and 94 normal controls) and validated in cohort 2 (47 patients with ESCC and 47 normal controls). Receiver-operating characteristics were employed to calculate diagnostic accuracy. Cumulative survival time was calculated by the Kaplan-Meier method and analyzed by the log-rank test.
RESULTS: In cohorts 1 and 2, levels of autoantibodies against L1CAM were all significantly higher in sera of patients with ESCC compared to normal controls (P < 0.05). Detection of autoantibodies against L1CAM provided a sensitivity of 26.2%, a specificity of 90.4%, and an area under the curve (AUC) of 0.603 (95% CI 0.535-0.672) in diagnosing ESCC in cohort 1, and a sensitivity of 27.7%, a specificity of 91.5%, and an AUC of 0.628 (95% CI 0.516-0.741). Similar results were observed in the diagnosis of early stage ESCC (25.2% sensitivity, 90.4% specificity, and an AUC of 0.611 (95% CI 0.533-0.689) in cohort 1, and 33.3% sensitivity, 91.5% specificity, and an AUC of 0.636 (95% CI 0.439-0.832) in cohort 2). Moreover, positive rates of autoantibodies against L1CAM had no statistical correlation with clinical outcome of ESCC (P > 0.05).
CONCLUSIONS: Our results suggest that circulating autoantibodies against L1CAM is a potential biomarker for the early detection of ESCC.

Bisphenol A (BPA) has been reported as a potential estrogenic substance that could affect human health and reproduction. In this study, a monoclonal antibody (Mab) against BPA was produced after the immunization of Balb/c mice with a conjugate of 4,4-bis (4-hydroxyphenyl) valeric acid coupling with keyhole limpet hemocyanin (BVA-KLH). The obtained Mab showed higher affinity against BPA and lower cross-reactivity toward 4,4\'-sulfonyldiphenol, diphenolic acid, hydroquinone, salicylic acid, and other common phenolic compounds. Basing on the Mab, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) was developed. Under the optimal conditions, the limit of detection (LOD) was found to be 0.1 ng mL(-1) with the linear working range of 0.45-10.56 ng mL(-1). After sample extraction, the fortified serum samples were detected with intra- and inter-assay recovery ranges of 81.2-92.9 and 84.4-94.4 %, respectively. Then, 100 children\'s sera were screened by ic-ELISA. The result showed that 54 % of the serum samples were BPA-positive. The positive samples were purified by immuno-affinity column (IAC) and further confirmed by high-performance liquid chromatography (HPLC) with fluorescence detector measured at λ ex/λ em 228/310 nm in acetonitrile-water solution (v:v, 40:60). The analysis of the unknown samples showed that ic-ELISA agreed well with the HPLC results. It also revealed that the ELISA developed here could be a useful tool for screening BPA in children\'s sera before the validation of HPLC.

Bullous pemphigoid (BP), a common autoimmune skin disease, is associated with IgG autoantibodies against the hemidesmosomal proteins, BP180 and BP230. In addition to IgG, IgE has been shown to play a role in the disease. However, the association between disease activity and IgE specific to the NC16A domain of BP180 in blister fluid remains unclear. Our objective was to evaluate the correlation between BP disease activity and BP180 NC16A-specific IgE sera and blister fluid titers, and to analyze changes during treatment. We evaluated the levels of anti-BP180 IgE autoantibodies in the sera and blister fluids of 37 BP patients using an Enzyme-linked immunosorbent assay. We also observed changes in the levels of these antibodies in 2 BP patients at 4 or 5 different time points (day 0 when the patient first visited our hospital, day 5, day 14, day 39 and day 62 for patient 1; day 0, day 4, day 8 and day 17 for patient 2). We also collected extra serum samples from the 2 patients when the disease was controlled (blister disappeared) (day 85, day 104 and day 146 for patient 1 and day 123, day 158 and day 189 for the other patient). IgE anti-BP180 antibodies were detected in the serum of 72.97 % of the patients. There was no correlation between disease activity scores and BP180 NC16A IgE titers in serum (r = -0.077, p > 0.05) or in blister fluid (r = 0.262, p > 0.05). The levels of the autoantibody in serum were positively correlated with that in blister fluid (r = 0.6651, p < 0.001); however, the levels continued to rise despite effective control of the disease in the initial two to 6 weeks of diagnosis. The level of this autoantibody reached a peak on day 39 for patient 1 and on day 17 for patient 2 although the systemic and topical medication of steroid had controlled the disease process effectively. We conclude that levels of anti-BP180 NC16A IgE are higher in the sera than blister fluids. These levels could generally reflect disease severity throughout the course of the disease, but not in the early stages of medication.