Human parvovirus B19 infection in immunocompetent adults: A diagnostic challenge due to its multiple clinical manifestations.

Seroprevalence of four zoonotic viral diseases in camels in Qatar.

Identification of novel B-cell epitopes on Hirame novirhabdovirus (HIRRV) G protein and development of a multi-epitope vaccine.

Background: Vibrio harveyi is a major bacterial pathogen threatening turbot aquaculture, necessitating the development of more effective vaccines. Bacterial ghosts (BGs), which are empty bacterial envelopes with preserved surface antigens, offer a promising alternative to traditional formaldehyde-killed vaccines that often suffer from reduced immunogenicity. Methods: We developed an optimized BGs vaccine for V. harveyi by combining the nonionic surfactant NP-40 with sodium hydroxide (NaOH). This NP-40/NaOH combination demonstrated a synergistic lytic effect, halving the minimum inhibitory concentration of NaOH required for complete inactivation. Results: The resulting BGs exhibited intact cellular morphology with transmembrane pores, efficient removal of cytoplasmic contents, and significantly better preservation of lipopolysaccharide structure compared to NaOH-alone treatment. Vaccination trials in turbot demonstrated that the NP-40/NaOH BGs provided the highest relative percent survival (RPS = 58.8%) upon challenge, outperforming both NaOH-alone BGs (RPS = 55.0%) and a traditional formaldehyde-killed vaccine (RPS = 34.8%). The superior protection was correlated with the induction of a more robust and sustained immune response, characterized by significantly higher levels of specific IgM antibodies, elevated lysozyme activity, and increased total serum protein. Conclusions: This study establishes the NP-40/NaOH protocol as an effective strategy for producing high-quality BGs with enhanced immunogenicity, presenting a potent vaccine candidate for controlling vibriosis in aquaculture.

Development of a recombinant adenovirus-vectored vaccine against Pseudomonas plecoglossicida in large yellow croaker (Larimichthys crocea).

Effect of oral administration of Bacillus subtilis spores displaying Vibrio harveyi FlgE protein inducing protective immune responses in grouper.

Synthetic peptides provide a promising basis for HIV vaccine development. Following their administration, the immune response is focused only on a specific epitope. Moreover, they are able to activate both humoral and cellular pathways of immune response, being safe and well tolerated. Due to low molecular weight, the synthetic peptides exhibit low immunogenicity, therefore requiring usage of various immunoadjuvants in immunogenic compositions. The V3 loops of gp120 envelope protein are among the main protective epitopes, with a number of monoclonal antibodies with broad neutralizing activity having been obtained to this antigen. We have studied the immunogenicity of peptides copying the V3 loop of the group M HIV-1 virus consensus sequence, and the Russian viral isolate RUA022a2. We have also assessed the possible impact of its administration route (subcutaneously versus intraperitoneally) and usage of an immunoadjuvant. poly(I:C), a synthetic analogue of double-stranded RNA, being a ligand of TLR3 innate immunity receptors, was used as an adjuvant. The studies were conducted on Balb/c mice. It has been shown that the route of administration did not affect an immune response development to the tested peptides. However, earlier production of specific IgG antibodies was observed in the groups treated with immunoadjuvant. At the same time, the antibody titer was slightly higher in the groups where peptides were administered with the adjuvant after the 3 rd (last) administration. No differences have been revealed in the isotypes of induced antibodies. IgG1 antibodies were predominantly induced in all groups. Specific IgM antibodies were detected only after 3 rd injection of the antigens. The antibody titer did not depend on the administration route, being slightly higher in the groups where peptides were administered with the poly(I:C) adjuvant. The induced antibodies did not exhibit neutralizing activity against the QF495.23.M.EnvA1 isolate. When studying antigen-specific cellular immune activation, the production of IFNγ, the Th1 response marker was detected only in poly(I:С)-treated groups. In addition, a low level of anti-inflammatory cytokine IL-10 was determined in groups where poly(I:С) was included in the immunogenic composition. Moreover, the highest IL-10 level was detected in groups with intraperitoneal administration. Our studies have shown that the use of poly(I:С) adjuvant promotes immune response to the synthetic peptides, thus contributing to earlier induction of specific antibodies as well as switching to the Th1 pathway. The data obtained may be used for development of vaccines against HIV and other viral infections, in order to increase their immunogenicity and ability of inducing a protective immune response.

Changes in the public IgM repertoire and its idiotypic connectivity in Alzheimer's disease and frontotemporal dementia.

Background: Healthcare workers (HCWs) are at high risk of breakthrough SARS-CoV-2 infections despite complete vaccination schedules. There are gaps in our understanding of the specific antibody isotypes and cytokine profiles produced during an infection following vaccination. In this study, we evaluated SARS-CoV-2−specific antibody isotypes and their association with cytokine production in HCWs with breakthrough infections. Methods: Serum samples from 114 HCWs were analyzed for antibody isotypes against the nucleoprotein (NCP) and the receptor binding domain (RBD) of the spike protein, as well as for a panel of 13 cytokines. Results: Vaccinated SARS-CoV-2+ HCWs showed a higher prevalence of anti-SARS-CoV-2 antibodies against NCP (IgM = 93.8%, IgG = 93.8%, IgA = 28.1%) and RBD (IgM = 46.9%, IgG = 100%, IgA = 90.6%). A specific IgM response to NCP was more frequent in vaccinated SARS-CoV-2+ individuals, whereas IgA responses were predominantly specific for RBD. Both pro- and anti-inflammatory cytokines were elevated in vaccinated HCWs with breakthrough infections compared with unvaccinated and uninfected individuals. Interestingly, infected IgG+ HCWs with IgM specific for both NCP and RBD exhibited significantly higher IL-8, IL-6, TNF-α, IFN-γ, IL-2, IL-10, and TGF-β concentrations. Conclusion. Our data show that breakthrough infections in vaccinated HCWs induce a robust pro-and anti-inflammatory cytokine profile, which is associated with a broader IgM response directed against both NCP and RBD.

Exploring the potential of Flavobacterium covae catalase and DNA starvation/stationary phase protein as recombinant protein vaccines against columnaris disease in channel catfish.

Abstract Description PFAS are a large group of synthetic compounds with unique chemical properties. PFAS are incorporated into consumer and industrial products (fire-retardant foams, cleaners, cosmetics, personal care products). While several legacy PFAS are identified by the NTP to be immunotoxic, not all have been tested. This study investigates dermal immunotoxic effects of occupationally relevant sulfonic acid PFAS in a murine model (PFBS, PFPeS, PFHxS, PFHpS) following 10- or 28-day dermal exposure of PFAS (0.3125-5%). Elevated levels of all PFAS were detected in the serum and urine, indicating absorption is occurring via the skin. PFPeS exposure decreased spleen weight and PFHxS and PFHpS decreased both spleen and thymus weights after 28-days of exposure. Investigation into immunotoxicity revealed both PFHxS and PFHpS significantly reduced the humoral immune response after a 10-day exposure with a reduction in both specific (PFC/106) and total (PFC/spleen) IgM antibody activity against sheep red blood cells. PFHxS and PFHpS exposure decreased total cellularity in the spleen and induced changes in CD4+ and CD8+ T-cells, B-cells, and dendritic cells. Phenotypic changes were also observed in the skin and draining lymph nodes after exposure to all compounds. These findings support dermal PFAS-induced functional deficits in adaptive and innate immune response. Further investigation into PFAS dermal exposure is needed to understand the hazards of skin exposure on immune function. Funding Sources This work was supported intramurally from the National Occupational Research Agenda (NORA) CAN 9390HTP. Topic Categories Immune Response Regulation: Cellular Mechanisms (IRC)

BackgroundFish nocardiosis caused by Nocardia seriolae is a severe bacterial disease in aquaculture, causing significant economic losses. The effectiveness of antibiotics in dealing with nocardiosis induced by N. seriolae is not satisfactory. NsICL is a potential virulence factor in N. seriolae based on its crucial role in the glyoxylate cycle, its identity as a secreted protein, and its established role in virulence and intracellular survival in homologous pathogens such as Mycobacterium tuberculosis. so, the NS-ΔICL deletion strain was constructed to investigate its function.MethodsThe NsICL gene was knocked out via homologous recombination to generate the mutant strain NS-ΔICL. Comparative analysis of morphology, growth, and virulence was performed between the mutant and wild-type strains. The NS-ΔICL strain was used to immunize hybrid snakehead (Channa maculata♀ × Channa argus♂), with immune responses evaluated through non-specific immune parameters, specific antibodies, and expression levels of immune-related genes. Protective efficacy was assessed by challenge tests.ResultsNS-ΔICL showed reduced virulence (LD50 = 2.60 × 105 cfu/fish) compared to the wild-type strain (LD50 = 4.32 × 104 cfu/fish). Immunized fish exhibited significantly higher levels of non-specific immune factors (AKP, ACP, POD, LZM) and specific IgM antibodies. Immune-related genes (MHCIα, CD4, IL-8) were upregulated in vaccinated fish. Relative percentage survival (RPS) was 77.03% in vaccinated fish after challenge tests, which indicating strong protective efficacy.ConclusionThe NS-ΔICL deletion strain was successfully constructed in this study. It can not only induce humoral and cellular immunity in fish but also effectively protect fish against N. seriolae infection. These results provide a foundation for the development of a live attenuated vaccine for treating fish nocardiosis.

Objective: To analyze the seroepidemiological characteristics of common respiratory pathogens in patients screened at a tertiary hospital in Zhangjiakou from 2018 to 2024. Methods: This single-center cross-sectional study utilized data from the laboratory information management system (LIS) of The First Affiliated Hospital of Hebei North University. We collected clinical data and serum-specific IgM antibody test results for 11 common respiratory pathogens (influenza A virus, influenza B virus, respiratory syncytial virus, parainfluenza virus, mycoplasma pneumoniae, chlamydia pneumoniae, legionella pneumophila, coxsackie A virus, coxsackie B virus, echovirus and adenovirus), excluding SARS-CoV-2, from January 1, 2018, to December 31, 2024. Comparative analyses were conducted across three periods: 2018-2019, 2020-2022, and 2023-2024. Statistical analyses were performed using SPSS 26.0, with categorical data presented as percentages and compared using χ2 tests. Results: From 2018 to 2024, a total of 35 665 patients with respiratory tract infection were screened, of which 10 531 were positive for at least one pathogen, with a total positive rate of 29.53% (10 531/35 665). Age-adjusted positive rates were highest in 2023-2024 compared to 2018-2019 and 2020-2022 (χ2=690.789, P<0.001). The specific data are as follows: 21.35% (2 476/11 598) in 2018-2019, 24.35% (2 942/12 081) in 2020-2022, and 35.73% (4 283/11 986) in 2023-2024. Among the 11 pathogens, mycoplasma pneumoniae had the highest overall positivity rate (11.99%, 4 278/35 665), followed by influenza B virus (10.83%, 3 861/35 665), the other nine pathogens showed lower rates (0.88%-4.97%). At different time stages, the positive rates of serum IgM antibodies of various pathogens showed different changing characteristics: in 2023-2024, the positive rates of serum specific IgM antibodies against mycoplasma pneumoniae, influenza B/A virus and adenovirus increased significantly compared with those in 2020-2022, from 10.35%, 11.91%, 3.68%, 0.43% to 12.11%, 14.97%, 5.37%, 4.43% respectively (χ2=59.150, P<0.001; χ2=579.484, P<0.001; χ2=116.263, P<0.001; χ2=654.125, P<0.001). The positive rates of serum IgM antibody in patients of different age groups also showed different changing trends. In 2023-2024, the proportion of people in 18 to 60 and ≥60 age groups increased compared with that in 2018-2019 (χ2=325.069, P<0.001; χ2=593.612, P<0.001), while the 0 to 3, 3 to 6, and 6 to 12 age groups showed declines (χ2=382.067, P<0.001; χ2=252.835, P<0.001; χ2=285.888, P<0.001). Regarding the composition of serum IgM antibodies in different infection patterns, the proportion of single-pathogen infections decreased in 2023-2024 compared with that in 2018-2019 (χ2=130.19, P<0.001), while the proportion of two and three pathogen co-positive increased (χ2=65.533, P<0.001; χ2=46.836, P<0.001).The most common single-pathogen infections were mycoplasma pneumoniae, influenza B/A virus and legionella pneumophila; the predominant dual-pathogen combinations were influenza A+B viruses, influenza B virus+mycoplasma pneumoniae, and mycoplasma pneumoniae+legionella pneumophila. Conclusion: From 2018 to 2024, the seroepidemiological characteristics of common respiratory pathogens changed significantly with different time stages. The positive rate of serum-specific IgM antibodies were influenced by the social environment and public health intervention measures. Serological testing is an important means for the monitoring of respiratory pathogens and the prevention and control of infections in this region.

Evaluation of humoral immunity and maternal antibody transfer in Nile tilapia (Oreochromis niloticus) broodstock following immunization with a bivalent vaccine.

Report of a novel pathogenic orthohantavirus in Tucuman, Argentina.

Decreased pathogenicity of triple-mutant of Aeromonas hydrophila flgK, flgL, flgE suggests its potential as a live attenuated vaccine for Carassius auratus.

BackgroundThe diagnosis of antiphospholipid syndrome (APS) uses standard antibodies (lupus anticoagulant (LAC), anticardiolipin antibodies (aCL) IgG/IgM, β2-glycoprotein I antibodies (β2GPI) IgG/IgM), which results in some patients with ‘seronegative APS’ being overlooked. The diagnostic value of an extended antibody profile, including antiphosphatidylserine/prothrombin complex (aPS/PT) and aCL/β2GPI IgA, requires clarification.ObjectiveThis study aimed to define antibody heterogeneity in APS and determine the diagnostic and risk-stratification value of novel antibodies.MethodsWe retrospectively enrolled 2994 patients with clinical features suggestive of APS who underwent testing for criteria antibodies (LAC, aCL IgG/IgM and β2GPI IgG/IgM) and extended markers (aPS/PT IgG/IgM and aCL/β2GPI IgA). Principal component analysis (PCA) explored antibody reactivity patterns. Multivariate logistic regression identified independent diagnostic predictors, and receiver operating characteristic curve analysis evaluated diagnostic performance. Associations between antibodies and clinical parameters defined clinical phenotypes.ResultsPCA revealed three dimensions explaining 73.56% of variance: principal component (PC)1 (IgG/LAC axis; 41.42%), PC2 (specific IgM axis; 18.12%) and PC3 (specific IgA axis; 14.02%). aPS/PT-IgM was a strong independent predictor of clinical diagnosis (adjusted OR 1.147, 95% CI 1.129 to 1.165, p<0.001). The area under the curve for diagnosing triple-negative APS was 0.868 for aPS/PT-IgM. Standard criteria antibodies lost independent significance in the full model. Phenotypic analysis identified three subtypes: a ‘classical type’ (PC1-High) with prolonged coagulation times and complement consumption; an ‘inflammatory type’ (PC3-High) with elevated systemic inflammation markers without complement consumption; and a ‘restricted type’ (PC2-High) associated with anaemia.ConclusionDistinct antiphospholipid antibody heterogeneity exists, categorisable into ‘classical’, ‘inflammatory’ and ‘restricted’ subtypes. This study identifies aPS/PT-IgM as a strong independent serological marker associated with clinical status. Incorporating aPS/PT-IgM into routine testing could significantly reduce seronegative APS misdiagnosis.

Effects of immersion vaccination in striped catfish (Pangasianodon hypophthalmus) using a cationic lipid-based mucoadhesive nanovaccine against Edwardsiella ictaluri.

Development and characterization of an innovative Flavobacterium oreochromis antigen-encapsulated hydrogel bead for enhancing oral vaccine delivery in hybrid red tilapia (Oreochromis spp.).

The lack of data on the features of the course and causes of the long-term consequences of the COVID-19 pandemic caused by the coronavirus 2 severe acute respiratory syndrome (SARS-CoV-2), including the patients with chronic pathology during the formation of post-covid syndrome (PCS), determines the relevance of the study. The objective: to perform serological determination of the main classes of immunoglobulins (Ig) -M (IgM) and -G (IgG) to SARS-CoV-2 in peripheral blood in patients of a urological hospital. Materials and methods. During research blood samples were analyzed from 12,860 patients admitted to inpatient treatment in the urological departments of the SI “Academician O. F. Vozianov Institute of Urology of NAMS of Ukraine”. All patients had a negative result of the SARS-CoV-2 antigen test. Information from patients on the incidence of COVID-19 and vaccination before hospitalization was limited and was not accepted for analysis. The time interval of the research was from 04/16/2021 to 06/02/2025. Blood samples were taken from patients on an empty stomach, testing was performed on the 1st day of peripheral blood collection for laboratory tests. To determine SARS-CoV-2-specific antibodies (AB) IgM and IgG, an express immunochromatographic analysis method was used. According to the manufacturer’s instructions, the test systems are intended for professional use. The sensitivity of the IgM test system is 87.9% and the specificity is 100%; the sensitivity of the IgG test system is 97.2% and the specificity is 100%. Statistical processing of the obtained results was performed using Microsoft Excel 2007. Results. Analysis of the results of serological determination of specific AB IgM and IgG to SARS-CoV-2 was performed in patients divided into 4 groups according to the Ig combination at the time of examination. It has been determined that in the absence of a positive result of the SARS-CoV-2 antigen test, the number of patients with specific SARS-CoV-2 AB in the combination IgM+IgG+ has not decreased, and the number of people with the combination IgM–IgG+ has increased. Specific AB to SARS-CoV-2 in the combination with IgM–IgG+ has 66.05% of patients. At the same time, a gradual increase in the percentage of such patients has been observed eventually. Specific AB to SARS-CoV-2 were absent in 19.92% of patients, their number gradually decreasing over time from 75% in April–May 2021 to 10–15% in April–May 2024 and early 2025. Conclusions. Monitoring of the immune system response to the production of SARS-CoV-2 specific IgM and IgG AB in peripheral blood is an important component of the characterization of the immune response and monitoring of patients with urological diseases. We see the prospect of research in the search for informative diagnostic biological markers of the transferred viral disease and in-depth study of the immune system response during the formation of PCS.