ABSTRACT
Dengue virus (DENV) is the most widely transmitted arbovirus in the world. Due to the lack of diagnostic technology to quickly identify the virus serotypes in patients, severe dengue hemorrhagic fever cases caused by repeated infections remain high. To realize the rapid differential diagnosis of different serotypes of DENV infection by immunological methods, in this study, four DENV serotype NS1 proteins were expressed and purified in mammalian cells. Monoclonal antibodies (MAbs) against NS1 protein were obtained by hybridoma technology after immunizing BALB/c mice. Enzyme-linked immunosorbent assay, indirect immunofluorescence assay, dot blotting, and Western blotting were used to confirm the reactivity of MAbs to viral native NS1 and recombinant NS1 protein. These MAbs include not only the universal antibodies that recognize all DENV 1-4 serotype NS1, but also serotype-specific antibodies against DENV-1, DENV-2 and DENV-4. Double antibody sandwich ELISA was established based on these antibodies, which can be used to achieve rapid differential diagnosis of serotypes of DENV infection. Preparation of DENV serotype-specific MAbs and establishment of an ELISA technology for identifying DENV serotypes has laid the foundation for the rapid diagnosis of DENV clinical infection.
Subject(s)
Animals , Humans , Mice , Antibodies, Monoclonal , Antibodies, Viral/metabolism , Dengue/diagnosis , Dengue Virus/immunology , Enzyme-Linked Immunosorbent Assay , Mice, Inbred BALB C , Sensitivity and Specificity , Serogroup , Viral Nonstructural Proteins/immunologyABSTRACT
<i>Streptococcus pneumoniae</i> is a major worldwide cause of morbidity and mortality. Pneumococcal carriage is considered to be an important source of horizontal spread of this pathogen within the community. Pneumococcal conjugate vaccine (PCV) is capable of inducing serotype-specific antibodies in sera of infants, and has been suggested to reduce nasopharyngeal carriage of vaccine-type pneumococci in children. PCV is generally immunogenic for pediatric patients with invasive pneumococcal disease, with an exception for the infecting serotypes. Based on evidences from the clinical trials of PCV, the health impact of childhood pneumococcal pneumonia appears to be high in developing countries where most of global childhood pneumonia deaths occur. PCV vaccination may prevent hundreds of deaths per 100,000 children vaccinated in developing countries, while PCV vaccination is expected to prevent less than 10 deaths per 100,000 children vaccinated in the developed countries. Therefore, the WHO has proposed a strategy to reduce the incidence of severe pneumonia by 75% in child less than 5 years of age compared to 2010 levels by 2025.
ABSTRACT
<i>Streptococcus pneumoniae</i> is a major worldwide cause of morbidity and mortality. Pneumococcal carriage is considered to be an important source of horizontal spread of this pathogen within the community. Pneumococcal conjugate vaccine (PCV) is capable of inducing serotype-specific antibodies in sera of infants, and has been suggested to reduce nasopharyngeal carriage of vaccine-type pneumococci in children. PCV7 is generally immunogenic for pediatric patients with invasive pneumococcal disease, with an exception for the infecting serotypes. Based on evidences from the clinical trials of PCV, the health impact of childhood pneumococcal pneumonia appears to be high in developing countries where most of global childhood pneumonia deaths occur. PCV vaccination may prevent hundreds of deaths per 100,000 children vaccinated in developing countries, while PCV vaccination is expected to prevent less than 10 deaths per 100, 000 children vaccinated in the developed countries. Therefore, the WHO has proposed a strategy to reduce the incidence of severe pneumonia by 75% in child less than 5 years of age compared to 2010 levels by 2025.
ABSTRACT
BACKGROUND: The changing nature of dengue epidemiology and control makes dengue one of the challenging infectious disease problems in the present time with certain inadequacies in existing knowledge base becoming apparent.OBJECTIVE: This quantitative and experimental study was conducted to provide recent local evidence that dengue virus transovarial transmission among field collected Aedes aegypti mosquitoes does occur and presents an important factor in the epidemiology and control of dengue.METHODS: Households in Quezon City, Philippines, a known dengue infection hotspot in 2011, were randomly selected (H9 and H14) for Aedes aegypti egg and larval collection. Mosquito larvae were captured using standard ovitraps and reared to adulthood in the entomology unit of the Molecular Diagnostics and Genotyping Laboratory at the University of the Philippines (UP), College of Medicine, Manila. Whole organism homogenate of adult mosquitoes were prepared for subsequent dengue virus molecular characterization and virulence testing. Both egg samples and their infection profile for dengue virus was determined by serotype specific RT-PCR.RESULTS: Molecular test results show that in each household and in each generation (parent, F1 and F2), there were detectable and strong dengue viral presence, predominantly the serotypes DEN-2, DEN-3 and DEN-4 in the Aedes aegypti mosquito homogenates.CONCLUSIONS: These laboratory evidences indicate that thransovarial transmission of dengue virus does occur in a high urban city like Quezon City where incidence of dengue is high.Thus, it is important to consider the existence of this phenomenon in existing and future dengue control programs to ensure effectiveness of community-based intervention strategies.
Subject(s)
Humans , Male , Female , Animals , Dengue Virus , Aedes , Serogroup , Larva , Entomology , Pathology, Molecular , Virulence , Genotype , DengueABSTRACT
Out of 200 serum samples collected from cattle (142) and buffaloes (58) of various ages and sexand subjected to latex agglutination test (LAT) using serotype specific peptides (O, A, Asia 1) and also with peptide for non-structural protein 2B (NSP-2B), 114 (70%) samples were positive against FMDV type ‘O’, 102 (51%) against serotype ‘A’ and 104 (52%) against serotype ‘Asia 1’. With NSP-2B peptide a total of 71 (35.5%) samples were positive. The results suggest that LAT could be used for the diagnosis of foot and mouth disease virus as it is easy, cheap and effective test.
Subject(s)
Amino Acid Sequence , Animals , Cattle , Foot-and-Mouth Disease/immunology , Foot-and-Mouth Disease Virus/classification , Latex Fixation Tests/methods , Microspheres , Molecular Sequence Data , Peptides/chemistry , Peptides/immunology , Serotyping , Vaccination , Viral Nonstructural Proteins/immunologyABSTRACT
There is an ongoing need for standardized, easily renewable immunoreagents for detecting African horsesickness virus (AHSV). Two phage displayed single-chain variable fragment (scFv) antibodies, selected from a semi-synthetic chicken antibody library, were used to develop double antibody sandwich enzyme-linked immunosorbent assays (DAS-ELISAs) to detect AHSV. In the DAS-ELISAs, the scFv previously selected with directly immobilized AHSV-3 functioned as a serotype-specific reagent that recognized only AHSV-3. In contrast, the one selected with AHSV-8 captured by IgG against AHSV-3 recognized all nine AHSV serotypes but not the Bryanston strain of equine encephalosis virus. Serving as evidence for its serogroup-specificity. These two scFvs can help to rapidly confirm the presence of AHSV while additional serotype-specific scFvs may simplify AHSV serotyping.