Changes in enterovirus serotype constituent ratios altered the clinical features of infected children in Guangdong Province, China, from 2010 to 2013.

Background: Enterovirus (EV)-related hand, foot, and mouth disease/herpangina (HFMD/HA) has been prevalent in Guangdong Province, China, since 2010.

Methods: Clinical data for EV-related HFMD/HA inpatients admitted to the Department of Paediatrics of Zhujiang Hospital from 2010 to 2013 were retrospectively reviewed. The corresponding EV serotypes were also determined by reverse transcription-polymerase chain reaction or BLAST analysis of the sequenced partial lengths of the viral protein1/5'-untranslated region.

Functional properties of DENV EDIII‑reactive antibodies in human DENV‑1‑infected sera and rabbit antiserum to EDIII.

The envelope domain III (EDIII) of the dengue virus (DENV) has been confirmed to be involved in receptor binding. It is the target of specific neutralizing antibodies, and is considered to be a promising subunit dengue vaccine candidate. However, several recent studies have shown that anti‑EDIII antibodies contribute little to the neutralizing or enhancing ability of human DENV‑infected serum.

Enterovirus-related diarrhoea in Guangdong, China: clinical features and implications in hand, foot and mouth disease and herpangina.

Background: A series of complications caused by enteroviruses, including meningitis, encephalitis, acute flaccid paralysis, acute cardiopulmonary failure, respiratory infection, and myocardial injury have been reported in hand, foot and mouth disease/herpangina (HFMD/HA). However, the complication of diarrhoea caused by enteroviruses has been neglected, and a summary of its clinical features and impact on HFMD/HA is unavailable.

Methods: We included inpatients with HFMD/HA admitted to the Paediatric Department of Zhujiang Hospital during 2009-2012.

The absence of exanthema is related with death and illness severity in acute enterovirus infection.

Objective: To clarify whether exanthema is related to illness severity in acute enterovirus infection in children.

Methods: The data of pediatric inpatients at Zhujiang Hospital during 2009-2012 with an acute enterovirus infection were reviewed retrospectively. Enterovirus infection was determined by real-time reverse transcription PCR.

Phenotypic and genomic characterization of human coxsackievirus A16 strains with distinct virulence in mice.

Human coxsackievirus A16 (CA16) infection results in hand, foot, and mouth disease (HFMD) along with other severe neurological diseases in children and poses an important public health threat in Asian countries. During an HFMD epidemic in 2009 in Guangdong, China, two CA16 strains (GD09/119 and GD09/24) were isolated and characterized. Although both strains were similar in plaque morphology and growth properties in vitro, the two isolates exhibited distinct pathogenicity in neonatal mice upon intraperitoneal or intracranial injection.

Dengue virus envelope domain III immunization elicits predominantly cross-reactive, poorly neutralizing antibodies localized to the AB loop: implications for dengue vaccine design.

Dengue virus (DENV) is a mosquito-borne virus that causes severe health problems. An effective tetravalent dengue vaccine candidate that can provide life-long protection simultaneously against all four DENV serotypes is highly anticipated. A better understanding of the antibody response to DENV envelope protein domain III (EDIII) may offer insights into vaccine development.

Evaluation and analysis of dengue virus enhancing and neutralizing activities using simple high-throughput assays.

The risk of antibody-dependent enhancement (ADE) of dengue virus (DENV) infection is a major obstacle for the development of dengue vaccine candidates. Here, we described a novel approach for assessment of ADE by measuring DENV nonstructural protein 1 (NS1) production in culture supernatants with Fcγ receptor-expressing K562 cells in ELISA format (ELISA-ADE). Enhancing activities quantified by measurement of kinetics of NS1 production were in a good agreement with the results of the virus titration assay.

Evaluation of human enterovirus 71 and coxsackievirus A16 specific immunoglobulin M antibodies for diagnosis of hand-foot-and-mouth disease.

Background: Hand-foot-and-mouth disease (HFMD) is caused mainly by the human enterovirus type 71 (HEV71) and the Coxsackievirus A group type 16 (CVA16). Large outbreaks of disease have occurred frequently in the Asia-Pacific region. Reliable methods are needed for diagnosis of HFMD in children.

Enzyme-linked immunosorbent assay-format tissue culture infectious dose-50 test for titrating dengue virus.

A dengue nonstructural protein 1 (NS1) antigen capture enzyme-linked immunosorbent assay (ELISA)-based tissue culture infectious dose-50 (TCID(50)) test (TCID(50)-ELISA) was developed as an alternative to the standard plaque assay for titrating dengue virus. Virus titers obtained by TCID(50)-ELISA were comparable to those obtained by the plaque assay and by the traditional TCID(50)-cytopathic effect (CPE) test (TCID(50)-CPE), with a better reproducibility and a lower coefficient of variation. Quantitative comparison of TCID(50)-ELISA and TCID(50)-CPE resulted in a correlation coefficient of 0.

[To evaluate the neutralizing abilities of anti-dengue virus antibodies with nonstructural protein 1 antigen capture enzyme-linked immunosorbent assay].

Objective: To produce neutralizing antibodies against envelope protein domain III (EDIII) of dengue virus serotype I (DENV-1) and evaluate the nonstructural protein 1 (NS1) antigen capture enzyme-linked immunosorbent assay (ELISA) for identification of antibody neutralizing abilities.

Methods: Five BALB/c mice and one New Zealand Rabbit were immunized with recombinant EDIII protein of DENV-1 for the production of hybridomas and hyperimmune sera. Indirect ELISA, immunofluorescence assay (IFA) and Western Blot analyses were applied to identify specificity of antibodies.

Development of an antigen capture immunoassay based on monoclonal antibodies specific for dengue virus serotype 2 nonstructural protein 1 for early and rapid identification of dengue virus serotype 2 infections.

The dengue virus (DENV) has four distinct serotypes (DENV1, DENV2, DENV3, and DENV4) that require differentiation for effective prevention of morbid diseases. The recently developed DENV1-specific NS1 antigen capture enzyme-linked immunosorbent assay (ELISA) based on the monoclonal antibodies (MAbs) that recognize distinct epitopes on nonstructural protein 1 (NS1) of a specific DENV serotype is convenient and cost-effective, but assays have not yet been developed for DENV serotypes 2 to 4. This paper describes the development and validation of a DENV2-specific NS1 antigen capture ELISA by selection and optimization of the pair of well-characterized MAbs that recognized epitopes specific for DENV2 NS1 from a large panel of MAbs.

Well-characterized monoclonal antibodies against cell wall antigen of Aspergillus species improve immunoassay specificity and sensitivity.

The diagnosis of invasive aspergillosis (IA) based on the detection of Aspergillus galactomannan (GM) is complicated by the presence of cross-reactive GM epitopes in patient specimens. We have developed a novel and specific Aspergillus antigen-capture enzyme-linked immunosorbent assay (ELISA) by the selection of two well-characterized monoclonal antibodies from 17 candidate antibodies. The epitopes recognized by the monoclonal antibodies were present on the cell walls of the hyphae and the conidia of Aspergillus species, which were circulating or excreted as immunodominant antigens during the acute phase of IA established in the animal models.

Serotype 1-specific monoclonal antibody-based antigen capture immunoassay for detection of circulating nonstructural protein NS1: Implications for early diagnosis and serotyping of dengue virus infections.

Rapid diagnosis and serotyping of dengue virus (DV) infections are important for timely clinical management and epidemiological control in areas where multiple flaviviruses are endemic. However, the speed and accuracy of diagnosis must be balanced against test cost and availability, especially in developing countries. We developed a specific antigen capture enzyme-linked immunosorbent assay (ELISA) for early detection and serotyping of DV serotype 1 (DV1) by using well-characterized monoclonal antibodies (MAbs) specific to nonstructural protein 1 (NS1) of DV1.

Antigenic cross-reactivity between severe acute respiratory syndrome-associated coronavirus and human coronaviruses 229E and OC43.

Cross-reactivity between antibodies to different human coronaviruses (HCoVs) has not been systematically studied. By use of Western blot analysis, indirect immunofluorescence assay (IFA), and enzyme-linked immunosorbent assay (ELISA), antigenic cross-reactivity between severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV) and 2 HCoVs (229E and OC43) was demonstrated in immunized animals and human serum. In 5 of 11 and 10 of 11 patients with SARS, paired serum samples showed a > or =4-fold increase in antibody titers against HCoV-229E and HCoV-OC43, respectively, by IFA.

Sensitive and specific monoclonal antibody-based capture enzyme immunoassay for detection of nucleocapsid antigen in sera from patients with severe acute respiratory syndrome.

A rapid antigen test for the diagnosis of severe acute respiratory syndrome (SARS) is essential for control of this disease at the point of management. The nucleocapsid (N) protein of SARS-associated coronavirus (SARS-CoV) is abundantly expressed in infected-cell culture filtrate as demonstrable by Western blotting using convalescent-phase sera from patients with SARS. We used monoclonal antibodies specifically directed against N protein to establish a sensitive antigen capture sandwich enzyme-linked immunosorbent assay (ELISA) for the detection of SARS-CoV.

Rapid and efficient preparation of monoclonal antibodies against SARS-associated coronavirus nucleocapsid protein by immunizing mice.

Objective: To develop a rapid and efficient method for preparing monoclonal antibodies (mAb) against SARS-associated coronavirus (SARS-Cov) nucleocapsid (N) protein.

Methods: BALB/c mice were injected with the recombinant N protein of SARS-Cov into the foot-pads for the immunization, and the popliteal lymph nodes were isolated 15 d later for mAb-producing hybridomas, from which the mAbs against the N protein of SARS-Cov were screened. The identification of the mAb against the N protein of SARS-Cov was performed using indirect enzyme-linked immunosorbent assay (ELISA), indirect fluorescent-antibody assay (IFA), and Western immunoblotting.

[Antibody response of patients with severe acute respiratory syndrome (SARS) to nucleocapsid antigen of SARS-associated coronavirus].

Objective: To assess serum antibody responses of patients with severe acute respiratory syndrome (SARS) to nucleocapsid (N) antigen of SARS-associated coronavirus.

Methods: The serum levels of IgM and IgG antibodies to N antigen were measured in 200 healthy blood donors and 13 SARS patients at different time points of acute and convalescent phases using indirect enzyme-linked immunosorbent assay (ELISA) with N fusion proteins of SARS-associated coronaviruses.

Results: The IgM positive critical value of 0.