Immunodiagnostic Methods Research Articles

Recent Advances in Quantum Dot-Based Lateral Flow Immunoassays for the Rapid, Point-of-Care Diagnosis of COVID-19.

The COVID-19 pandemic has spurred demand for efficient and rapid diagnostic tools that can be deployed at point of care to quickly identify infected individuals. Existing detection methods are time consuming and they lack sensitivity. Point-of-care testing (POCT) has emerged as a promising alternative due to its user-friendliness, rapidity, and high specificity and sensitivity. Such tests can be conveniently conducted at the patient's bedside. Immunodiagnostic methods that offer the rapid identification of positive cases are urgently required. Quantum dots (QDs), known for their multimodal properties, have shown potential in terms of combating or inhibiting the COVID-19 virus. When coupled with specific antibodies, QDs enable the highly sensitive detection of viral antigens in patient samples. Conventional lateral flow immunoassays (LFAs) have been widely used for diagnostic testing due to their simplicity, low cost, and portability. However, they often lack the sensitivity required to accurately detect low viral loads. Quantum dot (QD)-based lateral flow immunoassays have emerged as a promising alternative, offering significant advancements in sensitivity and specificity. Moreover, the lateral flow immunoassay (LFIA) method, which fulfils POCT standards, has gained popularity in diagnosing COVID-19. This review focuses on recent advancements in QD-based LFIA for rapid POCT COVID-19 diagnosis. Strategies to enhance sensitivity using QDs are explored, and the underlying principles of LFIA are elucidated. The benefits of using the QD-based LFIA as a POCT method are highlighted, and its published performance in COVID-19 diagnostics is examined. Overall, the integration of quantum dots with LFIA holds immense promise in terms of revolutionizing COVID-19 detection, treatment, and prevention, offering a convenient and effective approach to combat the pandemic.

Latent tuberculosis infection in liver transplant patients: a review.

Latent tuberculosis infection in liver transplant patients: a review.

Molecular detection and genetic diversity of Leucocytozoon sabrazesi in chickens in Thailand

Leucocytozoon sabrazesi is the intracellular protozoa of leucocytozoonosis, which is transmitted by the insect vectors and affects chickens in most subtropical and tropical regions of the globe, except South America, and causing enormous economic losses due to decreasing meat yield and egg production. In this study, L. sabrazesi gametocytes have been observed in the blood smears, and molecular methods have been used to analyse the occurrence and genetic diversity of L. sabrazesi in blood samples from 313 chickens raised in northern, western and southern parts of Thailand. The nested polymerase chain reaction (nested PCR) assay based on the cytb gene revealed that 80.51% (252/313) chickens were positive of L. sabrazesi. The phylogenetic analysis indicated that L. sabrazesi cytb gene is conserved in Thailand, showed 2 clades and 2 subclades with similarity ranged from 89.5 to 100%. The diversity analysis showed 13 and 18 haplotypes of the sequences from Thailand and from other countries, respectively. The entropy analyses of nucleic acid sequences showed 26 high entropy peaks with values ranging from 0.24493 to 1.21056, while those of amino acid sequences exhibited 5 high entropy peaks with values ranging from 0.39267 to 0.97012. The results; therefore, indicate a high molecular occurrence of L. sabrazesi in chicken blood samples with the associated factors that is statistically significant (p < 0.05). Hence, our results could be used to improve the immunodiagnostic methods and to find appropriate preventive control strategies or vaccination programs against leucocytozoonosis in order to mitigate or eliminate the harmful impact of this infection on chicken industry.

Taenia solium Cysticercosis: Present Scenario: A Review

Cysticercosis is one of the most important neglected parasitic diseases caused by the larval stage of the tapeworm Taenia solium. It is the most common cause of epilepsy in the areas with improper pig husbandry practices and poor sanitary conditions. In pig the larvae lodges in the muscle and subcutaneous tissue and seldom manifests any clinical sign. In human beings the larval stage resides in the CNS thus leading to the condition Neurocysticercosis. The disease can be diagnosed by using various neuroimaging techniques and immunodiagnostic methods. Available therapeutic options include cysticidal drugs, steroids, anti-epileptic drugs etc. The disease can be controlled by anti-parasitic treatment of the pig and humans residing in endemic areas, vaccinating the pigs, creating awareness and other measures.

Identification of cross-reactive markers to strengthen the development of immunodiagnostic methods for angiostrongyliasis and other parasitic infections

Angiostrongylus cantonensis is the main causative agent of eosinophilic meningoencephalitis (EoM) in humans. Molecular diagnostic methods are essential since the identification of larvae in cerebrospinal fluid (CSF) is extremely rare. To date, the detection of a 31 kDa antigen by Western blotting has been the primary immunodiagnostic method for EoM caused by A. cantonensis. However, cross-reactivity with other parasites has been observed. Therefore, we conducted a comparative analysis using sera from individuals with angiostrongyliasis. We also characterized proteins isolated from different cellular sources of A. cantonensis, Toxocara canis, Schistosoma mansoni, and Strongyloides stercoralis with mass spectrometry. A total of 115 cross-reactive proteins were identified. Three of these proteins, heat shock protein, an intermediate filament protein, and galectin 1, represent potential markers for cross-reactivity. In addition, synthetic peptides were generated from previously identified diagnostic targets and tested against sera from individuals infected with several other parasites. As a result, two other markers of cross-reactivity were identified: peptide #4 derived from the 14-3-3 protein and peptide #12 derived from the Lec-5 protein. In contrast, 34 proteins were exclusively present in the Angiostrongylus extracts and represent promising diagnostic molecules for specific identification of A. cantonensis infection. In particular, cytochrome oxidase subunit I is of great interest as a possible immunodiagnostic target for angiostrongyliasis.

Modern Tools for Rapid Diagnostics of Antimicrobial Resistance.

Fast, robust, and affordable antimicrobial susceptibility testing (AST) is required, as roughly 50% of antibiotic treatments are started with wrong antibiotics and without a proper diagnosis of the pathogen. Validated growth-based AST according to EUCAST or CLSI (European Committee on Antimicrobial Susceptibility Testing, Clinical Laboratory Standards Institute) recommendations is currently suggested to guide the antimicrobial therapy. Any new AST should be validated against these standard methods. Many rapid diagnostic techniques can already provide pathogen identification. Some of them can additionally detect the presence of resistance genes or resistance proteins, but usually isolated pure cultures are needed for AST. We discuss the value of the technologies applying nucleic acid amplification, whole genome sequencing, and hybridization as well as immunodiagnostic and mass spectrometry-based methods and biosensor-based AST. Additionally, we evaluate the potential of integrated systems applying microfluidics to integrate cultivation, lysis, purification, and signal reading steps. We discuss technologies and commercial products with potential for Point-of-Care Testing (POCT) and their capability to analyze polymicrobial samples without pre-purification steps. The purpose of this critical review is to present the needs and drivers for AST development, to show the benefits and limitations of AST methods, to introduce promising new POCT-compatible technologies, and to discuss AST technologies that are likely to thrive in the future.

Rapid and Sensitive Detection of anti-SARS-CoV-2 IgG, Using Lanthanide-Doped Nanoparticles-Based Lateral Flow Immunoassay.

The outbreak of 2019 coronavirus disease (COVID-19) has been a challenge for hospital laboratories because of the huge number of samples that must be tested for the presence of the causative pathogen, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Simple and rapid immunodiagnostic methods are urgently needed to identify positive cases. Here we report the development of a rapid and sensitive lateral flow immunoassay (LFIA) that uses lanthanide-doped polysterene nanoparticles (LNPs) to detect anti-SARV-CoV-2 IgG in human serum. A recombinant nucleocapsid phosphoprotein of SARS-CoV-2 was dispensed onto a nitrocellulose membrane to capture specific IgG. Mouse anti-human IgG antibody was labeled with self-assembled LNPs that served as a fluorescent reporter. A 100-μL aliquot of serum samples (1:1000 dilution) was used for this assay and the whole detection process took 10 min. The results of the validation experiment met the requirements for clinical diagnostic reagents. A value of 0.0666 was defined as the cutoff value by assaying 51 normal samples. We tested 7 samples that were positive by reverse-transcription (RT-)PCR and 12 that were negative but clinically suspicious for the presence of anti-SARS-CoV-2 IgG. One of the negative samples was determined to be SARS-CoV-2 IgG positive, while the results for the other samples were consistent with those obtained by RT-PCR. Thus, this assay can achieve rapid and sensitive detection of anti-SARS-CoV-2 IgG in human serum and allow positive identification in suspicious cases; it can also be useful for monitoring the progression COVID-19 and evaluating patients’ response to treatment.

Role of a modern laboratory in the diagnosis of allergic disorder

Use of modern certified methods makes it possible to identify the type of allergic reaction. Possibilities of laboratory diagnosis of allergic disorder using immunodiagnostic methods and molecular diagnostic technologies are presented. Examples of using analysis of the results in therapeutic practice, laboratory technologies for in vitro diagnosis of allergy are considered. Features of preanalytical stage of laboratory testing are presented.

Efficacy of Iron Oxide Nanoparticles in Diagnosis of Schistosomiasis

ABSTRACT Background: One of the worldwide major public health problems is urinary schistosomiasis that is caused by Schistosoma heamatobium. There are several immunodiagnostic methods used for that diagnosis of such disease, but some are more sensitive and specific than others. The tegumental Schistosoma-specific protein detection in serum samples is found out to be more valuable in diagnosis. Aim of the Work: To evaluate the efficacy of iron oxide nanoparticle for diagnosis of human schistosomiasis infections and to compare between ELISA-based iron oxide nanoparticle and traditional sandwich ELISA. Material and Methods: The tegumental antigen was purified from whole worms by DEAE-Sephadex G-75 ion-exchange chromatography and then was injected into rabbits to produce specific polyclonal antibodies (p Ab) which were then used as a primary capture in the indirect ELISA technique to reveal its reactivity using infected human sera. The anti- tegumental p Ab was then labeled with horse-radish peroxidase (HRP) and used as a secondary capture. Sandwich ELISA was done for serum samples of humans and hamsters infected with S. haematobium. Results: The sensitivity of the traditional sandwich ELISA with anti-tegumental p Ab was 85% and it increased by using the sandwich IMB-ELISA to be 95% in serum. The specificity of sandwich ELISA was 88.2% and it increased by using the sandwich IMB-ELISA to be 92.6%. Conclusion: The data obtained concluded that the IMB-ELISA appears to be a sufficiently sensitive and feasible assay for the detection of schistosomal antigenemia and the evaluation of its potential use in human schistosomiasis is in progress. Keywords: S. haematobium; diagnosis; ELISA; Immunomagnetic bead ELISA technique; Paramagnetic nanoparticles.

Comparative Analysis of Parasitological, Immunodiagnostic and Histopathological Methods in the Diagnosis of Human Giardiasis

Giardiasis/lambliosis is a disease caused by the presence of a protozoan Giardia lamblia (G. lamblia) in the upper portions of the human digestive tract (DT). This cosmopolitan parasite is present particularly in children, but in all other age groups and socioeconomic conditions as well. The studies undertaken in the Ni�ava District (southeastern Serbia) have demonstrated a high prevalence of infection caused by G. lamblia species using conventional microscopy of three stool samples with or without concentration technique (6.24%), i.e. using the immunoenzymatic method to confirm the presence of G. lamblia antigen in the stool (6.59%). The use of invasive methods in the diagnosis of giardiasis is warranted in individual selected cases, when the significance of the parasite should be assessed regarding its involvement in the pathogenetic mechanisms of damage to the digestive tract mucosa.

Evaluation of a Commercial Enzyme-Linked Immunosorbent Assay Kit and In-House Fasciola gigantica Cysteine Proteinases-Based Enzyme-Linked Immunosorbent Assays for Diagnosis of Human Fascioliasis.

Fascioliasis, caused by Fasciola hepatica and Fasciola gigantica infection, is a major food-borne trematodiasis in many places of the world, with the central region of Vietnam being reported as a highly endemic area. Stool examination for Fasciola eggs is not a sensitive method, and immunodiagnostic methods are preferable. We investigated various enzyme-linked immunosorbent assays (ELISAs) to evaluate their efficacy for fascioliasis diagnosis. Test sera used are primarily screened using an ELISA kit produced in Vietnam (VN kit; Viet Sinh Chemical Producing & Trading Co. Ltd., Ho Chi Minh City, Vietnam): Seropositive individuals having symptoms compatible with fascioliasis were regarded as clinically diagnosed fascioliasis cases. A commercial Fasciola IgG ELISA kit from Diagnostic Automation/Cortez Diagnostics, Inc. (USA kit; Woodland Hills, CA), which has been commonly used in Vietnam, was assessed and compared with in-house ELISA systems, including a cystatin-capture (CC) ELISA using crude worm extract (CWE) and an indirect ELISA using a synthetic peptide Ac-TPTCHWECQVGYNKTYDEE-NHMe designed from the F. gigantica cathepsin B (FgCB5) molecule. The USA kit was suitable for routine diagnosis after recalibration of the manufacturer's suggested cutoff point. Cystatin-capture ELISA with CWE provided good sensitivity and specificity with perfect agreement to the results of the USA kit. In dot-blot ELISA, recombinant FgCB5 reacted more strongly with human antisera than did other F. gigantica antigens tested. Enzyme-linked immunosorbent assay using the synthetic peptide fragment of the FgCB5 exhibited nearly 80% sensitivity and specificity, but the test results showed low agreement with CC-ELISA or the USA kit. In conclusion, the commercially available Fasciola IgG ELISA kit from the United States and the in-house CC ELISA using CWE are suitable for practical diagnosis for fascioliasis.

Development of a multiplexed antigen detection immunoassay for detection of viral agents

Purpose: The spread of infectious disease continues to present a challenge for modern global public health initiatives, as was evidenced by the recent Ebola outbreak in West Africa. In disease outbreaks, diagnostics are the first line of defense in identifying the causative agent, treatment decisions, and control and prevention of future outbreaks. Methods & Materials: We designed a multiplexed immunoassay centered on detection of viral antigens in serum/plasma samples for EBOV, LASV, MARV, CCHFV, RVFV, alphaviruses, and flaviviruses. This flexible, immunoassay system, based on the MAGPIX® platform has faster sample-to-answer time over traditional methods and higher throughput, as assays can be multiplexed. Assays were developed and validated against live and inactivated viral supernatants and other antigen types. Inclusivity and exclusivity panels were run to ensure no crossreactivity between assays. Results: Each assay was able to detect the appropriate target, whether in inactivated, recombinant, and live agent form. Limits of detection were generated in plaque forming units (pfu) per ml of live agent. Limits of detection were also established for appropriate recombinant reagents when available, as these reagents serve as the positive controls for the multiplexed assays when deployed to overseas partners. Conclusion: Development of robust and sustainable immunoassays is important as they have great potential for use during outbreak events to provide a more complete picture of the presence of viral agents. Immunoassays are capable of providing further insight to shape outbreak response. The recent Ebola outbreak demonstrated the great sensitivity of RT-PCR, but often patients remained positive by PCR well after other symptoms subsided. An integrated diagnostic system that uses sensitive and specific RT-PCR in combination with higher throughput, multiplexed immunodiagnostic methods can provide the highest confidence in a diagnostic result.

СОВРЕМЕННЫЕ МЕРЫ ПРОТИВОТУБЕРКУЛЁЗНОГО ИНФЕКЦИОННОГО КОНТРОЛЯ

For effective implementation of modern TB eradication measures should be available to data on TB transmission factors and epidemiology based on it pathogenesis, from infection before the outcome of its current. Review article reveals the modern requirements and methods of organizing anti-TB infection control. The results of the publications, their interpretation and comparison with the situation in Tajikistan are presented. The importance of following infection control measures at home, including the isolation of bacterioexcretion persons, timely verification of mycobacterium TB infection, vaccination and chemoprophylaxis to improve the TB epidemiological situation. It is noted that the evidence-based principles of preventing nosocomial transmission of TB infection have reduced the number of hospitalizations and minimized the duration of patients’ stay in TB hospitals, while increasing the cohorts of patients who are initially on outpatient chemotherapy. The review presented and the real level of anti-TB infection control in the Republic of Tajikistan, especially in the nidus of infection and among contact persons, indicates the urgent need to rethink approaches to preventing transmission of this disease. Keywords: Tuberculosis, infection control, disinfection , mycobacteria tuberculosis, immuno-diagnostic methods, prevention.

Transcriptome and excretory-secretory proteome of infective-stage larvae of the nematode Gnathostoma spinigerum reveal potential immunodiagnostic targets for development.

Background: Gnathostoma spinigerum is a harmful parasitic nematode that causes severe morbidity and mortality in humans and animals. Effective drugs and vaccines and reliable diagnostic methods are needed to prevent and control the associated diseases; however, the lack of genome, transcriptome, and proteome databases remains a major limitation. In this study, transcriptomic and secretomic analyses of advanced third-stage larvae of G. spinigerum (aL3Gs) were performed using next-generation sequencing, bioinformatics, and proteomics. Results: An analysis that incorporated transcriptome and bioinformatics data to predict excretory–secretory proteins (ESPs) classified 171 and 292 proteins into classical and non-classical secretory groups, respectively. Proteins with proteolytic (metalloprotease), cell signaling regulatory (i.e., kinases and phosphatase), and metabolic regulatory function (i.e., glucose and lipid metabolism) were significantly upregulated in the transcriptome and secretome. A two-dimensional (2D) immunomic analysis of aL3Gs-ESPs with G. spinigerum-infected human sera and related helminthiases suggested that the serine protease inhibitor (serpin) was a promising antigenic target for the further development of gnathostomiasis immunodiagnostic methods. Conclusions: The transcriptome and excretory–secretory proteome of aL3Gs can facilitate an understanding of the basic molecular biology of the parasite and identifying multiple associated factors, possibly promoting the discovery of novel drugs and vaccines. The 2D-immunomic analysis identified serpin, a protein secreted from aL3Gs, as an interesting candidate for immunodiagnosis that warrants immediate evaluation and validation.

Detection of &lt;em&gt;Ralstonia solanacearum&lt;/em&gt; in Asymptomatic Imported Seed Potato using a DNA-based Method

Potato is an economically important crop among vegetables grown in Sri Lanka that mainly relies on healthy seed potatoes. About 40% of the annual seed potato requirement is fulfilled by the import of seed potatoes from Netherland, USA, Germany and France. Import of seed potatoes makes possibilities to enter plant pathogenic pests and diseases to Sri Lanka. Bacterial wilt is one of the most destructive diseases of potato. Ralstonia solanacearum, which causes bacterial wilt of potato, is considered as an important quarantine significant plant pathogen in Sri Lanka. The currently available conventional methods such as culture methods, biochemical methods are time consuming, very laborious and not sensitive for the detection of R. solanacearum in imported seed potatoes. Although immunodiagnostic methods are rapid, the sensitivity is not enough to detect the bacterium in asymptomatic or latently infected seed potatoes. In this study, a DNA-based detection method was applied to screen seed potatoes imported into Sri Lanka and 5 out of 30 tested samples (17%) were positive for R. solanacearum. The seed potato samples detected as infected with R. solanacearum were further studied and it revealed that the Asian phylotype I and the American phylotype II were detected from seed potato samples imported to the country. Phylotype II (Race 3/biovar 2) was detected in seed potatoes imported from USA and France and both phylotype I and phylotype II (Race 3/biovar 2) were detected in seed potatoes imported from Netherland from where majority of seed potatoes are imported into the country. The quarantine measures should be strictly followed to avoid the spread and establishment of phylotype II, Race 3/biovar 2 strains within the country, as it is the extremely destructive potato pathogen which have a restricted distribution in higher elevations of Sri Lanka. Further, the DNA-based method can be used to identify the pathogen to avoid the introduction or entry of R. solanacearum into the country for the betterment of potato cultivation in Sri Lanka. KEYWORDS: Seed potato, Bacterial wilt, Ralstonia solanacearum, Quarantine pest, Rsol_fliC

Efficient immunodiagnosis of Citrus yellow mosaic virus using polyclonal antibodies with an expressed recombinant virion-associated protein.

Citrus yellow mosaic virus (CYMV) is a member of genus Badnavirus of the family Caulimoviridae. It is the causal agent of citrus yellow mosaic disease in citrus and causes reduction in yield. As the virus is vegetative propagated by grafting, development of high-throughput diagnosis methods based on serological techniques is a prerequisite for production of healthy virus-free planting material. The current study describes the development of polyclonal antibodies raised in rabbits against purified recombinant virion-associated protein (rVAP) encoded by ORF-II of CYMV. The specificity of developed antiserum was evaluated in immunosorbent electron microscopy (ISEM), antigen-coated plate-enzyme linked immunosorbent assay (ACP-ELISA) and immunocapture PCR (IC-PCR). The antiserum specifically reacted up to a dilution of 1:2000 in ACP-ELISA for detection of CYMV-infected plants. The antiserum was validated by screening CYMV-infected plants maintained in the glass house through ACP-ELISA. To the best for our knowledge, this is the first report on production of polyclonal antiserum using recombinant virion-associated protein as fusion protein, which could be used for screening CYMV-infected plants by ELISA and IC-PCR. These immunodiagnostic methods can be effectively employed in routine indexing of citrus and in quarantine process.

Clinical and epidemiologic characteristics of dengue and other etiologic agents among patients with acute febrile illness, Puerto Rico, 2012-2015.

Identifying etiologies of acute febrile illnesses (AFI) is challenging due to non-specific presentation and limited availability of diagnostics. Prospective AFI studies provide a methodology to describe the syndrome by age and etiology, findings that can be used to develop case definitions and multiplexed diagnostics to optimize management. We conducted a 3-year prospective AFI study in Puerto Rico. Patients with fever ≤7 days were offered enrollment, and clinical data and specimens were collected at enrollment and upon discharge or follow-up. Blood and oro-nasopharyngeal specimens were tested by RT-PCR and immunodiagnostic methods for infection with dengue viruses (DENV) 1–4, chikungunya virus (CHIKV), influenza A and B viruses (FLU A/B), 12 other respiratory viruses (ORV), enterovirus, Leptospira spp., and Burkholderia pseudomallei. Clinical presentation and laboratory findings of participants infected with DENV were compared to those infected with CHIKV, FLU A/B, and ORV. Clinical predictors of laboratory-positive dengue compared to all other AFI etiologies were determined by age and day post-illness onset (DPO) at presentation. Of 8,996 participants enrolled from May 7, 2012 through May 6, 2015, more than half (54.8%, 4,930) had a pathogen detected. Pathogens most frequently detected were CHIKV (1,635, 18.2%), FLU A/B (1,074, 11.9%), DENV 1–4 (970, 10.8%), and ORV (904, 10.3%). Participants with DENV infection presented later and a higher proportion were hospitalized than those with other diagnoses (46.7% versus 27.3% with ORV, 18.8% with FLU A/B, and 11.2% with CHIKV). Predictors of dengue in participants presenting <3 DPO included leukopenia, thrombocytopenia, headache, eye pain, nausea, and dizziness, while negative predictors were irritability and rhinorrhea. Predictors of dengue in participants presenting 3–5 DPO were leukopenia, thrombocytopenia, facial/neck erythema, nausea, eye pain, signs of poor circulation, and diarrhea; presence of rhinorrhea, cough, and red conjunctiva predicted non-dengue AFI. By enrolling febrile patients at clinical presentation, we identified unbiased predictors of laboratory-positive dengue as compared to other common causes of AFI. These findings can be used to assist in early identification of dengue patients, as well as direct anticipatory guidance and timely initiation of correct clinical management.

IgM and IgG responses in Schistosoma mansoni-infected mice using egg and worm antigens: Does response vary with parasitic burden and phase of infection?

Schistosomiasis is a chronic parasitic disease caused by trematodes of the genus Schistosoma, endemic in tropical and subtropical regions. The hepatic pathology of this parasitic disease could develop complications, such as fibrosis and cirrhosis, which can be fatal. The Venezuelan endemic area is considered as one of low transmission, which complicates the detection of infected individuals and signals the importance of improving the sensitivity of immunodiagnostic methods. Using ELISA, an evaluation was conducted of IgM and IgG responses to soluble antigens of eggs and female worms (SEA and SFWA) and excretion–secretion products of eggs and female worms (ESPE and ESPAW) in infected Balb/c mice with different parasitic burden and infection times. A high positivity rate by IgM detection was observed for all antigen preparations in 7-week infections (100% by SEA, SFWA, ESPE, and ESPWA in high parasitic burden) as well as a reduction of this immunoglobulin in chronic infection. Positivity rate for IgG detection was higher in 20-week infections (100% by ESPE in low burden, 100% by SEA and ESPE in medium burden, and 100% by ESPE and ESPAW in high burden conditions). The potential use of combined or unique antigenic preparations associated with IgM or IgG for detection of active infection, regardless the parasitic burden, was demonstrated. Differences between immunoglobulin responses show its application for phase-specific diagnosis.

Progress and application of immunodiagnostic methods of giardiasis

Giardia lamblia is an important intestinal protozoan which can cause diarrhea in humans. The detection of Giardia infection is performed through the detection methods of pathogen, immunoassay and molecular biology. Currently, the immunodiagnostic methods have good application and development prospect because of high sensitivity and specificity, simple and convenient, and time saving. In this article, we review the main progress and application of immunodiagnostic methods for Giardia infection.

Schistosoma-Specific 26 Kda Protein for a Diagnosis of Acute and Chronic Schistosomiasis

One of the world wide major public health problems is the schistosomiasis that is caused by Schistosoma (S.) heamatobium. It is also one of the main concerns for the public health community in Egypt. There are several immunodiagnostic methods used for that diagnosis of such disease, but some are more sensitive and specific than others. The purified 26 kDa Schistosoma-specific protein (PSPA-26) detection in serum samples is found out to be more valuable in diagnosis; it also helps in the early diagnosis which will lead to the early treatment before the irreversible damage takes place. PSPA-26 was purified from whole worms by DEAE-Sephadex G-75 ion exchange chromatography and then was injected into rabbits to produce specific polyclonal antibodies (anti-PSPA-26 pAb) which were then used as a primary capture in the indirect ELISA technique to reveal its reactivity using infected human sera. The anti-PSPA-26 was then labeled with horse-radish peroxidase (HRP) and used as a secondary capture. Sandwich ELISA was done for serum samples of human and hamsters infected with S. heamatobium. The results revealed a sensitivity of 85% for human and 80% for hamster's samples, and a specificity of 95% for human and 91.1% for hamsters samples by comparing them with those infected with other parasites and control samples. Data obtained concluded that PSPA-26 antigen can be used as a diagnostic marker for S. haematobium infection using the sandwich ELISA which is cost effective and applicable technique.