A Novel Detection Platform for Shrimp White Spot Syndrome Virus Using an ICP11-Dependent Immunomagnetic Reduction (IMR) Assay

Eco-efficiency assessment of disease-infected shrimp farming in Mexico using environmental impact assessment tools

Mexico ranks second in shrimp (Litopenaeus vannamei) production of in Latin America with significant annual growth, however, during 2011 shrimp production fell by almost 50 % due to the presence of the white spot syndrome virus (WSSV). In this context, a life cycle analysis (LCA) and data envelopment analysis (DEA) were performed on 76 commercial farms severely affected by the presence of WSSV in northwestern Mexico. The application of this combined methodology allowed a detailed quantification of different environmental impact categories. During the presence of WSSV, there was a negative effect on the feed conversion ratio (FCR) (>40 %), higher consumption of seawater (38 %), and energy (38 %). Consequently, operational outputs related to the discharge of nitrogen and phosphorus increased by 60 and 57 %, respectively. Similarly, CO₂ emissions, increased by 38 % relative to a typical year of production. Overall, the main critical points in the impact categories analyzed are related to food (98 %), use of diesel (23 %), and rearing (24 %), dominating pollutants emissions in all categories. Consequently, an improvement scenario was evaluated related to innovation in the formulation of foods supplied with immunostimulants, which confer protection against pathogenic microorganisms. This scenario lead to a reduction environmental impact of about 82 %. The results of this analysis will be a useful resource in the design of mitigation strategies with innovation processes that allow maintaining yields for shrimp producers in this region and at the same time reduce the environmental impacts generated.

Bootstrapping random forest and CHAID for prediction of white spot disease among shrimp farmers

Technology is playing an important role is healthcare particularly as it relates to disease prevention and detection. This is evident in the COVID-19 era as different technologies were deployed to test, detect and track patients and ensure COVID-19 protocol compliance. The White Spot Disease (WSD) is a very contagious disease caused by virus. It is widespread among shrimp farmers due to its mode of transmission and source. Considering the growing concern about the severity of the disease, this study provides a predictive model for diagnosis and detection of WSD among shrimp farmers using visualization and machine learning algorithms. The study made use of dataset from Mendeley repository. Machine learning algorithms; Random Forest classification and CHAID were applied for the study, while Python was used for implementation of algorithms and for visualization of results. The results achieved showed high prediction accuracy (98.28%) which is an indication of the suitability of the model for accurate prediction of the disease. The study would add to growing knowledge about use of technology to manage White Spot Disease among shrimp farmers and ensure real-time prediction during and post COVID-19.

Detection of white spot syndrome virus in seafood samples using a magnetosome-based impedimetric biosensor

White spot syndrome virus (WSSV) is a significant threat to the aquaculture sector, causing mortality among crabs and shrimps. Currently available diagnostic tests for WSSV are not rapid or cost-effective, and a new detection method is therefore needed. This study demonstrates the development of a biosensor by functionalization of magnetosomes with VP28-specific antibodies to detect WSSV in seafood. The magnetosomes (1 and 2 mg/ml) were conjugated with VP28 antibody (0.025-10 ng/µl), as confirmed by spectroscopy. The magnetosome-antibody conjugate was used to detect the VP28 antigen. The binding of antigen to the magnetosome-antibody complex resulted in a change in absorbance. The magnetosome-antibody-antigen complex was then concentrated and brought near a screen-printed carbon electrode by applying an external magnetic field, and the antigen concentration was determined using impedance measurements. The VP28 antigen (0.025 ng/µl) bound more efficiently to the magnetosome-VP28 antibody complex (0.025 ng/µl) than to the VP28 antibody (0.1 ng/µl) alone. The same assay was repeated to detect the VP28 antigen (0.01 ng/µl) in WSSV-infected seafood samples using the magnetosome-VP28 antibody complex (0.025 ng/µl). The WSSV in the seafood sample was also drawn toward the electrode due to the action of magnetosomes controlled by the external magnetic field and detected using impedance measurement. The presence of WSSV in seafood samples was verified by Western blot and RT-PCR. Cross-reactivity assays with other viruses confirmed the specificity of the magnetosome-based biosensor. The results indicate that the use of the magnetosome-based biosensor is a sensitive, specific, and rapid way to detect WSSV in seafood samples.

Clinical Feasibility of Biofunctionalized Magnetic Nanoparticles for Detecting Multiple Cardiac Biomarkers in Emergency Chest Pain Patients

BACKGROUND

The rapid diagnosis of acute myocardial infarction (AMI) is a clinical and operational priority in emergency departments. Serial serum levels of cardiac biomarkers play a crucial role in the evaluation of patients presenting with acute chest pain, so that an accurate and rapidly responsive assay of cardiac biomarkers is vital for emergency departments.

METHODS

Immunomagnetic reduction (IMR) has been developed for rapid and on-site assays with a small sample volume. IMR kits for three biomarkers [myoglobin, creatine kinase-MB (CK-MB), and troponin-I] have been developed by MagQu Co., Ltd., Taiwan (US patent: US20190072563A1). In this study, we examined correlations between IMR signals and biomarker concentrations. The measurement threshold of the IMR kits, dynamic ranges, interference tests in vitro, and reagent stability were tested. Clinical cases were included with serial IMR measurements to determine the time course and peak of IMR-measured cardiac biomarkers after AMI.

RESULTS

The correlations between IMR signals and biomarker concentrations fitted well to logistic functions. The measurement thresholds of the IMR kits (1.03 × 10^-8 ng/mL for myoglobin, 1.46 × 10^-6 ng/mL for CK-MB, and 0.08 ng/mL for troponin-I) were much lower than the levels detected in the patients with AMI. There was no significant interference in vitro. The peak times of IMR-detected myoglobin, CK-MB, and troponin-I after AMI were 8.2 hours, 24.4 hours, and 24.7 hours, respectively.

CONCLUSIONS

IMR is an accurate and sensitive on-site rapid assay for multiple cardiac biomarkers in vitro, and may play a role in the early diagnosis of AMI. Clinical trials are needed.

Evaluation of the Sensitivity of the Flow Through Assay for detection of White Spot Syndrome Virus (WSSV) using a cocktail of monoclonal antibodies

A panel of four monoclonal antibodies (C-05, C-14, C-38 and C-56) specific to VP28 of White spot syndrome virus (WSSV) were evaluated individually and in cocktail to increase sensitivity of the Flow Through Assay (FTA) for detection of the virus. Recombinant VP28 and semi purified WSSV was used as antigen for evaluation. Out of the total 11 cocktails and four individual of MAbs, 2 MAb cocktails C-05 + C-56 and C-14 + C-56 exhibited highest sensitivity in the FTA. The two MAb cocktail were 100 times more sensitive than 1-step PCR and nearly equivalent to 2-step PCR for the detection of WSSV. The detection limit of WSSV by MAb cocktail increased by two fold compared to the single MAb C-05 currently being used in (FTA).

Field-Usable Lateral Flow Immunoassay for the Rapid Detection of White Spot Syndrome Virus (WSSV)

Background

White spot disease (WSD), a major threat to sustainable aquaculture worldwide, is caused by White spot syndrome virus (WSSV). The diagnosis of WSD relies heavily on molecular detection of the virus by one-step PCR. These procedures are neither field-usable nor rapid enough considering the speed at which the virus spreads. Thus, development of a rapid, reliable and field-usable diagnostic method for the detection of WSSV infection is imperative to prevent huge economic losses.

Methods/Principal Findings

Here, we report on the development of a lateral flow immunoassay (LFIA) employing gold nanoparticles conjugated to a polyclonal antibody against VP28 (envelope protein of WSSV). The LFIA detected WSSV in ~20 min and showed no cross-reactivity with other shrimp viruses, viz. Monodon Baculovirus (MBV), Hepatopancreatic parvovirus (HPV) and Infectious Hypodermal and Hematopoietic Necrosis virus (IHHNV). The limit of detection (LOD) of the assay, as determined by real-time PCR, was 10³ copies of WSSV. In a time course infectivity experiment, ~10⁴ WSSV particles were injected in Litopenaeus vannamei. The LFIA could rapidly (~ 20 min) detect the virus in different tissues after 3 h (hemolymph), 6 h (gill tissue) and 12 h (head soft tissue, eye stalk, and pleopod) of infection. Based on these findings, a validation study was performed using 75 field samples collected from different geographical locations in India. The LFIA results obtained were compared with the conventional “gold standard test”, viz. one-step PCR. The analysis of results in 2x2 matrix indicated very high sensitivity (100%) and specificity (96.77%) of LFIA. Similarly, Cohen’s kappa coefficient of 0.983 suggested "very good agreement” between the developed LFIA and the conventional one-step PCR.

Conclusion

The LFIA developed for the rapid detection of WSSV has an excellent potential for use in the field and could prove to be a boon to the aquaculture industry.

Homogeneous Biosensing Based on Magnetic Particle Labels

The growing availability of biomarker panels for molecular diagnostics is leading to an increasing need for fast and sensitive biosensing technologies that are applicable to point-of-care testing. In that regard, homogeneous measurement principles are especially relevant as they usually do not require extensive sample preparation procedures, thus reducing the total analysis time and maximizing ease-of-use. In this review, we focus on homogeneous biosensors for the in vitro detection of biomarkers. Within this broad range of biosensors, we concentrate on methods that apply magnetic particle labels. The advantage of such methods lies in the added possibility to manipulate the particle labels by applied magnetic fields, which can be exploited, for example, to decrease incubation times or to enhance the signal-to-noise-ratio of the measurement signal by applying frequency-selective detection. In our review, we discriminate the corresponding methods based on the nature of the acquired measurement signal, which can either be based on magnetic or optical detection. The underlying measurement principles of the different techniques are discussed, and biosensing examples for all techniques are reported, thereby demonstrating the broad applicability of homogeneous in vitro biosensing based on magnetic particle label actuation.