Establishment and optimization of a liquid bead array for the simultaneous detection of ten insect-borne pathogens

Lyme Disease: An Overview

Lyme disease, a tick-borne multisystem disease, is caused by spirochete Borrelia burgdorferi (sensu lato). It is a common illness in temperate countries, especially the United States, but the incidence is increasing across continents due to increasing reforestation, travel and adventure tourism, increased intrusion in the vector habitat, and changing habitat of the vector. Transmission primarily occurs via bite of an infected tick (Ixodes spp.). The appearance of an erythema migrans rash following a tick bite is diagnostic of early Lyme disease even without laboratory evidence. Borrelia lymphocytoma and acrodermatitis chronica atrophicans along with multisystem involvement occur in late disseminated and chronic stages. A two-step serologic testing protocol using an enzyme-linked immunosorbent assay (ELISA) followed by confirmation of positive and equivocal results by Western immunoblot is recommended for the diagnosis. Transplacental transmission to infant occurs in the first trimester with possible congenital Lyme disease making treatment imperative during antenatal period. The treatment is most effective in the early stages of the disease, whereas rheumatological, neurological, or other late manifestations remain difficult to treat with antibiotics alone. Treatment with oral doxycycline is preferred for its additional activity against other tick-borne illnesses which may occur concurrently in 10%-15% of cases. New-generation cephalosporins and azithromycin are alternative options in patients with doxycycline contraindications. No vaccine is available and one episode of the disease will not confer life-long immunity; thus, preventive measures remain a priority. The concept of post-Lyme disease syndrome versus chronic Lyme disease remains contested for want of robust evidence favoring benefits of prolonged antibiotic therapy.

Microparticle-Based Detection of Viruses

Surveillance of viral pathogens in both point-of-care and clinical settings is imperative to preventing the widespread propagation of disease-undetected viral outbreaks can pose dire health risks on a large scale. Thus, portable, accessible, and reliable biosensors are necessary for proactive measures. Polymeric microparticles have recently gained popularity for their size, surface area, and versatility, which make them ideal biosensing tools. This review cataloged recent investigations on polymeric microparticle-based detection platforms across eight virus families. These microparticles were used as labels for detection (often with fluorescent microparticles) and for capturing viruses for isolation or purification (often with magnetic microparticles). We also categorized all methods by the characteristics, materials, conjugated receptors, and size of microparticles. Current approaches were compared, addressing strengths and weaknesses in the context of virus detection. In-depth analyses were conducted for each virus family, categorizing whether the polymeric microparticles were used as labels, for capturing, or both. We also summarized the types of receptors conjugated to polymeric microparticles for each virus family.

Quantitative multiplexed strategies for human Lyme disease serological testing

Lyme disease, which is primarily caused by infection with the bacterium Borrelia burgdorferi in the United States or other Borrelia species internationally, presents an ongoing challenge for diagnostics. Serological testing is the primary means of diagnosis but testing approaches differ widely, with varying degrees of sensitivity and specificity. Moreover, there is currently no reliable test to determine disease resolution following treatment. A distinct challenge in Lyme disease diagnostics is the variable patterns of human immune response to a plurality of antigens presented by Borrelia spp. during the infection. Thus, multiplexed testing approaches that capture these patterns and detect serological response against multiple antigens may be the key to prompt, accurate Lyme disease diagnosis. In this review, current state-of-the-art multiplexed diagnostic approaches are presented and compared with respect to their diagnostic accuracy and their potential for monitoring response to treatment.

Development and Inter-Laboratory Validation of Diagnostics Panel for Detection of Biothreat Bacteria Based on MOL-PCR Assay

Early detection of biohazardous bacteria that can be misused as biological weapons is one of the most important measures to prevent the spread and outbreak of biological warfare. For this reason, many instrument platforms need to be introduced into operation in the field of biological warfare detection. Therefore the purpose of this study is to establish a new detection panel for biothreat bacteria (Bacillus anthracis, Yersinia pestis, Francisella tularensis, and Brucella spp.) and confirm it by collaborative validation by using a multiplex oligonucleotide ligation followed by polymerase chain reaction and hybridization to microspheres by MagPix detection platform (MOL-PCR). Appropriate specific sequences in bacterial DNA were selected and tested to assemble the detection panel, and MOLigo probes (short specific oligonucleotides) were designed to show no cross-reactivity when tested between bacteria and to decrease the background signal measurement on the MagPix platform. During testing, sensitivity was assessed for all target bacteria using serially diluted DNA and was determined to be at least 0.5 ng/µL. For use as a diagnostic kit and easier handling, the storage stability of ligation premixes (MOLigo probe mixes) was tested. This highly multiplex method can be used for rapid screening to prevent outbreaks arising from the use of bacterial strains for bioterrorism, because time of analysis take under 4 h.

Simultaneous Detection of Bluetongue Virus Serotypes Using xMAP Technology

Bluetongue is an economically important disease of ruminants caused by the bluetongue virus (BTV). BTV is serologically diverse, which complicates vaccination strategies. Rapid identification of the causative BTV serotypes is critical, however, real-time PCR (RT-qPCR) can be costly and time consuming to perform when the circulating serotypes are unknown. The Luminex xMAP technology is a high-throughput platform that uses fluorescent beads to detect multiple targets simultaneously. We utilized existing BTV serotyping RT-qPCR assays for BTV-1 to BTV-24 and adapted them for use with the xMAP platform. The xMAP assay specifically detected all 24 BTV serotypes when testing reference strains. In all BTV-positive samples, the sensitivity of the BTV xMAP was 87.55% whereas the sensitivity of the serotype-specific RT-qPCR was 79.85%. The BTV xMAP assay allowed for the specific detection of BTV serotypes 1-24 at a lower cost than current RT-qPCR assays. Overall, the assay provides a useful novel diagnostic tool, particularly when analyzing large sample sets. The use of the BTV xMAP assay will allow for the rapid assessment of BTV epidemiology and may inform decision-making related to control and prevention measures.

A Practical Approach to the Diagnosis of Lyme Borreliosis: From Clinical Heterogeneity to Laboratory Methods

Clinical evaluation of Lyme Borreliosis (LB) is the starting point for its diagnosis. The patient's medical history and clinical symptoms are fundamental for disease recognition. The heterogeneity in clinical manifestations of LB can be related to different causes, including the different strains of Borrelia, possible co-infection with other tick transmitted pathogens, and its interactions with the human host. This review aims at describing the heterogeneous symptoms of Lyme Borreliosis, as well as offering a practical approach for recognition of the disease, both in terms of clinical features and diagnostic/research tools.