Comparison of stabilisers for development of a lyophilised multiplex reverse-transcription PCR mixture for rapid detection of foot and mouth disease virus serotypes

Development of Freeze-dried Reagents based Multiplex PCR Assay for the Detection of Common and Emerging Abortion-causing Pathogens

Bovine abortion is economically one of the most devastating problems faced by dairy farmers. Apart from non-infectious causes, several infectious pathogens are responsible for abortions, which sometimes manifests as abortion storms. Vaccine against several pathogens is available, in spite of that, abortions cause huge economic losses for the dairy sector. Timely and accurate identification of the etiological agent helps in adopting the mitigation steps to control the damage caused. In addition to the common abortion-causing pathogens such as Brucella abortus, Bovine herpesvirus-1 (BHV-1), bovine viral diarrhea virus (BVDV), several emerging viral causes are being investigated for their possible role in abortion, either exclusively or as co-infection. Molecular methods are widely accepted for the identification of the involved pathogens. However, these assays require individual screening against each pathogen which is time-consuming and uneconomical, hence the multiplex format of PCR assays has been adopted by several laboratories. Multiplexing in real-time PCR is a sensitive and reliable technique, but it requires trained manpower and sophisticated equipment which is largely unavailable in regional disease diagnostic laboratories in India. Hence, in this study, a user-friendly, ready-to-use, gel-based RT-PCR multiplex assay was developed for simultaneous detection of three common pathogens (B. abortus, BHV-1, and BVDV) and two emerging pathogens; bluetongue virus (BTV) as a cause of abortions in bovine and Schmallenberg virus (SBV). After the standardization of the assay, a panel of 211 samples was screened. A high degree of concordance was observed which indicates the developed multiplex PCR assay is reliable and has the potential for screening at regional diagnostic laboratories.

Optimization of Lyophilized LAMP and RT-PCR Reaction Mixes for Detection of Tuberculosis

Undoubtedly, one of the most infectious diseases in the world is tuberculosis. Key factor for tuberculosis control is to prevent possible contagion with rapid diagnosis and effective treatment. The culture method, which it takes several weeks to obtain results, is the gold standard method for laboratory diagnosis of tuberculosis. In order to prevent possible contagion of tuberculosis, diagnosis must be made in short time and treatment should be started as soon as possible. Normally, clinical samples are studied in advanced laboratories designed for this purpose. However, especially after the screening in rural areas, the transmission of the samples to the centers has many negative effects on the clinical material. Therefore, the latest trend molecular techniques in microbiological diagnosis are developing into point of care systems that can be applied in the field without laboratory infrastructure. The major challenge for molecular-based point-of-care tests is the need to store polymerase enzymes and some of the ingredients used in the cold chain. The aim of this study is to increase the resistance of the amplification reaction mixtures by lyophilizing the tuberculosis diagnosis. Lyophilization was performed on Loop-mediated isothermal amplification (LAMP) and Real-time PCR mixtures. For the lyophilization of LAMP and RT-PCR mixtures, two different experimental setups were tried from the literature except for the developed content. Chemicals such as stachyose, trehalose, glycerol and PEG 8000 are widely using as cryoprotectants. As a result, the developed content (0.5% PEG 8000, 2.0 % Stachyose) was determined the best cryoprotectant mixture. Accordingly, amplification mixtures can be produced with the developed lyophilization method and point of care kits can be developed.